Effects of Long-Term Storage on Hatchability and Incubation Length of Game Farmed Quail Eggs.

The long-term storage of eggs before incubation is a common practice in some alternative poultry systems but needs to be performed under conditions that preserve egg viability. The effects of the long-term storage of game farmed quail (Coturnix coturnix) eggs on weight loss during the storage and incubation periods, chick weight at hatch, hatchability, and incubation length were investigated. The eggs were arranged in six treatments submitted to 0-, 7-, 14-, 21-, 28-, and 35-day storage periods at 15.8 °C and 80% relative humidity. The storage length reduced the hatchability of eggs (p < 0.05) when the storage was extended to 35 days, decreasing by more than half compared to eggs stored up to 28 days. Egg weight loss during storage progressively increased with the storage length (p < 0.05). Chick weight at hatching was reduced in eggs stored for more than 14 days (p < 0.05), and relative chick weight decreased significantly in eggs stored for 35 days (p < 0.05). Incubation length progressively increased with the storage length (p < 0.05), achieving less hatching synchrony in eggs stored for a longer time (p < 0.05). In conclusion, game quail eggs store well with little deterioration up to 28 days at 15.8 °C and 80% relative humidity, allowing for extended storage when shipping long-shelf-life eggs or assembling batches large enough to fully set an incubator in farms with small breeding flocks.

Recommendations of the Spanish Society of Nephrology for the management of mineral and bone metabolism disorders in patients with chronic kidney disease: 2021 (SEN-MM).

As in 2011, when the Spanish Society of Nephrology (SEN) published the Spanish adaptation to the Kidney Disease: Improving Global Outcomes (KDIGO) universal Guideline on Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD), this document contains an update and an adaptation of the 2017 KDIGO guidelines to our setting. In this field, as in many other areas of nephrology, it has been impossible to irrefutably answer many questions, which remain pending. However, there is no doubt that the close relationship between the CKD-MBD/cardiovascular disease/morbidity and mortality complex and new randomised clinical trials in some areas and the development of new drugs have yielded significant advances in this field and created the need for this update. We would therefore highlight the slight divergences that we propose in the ideal objectives for biochemical abnormalities in the CKD-MBD complex compared to the KDIGO suggestions (for example, in relation to parathyroid hormone or phosphate), the role of native vitamin D and analogues in the control of secondary hyperparathyroidism and the contribution of new phosphate binders and calcimimetics. Attention should also be drawn to the adoption of important new developments in the diagnosis of bone abnormalities in patients with kidney disease and to the need to be more proactive in treating them. In any event, the current speed at which innovations are taking place, while perhaps slower than we might like, globally drives the need for more frequent updates (for example, through Nefrología al día).

Estimating ideology and polarization in European countries using Facebook data.

Researchers have studied political ideology and polarization in many different contexts since their effects are usually closely related to aspects and actions of individuals and societies. Hence, being able to estimate and measure the changes in political ideology and polarization is crucial for researchers, stakeholders, and the general public. In this paper, we model the ideology and polarization of 28 countries (the 27 EU member states plus the UK) using Facebook public posts from political parties' Facebook pages. We collected a three-year dataset from 2019 to 2021 with information from 234 political parties' Facebook pages and took advantage of the EU parliament elections of May 2019 to create our models. Our methodology works across 28 countries and benefits from being a low-cost running process that measures ideology and polarization at a high-resolution time scale. The results show our models are pretty accurate when validating them against 19 individual countries' elections as ground truth. Moreover, to make our results available to the research community, stakeholders, and individuals interested in politics, the last contribution of our paper is a website including detailed information about the political parties in our dataset. It also includes the temporal evolution of our ideology and polarization estimations. Therefore, our work delivers a novel tool that uses Facebook public data to create country metrics useful for different purposes. To the best of our knowledge, there is no prior work in the literature offering a solution that measures the ideology and polarization of all EU + UK countries.

The Quail Game Farming Sector in Spain.

Quail (Coturnix genus) game farms were characterised in Spain using variables related to their age, geographical distribution, farmed species, structure, size, and commercialisation, using a survey conducted on 21 farms in 2018. It was found that 38.1% of the sample represented complete-cycle farms, and 61.9%, which have no breeding flocks, undertook only the finishing phase of quail raising. The average size of the breeding flock, with regard to complete-cycle farms, was 1096 males and 3735 females, with a female/male ratio of 3.6, and 75% of these farms carried out self-replacement of breeding quails. The most farmed species was European quail (Coturnix coturnix), followed by Japanese quail (Coturnix japonica), and hybrids of both species. In addition to quail, all farms produced other gamebird species such as pheasant (Phasianus colchicus) and red-legged partridge (Alectoris rufa). The rearing phase, which began when the chicks were one-day-old, lasted 35.3 days on average (range: 25-49 days), with an average stocking density of 47.2 birds/m2 in the brooder house. The finishing phase, which was carried out in flying pens at a stocking density of 9.5 birds/m2, ended when the quails' average age was 60.5 days. All farms sold quails for release in hunting reserves (EUR 1.54 per bird) and for dog training (EUR 1.65 per bird) for almost 10 months of the year; only 62% sold quails for shooting after being thrown with an adapted clay-pigeon shooting machine (EUR 1.49 per bird). Transporting quails to their destination (95.2% of the farms) and releasing the birds in the client's hunting preserve (52.4% of the farms) were services offered by the farms, among others. The main advertising and promotional strategies undertaken by the quail game farms to gain a share of the market included maintaining a business website (85.7% of the farms) and attending game and agricultural fairs (47.6% of the farms). In conclusion, this alternative poultry sector has been consolidated in Spain, five decades since the establishment of the first game farms, and it satisfies a relevant part of the demand for quail hunting.

Assessment of Inorganic Phosphate Intake by the Measurement of the Phosphate/Urea Nitrogen Ratio in Urine.

In chronic kidney disease (CKD) patients, it would be desirable to reduce the intake of inorganic phosphate (P) rather than limit the intake of P contained in proteins. Urinary excretion of P should reflect intestinal absorption of P(inorganic plus protein-derived). The aim of the present study is to determine whether the ratio of urinary P to urinary urea nitrogen (P/UUN ratio) helps identify patients with a high intake of inorganic P.A cross-sectional study was performed in 71 patients affected by metabolic syndrome with CKD (stages 2-3) with normal serum P concentration. A 3-day dietary survey was performed to estimate the average daily amount and the source of P ingested. The daily intake ofPwas1086.5 ± 361.3mg/day; 64% contained in animal proteins, 22% in vegetable proteins, and 14% as inorganic P. The total amount of P ingested did not correlate with daily phosphaturia, but it did correlate with the P/UUN ratio (p < 0.018). Patients with the highest tertile of the P/UUN ratio >71.1 mg/g presented more abundant inorganic P intake (p < 0.038).The P/UUN ratio is suggested to be a marker of inorganic P intake. This finding might be useful in clinical practices to identify the source of dietary P and to make personalized dietary recommendations directed to reduce inorganic P intake.

Validation of a Histologic Scoring Index for C3 Glomerulopathy.

RATIONALE & OBJECTIVE: A previous study that evaluated associations of kidney biopsy findings with disease progression in patients with C3 glomerulopathy (C3G) proposed a prognostic histologic index (C3G-HI) that has not yet been validated. Our objective was to validate the performance of the C3G-HI in a new patient population. STUDY DESIGN: Multicenter, retrospective cohort study. SETTING & PARTICIPANTS: 111 patients fulfilling diagnostic criteria of C3G between January 1995 and December 2019, from 33 nephrology departments belonging to the Spanish Group for the Study of Glomerular Diseases (GLOSEN). PREDICTORS: Demographic, clinical parameters, C3G-HI total activity score, and the C3G-HI total chronicity score. OUTCOME: Time to kidney failure. ANALYTICAL APPROACH: Intraclass correlation coefficients and κ statistic were used to summarize inter-rater reproducibility for assessment of histopathology in kidney biopsies. The nonlinear relationships of risk of kidney failure with the total activity score and total chronicity score were modeled using Cox proportional hazards analysis that incorporated cubic splines. RESULTS: The study group included 93 patients with C3 glomerulonephritis and 18 with dense-deposit disease. Participants had an overall meanage of 35±22 (SD) years. Forty-eight patients (43%) developed kidney failure after a mean follow-up of 65±27 months. The overall inter-rater reproducibility was very good for the total activity score (intraclass correlation coefficient [ICC]=0.63) and excellent for total chronicity score (ICC=0.89). Baseline estimated glomerular filtration rate (eGFR), 24-hour proteinuria, and treatment with immunosuppression were the main determinants of kidney failure in a model with only clinical variables. Only tubular atrophy and interstitial fibrosis were identified as predictors in a model with histological variables. When the total activity score and total chronicity score were added to the model, only the latter was identified as an independent predictor of kidney failure. LIMITATIONS: Only a subset of the kidney biopsies was centrally reviewed. Residual confounding. CONCLUSIONS: We validated the performance of C3G-HI as a predictor of kidney failure in patients with C3G. The total chronicity score was the principal histologic correlate of kidney failure.

Acidosis metabólica en la enfermedad renal crónica: dificultades para una corrección adecuada / Successful correction of metabolic acidosis is difficult to achieve in chronic kidney disease

INTRODUCCIÓN: La acidosis metabólica (AM) es una alteración frecuente en la enfermedad renal crónica (ERC) que se asocia a numerosas complicaciones, por lo que su corrección es recomendable. El bicarbonato sódico oral es actualmente el tratamiento de elección. OBJETIVOS: Describir la prevalencia de AM en la ERC avanzada, y determinar cuáles son las características clínicas y bioquímicas que se asocian a una corrección adecuada. MATERIAL Y MÉTODOS: Estudio retrospectivo de observación en una cohorte de pacientes adultos con ERC estadio 4-5. Los criterios de inclusión fueron: no estar siendo tratado con alcalinos en el momento de la inclusión y tener al menos 3 medidas consecutivas de filtrado glomerular (FG) y parámetros bioquímicos durante un periodo > 3 meses. Los pacientes con un bicarbonato sérico < 22 mEq/l se incluyeron en el estudio de seguimiento, siendo tratados con bicarbonato sódico oral. Se consideró que la corrección fue adecuada cuando más de la mitad de las muestras y la media de los niveles de bicarbonato durante el seguimiento individual fueron ≥ 22 mEq/l. RESULTADOS: Se incluyeron 969 pacientes (edad 65± 14 años, 507 hombres) con FG medio 14,8± 4,5 ml/min/1,73 m2. Basalmente 530 pacientes (55%) que mostraron un bicarbonato sérico < 22 mEq/l fueron tratados con bicarbonato sódico y seguidos durante 15 meses. En tan solo 133 pacientes (25%) se alcanzó una corrección satisfactoria de la AM. Por regresión logística multivariable las principales características en los que se logró el control adecuado de la AM fueron: edad (OR = 1,03; IC. 95%1,01-1,05), FG basal (OR = 1,07; 1,02-1,12) y tratamiento con inhibidores de bomba protones (OR = 1,61; IC 95%: 1,06-2,44). En aquellos en los que se logró corrección de AM tuvieron progresión más lenta de ERC (-1,67± 3,71 vs. -4,36± 4,56 ml/min/1,73 m2/año, p < 0,0001) y menor concentración de potasio sérico promedio (5,1± 0,5 vs. 5,3± 0,5, p < 0,0001) que los del resto de pacientes, aunque no se observaron diferencias en la tasa de ingresos hospitalarios y ni en la mortalidad. CONCLUSIÓN: La AM es una alteración frecuente en la ERC avanzada, pero de difícil corrección con los tratamientos actuales. Debido al importante beneficio que puede suponer el control de la AM se deberían investigar nuevas terapias más efectivas

INTRODUCTION: Metabolic acidosis (MA) is a common complication of chronic kidney disease (CKD) and is associated with numerous adverse effects, which is why its correction is highly recommended. Oral sodium bicarbonate is the current treatment of choice. OBJECTIVES: To describe the prevalence of MA in advanced CKD patients and to determine the clinical and biochemical characteristics associated with its successful correction. MATERIAL AND METHODS: Retrospective, observational cohort study in adult patients with CKD stage 4-5. The inclusion criteria were: not being treated with alkali therapy at the time of inclusion, and to have at least three consecutive glomerular filtration rate (GFR) measurements and biochemical parameters during a minimum follow-up period of 3 months. Incident patients with serum bicarbonate < 22 mEq/l were included in the follow-up study and treated with oral sodium bicarbonate. Correction was considered successful when more than half of the samples and the mean bicarbonate levels during individual follow-up were ≥ 22 mEq/l. RESULTS: The study group consisted of 969 patients (age 65±14 years, 507 males) with a mean GFR of 14.8 ± 4.5 ml/min/1.73 m2. At baseline, 530 patients (55%) had serum bicarbonate < 22 mEq/l. They were treated with sodium bicarbonate and followed for 15 months. Satisfactory correction of MA was only achieved in 133 patients (25%). By multivariate logistic regression analysis, the main characteristics of patients with adequate control of MA were: age (OR = 1.03; 95% CI 1.01 - 1.05), baseline GFR (OR = 1.07; 1.02 - 1.12), and treatment with proton-pump inhibitors (OR = 1.61; 95% CI 1.06 - 2.44). Patients who achieved successful correction of MA showed slower CKD progression (-1.67 ± 3.71 vs -4.36 ± 4.56 ml/min/1.73 m2/year, P < .0001), and lower average serum potassium concentration (5.1 ± 0.5 vs 5.3 ± 0.5, P < .0001) than those who did not. However, there were no differences in the hospitalisation or mortality rate. CONCLUSION: MA is a common complication of advanced CKD but difficult to manage with current therapies. Due to the significant potential benefit of controlling MA, new, more effective therapies should be further researched

Manejo renal del potasio en la enfermedad renal crónica avanzada: diferencias entre pacientes con o sin hipercaliemia / Renal potassium handling in chronic kidney disease: Differences between patients with or wihtout hyperkalemia

INTRODUCCIÓN: La hipercaliemia (HK) es un hallazgo frecuente en la enfermedad renal crónica (ERC), sobre todo en sus estadios más avanzados. El mecanismo patogénico más común de esta alteración es la ingesta-absorción de potasio que sobrepasa la capacidad excretora renal. La investigación sobre el papel relativo de cada uno de los elementos patogénicos en el desarrollo de HK podría ayudar a su tratamiento. OBJETIVO: Analizar el manejo renal de potasio en pacientes con ERC avanzada prediálisis, y establecer qué diferencias existen entre los que presentan o no HK. MATERIAL Y MÉTODOS: Estudio transversal de observación en pacientes adultos con ERC estadio 4-5 prediálisis. Entre los pacientes incidentes en la consulta ERCA se seleccionaron aquellos clínicamente estables con capacidad para recoger adecuadamente la orina de 24horas. Se midieron parámetros bioquímicos en sangre y orina que incluyeron las concentraciones de sodio y potasio (K). Se calculó la fracción de excreción de K (FEK) y la carga de K relativa al filtrado glomerular (Ko/FG). Se definió la HK como una concentración de K sérico ≥ 5,5 mmol/l. RESULTADOS: Se incluyeron 212 pacientes (edad 65 ± 14 años, 92 mujeres) con un FG 15,0 ± 4,2 ml/min/1,73 m2. Sesenta y tres pacientes (30%) presentaban HK. Los pacientes con HK tenían un bicarbonato sérico más bajo (20,3 ± 3,1 vs. 22,8 ± 3,2 mEq/l, p < 0,0001), y un menor filtrado glomerular (14,1 ± 3,3 vs. 15,4 ± 4,4 ml/min/1,73 m2, p = 0,028), pero no mostraban diferencias en la excreción urinaria total de sodio o K. La FEK era inferior en los pacientes con HK con respecto a los que presentaban normocaliemia (32,1 ± 12,1% vs. 36,4 ± 14,3%, p = 0,038), mientras que la Ko/FG fue mayor (4,2 ± 1,5 vs. 3,7 ± 1,4 mmol por cada ml/min, p = 0,049). Existía una fuerte correlación lineal entre Ko/FG y FEK (R2 = 0,74), y en regresiones parciales se observó que a igual carga de K, la FEK era inferior en los pacientes con HK. Mediante regresión lineal y regresión logística multivariable, tanto la FEK como la Ko/FG fueron los principales determinantes del K sérico y de la HK. CONCLUSIONES: Aunque la carga de K relativa a la función renal (Ko/FG) se asocia de forma relevante a la HK de la ERC, la principal característica asociada a esta alteración bioquímica es la incompleta excreción renal compensatoria de K, expresada como una menor FEK

INTRODUCTION: Hyperkalemia (HK) is a common electrolyte disorder in chronic kidney disease (CKD), mainly in the advanced stages. A positive potassium balance due to reduced renal excretory capacity is likely the main pathogenic mechanism of HK. Research into the relative role of each pathogenic element in the development of HK in CKD may help to implement more suitable therapies. OBJECTIVE: To investigate renal potassium handling in advanced CKD patients, and to determine the differences between patients with or without HK. MATERIAL AND METHODS: Cross-sectional observational study in adult patients with stage 4-5 CKD pre-dialysis. Selection criteria included clinically stable patients and the ability to collect a 24 hour urine sample correctly. Blood and urinary biochemical parameters were analysed including sodium and potassium (K). Fractional excretion of K (FEK) and K load relative to glomerular filtration (Ku/GFR) were calculated. HK was defined as a serum K concentration ≥ 5.5 mmol/l. RESULTS: The study group consisted of 212 patients (mean age 65 ± 14 years, 92 females) with a mean GFR of 15.0 ± 4.2 ml/min/1.73 m2. 63 patients (30%) had HK. Patients with HK had lower mean bicarbonate levels with respect to patients with normal K levels (NK) (20.3 ± 3.1 vs. 22.8 ± 3.2 mEq/l, P < .0001), but no differences were noted in total urinary sodium and K excretion. While mean FEK values were lower in patients with HK (32.1 ± 12.1% vs. 36.4 ± 14.3%, P = .038), Ku/GFR values were significantly greater with respect to the NK subgroup (4.2 ± 1.5 vs. 3.7 ± 1.4 mmol/ml/min, P = 0,049). FEK showed a strong linear correlation with Ku/GFR (R2 = 0.74), and partial linear regressions demonstrated that at a similar Ku/GFR level, the FEK of patients with HK was lower than that of NK patients. By multivariate linear and logistic regression analyses, both FEK and Ku/GFR were shown to be the main determinants of K serum levels and HK. CONCLUSIONS: Although the K load relative to glomerular filtration (Ku/GFR) is an important determinant of HK in advanced CKD, the most noteworthy characteristic associated with HK in these patients was the limitation of compensatory urinary K excretion, as indicated by lower FEK

Efecto negativo del bloqueo del sistema renina-angiotensina sobre la progresión de la enfermedad renal crónica avanzada: ¿una cuestión de ajuste de dosis? / Detrimental effect of renin-angiotensin blockade on progression of chronic kidney disease at later stages: A matter of dosage adjustment?

INTRODUCCIÓN: El efecto renoprotector de los fármacos inhibidores del sistema renina-angiotensina (ISRA) ha sido cuestionado en la enfermedad renal crónica (ERC) avanzada. La combinación de tratamiento ISRA (doble bloqueo) puede, además, acelerar el deterioro de la función renal en algunas poblaciones de riesgo. Sin embargo, se desconoce si este efecto adverso está relacionado con la dosis total prescrita de ISRA o más específicamente con una interacción farmacológica. OBJETIVO: Investigar si la tasa de reducción de función renal en la ERC avanzada se asocia a la dosis total de ISRA, y si el doble bloqueo SRA deteriora la función renal independientemente de los principales factores de confusión. MATERIAL Y MÉTODOS: Estudio retrospectivo de observación en una cohorte de pacientes adultos con ERC estadios 4-5 prediálisis, tratados con ISRA desde al menos 3 meses antes de la inclusión en el estudio. Otros criterios de inclusión fueron: tener al menos 3 medidas consecutivas de filtrado glomerular durante un periodo superior a 3 meses. Las dosis equipotentes de ISRA fueron normalizadas (DEN-ISRA) a un peso corporal de 70 kg o a una superficie corporal de 1,73 m2. La asociación de DEN-ISRA o doble bloqueo con la progresión de ERC fue analizada mediante modelos de regresión lineal uni- y multivariante, tomando en cuenta las principales variables de confusión. RESULTADOS: Se incluyeron 813 pacientes (edad media: 64 ± 14 años; 430 hombres) con un filtrado glomerular medio de 14,9 ± 4,2 ml/min/1,73 m2; 729 pacientes eran tratados con ISRA monoterapia y 84 pacientes con doble bloqueo. La mediana de la DEN-ISRA en el grupo total de estudio fue de 0,91 (rangos IQ: 0,69-1,20). Los pacientes con doble bloqueo tenían una DEN-ISRA significativamente mayor que el resto (1,52 ± 0,49 vs. 0,93 ± 0,44; p < 0,0001). Mediante regresión lineal univariable, DEN-ISRA se correlacionó significativamente con la tasa de progresión de la ERC (R = -0,149; p < 0,0001). Los pacientes con doble bloqueo mostraron un deterioro más acelerado de la función renal que el resto (-6,19 ± 5,57 vs. -3,04 ± 5,37 ml/min/1,73 m2/año, p < 0,0001). Mediante regresión lineal multivariante, el tratamiento con doble bloqueo SRA mantuvo la asociación significativa e independiente con el deterioro de la función renal (beta = -0,094; p = 0,005), mientras que la DEN-ISRA no alcanzó significación estadística. CONCLUSIÓN: La DEN-ISRA se asocia de forma significativa con la tasa de progresión en pacientes con ERC avanzada. Sin embargo, el efecto negativo del doble bloqueo SRA sobre la progresión de la ERC parece independiente de la DEN-ISRA y de otros factores relevantes de confusión

INTRODUCTION: The renoprotective effect of renin-angiotensin (RAS) blockers (angiotensin converting enzyme inhibitors and angiotensin receptor blockers) has been questioned in patients with advanced chronic kidney disease (CKD). Moreover, combination therapy (dual RAS blockade) can further accelerate renal function decline in some populations at risk. However, it is unknown whether this adverse outcome is due to a dose-dependent effect or if it can be attributed more specifically to a drug interaction. Aim This study aims to investigate if the rate of renal function decline in advanced CKD patients is associated to the doses of RAS blockers, and if dual RAS blockade worsens renal function independently of major confounding factors. MATERIAL AND METHODS: Retrospective, observational study in an incident cohort of adult patients with CKD stage 4 or 5 not on dialysis, treated with RAS blockers for at least 3 months prior to the study inclusion. Inclusion criteria were: having at least three consecutive measurements of estimated glomerular filtration rate (eGFR) in a follow-up period > 3 months. Decline in renal function was estimated as the slope of the individual linear regression line of eGFR over follow-up time. Equipotent doses of RAS blockers were normalised for a body weight of 70 kg or a body surface area of 1.73 m2 (END-RASI). Associations of END-RASI or dual RAS blockade with the rate of renal function decline were analysed by uni- or multivariate linear regression models, accounting for major confounding variables. RESULTS: The study group consisted of 813 patients (mean age 64 ± 14 years, 430 males) with a mean eGFR 14.9 ± 4.2 ml/min/1.73 m2; 729 patients were on RAS blockade monotherapy and 84 on dual RAS blockade. Median END-RASI in the whole group was 0.91 (I.Q. ranges: 0.69-1.20). Patients on dual RAS blockade had significantly higher END-RASI than the rest of study patients (1.52 ± 0.49 vs. 0.93 ± 0.44; p < 0.0001). In univariate linear regression, END-RASI were significantly correlated with eGFR decline (R = -0.149; p < 0.0001). Patients on dual RAS blockade showed a significantly faster decline of renal function than the rest of the study patients (-6.19 ± 5.57 vs. -3.04 ± 5.37 ml/min/1.73 m2/year, p < 0.0001). By multivariate linear regression, while dual RAS blockade remained independent and significantly associated with faster renal function decline (beta = -0.094; p = 0.005), END-RASI (normalised either for body weight or surface area) did not reach statistical significance. CONCLUSION: END-RASI are significantly associated with the rate of renal function decline in advanced CKD patients. However, the detrimental effect of dual RAS blockade on CKD progression seems to be independent of END-RASI and other major confounding factors

Renal potassium handling in chronic kidney disease: Differences between patients with or wihtout hyperkalemia. / Manejo renal del potasio en la enfermedad renal crónica avanzada: diferencias entre pacientes con o sin hipercaliemia.

INTRODUCTION: Hyperkalemia (HK) is a common electrolyte disorder in chronic kidney disease (CKD), mainly in the advanced stages. A positive potassium balance due to reduced renal excretory capacity is likely the main pathogenic mechanism of HK. Research into the relative role of each pathogenic element in the development of HK in CKD may help to implement more suitable therapies. OBJECTIVE: To investigate renal potassium handling in advanced CKD patients, and to determine the differences between patients with or without HK. MATERIAL AND METHODS: Cross-sectional observational study in adult patients with stage 4-5 CKD pre-dialysis. Selection criteria included clinically stable patients and the ability to collect a 24hour urine sample correctly. Blood and urinary biochemical parameters were analysed including sodium and potassium (K). Fractional excretion of K (FEK) and K load relative to glomerular filtration (Ku/GFR) were calculated. HK was defined as a serum K concentration ≥5.5mmol/l. RESULTS: The study group consisted of 212 patients (mean age 65±14 years, 92 females) with a mean GFR of 15.0±4.2ml/min/1.73m2. 63 patients (30%) had HK. Patients with HK had lower mean bicarbonate levels with respect to patients with normal K levels (NK) (20.3±3.1 vs. 22.8±3.2 mEq/l, P<.0001), but no differences were noted in total urinary sodium and K excretion. While mean FEK values were lower in patients with HK (32.1±12.1% vs. 36.4±14.3%, P=.038), Ku/GFR values were significantly greater with respect to the NK subgroup (4.2±1.5 vs. 3.7±1.4 mmol/ml/min, P=0,049). FEK showed a strong linear correlation with Ku/GFR (R2=0.74), and partial linear regressions demonstrated that at a similar Ku/GFR level, the FEK of patients with HK was lower than that of NK patients. By multivariate linear and logistic regression analyses, both FEK and Ku/GFR were shown to be the main determinants of K serum levels and HK. CONCLUSIONS: Although the K load relative to glomerular filtration (Ku/GFR) is an important determinant of HK in advanced CKD, the most noteworthy characteristic associated with HK in these patients was the limitation of compensatory urinary K excretion, as indicated by lower FEK.

Detrimental effect of renin-angiotensin blockade on progression of chronic kidney disease at later stages: A matter of dosage adjustment? / Efecto negativo del bloqueo del sistema renina-angiotensina sobre la progresión de la enfermedad renal crónica avanzada: ¿una cuestión de ajuste de dosis?

INTRODUCTION: The renoprotective effect of renin-angiotensin (RAS) blockers (angiotensin converting enzyme inhibitors and angiotensin receptor blockers) has been questioned in patients with advanced chronic kidney disease (CKD). Moreover, combination therapy (dual RAS blockade) can further accelerate renal function decline in some populations at risk. However, it is unknown whether this adverse outcome is due to a dose-dependent effect or if it can be attributed more specifically to a drug interaction. Aim This study aims to investigate if the rate of renal function decline in advanced CKD patients is associated to the doses of RAS blockers, and if dual RAS blockade worsens renal function independently of major confounding factors. MATERIAL AND METHODS: Retrospective, observational study in an incident cohort of adult patients with CKD stage 4 or 5 not on dialysis, treated with RAS blockers for at least 3 months prior to the study inclusion. Inclusion criteria were: having at least three consecutive measurements of estimated glomerular filtration rate (eGFR) in a follow-up period >3 months. Decline in renal function was estimated as the slope of the individual linear regression line of eGFR over follow-up time. Equipotent doses of RAS blockers were normalised for a body weight of 70kg or a body surface area of 1.73m2 (END-RASI). Associations of END-RASI or dual RAS blockade with the rate of renal function decline were analysed by uni- or multivariate linear regression models, accounting for major confounding variables. RESULTS: The study group consisted of 813 patients (mean age 64±14 years, 430 males) with a mean eGFR 14.9±4.2ml/min/1.73m2; 729 patients were on RAS blockade monotherapy and 84 on dual RAS blockade. Median END-RASI in the whole group was 0.91 (I.Q. ranges: 0.69-1.20). Patients on dual RAS blockade had significantly higher END-RASI than the rest of study patients (1.52±0.49 vs. 0.93±0.44; p<0.0001). In univariate linear regression, END-RASI were significantly correlated with eGFR decline (R=-0.149; p<0.0001). Patients on dual RAS blockade showed a significantly faster decline of renal function than the rest of the study patients (-6.19±5.57 vs. -3.04±5.37ml/min/1.73m2/year, p<0.0001). By multivariate linear regression, while dual RAS blockade remained independent and significantly associated with faster renal function decline (beta=-0.094; p=0.005), END-RASI (normalised either for body weight or surface area) did not reach statistical significance. CONCLUSION: END-RASI are significantly associated with the rate of renal function decline in advanced CKD patients. However, the detrimental effect of dual RAS blockade on CKD progression seems to be independent of END-RASI and other major confounding factors.

Successful correction of metabolic acidosis is difficult to achieve in chronic kidney disease. / Acidosis metabólica en la enfermedad renal crónica: dificultades para una corrección adecuada.

INTRODUCTION: Metabolic acidosis (MA) is a common complication of chronic kidney disease (CKD) and is associated with numerous adverse effects, which is why its correction is highly recommended. Oral sodium bicarbonate is the current treatment of choice. OBJECTIVES: To describe the prevalence of MA in advanced CKD patients and to determine the clinical and biochemical characteristics associated with its successful correction. MATERIAL AND METHODS: Retrospective, observational cohort study in adult patients with CKD stage 4-5. The inclusion criteria were: not being treated with alkali therapy at the time of inclusion, and to have at least three consecutive glomerular filtration rate (GFR) measurements and biochemical parameters during a minimum follow-up period of 3 months. Incident patients with serum bicarbonate<22 mEq/l were included in the follow-up study and treated with oral sodium bicarbonate. Correction was considered successful when more than half of the samples and the mean bicarbonate levels during individual follow-up were≥22 mEq/l. RESULTS: The study group consisted of 969 patients (age 65±14 years, 507 males) with a mean GFR of 14.8±4.5ml/min/1.73 m2. At baseline, 530 patients (55%) had serum bicarbonate<22mEq/l. They were treated with sodium bicarbonate and followed for 15 months. Satisfactory correction of MA was only achieved in 133 patients (25%). By multivariate logistic regression analysis, the main characteristics of patients with adequate control of MA were: age (OR=1.03; 95% CI 1.01 - 1.05), baseline GFR (OR=1.07; 1.02 - 1.12), and treatment with proton-pump inhibitors (OR=1.61; 95% CI 1.06 - 2.44). Patients who achieved successful correction of MA showed slower CKD progression (-1.67±3.71 vs -4.36±4.56ml/min/1.73 m2/year, P<.0001), and lower average serum potassium concentration (5.1±0.5 vs 5.3±0.5, P<.0001) than those who did not. However, there were no differences in the hospitalisation or mortality rate. CONCLUSION: MA is a common complication of advanced CKD but difficult to manage with current therapies. Due to the significant potential benefit of controlling MA, new, more effective therapies should be further researched.

Asociación entre hiperkaliemia y evolución clínica en la enfermedad renal crónica avanzada / Association of hyperkalemia with clinical outcomes in advanced chronic kidney disease

INTRODUCCIÓN: Los pacientes con enfermedad renal crónica (ERC) tienen un alto riesgo de desarrollo de hiperkaliemia (HK). La relación entre HK y una mala evolución (mortalidad o progresión de la insuficiencia renal) en la ERC avanzada es controvertida. OBJETIVOS: Determinar la incidencia, prevalencia, y factores relacionados con la HK en una cohorte de pacientes con ERC, y su relación con la mortalidad, tasa de hospitalización, progresión de la ERC, y necesidad de inicio de diálisis. MATERIAL Y MÉTODOS: Estudio retrospectivo de observación en una cohorte de pacientes adultos con ERC estadio 4-5. Los criterios de inclusión fueron: tener al menos 3 medidas consecutivas de filtrado glomerular (FG) durante un periodo superior a 3 meses. HK se definió como un K sérico ≥ 5,5 mmol/l. La asociación entre HK y las variables de evolución fue ajustada a los principales factores de confusión mediante análisis mutivariantes. RESULTADOS: Se incluyeron 1079 pacientes (574 hombres, edad media: 65 ± 14 años) con un FG basal 14,8 ± 4,5 ml/min/1,73 m2. El tiempo medio de seguimiento fue de 15 meses y se determinaron una mediana de 7 muestras por paciente. Basalmente un 26% de pacientes tenía HK, un 68% en al menos una muestra durante el periodo individual de seguimiento, y un 33% de forma crónica (HK > 50% del seguimiento individual). Mediante regresión logística multivariable los mejores determinantes de la HK fueron: sexo masculino (OR = 1,529; IC 95% [1,154-2,025], p = 0,003), bicarbonato sérico (OR = 0,863, [0,829-0,900], p < 0,0001), tratamiento diurético (OR = 0,743, [0,556-0,992], p = 0,044), y tratamiento con inhibidores del sistema renina-angiotensina (OR = 4,412, [2,915-6,678], p < 0,0001). Estos pacientes con HK mostraron una progresión de la ERC significativamente más acelerada (−4,05 ± 5,22 vs. −2,69 ± 5,61 ml/min/1,73 m2/año, p < 0,0001), e inicio más frecuente de diálisis (63% vs. 57%, p = 0,115), pero menos mortalidad (9% vs. 17%, p = 0,003), y tasa de hospitalización (2,68 ± 5,94 vs. 3,16 ± 6,77 días/año, p = 0,301) que el resto de los pacientes estudiados. Sin embargo en el análisis multivariante, HK no se asoció de forma independiente con ninguna de las variables de evolución investigadas. CONCLUSIÓN: HK es un hallazgo bioquímico muy frecuente en la ERC avanzada, que se asocia con algunos medicamentos de uso habitual. Sin embargo, HK no se asocia de forma independiente con ninguna de las variables de mala evolución clínica estudiadas

INTRODUCTION: Patients with advanced chronic kidney disease (CKD) are at greatest risk of hyperkalemia (HK). The relationship between HK and negative outcomes (mortality or progression of renal insufficiency) in non-dialysis dependent CKD patients is controversial. AIMS: To determine the incidence, prevalence, and factors related with HK in a cohort of CKD patients, and its relationship with mortality, hospitalization rate, CKD progression, and dialysis initiation. MATERIAL AND METHODS: A retrospective, observational study in an incident cohort of adult patients with stage 4 or 5 CKD not on dialysis. Inclusion criteria were: having at least three consecutive estimated glomerular filtration rate (eGFR) measurements in a follow-up period > 3 months. Decline in renal function was estimated as the slope of the individual linear regression line of eGFR over follow-up time. HK was defined as serum K levels ≥ 5.5 meq/l. Associations of HK with outcomes were adjusted for major confounding variables in the multivariate analysis. RESULTS: The study group consisted of 1079 patients (574 males, mean age: 65 ±14 years) with mean baseline eGFR 14.8 ± 4.5 ml/min/1,73 m2. Mean follow-up time was 15 months with a median of 7 serum sample determinations per patient. HK was observed at baseline in 26% of patients; in at least one serum sample during the individual follow-up period in 68%; or chronically (>50% of samples) in 33% of patients. By multivariate logistic regression, the best determinants of chronic HK were: male sex (OR = 1.529; 95% CI [1.154-2.025], p = .003), serum bicarbonate (OR = 0.863 [0.829-0.900], p <.0001), diuretic treatment (OR = 0.743 [0.556-0.992], p = .044), and angiotensin converting enzyme inhibitor and/or angiotensin receptor blockers (OR = 4.412 [2.915-6.678], p <.0001). Patients whose serum K levels were in the upper quartile showed a significantly faster CKD progression (-4.05±5.22 vs. -2.69 ± 5.61 ml/min/1.73 m2/year, p <.0001), and more frequent dialysis initiation (63% vs. 57%, p = .115), though lower mortality (9% vs. 17%, p = .003) and hospitalization rates (2.68 ± 5.94 vs. 3.16 ± 6.77 days per year, p = .301) than the other study patients. However, in the multivariate analysis, average serum K levels were not independently associated with the clinical outcomes investigated. CONCLUSION: HK is a common biochemical finding in non-dialysis dependent CKD patients, mainly associated with prescribed medication. However, HK was not independently associated with major negative clinical outcomes

Association of hyperkalemia with clinical outcomes in advanced chronic kidney disease. / Asociación entre hiperkaliemia y evolución clínica en la enfermedad renal crónica avanzada.

INTRODUCTION: Patients with advanced chronic kidney disease (CKD) are at greatest risk of hyperkalemia (HK). The relationship between HK and negative outcomes (mortality or progression of renal insufficiency) in non-dialysis dependent CKD patients is controversial. AIMS: To determine the incidence, prevalence, and factors related with HK in a cohort of CKD patients, and its relationship with mortality, hospitalization rate, CKD progression, and dialysis initiation. MATERIAL AND METHODS: A retrospective, observational study in an incident cohort of adult patients with stage 4 or 5 CKD not on dialysis. Inclusion criteria were: having at least three consecutive estimated glomerular filtration rate (eGFR) measurements in a follow-up period >3 months. Decline in renal function was estimated as the slope of the individual linear regression line of eGFR over follow-up time. HK was defined as serum K levels ≥5.5 meq/l. Associations of HK with outcomes were adjusted for major confounding variables in the multivariate analysis. RESULTS: The study group consisted of 1079 patients (574 males, mean age: 65±14 years) with mean baseline eGFR 14.8±4.5 ml/min/1,73 m2. Mean follow-up time was 15 months with a median of 7 serum sample determinations per patient. HK was observed at baseline in 26% of patients; in at least one serum sample during the individual follow-up period in 68%; or chronically (>50% of samples) in 33% of patients. By multivariate logistic regression, the best determinants of chronic HK were: male sex (OR = 1.529; 95% CI [1.154-2.025], p = .003), serum bicarbonate (OR = 0.863 [0.829-0.900], p <.0001), diuretic treatment (OR = 0.743 [0.556-0.992], p = .044), and angiotensin converting enzyme inhibitor and/or angiotensin receptor blockers (OR = 4.412 [2.915-6.678], p <.0001). Patients whose serum K levels were in the upper quartile showed a significantly faster CKD progression (-4.05±5.22 vs. -2.69±5.61 ml/min/1.73 m2/year, p <.0001), and more frequent dialysis initiation (63% vs. 57%, p = .115), though lower mortality (9% vs. 17%, p = .003) and hospitalization rates (2.68±5.94 vs. 3.16±6.77 days per year, p = .301) than the other study patients. However, in the multivariate analysis, average serum K levels were not independently associated with the clinical outcomes investigated. CONCLUSION: HK is a common biochemical finding in non-dialysis dependent CKD patients, mainly associated with prescribed medication. However, HK was not independently associated with major negative clinical outcomes.

Phosphate control in reducing FGF23 levels in hemodialysis patients.

BACKGROUND: In hemodialysis patients, high levels of Fibroblast Growth Factor 23 (FGF23) predict mortality. Our study was designed to test whether the control of serum phosphate is associated with a reduction in serum FGF23 levels. Additionally other variables with a potential effect on FGF23 levels were evaluated. MATERIAL AND METHODS: The effect of sustained (40-weeks) control of serum phosphate on FGF23 levels (intact and c-terminal) was evaluated in 21 stable hemodialysis patients that were not receiving calcimimetics or active vitamin D. Patients received non-calcium phosphate binders to maintain serum phosphate below 4.5 mg/dl. In an additional analysis, values of intact-FGF23 (iFGF23) and c-terminal FGF23 (cFGF23) from 150 hemodialysis patients were correlated with parameters of mineral metabolism and inflammation. Linear mixed models and linear regression were performed to evaluate longitudinal trajectories of variables and the association between FGF23 and the other variables examined. RESULTS: During the 40-week treatment, 12 of 21 patients achieved the target of serum phosphate <4.5 mg/dl. In these 12 patients, iFGF23 decreased to less than half whereas cFGF23 did not reduce significantly. In patients with serum phosphate >4.5 mg, iFGF23 and cFGF23 increased two and four-fold respectively as compared with baseline. Furthermore, changes in serum phosphate correlated with changes in C-reactive protein (hs-CRP). In our 150 hemodialysis patients, those in the higher tertile of serum phosphate also showed increased hs-CRP, iPTH, iFGF23 and cFGF23. Multiple regression analysis revealed that iFGF23 levels directly correlated with both serum phosphate and calcium, whereas cFGF23 correlated with serum phosphate and hs-CRP but not with calcium. CONCLUSIONS: The control of serum phosphate reduced iFGF23. This reduction was also associated with a decreased in inflammatory parameters. Considering the entire cohort of hemodialysis patients, iFGF23 levels correlated directly with serum phosphate levels and also correlated inversely with serum calcium concentration. The levels of cFGF23 were closely related to serum phosphate and parameters of inflammation.

Patterns of progression of chronic kidney disease at later stages.

BACKGROUND: At later stages of chronic kidney disease (CKD), a pattern of linear and irreversible renal function decline is thought to be the most common. The objective of this study was to describe the characteristics of the different patterns of CKD progression, and to investigate potentially modifiable factors associated with the rate of decline of renal function. METHODS: This was a retrospective, observational study in a cohort of adult patients with CKD Stage 4 or 5 not on dialysis. Decline in renal function was estimated as the slope of the individual linear regression line of estimated glomerular filtration rate (eGFR) over time. The following patterns of CKD progression were considered: unidentifiable, linear, nonlinear (curvilinear) and positive (improvement of renal function). RESULTS: The study group consisted of 915 patients (mean ±SD age 65 ± 14 years, 48% females, median follow-up time 16 months). A linear pattern was observed in 38%, unidentifiable in 23%, nonlinear in 24% and positive in 15% of the study patients. The mean eGFR slope was: -3.35 ± 4.45 mL/min/year. Linear and unidentifiable patterns were associated with more rapid loss of renal function. By multiple linear and logistic regression analysis, the magnitude of proteinuria, the systolic blood pressure and the treatment with dual renin-angiotensin system blockade were associated with more rapid CKD progression. On the contrary, older age and discontinuation of commonly prescribed medication with potential influence on renal function or eGFR measurements were associated with slower CKD progression. CONCLUSIONS: A majority of patients with advanced CKD show patterns of renal function decline different from linear, and several of the main determinants of CKD progression are potentially modifiable.

Cambios de la función renal tras la suspensión de análogos de vitamina D en la enfermedad renal crónica avanzada / Changes in renal function after discontinuation of vitamin D analogues in advanced chronic kidney disease

Antecedentes: En la práctica clínica habitual la prescripción de análogos de vitamina D (AVD) en la enfermedad renal crónica (ERC) se asocia con frecuencia a un descenso de la función renal estimada cuyo origen no es bien conocido. Objetivos: Analizar el efecto de la suspensión de un tratamiento previo con AVD en ERC avanzada, y determinar los factores asociados con los cambios de función renal. Material y métodos: Estudio de cohorte retrospectivo en pacientes adultos incidentes con ERC avanzada. El subgrupo caso estaba siendo tratado con AVD y esta medicación fue suspendida en la primera visita. El subgrupo control no había sido tratado con AVD y fueron elegidos por criterios de coincidencia para datos relevantes relacionados con la progresión de la ERC. La variable de resultado principal fue el cambio de filtrado glomerular, tanto el estimado (FG-MDRD) como el medido (media del aclaramiento de creatinina y urea), con respecto al siguiente control analítico. Parámetros basales relacionados con el metabolismo mineral y la generación de creatinina fueron analizados como determinantes potenciales de los cambios de la función renal. Resultados: Se incluyeron 67 pacientes casos y otros 67 controles. El 67% de los casos mejoró la función renal, mientras que el 72% de los controles empeoró (p<0,0001). El cambio FG-MDRD en casos y controles fue +0,455±0,997 vs. −0,436±1,103ml/min/1,73 m2/mes (p<0,0001), respectivamente. La excreción total de creatinina era ligeramente superior en los casos, pero la diferencia con respecto a los controles no fue significativa. Por regresión logística y lineal multivariante, el calcio sérico total basal fue uno de los principales determinantes tanto de la recuperación de la función renal (odds ratio=3,49; p=0,001), como de la magnitud de esta recuperación (beta=0,276; p=0,001). Conclusiones: La suspensión de AVD en pacientes con ERC se asocia con una mejoría significativa de la función renal estimada. La magnitud de estos cambios se relaciona principalmente con la calcemia basal (AU)

Background: In routine clinical practice, the prescription of vitamin D analogues (VDA) in patients with chronic kidney disease (CKD) is often associated with a decline of the estimated renal function. The reason for this is not fully understood. Aims: To analyse the effects of VDA discontinuation in advanced CKD and to determine the factors associated with changes in renal function. Material and methods: Retrospective cohort study of adult patients with advanced CKD. The case subgroup was treated with VDA and this medication was discontinued at baseline (the first visit). The control subgroup was not treated with VDA and they were selected according to comparability principles for CKD progression by propensity score matching. The primary outcome measure was a change to both the estimated glomerular filtration rate (MDRD-GFR) and the measured glomerular filtration rate (mGFR by combined creatinine and urea clearances). Baseline parameters related to mineral metabolism and creatinine generation were analysed as potential determinants of renal function changes. Results: The study sample consisted of 67 cases and 67 controls. Renal function improved in 67% of cases and worsened in 72% of controls (p<0.0001). Changes in MDRD-GFR for the case subgroup and the control subgroup were +0.455±0.997 vs. −0.436±1.103ml/min/1.73 m2/month (p<0.0001), respectively. Total creatinine excretion was slightly higher in cases than in controls but the difference was not significant. According to multivariate logistic and linear regression analyses, baseline total serum calcium was one of the best determinants of both renal function recovery (Odds ratio=3.49; p=0.001), and of the extent of renal function recovery (beta=0.276; p=0.001). Conclusions: Discontinuation of VDA treatment in CKD patients is associated with significant recovery of estimated renal function. The extent of these changes is mainly associated with baseline total serum calcium (AU)

Changes in renal function after discontinuation of vitamin D analogues in advanced chronic kidney disease. / Cambios de la función renal tras la suspensión de análogos de vitamina D en la enfermedad renal crónica avanzada.

BACKGROUND: In routine clinical practice, the prescription of vitamin D analogues (VDA) in patients with chronic kidney disease (CKD) is often associated with a decline of the estimated renal function. The reason for this is not fully understood. AIMS: To analyse the effects of VDA discontinuation in advanced CKD and to determine the factors associated with changes in renal function. MATERIAL AND METHODS: Retrospective cohort study of adult patients with advanced CKD. The case subgroup was treated with VDA and this medication was discontinued at baseline (the first visit). The control subgroup was not treated with VDA and they were selected according to comparability principles for CKD progression by propensity score matching. The primary outcome measure was a change to both the estimated glomerular filtration rate (MDRD-GFR) and the measured glomerular filtration rate (mGFR by combined creatinine and urea clearances). Baseline parameters related to mineral metabolism and creatinine generation were analysed as potential determinants of renal function changes. RESULTS: The study sample consisted of 67 cases and 67 controls. Renal function improved in 67% of cases and worsened in 72% of controls (p<0.0001). Changes in MDRD-GFR for the case subgroup and the control subgroup were +0.455±0.997 vs. -0.436±1.103ml/min/1.73 m2/month (p<0.0001), respectively. Total creatinine excretion was slightly higher in cases than in controls but the difference was not significant. According to multivariate logistic and linear regression analyses, baseline total serum calcium was one of the best determinants of both renal function recovery (Odds ratio=3.49; p=0.001), and of the extent of renal function recovery (beta=0.276; p=0.001). CONCLUSIONS: Discontinuation of VDA treatment in CKD patients is associated with significant recovery of estimated renal function. The extent of these changes is mainly associated with baseline total serum calcium.

High levels of both serum gamma-glutamyl transferase and alkaline phosphatase are independent preictors of mortality in patients with stage 4-5 chronic kidney disease. / Niveles séricos elevados de gamma-glutamil transferasa y fosfatasa alcalina son predictores independientes de mortalidad en la enfermedad renal crónica estadio 4-5.

INTRODUCTION: High serum gamma-glutamyl transferase (GGT) levels are associated with increased mortality in the general population. However, this association has scarcely been investigated in patients with chronic kidney disease (CKD). This study aims to investigate the clinical characteristics of CKD patients with abnormally elevated serum GGT, and its value for predicting mortality. MATERIAL AND METHODS: Retrospective observational study in a population cohort of adults with stage 4-5 CKD not yet on dialysis. Demographic, clinical, and biochemical parameters of prognostic interest were recorded and used to characterise CKD patients with high levels of GGT (>36 IU/l). Cox proportional hazard regression models were used to analyse the influence of baseline serum GGT and alkaline phosphatase (ALP) levels on mortality for whatever reason. RESULTS: The study group consisted of 909 patients (mean age 65±15 years). Abnormally elevated GGT or ALP levels at baseline were observed in 209 (23%) and 172 (19%) patients, respectively, and concomitant elevations of GGT and ALP in 68 (7%). High GGT levels were associated with higher comorbidity burden, and a biochemical profile characterised by higher serum concentration of uric acid, triglycerides, alanine aminotransferase, ferritin, and C-reactive. During the study period, 365 patients (40%) died (median survival time=74 months). In adjusted Cox regression models, high levels of GGT (hazard ratio [HR]=1.39;CI 95%: 1.09-1.78, P=.009) and ALP (HR=1.31; CI95%: 1.02-1.68, P=.038) were independently associated with mortality. CONCLUSION: High serum levels of GGT are independent predictors of mortality in CKD patients.