To examine the relationship between lifestyle and sociodemographic risk factors and mortality, a population-based prospective cohort study was conducted in two areas of Gunma Prefecture, Japan, and a cohort consisting of 11, 565 subjects aged 40-69 at baseline in 1993 was followed. During the five-year follow-up period, 201 men and 103 women died. The relative risks (RRs) of risk factors were estimated by the Cox proportional-hazards model. Significant RRs with multivariate adjustment for all-cause mortality was observed for body mass index (BMI). The curve for the relationship between BMI and all-cause mortality was L-shaped in men and Ushaped in women, with the lowest RRs at a BMI of 22-25 in both men and women. Other significant RRs for all-cause mortality were observed for obesity in the subjects' 30's in both men and women (RR: 2.42 and RR: 2.75), poor perceived health status in men (RR: 4.55), and having had a health examination in the past three years in both men and women (RR: 0.49 and RR: 0.46). These results suggested that increased risk of death was independently associated with a lower BMI, obesity in the subjects' 30's, and not undergoing health examinations, among both men and women, and poor perceived health status among men.
J Epidemiol, 2001 ; 11 : 51-60