Elevated BP in young adults confers excess CVD risk

Young adults with hypertension had elevated risk for CVD events, according to two studies published in JAMA.

In an American cohort, participants with elevated BP, stage 1 hypertension or stage 2 hypertension as defined by the 2017 American College of Cardiology/American Heart Association hypertension guideline by age 40 years had higher risk for subsequent CVD events compared with those who had normal BP before age 40 years. In a Korean cohort, a similar trend was found in young adults with stage 1 or 2 hypertension vs. young adults with normal BP.

American cohort

In the American study, researchers analyzed 4,851 adults from the CARDIA cohort aged 18 to 30 years at baseline (mean age at follow-up; 36 years; 55% women; 50% black; 4% taking antihypertensive medications).

Based on BP measured at baseline and at the last follow-up visit before age 40 years, participants were stratified into those with normal BP (untreated systolic BP < 120 mm Hg/untreated diastolic BP < 80 mm Hg), those with elevated BP (untreated systolic BP 120-129 mm Hg/untreated diastolic BP < 80 mm Hg), those with stage 1 hypertension (untreated systolic BP 130-139 mm Hg or untreated diastolic BP 80-89 mm Hg) and those with stage 2 hypertension (untreated systolic BP 140 mm Hg, untreated diastolic BP 90 mm Hg or treatment with antihypertensive medication).

The primary outcome was CVD events, defined as fatal or nonfatal CHD, HF, stroke, transient ischemic attack or intervention for peripheral artery disease. Median follow-up was 18.8 years.

During the study period, there were 228 incident CVD events, including 109 CHD, 63 stroke, 48 HF and eight interventions for PAD, Yuichiro Yano, MD, PhD, from the department of community and family medicine at Duke University, and colleagues reported.

Incident rates were lowest in those with normal BP (1.37 per 1,000 person-years; 95% CI, 1.07-1.75) and highest in those with stage 2 hypertension (8.04 per 1,000 person-years; 95% CI, 6.45-10.03), according to the researchers.

After multivariable adjustment, compared with the normal-BP group, those with elevated BP (HR = 1.67; 95% CI, 1.01-2.77), stage 1 hypertension (HR = 1.75; 95% CI, 1.22-2.53) and stage 2 hypertension (HR = 3.49; 95% CI, 2.42-5.05) all had greater risk for CVD events, Yano and colleagues wrote.

Korean cohort

The Korean study included a population-based cohort of 2,488,101 adults aged 20 to 39 years (median age, 31 years; 32% women) with at least two BP measurements documented by the National Health Insurance program between 2002 and 2005.

Participant stratification by BP was the same as in the American study.

The primary outcome was CVD, defined as CVD hospitalization for at least 2 days or CVD death. Secondary outcomes included CHD and stroke. Median follow-up was 10 years.

According to the researchers, for men, compared with participants with normal BP, those with stage 1 hypertension had greater risk for CVD (difference, 51 per 100,000 person-years; 95% CI, 48-55; adjusted HR = 1.25; 95% CI, 1.21-1.28), CHD (difference, 31 per 100,000 person-years; 95% CI, 28-33; aHR = 1.23; 95% CI, 1.19-1.27) and stroke (difference, 23 per 100,000 person-years; 95% CI, 21-26; aHR = 1.3; 95% CI, 1.25-1.36).

A similar dichotomy in the normal-BP and stage 1 hypertension groups was seen in women (difference in incident CVD events, 40 per 100,000 person-years; 95% CI, 35-45; aHR = 1.27; 95% CI, 1.21-1.34; difference in incident CHD events, 14 per 100,000 person-years; 95% CI, 11-18; aHR = 1.16; 95% CI, 1.08-1.25; difference in incident stroke events, 28 per 100,000 person-years; aHR = 1.37; 95% CI, 1.29-1.46), they wrote.

Results for stage 2 hypertension vs. normal BP were similar, Joung Sik Son, MD, MSc, from the department of family medicine at Seoul National University Hospital in South Korea, and colleagues wrote.

Major changes needed

In a related editorial, Ramachandran S. Vasan, MD, wrote: “Overall, these data emphasize that primary prevention of higher blood pressure levels must begin in childhood.

“Optimal blood pressure targets in relation to plausible clinical benefit vs. possible harm due to long-term blood pressure-lowering treatments need to be clearly delineated for young adults with non-normal blood pressure levels according to the ACC/AHA classification,” wrote Vasan, from Boston University School of Public Health and the Framingham Heart Study.

In another editorial, Naomi D.L. Fisher, MD, from Brigham and Women’s Hospital, and Gregory Curfman, MD, deputy editor of JAMA, called for great changes at the population level.

“Changes on a large scale must be shaped by contributions from arenas as disparate as governmental and public health agencies, academia, medical associations, technology firms and the food industry,” they wrote. “Half of U.S. adults have hypertension, and the vast proportion of those newly diagnosed with stage 1 hypertension should be educated about and treated with lifestyle measures. All patients will benefit from regular exercise, achieving and maintaining normal body weight, and reducing dietary sodium, but individual patient efforts will not succeed without vast support from health care systems. Public awareness of the dangers of hypertension and the potential benefits of effective preventive efforts must continue to expand.” – by Erik Swain

References:

Fisher NDL, et al. JAMA. 2018;doi:10.1016/jama.2018.16760.

Son JS, et al. JAMA. 2018;doi:10.1016/jama.2018.16501.

Vasan RS. JAMA. 2018;doi:10.1016/jama.2018.16068.

Yano Y, et al. JAMA. 2018;doi:10.1016/jama.2018.13551.

Disclosures: Curfman, Fisher, Vasan, Yano and all authors of the Korean study report no relevant financial disclosures. Please see the American study for a list of the other authors’ relevant financial disclosures.