Pan Yu, Guo Li Li, Jin Hui Min
Division of Nephrology, No. 3 People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Am J Clin Nutr. 2008 Sep;88(3):660-6. doi: 10.1093/ajcn/88.3.660.
A low-protein diet (LPD) has been proposed for many years to delay the progression of diabetic nephropathy. However, the efficacy of an LPD with respect to renal outcome is disputed.
We aimed to determine the effect of an LPD on renal function in patients with type 1 or 2 diabetic renal diseases by using a meta-analysis of randomized controlled trials.
Medline, EMBASE, and the Cochrane Central Register of Controlled Trials were searched. Eight studies met the inclusion criteria for our meta-analysis: a duration of >6 mo, use of a randomized control group, availability of outcome data for changes in glomerular filtration rate (GFR) or creatinine clearance rate (CCR), and albuminuria or proteinuria in patients with type 1 or 2 diabetic nephropathy. Data were combined by means of a fixed-effects model. Weighted mean differences (WMD) were calculated for the change in GFR or CCR, glycated hemoglobin (HbA(1c)), and serum albumin between the LPD and control groups. A random-effects model was also used to calculate the standardized mean difference for the change in urinary albumin excretion or proteinuria.
Overall, a change in WMD for GFR or CCR was not significantly associated with an LPD, but a decrease in WMD for HbA(1c) was significant in the LPD group (P = 0.005). Although the benefit of LPD therapy on proteinuria was significant (P = 0.003), great heterogeneity was observed. In a subgroup analysis, LPD resulted in lower serum albumin concentrations.
LPD was not associated with a significant improvement of renal function in patients with either types 1 or 2 diabetic nephropathy.
多年来一直有人提出采用低蛋白饮食（LPD）来延缓糖尿病肾病的进展。然而，LPD对肾脏结局的疗效存在争议。
我们旨在通过对随机对照试验进行荟萃分析，确定LPD对1型或2型糖尿病肾病患者肾功能的影响。
检索了医学期刊数据库（Medline）、荷兰医学文摘数据库（EMBASE）和考克兰系统评价数据库（Cochrane Central Register of Controlled Trials）。八项研究符合我们荟萃分析的纳入标准：持续时间>6个月、使用随机对照组、可获得肾小球滤过率（GFR）或肌酐清除率（CCR）变化的结局数据，以及1型或2型糖尿病肾病患者的白蛋白尿或蛋白尿数据。数据通过固定效应模型进行合并。计算LPD组和对照组之间GFR或CCR变化、糖化血红蛋白（HbA1c）和血清白蛋白的加权平均差（WMD）。还使用随机效应模型计算尿白蛋白排泄或蛋白尿变化的标准化平均差。
总体而言，GFR或CCR的WMD变化与LPD无显著相关性，但LPD组HbA1c的WMD下降显著（P = 0.005）。尽管LPD治疗对蛋白尿的益处显著（P = 0.003），但观察到存在很大异质性。在亚组分析中，LPD导致血清白蛋白浓度降低。
LPD与1型或2型糖尿病肾病患者肾功能的显著改善无关。
