Risk factors for sudden unexpected death among workers: A nested case-control study in central Japan

Background. Few studies have focused on sudden death among apparently healt hy workers, and the risk factors have not been fully discussed. Methods. A nested case-control study was conducted among 164,017 male emplo yees receiving annual medical checkups in Japan. Most recent medical checku p data of 242 sudden death victims (mean age, 48.0 years) were compared wit h corresponding data of 505 age-, workplace-, and job-type-matched male con trols. Odds ratios (ORs) and their 95% confidence intervals (CIs) for each variable were calculated by logistic regression. Results. OR (95% CI) significantly increased with advancing blood pressure, reaching 6.6 (3.4-13.1) for systolic blood pressure greater than or equal to 160 mm Hg relative to that < 120 mm Hg. Hypo-HDL-cholesterolemia, hyperu ricemia, increased aminotransferases, and abnormal urinary findings were as sociated with the risk in a dose-dependent manner. The presence of arrhythm ias and ST-T abnormalities as well as abnormal Q waves on electrocardiogram s yielded a 3.5 to 4.8 times greater risk of sudden death. As for lifestyle s, heavy smoking was a positive, and light drinking was a negative risk fac tor. Multivariate analysis revealed that hypertension, proteinuria, glucosu ria, arrhythmias, ST-T abnormalities, and light drinking were independent p redictors for sudden death. Conclusion. These findings suggest that periodic medical checkups can help to predict and prevent employee sudden death. (C) 2001 American Health Foun dation and Academic Press.