Predictors of significant short-term increases in blood pressure in a community-based population.

BACKGROUND: Blood pressure predicts the risk of cardiovascular disease events in a linear, graded manner. Factors associated with significant short-term increases in blood pressure are not well established. We aimed to identify predictors of a significant increase in blood pressure over a 1-year period among nonhypertensive, community-dwelling adults.
METHODS: From the community-based Heart Strategies Concentrating on Risk Evaluation study, 509 nonhypertensive adults (mean age 58 years; 68% were female; 24% were black) had baseline and 1-year assessments of blood pressure. Demographics, medical history, anthropometrics, lipids/lipoproteins, physical activity, and psychologic status were measured at both intervals. A "significant" increase in blood pressure was defined as an increase in systolic blood pressure of greater than 20 mm Hg, diastolic blood pressure of greater than 10 mm Hg, or initiation of antihypertensive medication.
RESULTS: At 1 year, 22% of participants had a significant increase in blood pressure. In multivariable analysis, baseline body mass index (BMI) and a greater than 5% increase in weight or waist circumference were associated with a significant increase in blood pressure (adjusted relative risk 2.09; 95% confidence interval, 1.35-3.21). The adverse effect of an increase in weight and waist circumference on blood pressure was evident in subgroup analyses by age, race, baseline BMI, and regular exercise.
CONCLUSIONS: Baseline BMI and a greater than 5% increase in weight or waist circumference over 1 year are associated with a significant increase in blood pressure. These data emphasize the need for weight maintenance. They also serve to stratify individuals who may benefit from close clinical observation and preventive intervention.