Elevated blood pressure and stage 1 and 2 hypertension before age 40 puts young adults at higher risk for cardiovascular disease (CVD) events later in life compared to those with normal blood pressure, according to a new study published in JAMA.
In 2017, the American Heart Association and American College of Cardiology announced new guidelines that lowered the threshold of high blood pressure (BP) to a systolic BP of 130 mmHg and a diastolic BP above 80 mmHg. The lower threshold increased the prevalence of hypertension 2-fold to 3-fold among young adults.
According to a new study published in JAMA, elevated blood pressure and stage 1 and 2 hypertension before age 40, based on these new guidelines, are indicators of higher risk for cardiovascular disease (CVD) events later in life compared to those with normal blood pressure.
Researchers studied data coming from the Coronary Artery Risk Development in Young Adults study, which enrolled 5115 participants aged 18-30 from 4 US field centers in 1985 and 1986. Following baseline examination, participants had follow-up examinations at years 2, 5, 7, 10, 15, 20, 25, and 30.
Following adjustment for exclusion criteria, the researchers assessed 4851 participants. Using blood pressure obtained at 2 or more clinic visits before age 40 over a median of 10.7 years, 2574 participants were categorized as having normal BP, 445 were categorized as having elevated BP, 1195 were categorized as having stage 1 hypertension, and 638 were categorized as having stage 2 hypertension.
Participants with elevated BP, stage 1 hypertension, and stage 2 hypertension before age 40 were older, less likely to be women, and more likely to be African American than those with normal BP. At baseline and when follow-up started, participants with stage 1 and 2 hypertension had higher body mass index levels, lower education levels, higher glucose and total cholesterol levels, and lower HDL cholesterol levels compared to those with normal BP.
During a median follow-up of 18.8 years, there were 228 CVD events and 319 all-cause deaths. The most common CVD events were coronary heart disease and stroke, and all CVD events occurred before age 60.
Incidence was highest among those with stage 2 hypertension (8.04 per 1000 person-years), followed by stage 1 hypertension (3.15 per 1000 person-years), elevated BP (2.74 per 1000 person-years), and normal BP (1.37 per 1000 person-years). Hazard ratios for CVD events were 1.67 for elevated BP, 1.75 for stage 1 hypertension, and 3.49 for stage 2 hypertension before age 40.
“Although participants with stage 1 hypertension in the current study had a significantly higher hazard ratio for CVD than their counterparts with normal BP, their absolute risk was low,” explained the researchers. “However, the lifetime risk for CVD events among young adults with stage 1 hypertension may be high.”
They also noted that the higher CVD risk associated with elevated BP compared to normal BP became evident after the initial 10 years of follow-up.
Yano Y, Reis J, Colangelo L, et al. Association of blood pressure classification in young adults using the 2017 American College of Cardiology/American Heart Assocaition blood pressure guidelines with cardiovascular events later in life [published online November 6, 2018]. JAMA. doi: doi:10.1001/jama.2018.13551.