Abstract：
Occupational heat stress increases the risk of acute kidney injury (AKI). This study presents a secondary analysis to generate novel hypotheses for future studies by investigating the diagnostic accuracy of thermal, hydration, and heart rate assessments in discriminating positive AKI risk following physical work in the heat in unacclimatized individuals. Unacclimatized participants (n = 13, 3 women, age: ∼23 years) completed four trials involving 2 h of exercise in a 39.7 ± 0.6 °C, 32 ± 3% relative humidity environment that differed by experimental manipulation of hyperthermia (i.e., cooling intervention) and dehydration (i.e., water drinking). Diagnostic accuracy was assessed via receiver operating characteristic curve analysis. Positive AKI risk was identified when the product of concentrations insulin-like growth factor binding protein 7 and tissue inhibitor of metalloproteinase-2 [IGFBP7∙TIMP-2] exceeded 0.3 (ng∙mL-1)2∙1000-1. Peak absolute core temperature had the acceptable discriminatory ability (AUC = 0.71, p = 0.009), but a relatively large variance (AUC 95% CI: 0.57-0.86). Mean body temperature, urine specific gravity, urine osmolality, peak heart rate, and the peak percent of both maximum heart rate and heart rate reserve had poor discrimination (AUC = 0.66-0.69, p ≤ 0.051). Mean skin temperature, percent change in body mass and plasma volume, and serum sodium and osmolality had no discrimination (p ≥ 0.072). A peak increase in mean skin temperature of >4.7 °C had a positive likelihood ratio of 11.0 which suggests clinical significance. These data suggest that the absolute value of peak core temperature and the increase in mean skin temperature may be valuable to pursue in future studies as a biomarker for AKI risk in unacclimatized workers.
摘要：
职业热应激增加急性肾损伤（AKI）的风险。本研究提出了二次分析，通过调查热的诊断准确性，为未来的研究产生新的假设，水合作用,和心率评估，以区分未适应的个体在高温下进行体力劳动后的积极AKI风险。未适应环境的参与者(n=13，3名女性，年龄：~23岁)完成了4项试验，涉及在39.7±0.6°C下进行2小时运动，32±3%相对湿度的环境，与热疗的实验操作不同(即，冷却干预)和脱水(即，饮用水)。通过受试者工作特征曲线分析评估诊断准确性。当胰岛素样生长因子结合蛋白7和金属蛋白酶2的组织抑制剂[IGFBP7·TIMP-2]的浓度乘积超过0.3（ng·mL-1）2·1000-1时，确定了阳性AKI风险。峰值绝对核心温度具有可接受的判别能力（AUC=0.71，p=0.009），但方差相对较大(AUC95%CI：0.57-0.86)。平均体温,尿液比重,尿液渗透压,峰值心率,最大心率和心率储备的峰值百分比差异均较差(AUC=0.66-0.69,p≤0.051).平均皮肤温度,体重和血浆体积的百分比变化，血清钠和渗透压没有区别（p≥0.072）。平均皮肤温度>4.7°C的峰值增加具有11.0的正似然比,这表明临床意义。这些数据表明，峰值核心温度的绝对值和平均皮肤温度的升高可能在未来的研究中作为未适应环境的工人的AKI风险的生物标志物。
