Trajectories of overweight and body mass index in adulthood and blood pressure at age 53: the 1946 British birth cohort study.

OBJECTIVE: To assess the relationship between patterns of overweight during adulthood and systolic (SBP) and diastolic (DBP) blood pressure (BP) at age 53. METHOD: Data are from 3035 male and female participants of the 1946 British birth cohort study. Body mass index (BMI) was obtained at ages 20, 26, 36, 43 and 53 years. Censored regression models accounting for medication were used to investigate associations of BP at 53 years with overweight (BMI > 25 kg/m) at each age, age at first overweight and conditional weight gain. Sex interactions were also examined. RESULTS: Overweight at all ages except for 20 years in men was positively associated with BP at 53 years. After adjusting for current BMI, only overweight at age 43 contained additional information on BP in men. Men who were overweight at age 26 had a SBP 8.7 mmHg higher [95% confidence interval (CI) 4.4-13.0] than those first overweight at 53 years. Similar patterns but smaller associations were seen in women [P(interaction) < 0.001). All periods of adult weight gain (26-36, 36-43, 43-53 years) were associated with a higher BP. BMI tracked strongly through adulthood, the BMI at 53 years in men first overweight at 26 was 30.9 kg/m (95% CI 30.5-31.4) compared to 26.4 (95% CI 26.3-26.6) in those first overweight at age 53. CONCLUSIONS: Early adult overweight and all periods of adult weight gain irrespective of earlier BMI were associated with higher BPs. This highlights the importance for later health of preventing overweight in early adulthood.