Effect of body weight changes on changes in ambulatory and standardized non-physician blood pressures over three years

PURPOSE: This study examines the relationship of changes in body mass index (BMI) to changes in measures of both casual and ambulatory blood pressures over three years. METHODS: In this prospective study of men aged 30-60 years, a cohort of 198 participants was followed for three years. Height, weight, demographic cha racteristics, and casual and ambulatory measures of blood pressure (BP) wer e obtained at baseline and 3-year follow-up. RESULTS: Change in BMI was significantly associated with change in all ambu latory (awake, work, home, and sleep) and casual systolic and diastolic blo od pressures. After controlling for age and race/ ethnicity, the associatio n remained significant for nine of the twelve BP change measures. Further t ests show that the effect of a change in BMI on BP change does not vary acr oss the six systolic blood pressures or across the six diastolic measures. An average-height man gaining 5 kg (11 pounds) typically exhibited a 2.5 mm Hg increase in systolic and a 1.8 mm Hg increase in diastolic casual and a mbulatory BPs. There is no evidence that changes in BP were associated with age, race/ethnicity (blacks vs. Hispanics vs. whites), or the average of t he baseline and follow-up levels of BMI. In addition, the impact of weight gain is similar in magnitude, but in the opposite direction, to that of wei ght loss. CONCLUSIONS: Changes in BMI over three years predict changes in ambulatory and standardized non-physician BPs. These changes in BP are nor related to average BMI level or age. Ann Epidemiol 1999;9:489-497. (C) 1999 Elsevier S cience Inc. All rights reserved.