Canney Mark, Sexton Donal J, O'Connell Matthew D L, Kenny Rose Anne, Little Mark A, O'Seaghdha Conall M
The Irish Longitudinal Study on Ageing, Department of Medical Gerontology, Trinity College Dublin, Ireland.
Trinity Health Kidney Centre, Trinity Centre for Health Sciences, Tallaght Hospital, Dublin, Ireland.
J Gerontol A Biol Sci Med Sci. 2017 Oct 12;72(11):1554-1560. doi: 10.1093/gerona/glx039.
The burden of chronic kidney disease is highest among older adults but the significance of a diminished level of kidney function in this heterogeneous population is poorly understood. We sought to examine the relationship between estimated glomerular filtration rate (eGFR) and objective physical performance in older adults.
Cross-sectional analysis of 4,562 participants from The Irish Longitudinal Study on Ageing, a national cohort of community-dwelling adults aged ≥50 years. We used multivariable linear or quantile regression to model the association between categories of cystatin C (eGFRcys) or creatinine eGFR (eGFRcr) and the following outcomes: gait speed, timed-up-and-go (TUG) and grip strength. Relationships were further explored using natural eGFR splines. We examined effect modification by age in the relationship between eGFR and gait speed.
Mean (SD) age was 61.8 (8.3) years, 53.6% were female and median (IQR) eGFRcys was 82 (70-94) mL/min/1.73m2. In multivariable-adjusted models, participants in the lowest eGFRcys category (< 45 mL/min/1.73m2) had 3.32 cm/s (95% confidence interval [95%CI] 0.02-6.62) slower mean gait speed, 1.32 kg (95%CI 0.20-2.44) lower mean grip strength, and 0.31 seconds (95% CI -0.04 to 0.65) longer median TUG versus the reference group (eGFRcys ≥ 90 mL/min/1.73m2). The relationship between eGFRcys and outcomes appeared linear but varied by age. The association between eGFRcr and outcomes tended towards a U-shape.
Cystatin C eGFR was linearly related to poorer physical performance beyond middle age among community-dwelling adults. The non-linear relationships observed with eGFRcr underscore the limitations of creatinine as a predictor of frailty outcomes in older individuals.
慢性肾脏病负担在老年人中最为沉重，但在这个异质性群体中，肾功能水平下降的意义却鲜为人知。我们试图研究老年人估计肾小球滤过率（eGFR）与客观身体表现之间的关系。
对来自爱尔兰老龄化纵向研究的4562名参与者进行横断面分析，该研究是一个全国性队列，参与者为年龄≥50岁的社区居住成年人。我们使用多变量线性或分位数回归来模拟胱抑素C估算肾小球滤过率（eGFRcys）或肌酐估算肾小球滤过率（eGFRcr）类别与以下结果之间的关联：步速、从座椅站起行走并返回（TUG）和握力。使用自然eGFR样条进一步探索关系。我们研究了eGFR与步速之间关系中年龄的效应修正。
平均（标准差）年龄为61.8（8.3）岁，53.6%为女性，eGFRcys中位数（四分位间距）为82（70 - 94）mL/min/1.73m²。在多变量调整模型中，与参考组（eGFRcys≥90 mL/min/1.73m²）相比，最低eGFRcys类别（<45 mL/min/1.73m²）的参与者平均步速慢3.32 cm/s（95%置信区间[95%CI] 0.02 - 6.62），平均握力低1.32 kg（95%CI 0.20 - 2.44），TUG中位数长0.31秒（95%CI -0.04至0.65）。eGFRcys与结果之间的关系呈线性，但因年龄而异。eGFRcr与结果之间的关联呈U形趋势。
在社区居住成年人中，胱抑素C eGFR与中年以后较差的身体表现呈线性相关。观察到的eGFRcr的非线性关系凸显了肌酐作为老年人虚弱结局预测指标的局限性。
