Urine albumin and serum uric acid are important determinants of serum 25 hydroxyvitamin D level in pre-dialysis chronic kidney disease patients.

Low serum 25 hydroxyvitamin D (25 OH D) is common among chronic kidney disease (CKD) patients. This cross-sectional study is looking for the different factors associated with serum 25 OH D among pre-dialysis CKD. 1624 adult stage 3-5 CKD patients were studied beside 200 normal control subjects. All candidates were tested for body mass index (BMI), estimated glomerular filtration rate (eGFR), calcium (Ca), phosphorus (P), parathormone (PTH), 25 OH D, albumin, and uric acid (UA), and urine albumin/creatinine ratio (ACR). Multivariate linear regression analysis was done to determine predictors of 25 OH D. 98.6% of CKD patients have inadequate level of 25 OH D vs 48% of normal subjects. Serum 25 OH D was significantly lower in CKD patients (mean ± S.D = 16.54 ± 5.8 vs 37.79 ± 3.58 ng/mL for CKD vs control group respectively, p < .001). Serum level of 25 OH D has significant positive correlation with Ca (r = 0.337, p < .001), and significant negative correlation with P, PTH, UA, and ACR (r = -0.440, -0. 679, -0.724, and -0.781respectively, p < .001 in all). The independent predictors of 25 OH D were Ca, P, UA, PTH, and ACR (R square = 0.7, ß = -0.087, -0.226, -0.313, -0.253, and -0.33 respectively, p < .001 in all). In conclusion, pre-dialysis CKD patients frequently suffer low 25 OH D. Among the different abnormalities related to CKD, urine albumin excretion rate and UA are the most important predictors of 25 OH D in these patients.

Vitamin-D deficiency is encountered in almost all egyptian stage 3-5 chronic kidney disease patients in spite of the sunny weather.

Currently, there is no available data about Vitamin D status among Egyptian chronic kidney disease (CKD) patients. This cross-sectional study is looking for the prevalence of Vitamin D deficiency among Stage 3a-5 CKD Egyptian patients and its possible associations. We studied 1624 Stage 3a-5 CKD adults (689 males and 935 females) together with 200 normal control persons. All the recruited candidates were tested for body mass index (BMI); serum levels of blood urea nitrogen, creatinine, calcium (Ca), phosphorus (P), parathyroid hormone (PTH), 25 hydroxy vitamin D (25(OH)D), albumin, and uric acid (UA); urine albumin/creatinine ratio (ACR), and estimated glomerular filtration rate. The optimal level of Vitamin D was encountered in only 1.4% of CKD patients versus 52% of the normal controls. A total of 1107 (68.2%) CKD patients versus 23 (11.5%) controls had serum 25(OH)D <20 ng/mL (mean ± standard deviation = 16.8 ± 5.8 versus 37.3±7.6 ng/mL for CKD versus control group, respectively, P <0.001). There was a highly statistically significant positive correlation between serum 25(OH)D and serum Ca (r = 0.299, P <0.001) and a highly statistically significant negative correlation between serum 25(OH)D on the one hand and serum P, serum PTH, serum UA, and urine ACR on the other hand (r = -0.46, -0.69, -0.73, and -0.8, respectively, P <0.001). Vitamin D deficiency is very common among Egyptian CKD patients. Serum P, UA, and urine ACR ratio are the most important variables which are found to be negatively associated with serum 25(OH)D.

Incidence and Characteristics of de novo Renal Cryoglobulinemia After Direct-Acting Antivirals Treatment in an Egyptian Hepatitis C Cohort.

INTRODUCTION: The side effects profile of the new direct--acting antivirals for the treatment of hepatitis C virus (HCV) is not fully elucidated. OBJECTIVE: In this cross-sectional study, we aim to describe the incidence and characteristics of a novel observation of de novo renal cryoglobulinemic glomerulonephritis after successful treatment with DAA. METHODOLOGY: A total of 12,985 Hepatitis C Patients (genotype IV) received the new DAA. After successful treatment, patients with deranged renal functions or proteinuria were referred to the nephrology department for assessment. The clinical manifestations ranged from lower limb edema to the development of purpura skin lesions. Cryoglobulins were tested in the serum using the PCR detection. RESULTS: Fifty patients had detectable de novo cryoglobulins in the serum. The most common type in renal biopsies was membranoproliferative glomerulonephritis (52%) and chronic kidney disease (CKD) developed in 46% of cases. CONCLUSION: De novo cryoglobulinemic glomerulonephritis and progression to CKD may rarely complicate successful treatment of HCV using direct-acting antivirals.

Serum 25-hydroxyvitamin D level is negatively associated with serum phosphorus level among stage 3a-5 chronic kidney disease patients / El nivel de 25-hidroxivitamina D sérica está asociado negativamente con el nivel de fósforo sérico en pacientes con enfermedad renal crónica en estadio 3a-5

BACKGROUND: Serum 25-hydroxyvitamin D (25(OH)D) negatively correlates with serum phosphorus level of stage 3a-5 chronic kidney disease (CKD) patients. So far, no explanation has been provided for this negative association. OBJECTIVE: To confirm this negative association and determine if this relationship is mediated through other known co-morbid factors. Cases and methods: One hundred (57 male and 43 female) pre-dialysis stage 3a-5 CKD patients were selected. Estimated glomerular filtration rate (eGFR), serum calcium (Ca), phosphorus (P), 25 (OH)D, parathyroid hormone (PTH), and intact fibroblast growth factor-23 (FGF23) were assessed. A correlation analysis between serum 25(OH)D and the different parameters studied was performed. Multivariate linear regression analysis was carried out to determine predictors of 25(OH)D. RESULTS: The negative association between serum 25 (OH)D and serum P was confirmed in univariate and multivariate correlation analysis. On the other hand, we failed to detect a significant association between 25 (OH)D and serum FGF23. Serum P is the most important independent predictor of 25 (OH)D in these patients (partial R2 = 0.15, p < 0.0001). CONCLUSION: Serum P is likely to have a direct negative impact on serum 25 (OH)D. Further studies are needed to determine the underlying mechanism

ANTECEDENTES: La 25-hidroxivitamina D (25(OH)D) sérica se correlaciona negativamente con el nivel de fósforo sérico en pacientes con enfermedad renal crónica (ERC) en estadio 3a-5. Hasta la fecha, no se dispone de ninguna explicación sobre esta asociación negativa. OBJETIVO: Confirmar la asociación negativa y averiguar si esta relación está mediada por otros factores de comorbilidad conocidos. Casos y métodos: Se seleccionaron 100 pacientes (57 varones y 43 mujeres) con ERC en estadio 3a-5 prediálisis. Se evaluaron la tasa de filtración glomerular estimada (TFRe), el calcio sérico (Ca), el fósforo (P), la 25(OH)D, la hormona paratiroidea (HPT) y el factor de crecimiento de fibroblastos 23 intacto (FGF23). Se realizó un análisis de correlación entre la 25(OH)D sérica y los distintos parámetros estudiados. Se llevó a cabo un análisis de regresión lineal multivariable para determinar los factores pronósticos de 25(OH)D. RESULTADOS: Se confirmó la asociación negativa entre la 25(OH)D sérica y el P sérico en análisis de correlación univariable y multivariable. Por otro lado, no detectamos ninguna asociación significativa entre la 25(OH)D y el FGF23 sérico. El P sérico es el factor predictivo independiente más importante de la 25(OH)D en estos pacientes (R2 parcial=0,15; p < 0,0001). CONCLUSIÓN: Es probable que el P sérico tenga un impacto negativo directo sobre la 25 (OH)D sérica. Es necesario realizar más estudios para averiguar el mecanismo subyacente

Serum 25-hydroxyvitamin D level is negatively associated with serum phosphorus level among stage 3a-5 chronic kidney disease patients.

BACKGROUND: Serum 25-hydroxyvitamin D (25(OH)D) negatively correlates with serum phosphorus level of stage 3a-5 chronic kidney disease (CKD) patients. So far, no explanation has been provided for this negative association. OBJECTIVE: To confirm this negative association and determine if this relationship is mediated through other known co-morbid factors. CASES AND METHODS: One hundred (57 male and 43 female) pre-dialysis stage 3a-5 CKD patients were selected. Estimated glomerular filtration rate (eGFR), serum calcium (Ca), phosphorus (P), 25(OH)D, parathyroid hormone (PTH), and intact fibroblast growth factor-23 (FGF23) were assessed. A correlation analysis between serum 25(OH)D and the different parameters studied was performed. Multivariate linear regression analysis was carried out to determine predictors of 25(OH)D. RESULTS: The negative association between serum 25(OH)D and serum P was confirmed in univariate and multivariate correlation analysis. On the other hand, we failed to detect a significant association between 25(OH)D and serum FGF23. Serum P is the most important independent predictor of 25(OH)D in these patients (partial R2=0.15, p<0.0001). CONCLUSION: Serum P is likely to have a direct negative impact on serum 25(OH)D. Further studies are needed to determine the underlying mechanism.

Fibroblast growth factor-23 is a strong predictor of insulin resistance among chronic kidney disease patients.

Insulin resistance (IR) is very common among chronic kidney disease (CKD) patients. Disturbance in mineral and bone metabolism (MBD) seems to play a role in the pathogenesis of insulin resistance. Fibroblast growth factor-23 (FGF23) is evolving as the most important link between MBD and many pathologic sequences of CKD. The aim was to evaluate IR in pre-dialysis CKD patients looking for a possible association to mineral metabolism among CKD patients. A total of 100 stage 3-5 CKD patients were selected beside 20 normal control subjects. Homeostatic model assessment of insulin resistance (HOMA-IR) was used to assess IR in selected cases. Both groups were compared for fasting blood glucose (FBG), fasting blood insulin (FBI), HOMA-IR, estimated glomerular filtration rate (eGFR), serum calcium (Ca), phosphorus (P), 25 hydroxy vitamin D (25 OH vit D), parathormone (PTH), and uric acid (UA). Correlation study between HOMA_IR and different studied parameters was performed. HOMA-IR is significantly higher in CKD (8.87 ± 3.48 vs. 3.97 ± 0.34 in CKD vs. control, respectively, p < .001). In addition CKD patients have significantly higher FGF23 (235 ± 22.96 vs. 139 ± 12.3 pg/mL, p < .001), PTH (76.9 ± 15.27 vs. 47.9 ± 2.52 pg/mL, p < .001), P (4.3 ± 0.67 vs. 3.6 ± 0.23 mg/dL, p < .001), and UA (5 ± 1.22 vs. 4.85 ± 0.48 mg/dL, p < .001) and significantly lower Ca (8.2 ± 0.3 vs. 8.9 ± 0.33 mg/dL, p < .001), and 25 (OH) vit D (17 ± 5.63 vs. 37 ± 3.43 ng/mL, p < .001). Stepwise linear regression analysis revealed that BMI, GFR, Ca, P, and FGF23 were the only significant predictors of HOMA IR. Increased IR in CKD is a consequence of the uremic status and is intimately associated with disturbed phosphate metabolism and FGF23. Further studies are needed to look for an underlying mechanism.