Photo: American Heart Association News
Gender gaps in blood pressure, physical activity, and smoking have widened among young adults in the United States, new research finds, suggesting that prevention approaches should be carefully tailored to help people achieve ideal lifelong cardiovascular health.
Overall heart health stayed about the same among more than 10,000 people ages 20 to 39 from 2007 to 2018, and women had better overall scores than men, according to the study, published Thursday in the Journal of the American Heart Association. But when researchers looked at individual risk factors, notable trends emerged.
The percentage of young men with normal blood pressure declined, from 54% in 2007 to 47% in 2018, but remained steady at about 80% among young women. Optimal physical activity—at least three days a week with moderate to vigorous activity—declined among the women, from 57% to 49%. But it stayed the same among the men, with about half getting enough exercise. Not smoking became more common among young women, increasing from 64% to 71%, but stayed the same in the men, at about half.
Yet for both the men and women, risk factors were persistently suboptimal, the researchers said. For example, only about a third reported having a healthy body mass index and eating a healthy diet as of 2018.
"Cardiovascular disease remains the dubious distinction of being the leading killer in the U.S., and over the last two decades, in the world," said the study's senior author, Dr. Pradeep Natarajan, director of preventive cardiology at Massachusetts General Hospital in Boston. "(Risk) factors earlier in life magnify future risk for cardiovascular disease."
The researchers found even wider gaps for some risk factors among the young adults when they pooled a decade's worth of data based on race. For example, 84% of Hispanic women but only 53% of Hispanic men in the study had normal blood pressure. For physical activity, 65% of Black women had attained ideal levels compared to 50% of Black men. But among white people, ideal physical activity was slightly more common in men.
"Identifying these issues earlier in life and then addressing them earlier in life will have substantial gains later on," Natarajan said. "But risk identification earlier in life is really not at the forefront of clinical medicine." Current models to predict cardiac risk tend to work best for people ages 40 through 70, he added, and research is lacking among adults under 40.
Dr. Carissa Baker-Smith, director of pediatric preventive cardiology at Nemours Children's Health in Wilmington, Delaware, said recommendations for checking cardiac risk factors in children and young adults are not well followed in clinical practice.
"Current guidelines recommend that cholesterol levels be checked between ages 9 and 11, and again between ages 17 to 21," if the child has no known family history of high cholesterol and early heart disease, and earlier if there is a known family history, said Baker-Smith, who was not involved in the study. "Screening for (cardiovascular disease) risk factors is not something that is universally carried out in young adults and adolescents. I believe that one challenge is general providers may not fully understand how to interpret or manage the results."
Experts say more research is needed to better understand what causes differences in cardiac risk factors—for example, whether people have primary care physicians and how often they see them, as well as the impact of quality of care, socioeconomic status, and other social determinants of health.
"I think understanding what the drivers were behind those differences would lead to better intervention strategies," Baker-Smith said, adding that it would also be useful for a study to track individuals over time to better understand how risk factors earlier in life affect heart health later.
That was a limitation of the current study, which looked back at existing nationwide survey data. Another limitation noted by the researchers is that the gender and race classifications did not include non-binary genders or details on race and ethnicity.
The study's lead author, Dr. So Mi Cho, hopes the findings raise awareness among clinicians and the public about the importance of "primordial" prevention—that is, preventing the development of risk factors rather than addressing them once they are detected.
"The motivation behind this study was to emphasize the earlier on the better," said Cho, a postdoctoral fellow at the Broad Institute of MIT and Harvard in Cambridge, Massachusetts. "When you can know it earlier on, the more efficient and effective prevention approaches would be, rather than letting it deteriorate for a long time and finding it out much later in life."