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Clin J Am Soc Nephrol. 2013 Dec;8(12):2091-9. doi: 10.2215/CJN.02870313. Epub 2013 Oct 31.
Kidney disease is associated with physiologic changes that may predispose to frailty. This study sought to investigate whether lower levels of kidney function were associated with prevalent or incident frailty in Cardiovascular Health Study (CHS) participants.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: CHS enrolled community-dwelling adults age ≥65 years between 1989-1990 and 1992-1993. To examine prevalent frailty, included were 4150 participants without stroke, Parkinson disease, prescribed medications for Alzheimer disease or depression, or severely impaired cognition. To examine incident frailty, included were a subset of 3459 participants without baseline frailty or development of exclusion criteria during follow-up. The primary predictor was estimated GFR (eGFR) calculated using serum cystatin C (eGFR(cys)). Secondary analyses examined eGFR using serum creatinine (eGFR(SCr)). Outcomes were prevalent frailty and incident frailty at 4 years of follow-up. Frailty was ascertained on the basis of weight loss, exhaustion, weakness, slowness, and low physical activity.
The mean age was 75 years and the median eGFR(cys) was 73 ml/min per 1.73 m(2). Among participants with an eGFR(cys) <45 ml/min per 1.73 m(2), 24% had prevalent frailty. In multivariable analysis and compared with eGFR(cys) ≥90 ml/min per 1.73 m(2), eGFR(cys) categories of 45-59 (odds ratio [OR], 1.80; 95% confidence interval [CI], 1.17 to 2.75) and 15-44 (OR, 2.87; 95% CI, 1.72 to 4.77) were associated with higher odds of frailty, whereas 60-75 (OR, 1.14; 95% CI, 0.76 to 1.70) was not. In multivariable analysis, eGFR(cys) categories of 60-75 (incidence rate ratio [IRR], 1.72; 95% CI, 1.07 to 2.75) and 15-44 (IRR, 2.28; 95% CI, 1.23 to 4.22) were associated with higher incidence of frailty whereas 45-59 (IRR, 1.53; 95% CI, 0.90 to 2.60) was not. Lower levels of eGFR(SCr) were not associated with higher risk of prevalent or incident frailty.
In community-dwelling elders, lower eGFR(cys) was associated with a higher risk of prevalent and incident frailty whereas lower eGFR(SCr) was not. These findings highlight the importance of considering non-GFR determinants of kidney function.
肾脏疾病与可能导致虚弱的生理变化有关。本研究旨在探讨较低的肾功能水平是否与心血管健康研究（CHS）参与者中普遍存在或新出现的虚弱有关。
设计、地点、参与者和测量：CHS 纳入了年龄在 1989-1990 年和 1992-1993 年之间的社区居住的≥65 岁成年人。为了研究普遍存在的虚弱，纳入了 4150 名没有中风、帕金森病、服用阿尔茨海默病或抑郁症药物或严重认知障碍的参与者。为了研究新出现的虚弱，纳入了 3459 名参与者的亚组，这些参与者在随访期间没有基线虚弱或出现排除标准。主要预测因素是使用血清胱抑素 C（eGFR(cys)）计算的估计肾小球滤过率（eGFR）。二次分析使用血清肌酐（eGFR(SCr)）检查 eGFR。结果是 4 年随访时普遍存在的虚弱和新出现的虚弱。虚弱是根据体重减轻、疲劳、虚弱、缓慢和低体力活动来确定的。
平均年龄为 75 岁，中位 eGFR(cys)为 73 ml/min/1.73m2。在 eGFR(cys) <45 ml/min/1.73m2 的参与者中，24%有普遍存在的虚弱。在多变量分析中，与 eGFR(cys)≥90 ml/min/1.73m2 相比，eGFR(cys)为 45-59（比值比[OR]，1.80；95%置信区间[CI]，1.17 至 2.75）和 15-44（OR，2.87；95% CI，1.72 至 4.77）与虚弱的几率更高相关，而 60-75（OR，1.14；95% CI，0.76 至 1.70）则不然。在多变量分析中，eGFR(cys)为 60-75（发病率比[IRR]，1.72；95% CI，1.07 至 2.75）和 15-44（IRR，2.28；95% CI，1.23 至 4.22）与虚弱的发生率较高相关，而 45-59（IRR，1.53；95% CI，0.90 至 2.60）则不然。较低的 eGFR(SCr)与较高的普遍存在或新出现的虚弱风险无关。
在社区居住的老年人中，较低的 eGFR(cys)与普遍存在和新出现的虚弱风险增加有关，而较低的 eGFR(SCr)则不然。这些发现强调了考虑非肾小球滤过率决定因素对肾脏功能的重要性。
