A longitudinal study of blood pressure variability in African-American and European American youth.

OBJECTIVES: High blood pressure variability is increasingly used as a predictor of target-organ damage and cardiovascular events. However, little is known about blood pressure variability changes with age and its possible sociodemographic, anthropometric, and genetic moderators.
METHODS: Twenty-four-hour ambulatory blood pressure was measured up to 12 times over a 15-year period in 344 European Americans and 297 African-Americans with an average age of 14 years at the initial visit. Blood pressure variability was indexed by the weighted 24-h standard deviation of ambulatory blood pressure recordings.
RESULTS: Both systolic and diastolic blood pressure variability increased with age and ambulatory blood pressure mean values. Men had higher levels of blood pressure variability (P < 0.001) and showed steeper linear increase rates with age than women. African-Americans showed higher values of blood pressure variability (P < 0.05) than European Americans. Body mass index and waist circumference were also associated with higher blood pressure variability levels (P < 0.001). Individuals with higher father's education level showed lower blood pressure variability. In the full model which included all the above factors, ethnic difference in systolic blood pressure variability was no longer significant.
CONCLUSION: The results of the present study suggest that men and African-Americans have higher blood pressure variability than women and European Americans. Apart from these ethnicity and sex effects, blood pressure variability increases with increases in age (especially in men), ambulatory blood pressure mean values and adiposity as well as decreased socioeconomic status.