Shift, shift change, and risk of death from heart-disease at work.
Am J Epidemiol 1995 Jun; 141(11)(Suppl):S18
Some epidemiologic studies suggest rotating shift workers are at increased risk of cardiovascular disease, but there are no studies on the effect of shift for workers who do not rotate. Workers on late shifts may suffer from disrupted sleep cycles and disruption of circadian patterns of heart rate or blood pressure, or increased psychosocial stress. To determine whether current shift or recent change in shift was a risk factor for heart disease, we conducted a nested case-control study of heart disease death at work within a cohort of 21,000 men working at heavy equipment plants. We identified 163 men who died of ischemic heart disease at work, and compared them to 781 controls who were working at the same age but did not die. Plant records were used to determine time on current shift. At the time of case death, 72% of subjects were working on first shift, 22% on second, and 6% on third. The average time on shift without shift change was 9 years. There was little evidence of any difference in heart disease risk by current shift. There was some indication that recent shifting from afternoon or night shift to day shift had a protective effect initially, which wore off over time. However, no corresponding negative effect was found for a change from first to second/third shift, regardless of when the shift took place. Our analyses were limited by the small number of workers on the third shift, and lack of control over baseline cardiovascular risk factors.
Biological-effects; Biological-monitoring; Cardiopulmonary-function; Cardiopulmonary-system-disorders; Cardiovascular-system; Cardiovascular-system-disease; Cardiovascular-system-disorders; Circadian-rhythms; Epidemiology; Exposure-assessment; Occupational-hazards; Occupational-health; Risk-analysis; Shift-work; Shift-workers; Sleep-deprivation; Statistical-analysis; Work-analysis; Work-environment; Worker-health; Workplace-studies; Work-practices
National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, DSHEFS, 4676 Columbia Parkway, Cincinnati, OH 45226
American Journal of Epidemiology. Abstracts of the 28th Annual Meeting of the Society for Epidemiologic Research, Snowbird, Utah, June 21-24, 1995