Hypertension in young adulthood increases later mortality risk

Elevated blood pressure in early adulthood is associated with a greater risk of death decades later, including overall mortality and mortality from cardiovascular disease (CVD) and coronary heart disease (CHD), although not from stroke, a study found.

Researchers analyzed results from the Harvard Alumni Health Study, which tracked 18,881 male Harvard students using a physical exam at university entry (mean age, 18.3 years) between the years of 1916 and 1950 and a mailed health questionnaire at middle-age (mean age, 45.8 years) in the 1960s.

In the initial standardized physical exam, information on smoking, blood pressure, height and weight was recorded. In the mailed questionnaires, study participants were asked if they had received a physician diagnosis of hypertension. From the death certificates, the researchers determined whether the cause of death was from CVD, CHD, stroke, or another cause through 1998.

Results appeared in the Nov. 29 Journal of the American College of Cardiology.

Compared with men who were normotensive (<120/80 mm Hg), there was an elevated risk of coronary heart disease mortality (1,917 deaths) in those who were pre-hypertensive (120 to 139/80 to 89 mm Hg) (hazard ratio [HR], 1.21; 95% CI, 1.07 to 1.36), stage 1 hypertensive (140 to 159/90 to 99 mm Hg) (HR, 1.46; 95% CI, 1.25 to 1.70), and stage 2 hypertensive (≥160/100 mm Hg) (HR, 1.89; 95% CI, 1.46 to 2.45) (P for trend <0.001). The results were adjusted for age, body mass index, smoking, and physical activity at college entry. Similar associations were apparent for total and CVD mortality, but not stroke mortality.

Overall, the researchers found that standard deviation (SD) (13.1 mm Hg) increases in systolic blood pressure at the initial evaluation were associated with a 5% increase in all-cause mortality, an 8% increase in CVD mortality, and a 14% increase in CHD mortality. After the researchers accounted for middle-age hypertension, estimates were somewhat attenuated, but the pattern remained. The 1-SD elevation was associated with a 4% increased risk of CVD death after adjustment for hypertension in middle age. Hypertension status in middle age was associated with a twofold increased risk of CVD.

“The lack of an association between university blood pressure and total stroke mortality is surprising,” the authors wrote. “The weaker association for stroke versus CHD mortality may reflect blood pressure-related atherosclerosis taking place earlier in adulthood compared with the antecedents of stroke.” According to the researchers, the results lend weight to the idea of beginning blood pressure-lowering strategies earlier in life. “However, there is a lack of clinical trial data to assess the efficacy and potential harm of such intervention,” they cautioned.

An accompanying editorial stated, “The clinical implications of this inference are potentially profound. Despite adult hypertension guidelines that recommend treatment of hypertension regardless of age, young adults with hypertension are less likely than older age groups to be aware of their hypertension, to be on treatment, and to have their hypertension adequately controlled.”

Reasons why hypertension treatment may have lagged in younger patients include a lack of health insurance, a lack of usual source of care, and the tendency to seek only episodic care, the editorial speculated. Physicians may also be reluctant to label younger patients with the diagnosis and harbor concerns over treating a disease when the benefits may be several decades in the future and the long-term safety of treatment may be questioned.