Effect of long-term body weight change on the incidence of hypertension in Japanese men and women

Objective: To elucidate the effect of long-term body weight changes on the subsequent incidence of hypertension in a large sample of community-residing Japanese males and females. Methods: Subjects were 3431 men and 2409 women, between 30 and 69 y old, who underwent annual periodic health examinations from 1987 (baseline year) until 1996. They were free from hypertension during the first 5 y from the baseline year. Body weight change index between 1987 and 1992 was the body mass index (BMI) (weight (kg) over height (m) squared) slope. Multiple logistic analysis was performed to assess the effect of BMI slope on the incidence of hypertension during the subsequent 5 ys (1992-1996), while controlling for baseline age, BMI, systolic blood pressure (SBP), diastolic blood pressure (DBP) and smoking habit. Results: During the first 5 y, the prevalence of overweight males (25.0<BMI<30.0) significantly increased from 18.4 to 23.5% in males and from 10.4 to 14.1% in females. In all, 11.7% of the males and 8.9% of the females developed hypertension between 1992 and 1996. Those who developed hypertension had a significantly higher baseline age, BMI, SBP and DBP both in males and females. The baseline smoking rate among the females who developed hypertension was significantly lower than those who did not develop the hypertension. After adjustment of these covariables by the multiple logistic analysis, the BMI slope was positively correlated with the incidence of hypertension both in females and males significantly. Conclusions: Weight gain increased the risk of developing hypertension independent of age and blood pressure level among relatively lean Japanese men and women.