- normal body mass index (risk ratio [RR] 1.37 [95% CI, 1.08–1.75])
- ideal physical activity (RR, 1.28 [95% CI, 0.99–1.65])
- never smoking (RR, 1.48 [95% CI, 0.99–2.20])
Jackson Heart Study participants who maintained a healthy BP, BMI, and never smoked were at lower risk for incident CVD, suggesting targets for intervention in high-risk populations.
In a recent analysis of participants in the Jackson Heart Study (JHS) of Black Americans, researchers found that one-third of individuals who had "healthy" blood pressure (BP) (<120/<180 mm Hg) at study baseline were able to maintain that level over a median follow-up of 5.9 years.
Further, the incidence rate of cardiovascular disease among those who maintained that healthy BP was significantly lower than for those who did not maintain a normal BP.
The findings, reported in March in the journal Hypertension, suggest that although mean BP tends to increase with age, there may be factors that can mitigate that rise.
The study findings are particularly important because more than half of Black adults in the US have hypertension, noted lead author Shakia Hardy, PhD, assistant professor of epidemiology in the School of Public Health at the University of Alabama at Birmingham in an American Heart Association statement. Moreover, the hypertension-related cardiovascular (CV) death rate among Blacks is nearly twice as high as among Whites.
Hardy noted, too, that most research overlooks the possibility that even in a group of high-risk individuals, such as those in the JHS, "there are people that have normal blood pressure, and they are able to keep it across their life course."
In this study, 2 factors stood out among those whose blood pressure stayed healthy: They were more likely to have maintained a normal body mass index (BMI) and ideal levels of physical activity.
Hardy and colleagues determined the proportion of JHS participants that maintained a normal BP at 4 visits over a median 8-year span. Normal BP was defined as <120/<80 mm Hg without antihypertensive medication.
Of the 757 participants (mean age 46 years) identified with normal BP at baseline, 262 (34.6%) maintained that level across follow-up.
Among those with normal baseline BP, factors recorded at baseline that were associated with maintenance of normal BP over time were: normal BMI, ideal physical activity, and never smoking.
Also associated with maintaining normal BP were maintaining normal BMI (RR, 1.42 [95% CI, 1.10–1.84]) and ideal physical activity (RR, 1.51 [95% CI, 1.18–1.94]) at all 4 study visits.
Over 5.9 years of follow-up, the CVD incidence rate per 1000 person years was:
Researchers saw no correlation between maintaining healthy blood pressure and diet – or with psychosocial factors such as stress.
Hardy suggested in the AHA statement that the apparent lack of an observed association between healthy eating and BP might be related to the fact that at inception of the JHS, dietary patterns were not ideal.
More important for health care professionals, however, is the information on BMI and physical activity—areas, says Hardy, that are ripe for targeting against high blood pressure.
A further message, from Cheryl Anderson, professor and dean of the Herbert Wertheim School of Public Health and Human Longevity Science at the University of California San Diego and a co-author on an AHA scientific statement on cardiovascular health in African Americans, is not to simply assume that people who are metabolically healthy today are going to stay that way. They need support to stay the course so that the clinician’s first intervention isn’t when they have hypertension.