Studies used ACC/AHA 2017 guidelines to assess risk
Even slightly elevated blood pressure (BP) in early adulthood was a clinically meaningful risk factor for heart attack, stroke, and other cardiovascular events later in life, according to two research groups.
The results of the studies, both published in JAMA, suggest that following new and controversial hypertension guidelines may help identify young adults at increased risk for cardiovascular disease.
The American College of Cardiology (ACC)/American Heart Association (AHA) 2017 hypertension classification update reduced the threshold for hypertension from 140/90 mmHg to 130/80 mmHg, with stage 1 hypertension defined as a systolic BP (SBP) of 130 to 139 mmHg or a diastolic BP (DBP) of 80 to 89 mmHg.
The lower threshold effectively tripled the prevalence of hypertension among men younger than age 40 in the U.S. and doubled the prevalence among young adult women in their 20s and 30s.
"The impact of elevated blood pressure at this stage of life has not been widely studied," said the author of an accompanying editorial, Ramachandran S. Vasan, MD, of Boston University School of Medicine.
"These studies tell us that high blood pressure in young adulthood is associated with a risk of developing heart disease, but many questions remain," Vasan told MedPage Today.
In the first of the two studies, a prospective cohort trial that included nearly 5,000 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study, Yuichiro Yano, MD, PhD, of Duke University in Durham, North Carolina, and colleagues examined the impact of early adulthood elevated blood pressure, defined by the 2017 ACC/AHA guidelines, and subsequent cardiovascular event risk.
The CARDIA trial, which started in March 1985, enrolled 5,115 African American and white participants between the ages of 18 and 30.
Using the highest BP measured from the first examination to the examination closest to, but not after, age 40, each participant was categorized as having:
- Normal BP (untreated SBP <120 mmHg and DBP<80 mmHg; n = 2574)
- Elevated BP (untreated SBP 120-129 mmHg and DBP <80 mmHg; n = 445)
- Stage 1 hypertension (untreated SBP 130-139 mmHg or DBP 80-89 mmHg; n = 1194)
- Stage 2 hypertension (SBP ≥140 mmHg, DBP ≥90 mmHg, or taking antihypertensive medication; n = 638)
The final cohort included 4,851 adults (mean age when follow-up for outcomes began of 35.7 [SD, 3.6]; 2,657 women [55%]; 2,441 African American [50%]; 206 taking antihypertensive medication [4%]).
During a median follow-up of 18.8 years, 228 incident CVD events occurred (coronary heart disease [CHD], 109; stroke, 63; heart failure, 48; and peripheral artery disease [PAD], 8). CVD incidence rates for normal BP, elevated BP, stage 1 hypertension, and stage 2 hypertension were 1.37 (95% CI, 1.07-1.75), 2.74 (95% CI, 1.78-4.20), 3.15 (95% CI, 2.47-4.02), and 8.04 (95% CI, 6.45-10.03) per 1,000 person-years, respectively.
After multivariable adjustment, hazard ratios for CVD events for elevated BP, stage 1 hypertension, and stage 2 hypertension versus normal BP were 1.67 (95% CI, 1.01-2.77), 1.75 (95% CI, 1.22-2.53), and 3.49 (95% CI, 2.42-5.05), respectively.
The second study published in JAMA also used the ACC/AHA guidelines to assess a nationwide Korean database of nearly 2.5 million people, whose median age at baseline was 31. A total of 44,813 CVD events were reported among the cohort during a median follow-up of 10 years.
Compared with men with normal BP, men with stage 1 hypertension had:
- Higher risk of CVD (incidence, 215 versus 164 per 100,000 person-years; difference, 51 per 100,000 person-years [95% CI, 48-55]; adjusted HR, 1.25 [95% CI, 1.21-1.28])
- Higher CHD risk (incidence, 134 versus 103 per 100,000 person-years; difference, 31 per 100,000 person-years [95% CI, 28-33]; adjusted HR, 1.23 [95% CI, 1.19-1.27])
- Higher stroke risk (incidence, 90 versus 67 per 100 000 person-years; difference, 23 per 100,000 person-years [95% CI, 21-26]; adjusted HR, 1.30 [95% CI, 1.25-1.36])
Compared with women with normal BP, women with stage 1 hypertension had:
- Increased risk of CVD (incidence, 131 versus 91 per 100,000 person-years; difference, 40 per 100,000 person-years [95% CI, 35-45]; adjusted HR, 1.27 [95% CI, 1.21-1.34])
- Higher risk for CHD (incidence, 56 versus 42 per 100,000 person-years; difference, 14 per 100,000 person-years [95% CI, 11-18]; adjusted HR, 1.16 [95% CI, 1.08-1.25])
- Higher stroke risk (incidence, 79 versus 51 per 100,000 person-years; difference, 28 per 100,000 person-years [95% CI, 24-32]; adjusted HR [1.37, 95% CI, 1.29-1.46])
In his editorial, Vasan wrote that despite the new data provided by the two studies "major gaps exist in current knowledge regarding the epidemiology, diagnosis, risk stratification, and management of higher blood pressure levels in young adults."
Key areas of future study, he said, should include the following:
- Exploring the impact of higher BP during childhood on later cardiovascular risk
- Understanding the impact of individual characteristics on long-term CVD risk
- Developing a better understanding of the benefits and risks of drug treatment of non-normal BP in young adults
"Bridging these critical gaps may help define how, when, and what measures could be implemented to maintain an optimal blood pressure profile from childhood through young adulthood and beyond," Vasan wrote. "Answers to these questions will be a public health legacy to the current generation of children and young adults and to their future offspring."
The CARDIA study was supported by the National Heart, Lung, and Blood Institute, the University of Alabama at Birmingham, Northwestern University, the Kaiser Foundation Research Institute, the American Heart Association, and others.
The study by Son and co-authors received funding from the Ministry of Health and Welfare of Korea, the National Research Foundation of Korea, and the Ministry of Education of Korea.
Son and co-authors reported having no conflicts of interest.
Yano reported having no conflicts of interest; two co-authors reported financial relationships with Amgen, Novartis, and Amarain.
Vasan reported having no conflicts of interest, and support from the Evans Medical Foundation and the Jay and Louis Coffman endowment from Boston University School of Medicine.
Reviewed by Henry A. Solomon, MD, FACP, FACCClinical Associate Professor, Weill Cornell Medical College and Dorothy Caputo, MA, BSN, RN, Nurse Planner
Source Reference: Yano Y, et al “Association of blood pressure classification in young adults using the 2017 American College of Cardiology/American Heart Association blood pressure guidelines with cardiovascular events later in life” JAMA 2018; 320(17): 1774-1782.
Source Reference: Son JS, et al “Association of blood pressure classification in Korean young adults according to the 2017 ACC/AHA Guidelines with subsequent cardiovascular disease” JAMA 2018; 320(17): 1783-1792.
Source Reference: Vasan RS “High blood pressure in young adulthood and risk of premature cardiovascular disease: Calibrating treatment benefits to potential harm” JAMA 2018; 320(17): 1760-1763.
Read the original article on Medpage Today: High BP in Early Adulthood Linked to Increased CVD Risk