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 (rs = − 0.229), LPA (rs = 0.265), and MVPA (rs = 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.

中文翻译：

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老年人的久坐行为、身体活动和肾功能：等时替代模型。

缺乏身体活动和久坐行为（久坐）会导致肾功能障碍。然而，行为改变（例如用体力活动代替久坐行为）对肾功能的潜在益处尚不清楚。我们使用等时替换来模拟行为对肾功能的潜在影响，通过将在一种行为上花费的时间替换为另一种行为。在 174 名日本老年人（年龄，50-83 岁；女性，76%）中，使用以下方法评估了久坐行为、轻度体育活动 (LPA) 和中等至高强度体育活动 (MVPA) 所花费的时间单轴加速度计。通过从血清肌酐和胱抑素 C 水平估计的肾小球滤过率 (eGFR) 评估肾功能。在单变量分析中，eGFR 显着，尽管微弱，与久坐行为所花费的时间 (rs = − 0.229)、LPA (rs = 0.265) 和 MVPA (rs = 0.353) 相关。在等时替代模型中，用等效的 LPA 时间替代 30 分钟/天的久坐行为与 eGFR 没有显着相关性（β = 2.26，p = 0.112）；然而，用同等时间的 MVPA 替代与 eGFR 有益相关（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）可能会影响肾功能，并且用 MVPA 代替久坐行为可能有益于老年人的肾脏健康。用等效的 LPA 时间代替 30 分钟/天的久坐行为与 eGFR 没有显着相关性（β = 2.26，p = 0.112）；然而，用同等时间的 MVPA 替代与 eGFR 有益相关（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）可能会影响肾功能，并且用 MVPA 代替久坐行为可能有益于老年人的肾脏健康。用等效的 LPA 时间代替 30 分钟/天的久坐行为与 eGFR 没有显着相关性（β = 2.26，p = 0.112）；然而，用同等时间的 MVPA 替代与 eGFR 有益相关（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）可能会影响肾功能，并且用 MVPA 代替久坐行为可能有益于老年人的肾脏健康。