Work

Mo034dietary Patterns for People With Chronic Kidney Disease: Meta-analysis of Randomized Clinical Trials

Year: 2017

Type: review

Study designs: Systematic Review, Meta-Analysis

Abstract: INTRODUCTION AND AIMS: Dietary interventions are considered a priority research uncertainty among patients with chronic kidney disease (CKD) and clinicians. However, there is little evidence that dietary interventions improve clinical outcomes in the setting of renal disease. We aimed to conduct a systematic review and meta-analysis on the effects of adherence to dietary patterns on clinical outcomes including mortality and kidney function in people with CKD. METHODS: In this Cochrane systematic review with meta-analysis, we searched the Cochrane Kidney Transplant specialized register for randomized clinical trials of dietary interventions compared with dietary interventions, lifestyle advice or standard care in adults and children with CKD. Treatment estimates were summarized as relative risks (RR) together with associated 95% confidence intervals (CI). Risks of bias were assessed using standard Cochrane methodology. Evidence quality was adjudicated using GRADE criteria. RESULTS: We included 17 studies involving 1639 people with chronic kidney disease. Three studies involved 341 people treated with dialysis, four studies involved 168 recipients of a kidney transplant, and 10 studies involved 1130 people with chronic kidney disease stages 1 to 5. Eleven studies (900 people) evaluated dietary counselling with or without lifestyle advice and six evaluated dietary patterns (739 people), including one study (191 people) of a carbohydrate-restricted low-iron, polyphenol enriched diet, two studies (181 people) of increased fruit and vegetable intake, two studies (355 people) of a Mediterranean diet and one study (12 people) of a high protein/low carbohydrate diet. Risks of bias in the included studies were generally high or unclear, lowering confidence in the results. Participants were followed up for a median of 12 months (range 1 to 46.8 months). Studies were not designed to examine all-cause mortality or cardiovascular events. In very-low quality evidence, dietary interventions had uncertain effects on all-cause mortality or end-stage kidney disease. Across all 17 studies, outcome data for cardiovascular events were absent. Dietary interventions in low quality evidence were associated with a higher health-related quality of life (2 studies: mean difference in SF-36 score 11.46, 95% CI 7.73-15.18). Adverse events were generally not reported. Dietary interventions lowered systolic blood pressure (3 studies: MD -9.26 mmHg, 95% CI -13.48 to -5.04) and diastolic blood pressure (2 studies: MD -8.64 mmHg 95% CI -13.3 to -3.98) compared to a control diet. Dietary interventions were associated with a higher estimated glomerular filtration rate (5 studies: MD 6.27 ml/min/ 1.73 m2, 95% CI 2.12-10.42) and serum albumin levels (6 studies: MD 0.16 mg/dl, 95% CI 0.07-0.24). CONCLUSIONS: Dietary interventions have uncertain effects on mortality, cardiovascular events and end-stage kidney disease among people with CKD as these outcomes were rarely measured or reported. Dietary interventions are associated with higher health-related quality of life, estimated glomerular filtration rate, and serum albumin, and lower blood pressure.

Source: Nephrology Dialysis Transplantation

DOI: 10.1093/ndt/gfx119.mo034