Pilot study to investigate differences in middle molecules, oxidative stress and markers of peripheral vascular disease in patients treated by high flux haemodialysis and haemodiafiltration.

BACKGROUND: Dialysis patients have an increased risk of mortality. Recently treatment with haemodiafiltration (HDF) has been reported to reduce mortality, particularly cardiovascular mortality, compared to standard high-flux haemodialysis (HD). However, why HDF may offer a survival advantage remains to be determined. So, we conducted a pilot study to explore differences in middle-molecules, inflammation and markers of vascular disease in patients treated by HD and HDF. METHODS: Observational cross-sectional study measuring serum ß2-microglobulin (ß2M), Advanced Glycosylation End Products (AGEs) by skin autofluorescence (SAF), oxidative stress with ischaemia modified albumin ratio (IMAR) and peripheral vascular disease assessment using Ankle-Brachial Index (ABI), and arterial stiffness using Cardio-Ankle Vascular Index (CAVI). RESULTS: We studied 196 patients, mean age 69.1 ± 12.4 years, 172 (87.8%) treated by HD and 24 (12.2%) by HDF. Age, body mass index, co-morbidity and dialysis vintage were not different between HD and HDF groups. Middle molecules; ß2M (31±9.9 vs 31.2±10 ug/mL) and SAF (2.99±0.72 vs 3.0±0.84 AU), ABI (1.06±0.05 vs 1.07±0.10) and CAVI (9.34±1.55 vs 9.35±1.23) were not different, but IMAR was higher in the HD patients (38.4±14.8 vs 31.3 ± 17.4, P = 0.035). CONCLUSIONS: In this pilot observational study, we found patients treated by HDF had lower oxidative stress as measured by IMAR, with no differences in middle molecules. Lower oxidative stress would be expected to have diverse protective effects on the cardiovascular system Although we found no differences in ABI and CAVI, future studies are required to determine whether reduced oxidative stress translates into clinically relevant differences over time.

Abdominal aorta and pelvic artery calcifications on plain radiographs may predict mortality in chronic kidney disease, hemodialysis and renal transplantation.

PURPOSE: Vascular calcification is common in chronic kidney disease (CKD) and predicts poor patient outcomes. While computed tomography is the gold standard for evaluation of vascular calcification, plain radiograph offers a simpler and less costly alternative. The calcification of abdominal aorta, iliac and femoral arteries has been evaluated by plain radiograph, but the data on their outcome predictabilities are still limited. The present study investigated the role of abdominal aortic calcification (AAC) and pelvic arterial calcification (PAC) in predicting overall morality in non-dialysis CKD stages 2-5 (CKD 2-5), maintenance hemodialysis (HD) and long-term kidney transplant (KT) patients. METHODS: Four hundred and nineteen patients were included. Lateral abdominal and pelvic radiographs were obtained. The degree of AAC and PAC was evaluated according to the methods described previously by Kaupplia et al. and Adragao et al. Patients were followed prospectively for 5 years. RESULTS: AAC and PAC scores correlated well with the correlation coefficients of 0.442 for CKD 2-5, 0.438 for HD and 0.586 for KT (p < 0.001). Patients with AAC score > 6 or PAC score > 1 were older, showed higher prevalence of DM and had higher serum phosphate and PTH but lower serum albumin and eGFR. A more severe degree of AAC was associated with an increase in KT duration, whereas a more severe degree of PAC was associated with worsening kidney function and prolonged dialysis vintage. Kaplan-Meier survival curves revealed AAC score > 6 as a significant predictor of all-cause mortality in CKD 2-5 but not in HD or KT, whereas PAC score > 1 was a significant predictor of all-cause mortality in all three populations. After adjusting for age, the predictability of AAC was lost, whereas PAC remained an independent predictor of mortality in all three populations. Adjustments for cardiovascular and CKD risk factors including age, gender, BMI, DM, serum albumin, calcium and phosphate attenuated the predictability of PAC in HD but not in CKD 2-5 or KT patients. CONCLUSION: PAC was better than AAC in predicting mortality in CKD, HD and KT patients.

Effectiveness of Integrated Care on Delaying Progression of stage 3-4 Chronic Kidney Disease in Rural Communities of Thailand (ESCORT study): a cluster randomized controlled trial.

BACKGROUND: In developing countries, renal specialists are scarce and physician-to-patient contact time is limited. While conventional hospital-based, physician-oriented approach has been the main focus of chronic kidney disease (CKD) care, a comprehensive multidisciplinary health care program (Integrated CKD Care) has been introduced as an alternate intervention to delay CKD progression in a community population. The main objective is to assess effectiveness of Integrated CKD Care in delaying CKD progression. METHODS: We carried out a community-based, cluster randomized controlled trial. Four hundred forty-two stage 3-4 CKD patients were enrolled. In addition to the standard treatments provided to both groups, the patients in the intervention group also received "Integrated CKD Care". This was delivered by a multidisciplinary team of hospital staff in conjunction with a community CKD care network (subdistrict healthcare officers and village health volunteers) to provide group counseling during each hospital visit and quarterly home visits to monitor compliance with the treatment. Duration of the study was 2 years. The primary outcome was difference of mean eGFR between the intervention and the control groups over the study period. RESULTS: The mean difference of eGFR over time in the intervention group was significantly lower than the control group by 2.74 ml/min/1.73 m2 (95%CI 0.60-4.50, p = 0.009). Seventy composite clinical endpoints were reported during the study period with significantly different incidences between the control and the intervention groups (119.1 versus 69.4 per 1000 person-years; hazard ratio (HR) 0.59, 95% CI 0.4-0.9, p = 0.03). CONCLUSION: Integrated CKD Care can delay CKD progression in resource-limited settings. TRIAL REGISTRATION: ( NCT01978951 ). Prospectively registered as of December 8, 2012.

Hyperparathyroidism and increased fractional excretion of phosphate predict allograft loss in long-term kidney transplant recipients.

BACKGROUND: After kidney transplantation, fibroblast growth factor-23 (FGF-23) normally returns to baseline within 1 year whereas hyperparathyroidism persists in most kidney transplant (KT) recipients. As a result, serum phosphate remains relatively low in association with increased serum calcium and urinary phosphate excretion when compared to chronic kidney disease patients. The relationship between mineral metabolism and outcomes in long-term KT recipients has not been extensively studied. This study investigated whether the alteration in mineral metabolism influenced graft survival in long-term KT recipients. METHODS: This study included 273 KT recipients after 1 year of transplantation. Mineral parameters were obtained at the time of enrolment and patients were followed prospectively for an average of 71 months. RESULTS: Graft loss (death-censored) occurred in 41 (15%) patients. In univariate analysis, deceased donor transplantation, decreased serum albumin and estimated glomerular filtration rate, increased serum phosphate, parathyroid hormone (PTH), FGF-23 and fractional excretion of phosphate (FePi) predicted future allograft loss. After adjustments for cardiovascular disease risk factors, donor type, dialysis vintage, serum albumin and allograft function, only increased PTH and FePi remained associated with the outcome. Relationships between increased serum phosphate and FGF-23 with graft survival were lost after adjustments. Adjusted survival curves revealed the association between PTH > 90 pg/mL and FePi > 20% with worse graft survival. CONCLUSIONS: Hyperparathyroidism and increased FePi predicted allograft loss in long-term KT recipients.

Effectiveness of integrated care on delaying chronic kidney disease progression in rural communities of Thailand (ESCORT study): rationale and design of the study [NCT01978951].

BACKGROUND: In developing countries, accessibility to specialists, and physician to patient contact time is limited. In Thailand, A unique community health service is provided by subdistrict health care officers and Village Health Volunteers (VHVs). If the personnel were trained on proper chronic kidney disease (CKD) care, CKD progression would be delayed. METHODS/DESIGN: We conducted a community-based, cluster randomized controlled trial at Kamphaeng Phet Province, located about 400 kilometers north of Bangkok. Two out of eleven districts of the province were randomly selected. Approximatly 500 stage 3-4 CKD patients from 2 districts were enrolled. Patients in both groups will be treated with standard guidelines. The patients in intervention group were provided the additional treatments by multidisciplinary team in conjunction with community CKD care network (subdistrict health care officers and VHVs) which will provide group counseling during each hospital visit and quarterly home visits to monitor dietary protein and sodium intake, blood pressure measurement and drug compliance. Duration of the study is 2 years. The primary outcome is the difference of rate of eGFR decline. The secondary outcomes are laboratory parameters and incidence of clinical endpoints such as mortality rate and cardiovascular events, end-stage renal disease (ESRD), etc. DISCUSSION: Insights of this study may set forth a new standard of community-based CKD care. TRIAL REGISTRATION: NCT01978951.

Vascular calcification in long-term kidney transplantation.

AIM: Vascular calcification (VC) is common among patients with chronic kidney disease (CKD) due to the strong prevalence of cardiovascular and CKD-related risk factors such as diabetes mellitus (DM), hypertension and phosphate retention. Kidney transplantation improves kidney function and abnormal mineral metabolism at the same time. It remains unclear whether kidney transplantation favourably impacts VC in the long-term. METHODS: The present study examined VC in 132 kidney transplant (KT) recipients who had been transplanted for longer than one year. The severity of VC was compared to 129 CKD stages 5-5D patients on a kidney transplant (KT) waiting list. RESULTS: The median KT vintage was 88 months. The prevalence of VC among KT and CKD patients were 54.5% and 62.8%, respectively, (P = 0.2). There were no differences in age, gender, body mass index (BMI), the prevalence of DM or CVD between the two groups. Among patients with calcification, a more severe degree was observed in KT recipients (P = 0.01). Aging, DM, CVD and dialysis vintage were associated with significant VC in both groups. The degree of VC in KT recipients was more pronounced than that in CKD patients among those who experienced prolonged dialysis vintage (>2 years) (P = 0.04). Among KT recipients, the severity of VC increased with the length of time after transplantation and became more substantial after 5 years. CONCLUSIONS: Long-term KT recipients demonstrated a more severe degree of VC compared to matched CKD stages 5-5D patients. The severity of VC became more pronounced among those with longer transplant vintage and was in part influenced by past dialysis experience.

Mineral metabolism and outcomes in chronic kidney disease stage 2-4 patients.

BACKGROUND: Marked hyperphosphatemia, hyperparathyroidism and 25-hydroxyvitamin D deficiency are associated with mortality in dialysis patients. Such data in chronic kidney disease stage 2-4 population are limited. It has been suggested that high-normal serum phosphate predicts worse renal and patient outcomes. The data regarding parathyroid hormone and outcomes in this population is limited. The present study examined mineral metabolism and its association with the development of end-stage renal disease and mortality in stage 2-4 chronic kidney disease patients. METHODS: This is a prospective cohort study that included 466 non-dialysis chronic kidney disease stage 2-4 patients. Mineral parameters were obtained at the time of enrollment and the patients were followed prospectively for 25 (1-44) months or until they reached the endpoints of end-stage renal disease or mortality. RESULTS: Hyperparathyroidism and 25-hydroxyvitamin D deficiency began to occur in the early stages of chronic kidney disease, whereas significant hyperphosphatemia only developed in the later stages. High-normal and mildly elevated serum phosphate (>4.2 mg/dL) predicted the composite outcome of end-stage renal disease or mortality after adjustments for cardiovascular risk factors, chronic kidney disease stage and other mineral parameters. Parathyroid hormone levels above the upper limit of normal (>65 pg/mL) predicted the future development of end-stage renal disease and the composite outcome of end-stage renal disease or mortality after adjustments. 25-hydroxyvitamin D deficiency (<15 ng/mL) was also associated with worse outcomes. CONCLUSIONS: In chronic kidney disease, hyperparathyroidism developed prior to significant hyperphosphatemia confirming the presence phosphate retention early in the course of chronic kidney disease. High-normal serum phosphate and mildly elevated parathyroid hormone levels predicted worse renal and patient outcomes. This data emphasizes the need for early intervention in the care of chronic kidney disease stage 2-4 patients.