Journal Scan Summary
Title: Body Mass Index and Risk of Incident Hypertension Over the Life Course: The Johns Hopkins Precursors Study
Date Posted: March 15, 2013
Authors: Shihab HM, Meoni LA, Chu AY, et al.
Citation: Circulation 2012;126:2983-2989.
[PubMed ® abstract]
What is the association of body mass index (BMI) in young adulthood, into middle age, and through late life with risk of developing hypertension?
The association of BMI over the lifetime of white men and the development of hypertension was evaluated in 1,132 participants in The Johns Hopkins Precursors Study, a prospective cohort study. Estimated cumulative incidence of hypertension was assessed by BMI category of normal to obese and as a time-dependent continuous variable with BMI at ages 25, 45, and 65 years.
Over a median follow-up period of 46 years, 508 men developed hypertension. Obesity (BMI ¥30 kg/m2) in young adulthood was strongly associated with incident hypertension (hazard ratio [HR], 4.17; 95% confidence interval [CI], 2.34-7.42). Overweight (BMI 25 to <30 kg/m2) also signaled increased risk (HR, 1.58; 95% CI, 1.28-1.96). Men of normal weight at age 25 years who became overweight or obese at age 45 years were at increased risk compared with men of normal weight at both times (HR, 1.57; 95% CI, 1.20-2.07), but not men who were overweight or obese at age 25 years who returned to normal weight at age 45 years (HR, 0.91; 95% CI, 0.43-1.92). After adjustment for time-dependent number of cigarettes smoked, cups of coffee, alcohol intake, physical activity, parental premature hypertension, and baseline BMI, the rate of change in BMI over the life course increased the risk of incident hypertension in a dose-response fashion, with the highest risk among men with the greatest increase in BMI (HR, 2.52; 95% CI, 1.82-3.49).
The findings underscore the importance of higher weight and weight gain in increasing the risk of hypertension from young adulthood through middle age and into late life.
To place this in perspective, for a 5-foot 9-inch-tall man at age 25 years, a 10-lb weight gain over the life course translates to an 18% increased risk of hypertension. When this study was designed, the relationship between blood pressure, insulin resistance, and visceral obesity was not known. More recent observational studies may help define the relationship between the lifelong development of visceral obesity, hypertension, and other variables of the metabolic syndrome.
Melvyn Rubenfire, MD, F.A.C.C. (Disclosure)
Prevention/Vascular, General Cardiology
© 2013 American College of Cardiology Foundation