Effects of Longitudinal Changes in Lifestyle-Related Risk Factors on the Incidence of Major Adverse Cardiac and Cerebrovascular Disease in Young Adults

Metabolic syndrome (MetS) is one focus of healthcare system reform in Japan. We examined the effects of changes in individual risk factors over time on the incidence of major adverse cardio-cerebrovascular events (MACCE) in adults under the age of 50 years. Study participants under the age of 50 with neither hypertension nor hyperglycemia at baseline were analyzed. We used a parametric proportional hazard model to determine the effect of changes in abdominal circumference, blood pressure, serum lipids, and blood glucose on the incidence of MACCE.A total of 6,125 women and 6,403 men were subject to the analyses. The incidence rate of MACCE per 1,000 person-years was 1.17 for women and 2.42 for men. In men under the age of 50, an increase in abdominal circumference was associated with an increase in MACCE incidence (hazard ratio per 1 cm increase: 1.10; 95% confidence interval [CI], 1.04-1.17), whereas no statistically significant association was observed in women. Compared with Visit 1, if the abdominal circumference increased by 4 cm at Visit 3, the hazard ratio for developing MACCE was approximately 1.5 (hazard ratio 1.48; 95% CI, 1.18-1.86). In men under the age of 50, increases in abdominal circumference and systolic blood pressure were associated with an increased risk of developing MACCE, regardless of the degree of obesity at baseline. Therefore, encouraging young adults to improve their health before developing MetS may reduce the risk of MACCE.