Primary causes of heat-related illness (HRI) at work are:Introduction
Empirical research has not been performed to investigate the effect of underlying health problems to HRI.Methods
A case-control study was performed by asking occupational health staffs to report all HRI cases occurred at their workplaces in 2015 and 2016. One co-worker control of the same gender at the closest in age was also reported for each case. Target population included:Methods
Their results of the periodic health examination were collected to evaluate the underlying health problems of obesity (BMI >25), impaired glucose tolerance, IGT (HbA1c≥6.5%, fast blood sugar ≥126 mg/dL, and/or casual blood sugar ≥200 mg/dL), high blood pressure, HBP (≥140/90 mmHg), and dyslipidemia (LDL-C ≥140 mg/dL, HDL-C <40 mg/dL, or TG ≥150 mg/dL). Data were statistically compared between the case and the control using JMP Pro 13.Results
Overall incidence rate of HRI at the examined workplaces was 0.065% (114 cases/1 76 094 person-year). A total of 102 pairs (n=204) could be compared. Cases showed higher BMI (p=0.046) and visceral circumference (p=0.045). Cases and controls included 12 and 2 persons with IGT, respectively (p=0.005). Multiple logistic regression analysis revealed increase of HbA1c elevated the risk of developing HRI (OR 16.76 [95% CI: 2.44 to 165.5], p=0.0014), whereas LDL-cholesterol showed protective effect (OR 0.97 [0.95–0.99], p<0.001).Conclusion
Significantly elevated risk of developing heat-related illness was observed among workers with IGT. Impaired endothelium-dependent vasodilatation among workers with IGT may decrease heat dissipation by conduction, convection, radiation, and sweat evaporation and may pose a risk to develop HRI.