Kidney Health Research Institute, Geisinger Health System, Danville, PA; Department of Epidemiology and Health Services Research, Geisinger Health System, Danville, PA; Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University, Baltimore, MD; and Divison of Nephrology, Johns Hopkins University, Baltimore, MA.
Kidney Health Research Institute, Geisinger Health System, Danville, PA; Department of Epidemiology and Health Services Research, Geisinger Health System, Danville, PA; Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University, Baltimore, MD; and Divison of Nephrology, Johns Hopkins University, Baltimore, MA.
Adv Chronic Kidney Dis. 2018 Jan;25(1):31-40. doi: 10.1053/j.ackd.2017.10.007.
As the prevalence of obesity continues to increase worldwide, an increasing number of people are at risk for kidney disease. Thus, there is a critical need to understand how best to assess kidney function in this population, and several challenges exist. The convention of indexing glomerular filtration rate (GFR) to body surface area (BSA) attempts to normalize exposure to metabolic wastes across populations of differing body size. In obese individuals, this convention results in a significantly lower indexed GFR than unindexed GFR, which has practical implications for drug dosing. Recent data suggest that "unindexing" estimated GFR (multiplying by BSA/1.73 m) for drug dosing may be acceptable, but pharmocokinetic data to support this practice are lacking. Beyond indexing, biomarkers commonly used for estimating GFR may induce bias. Creatinine is influenced by muscle mass, whereas cystatin C correlates with fat mass, both independent of kidney function. Further research is needed to evaluate the performance of estimating equations and other filtration markers in obesity, and determine whether unindexed GFR might better predict optimal drug dosing and clinical outcomes in patients whose BSA is very different than the conventional normalized value of 1.73 m.
随着肥胖症在全球范围内的流行率不断上升，越来越多的人面临患肾病的风险。因此，迫切需要了解如何最好地评估这一人群的肾功能，而这其中存在一些挑战。将肾小球滤过率（GFR）与体表面积（BSA）相关联的常规做法旨在使不同体型人群对代谢废物的暴露程度标准化。在肥胖个体中，这种常规做法导致指数化 GFR 显著低于未指数化 GFR，这对药物剂量具有实际影响。最近的数据表明，“未指数化”估计 GFR（乘以 BSA/1.73 m）用于药物剂量可能是可以接受的，但缺乏支持这种做法的药代动力学数据。除了指数化之外，常用于估计 GFR 的生物标志物可能会引起偏差。肌氨酸酐受肌肉质量影响，胱抑素 C 与脂肪质量相关，两者均独立于肾功能。需要进一步研究来评估估计方程和其他滤过标志物在肥胖症中的表现，并确定未指数化 GFR 是否可以更好地预测药物剂量和临床结局，特别是在患者的 BSA 与常规标准化值 1.73 m 有很大差异的情况下。
