School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, LE11 3TU, UK.
Loughborough College, Loughborough, LE11 3BT, UK.
Eur J Appl Physiol. 2024 Apr;124(4):1085-1096. doi: 10.1007/s00421-023-05328-8. Epub 2023 Oct 17.
Recent studies have shown that hypohydration can increase renal injury. However, the contribution of hypohydration to the extent of renal injury is often confounded by exercise induced muscle damage. Therefore, the aim of the present study was to investigate the effect of manipulating hydration status during moderate-intensity cycling in the heat on biomarkers of renal injury.
Following familiarisation, fourteen active males (age: 21 [20-22] y; BMI: 22.1 ± 1.9 kg/m; O: 55 ± 9 mL/kg/min) completed two experimental trials, in a randomised cross-over design. Experimental trials consisted of up to 120 min of intermittent cycling (~ 50% W) in the heat (~ 35 °C, ~ 50% relative humidity). During exercise, subjects consumed either a water volume equal to 100% body mass losses (EU) or minimal water (HYP; 75-100 mL) to induce ~ 3% body mass loss. Blood and urine samples were collected at baseline, 30 min post-exercise and 24 h post-baseline, with an additional urine sample collected immediately post-exercise.
Thirty minutes post-exercise, body mass and plasma volume were lower in HYP than EU (P < 0.001), whereas serum and urine osmolality (P < 0.001), osmolality-corrected urinary kidney injury molecule-1 concentrations (HYP: 2.74 [1.87-5.44] ng/mOsm, EU: 1.15 [0.84-2.37] ng/mOsm; P = 0.024), and percentage change in osmolality-corrected urinary neutrophil gelatinase-associated lipocalin concentrations (HYP: 61 [17-141] %, EU: 7.1 [- 4 to 24] %; P = 0.033) were greater in HYP than EU.
Hypohydration produced by cycling in the heat increased renal tubular injury, compared to maintaining euhydration with water ingestion.
最近的研究表明，脱水会增加肾脏损伤。然而，脱水对肾脏损伤程度的影响往往因运动引起的肌肉损伤而变得复杂。因此，本研究的目的是探讨在热环境中进行中等强度踏车运动时调节水合状态对肾脏损伤生物标志物的影响。
在熟悉阶段后，14 名活跃男性（年龄：21[20-22]岁；BMI：22.1±1.9kg/m；O：55±9mL/kg/min）以随机交叉设计完成了两项实验试验。实验试验包括在热环境（35°C，50%相对湿度）中进行长达 120 分钟的间歇性踏车运动（50%W）。在运动过程中，受试者摄入的水体积要么等于体重损失的 100%（EU），要么摄入最小量的水（HYP；75-100mL）以导致3%的体重损失。在基线、运动后 30 分钟和基线后 24 小时采集血液和尿液样本，并在运动后立即采集额外的尿液样本。
运动后 30 分钟，HYP 组的体重和血浆体积低于 EU 组（P<0.001），而血清和尿液渗透压（P<0.001）、渗透压校正后的尿肾损伤分子-1 浓度（HYP：2.74[1.87-5.44]ng/mOsm，EU：1.15[0.84-2.37]ng/mOsm；P=0.024）和渗透压校正后的尿中性粒细胞明胶酶相关脂质运载蛋白浓度的变化百分比（HYP：61[17-141]%，EU：7.1[-4 至 24]%；P=0.033）在 HYP 组均高于 EU 组。
与摄入水以保持水合状态相比，在热环境中踏车运动导致的脱水会增加肾小管损伤。
