Cross-shift Acute Kidney Injury Risk In U.S. Construction Workers In The Summer

PURPOSE: Occupational heat stress frequently increases the risk of cross-shift acute kidney injury (AKI), as evidenced by elevations in serum creatinine and novel biomarkers. Data from lab-based models indicate a positive correlation between peak core temperature and AKI risk. Construction workers regularly engage in intense manual labor in the heat, but AKI risk has never been explored in U.S. construction workers. We tested the hypothesis that cross-shift changes in AKI risk are positively correlated with peak core temperatures in U.S. construction workers in the summer. METHODS: Data were collected at road (n = 7, Southwest U.S.) and commercial building (n = 32, Midwest U.S.) construction sites in July 2023. Commercial building workers included carpenters (n = 6), concrete workers (n = 13), laborers (n = 8; 3 women) and roofers (n = 5). All workers were observed during a single workday, with an average worksite heat index of 27.8 ± 3.9 °C (min: 21.5 °C; max: 35.2 °C). Core (intestinal) temperature was measured throughout study days (n = 35). Urine was collected and nude body weight was recorded pre- and post-workday (n = 39). AKI risk was quantified as the product of urine insulin-like growth factor-binding protein 7 and urine tissue inhibitor of metalloproteinase 2 ([IGFBP7•TIMP-2]) normalized to urine specific gravity (USG). RESULTS: Average and peak core temperatures were 37.4 ± 0.3 °C (min: 36.8 °C; max: 37.9 °C) and 37.9 ± 0.3 °C (min: 37.3 °C; max: 38.6 °C). Body weight decreased by 1.0 ± 0.9% (min: -2.8%; max: +1.2%). USG did not differ from pre (1.022 ± 0.007) to post (1.022 ± 0.007) work shift (p = 0.615; dz = 0.11). AKI risk [IGFBP7•TIMP-2] did not differ from pre (0.44 ± 0.57) to post (1.89 ± 8.38) work shift (p = 0.091; dz = 0.36). Changes in [IGFBP7•TIMP-2] were not significantly correlated with percent changes in body weight (r = -0.220; p = 0.179) but were correlated with average (r = 0.515; p = 0.002) and peak (r = 0.554; p = 0.001) core temperature. CONCLUSIONS: Moderate positive correlations between changes in [IGFBP7•TIMP-2] and both average and peak core temperature suggest that elevated core temperature associated with heavy work in hot environments may contribute to rises in cross-shift AKI risk in U.S. construction workers. The Center for Construction Research and Training (Small Study #22-5-PS) & R01OH011528.