Chang Alex, Greene Tom H, Wang Xuelei, Kendrick Cynthia, Kramer Holly, Wright Jackson, Astor Brad, Shafi Tariq, Toto Robert, Lewis Julia, Appel Lawrence J, Grams Morgan
Division of Nephrology, Geisinger Health System, Danville, PA, USA.
Department of Population Health Sciences, University of Utah, Salt Lake City, UT, USA.
Nephrol Dial Transplant. 2015 Nov;30(11):1870-7. doi: 10.1093/ndt/gfv219. Epub 2015 Jun 17.
Little is known about the effect of weight loss/gain on kidney function. Analyses are complicated by uncertainty about optimal body surface indexing strategies for measured glomerular filtration rate (mGFR).
Using data from the African-American Study of Kidney Disease and Hypertension (AASK), we determined the association of change in weight with three different estimates of change in kidney function: (i) unindexed mGFR estimated by renal clearance of iodine-125-iothalamate, (ii) mGFR indexed to concurrently measured BSA and (iii) GFR estimated from serum creatinine (eGFR). All models were adjusted for baseline weight, time, randomization group and time-varying diuretic use. We also examined whether these relationships were consistent across a number of subgroups, including tertiles of baseline 24-h urine sodium excretion.
In 1094 participants followed over an average of 3.6 years, a 5-kg weight gain was associated with a 1.10 mL/min/1.73 m(2) (95% CI: 0.87 to 1.33; P < 0.001) increase in unindexed mGFR. There was no association between weight change and mGFR indexed for concurrent BSA (per 5 kg weight gain, 0.21; 95% CI: -0.02 to 0.44; P = 0.1) or between weight change and eGFR (-0.09; 95% CI: -0.32 to 0.14; P = 0.4). The effect of weight change on unindexed mGFR was less pronounced in individuals with higher baseline sodium excretion (P = 0.08 for interaction).
The association between weight change and kidney function varies depending on the method of assessment. Future clinical trials should examine the effect of intentional weight change on measured GFR or filtration markers robust to changes in muscle mass.
关于体重减轻/增加对肾功能的影响，人们了解甚少。由于测量肾小球滤过率（mGFR）的最佳体表面积指数策略存在不确定性，分析变得复杂。
利用非裔美国人肾脏疾病与高血压研究（AASK）的数据，我们确定了体重变化与三种不同肾功能变化估计值之间的关联：（i）通过碘-125-碘他拉酸盐肾清除率估计的未指数化mGFR，（ii）根据同时测量的体表面积指数化的mGFR，以及（iii）根据血清肌酐估计的肾小球滤过率（eGFR）。所有模型均根据基线体重、时间、随机分组和随时间变化的利尿剂使用情况进行了调整。我们还研究了这些关系在多个亚组中是否一致，包括基线24小时尿钠排泄三分位数。
在平均随访3.6年的1094名参与者中，体重增加5 kg与未指数化mGFR增加1.10 mL/min/1.73 m²（95%CI：0.87至1.33；P<0.001）相关。体重变化与根据同时测量的体表面积指数化的mGFR之间无关联（每增加5 kg体重，0.21；95%CI：-0.02至0.44；P = 0.1），体重变化与eGFR之间也无关联（-0.09；95%CI：-0.32至0.14；P = 0.4）。体重变化对未指数化mGFR的影响在基线钠排泄较高的个体中不太明显（交互作用P = 0.08）。
体重变化与肾功能之间的关联因评估方法而异。未来的临床试验应研究有意改变体重对测量的GFR或对肌肉量变化有抵抗力的滤过标志物的影响。
