Association Between Occupational Heat Stress and Kidney Disease Among 37 816 Workers in the Thai Cohort Study (TCS)
Benjawan Tawatsupa1,2, Lynette L-Y Lim2, Tord Kjellstrom2,3, Sam-ang Seubsman2,4,
Adrian Sleigh2, and the Thai Cohort Study Team*
1Health Impact Assessment Division, Department of Health, Ministry of Public Health, Nonthaburi, Thailand
2National Centre for Epidemiology and Population Health, The Australian National University, Canberra ACT, Australia
3Centre for Global Health Research, Ume? University, Ume?, Sweden
4Thai Health-Risk Transition: National Cohort Study, School of Human Ecology, Sukhothai Thammathirat Open University, Nonthaburi, Thailand
Received August 4, 2011; accepted December 5, 2011; released online February 18, 2012
ABSTRACT
Background: We examined the relationship between self-reported occupational heat stress and incidence of selfreported doctor-diagnosed kidney disease in Thai workers.
Methods: Data were derived from baseline (2005) and follow-up (2009) self-report questionnaires from a large national Thai Cohort Study (TCS). Analysis was restricted to full-time workers (n = 17 402 men and 20 414 women) without known kidney disease at baseline. We used logistic regression models to examine the association of incident kidney disease with heat stress at work, after adjustment for smoking, alcohol drinking, body mass index, and a large number of socioeconomic and demographic characteristics.
Results: Exposure to heat stress was more common in men than in women (22% vs 15%). A significant association between heat stress and incident kidney disease was observed in men (adjusted odds ratio [OR] = 1.48, 95% CI: 1.01–2.16). The risk of kidney disease was higher among workers reporting workplace heat stress in both 2005 and 2009. Among men exposed to prolonged heat stress, the odds of developing kidney disease was 2.22 times that of men without such exposure (95% CI 1.48–3.35, P-trend <0.001). The incidence of kidney disease was even higher among men aged 35 years or older in a physical job: 2.2% exposed to prolonged heat stress developed kidney disease compared with 0.4% with no heat exposure (adjusted OR = 5.30, 95% CI 1.17–24.13).
Conclusions: There is an association between self-reported occupational heat stress and self-reported doctordiagnosed kidney disease in Thailand. The results indicate a need for occupational health interventions for heat stress among workers in tropical climates.
Key words: occupational heat stress; kidney disease; Thai Cohort Study; Thailand
Advance Publication by J-STAGE
J Epidemiol 2012
doi:10.2188/jea.JE20110082
