Associations between metabolic syndrome and mortality from cardiovascular disease in Japanese general population, findings on overweight and non-overweight individuals - Ibaraki prefectural health study

Background: The impact of being overweight, as a component of the metabolic syndrome (MetS), for cardiovascular disease (CVD) mortality was investigated and compared with the predictive value of MetS by 2 different definitions. Methods and Results: A 12-year prospective study of 30,774 Japanese men and 60,383 women aged 40-79 years was conducted. The multivariate hazard ratio (HR; 95% confidence interval) of total CVD mortality for overweight subjects with ≥2 additional risk factors with reference to subjects with 0 of 4 MetS components was 1.83 (1.41-2.38) for men and 1.90 (1.45-2.49) for women, and for non-overweight subjects with ≥2 additional risk factors 1.75 (1.38-2.24) and 1.97 (1.52-2.55), respectively. The proportion of excess CVD deaths in the latter group was 1.5-fold higher than that in the former group. Multivariate HRs of coronary heart disease and total CVD mortality for MetS by the modified criteria of the American Heart Association/National Heart, Lung, and Blood Institute were 1.62 (1.31-2.00) and 1.23 (1.09-1.39), respectively, for men and 1.32 (1.05-1.65) and 1.12 (1.00-1.25), respectively, for women. The respective HRs for MetS by the International Diabetic Federation definition did not reach statistical significance, except for coronary heart disease in men. Conclusions: Non-overweight individuals with metabolic risk factors, as well as overweight individuals with such factors, should be targeted to reduce the CVD burden in the general population.