Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan.
Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
BMC Nephrol. 2020 Jun 3;21(1):211. doi: 10.1186/s12882-020-01869-8.
Physical inactivity and sedentary behaviour (too much sitting) can contribute to renal dysfunction. However, the potential benefits of behavioural change (e.g. replacing sedentary behaviour with physical activity) on renal function are not well understood. We used isotemporal substitution to model potential impacts of behaviours on renal function by replacing time spent in one behaviour to another.
In 174 older Japanese adults (age, 50-83 years; females, 76%), the time spent in sedentary behaviour, light-intensity physical activity (LPA), and moderate- to vigorous-intensity physical activity (MVPA) were assessed using an uniaxial accelerometer. Renal function was evaluated by the estimated glomerular filtration rate (eGFR) from serum creatinine and cystatin C levels.
In univariate analyses, eGFR was significantly, albeit weakly, correlated with time spent in sedentary behaviour (r = - 0.229), LPA (r = 0.265), and MVPA (r = 0.353). In the isotemporal substitution models, replacement of 30 min/day of sedentary behaviour with an equivalent LPA time was not significantly associated with eGFR (β = 2.26, p = 0.112); however, replacement with an equivalent time of MVPA was beneficially associated with eGFR (β = 5.49, p < 0.05).
These cross-sectional findings suggest that sedentary behaviour (detrimentally) and physical activity (beneficially) may affect renal function and that replacing sedentary behaviour with MVPA may benefit renal health in older adults.
身体活动不足和久坐行为（坐得太久）可导致肾功能障碍。然而，行为改变（例如，用体力活动替代久坐行为）对肾功能的潜在益处尚不清楚。我们使用等时替代法，通过用一种行为替代另一种行为来模拟行为对肾功能的潜在影响。
在 174 名年龄在 50-83 岁的老年日本成年人（女性 76%）中，使用单轴加速度计评估久坐行为、低强度体力活动（LPA）和中高强度体力活动（MVPA）的时间。通过血清肌酐和胱抑素 C 水平估算肾小球滤过率（eGFR）来评估肾功能。
在单变量分析中，eGFR 与久坐行为（r=-0.229）、LPA（r=0.265）和 MVPA（r=0.353）时间呈显著但较弱的相关性。在等时替代模型中，用 30 分钟/天的久坐行为时间替代等量的 LPA 时间与 eGFR 无显著相关性（β=2.26，p=0.112）；然而，用等量的 MVPA 替代与 eGFR 呈正相关（β=5.49，p<0.05）。
这些横断面研究结果表明，久坐行为（有害）和体力活动（有益）可能影响肾功能，用 MVPA 替代久坐行为可能有益于老年人的肾脏健康。
