NEW ORLEANS — Twice as many young black women as young white women have hypertension, according to an analysis of data for women aged 18 to 35 years in the National Health and Nutrition Examination Survey (NHANES) database.
In a study presented at the American Heart Association’s Hypertension 2019 Scientific Sessions, hypertension affected 49% of young black women, vs 28% of their white counterparts.
“Adjusting for age, marital status, and a host of health behaviors and indicators, we found that young black women had twice the prevalence of hypertension as white women,” said Anika L. Hines, PhD, MPH, assistant professor in the Department of Health Behavior and Policy at Virginia Commonwealth University School of Medicine, Richmond.
Compared to white women, black women are at higher risk for cardiovascular disease and its risk factors, including earlier age of onset, and they have nearly double the risk of developing hypertension by age 55 years. Despite this increased risk, little attention has been given to racial disparities in hypertension during young adulthood, Hines said.
“While there are relative differences at all ages, they are most pronounced at younger ages than older,” she noted. “We think there are opportunities for early intervention to prevent future morbidity from chronic disease.”
Data From NHANES Medical Exams
To provide more insight into this race-related risk, Hines and colleagues compared the prevalence of hypertension among young African American/black women and white women, adjusting for other demographic, health behavior, and health status covariates. Their cross-sectional analysis involved 442 women (231 white, 211 black) aged 18 to 35 who participated in the medical examination portion of the NHANES program between 1999 and 2014.
Compared to white women, black women in this age group were less likely to be married, had lower income, were less likely to smoke, and were more likely to report fair or poor self-rated health. In addition, black women demonstrated higher mean systolic blood pressure than whites (116.7 mmHg vs 124.3 mmHg; P < .0001) and diastolic blood pressure (71.7 mmHg vs 74.8 mmHg; P = .04). This translated into significantly more diagnoses of hypertension, Hines reported.
Hypertension in this analysis was defined by pre-2017 guidelines: blood pressure ≥140/90 mmHg or treatment with an antihypertensive agent. The blood pressure measurement was derived from three separate readings taken in one setting, with appropriately sized and calibrated cuffs.
Twice the Likelihood of Hypertension
The researchers found that hypertension was present in 49% of young black women compared to 28% of white women (P = .0090). The difference was striking in all three models used in the analysis, Hines said.
In the unadjusted model, black women were 75% more likely to have the disease (95% confidence interval [CI], 1.15 – 2.66). When adjusted for age, marital status, annual income, and educational attainment, the risk was 74% greater (95% CI, 1.06 – 2.86).
Most importantly, in the model that adjusted for the above factors plus health insurance coverage, smoking, drinking, self-rated health status, history of stroke, and history of diabetes, black women aged 18 to 35 were 2.04 times as likely to have hypertension as young white women (95% CI, 1.14 – 3.65).
Hines acknowledged the possibility of selection bias. “Not everyone opts into the medical exam portion of the survey…. It’s possible that those who did so may have had some health concerns,” she said.
However, on the basis of these data, which were derived from a sample of 442 women, and “adjusting for other factors, race served as the strongest predictor of hypertension among young women aged 18 to 35 years,” she said.
The findings evoked some brisk discussion, with hypertension experts suggesting that several potentially relevant factors were missing from the adjusted analysis. These included data on body weight or body mass index and the use of oral contraceptives. One listener asked whether any black participants had been born in Africa, “as it’s known that they have lower blood pressure” than American blacks, but these data were not available.
Hines agreed that such information could be informative. “It could also matter generationally — that is, whether you’re a first-generation or second-generation African American — since many immigrants ultimately conform to trends in American health behaviors,” she added.
Sandra J. Taler, MD, professor of medicine at the Mayo Clinic, Rochester, Minnesota, was impressed by the study. “It’s a great idea to look at young people and see the trends that will likely get worse,” she said.
She suggested that Hines break down the data by period to evaluate whether more hypertension and more differences are seen during the most recent years. She also said she would like to know how many young women would be considered to have hypertension using the more recent (2017) definition of ≥130/80 mmHg.
She echoed points made during the discussion in noting that obesity may well be a factor, along with use of oral contraceptives and perhaps use of stimulants for attention-deficit disorder. “A perfect study would analyze and/or control for these,” she told Medscape Medical News.
“But overall, we know that blacks have much higher hypertension rates than whites and more morbidity, and it looks like this starts young. It would be a great area for intervention,” she said. “I think these young women may often be dismissed by clinicians.”
Hines and Taler had disclosed no relevant financial relationships.
Hypertension 2019 Scientific Sessions: Abstract 002, presented September 6, 2019.