Keeping Systolic BP Below 130 May Help Women Live Into Their 90s: WHI Data

Maintaining a systolic blood pressure below 130 mm Hg may increase the probability of survival to age 90 in healthy older women, with or without BP-lowering medications, data from the Women’s Health Initiative (WHI) suggest.

The apparent protective effect of a systolic BP in the range of 110 to 130 mm Hg was consistent across sociodemographic and lifestyle factors, with those aged 65 to 75 displaying the strongest association with respect to survival to age 90 when systolic BP was kept in that range.

“These findings should encourage primary care physicians, policymakers, and other stakeholders to ensure adequate blood pressure management even at older ages,” lead author Bernhard Haring, MD, MPH (Saarland University, Homburg, Germany), said in an email. “Preventive measures and risk factor control, and if necessary, initiation of blood pressure medication to ensure a systolic blood pressure level following guideline recommendations even at higher age, are therefore warranted.”

The study population consisted of 16,570 participants (6% Black) who were enrolled in the Women’s Health Initiative at a mean age of 70.6 years between 1993 and 1998. Participants were generally healthy and postmenopausal at the time of enrollment and were part of the WHI’s randomized clinical trials portion, which involved annual BP measurements.

Compared with those who did not survive to age 90, people who did were slightly older at enrollment and more likely to be non-Hispanic white, married, or a college graduate and to have a higher income. They were also more likely to be overweight or obese, never smokers, current alcohol users, and physically active and more apt to report healthier diets. Survivors to age 90 were less likely than those who died at younger ages to have a history of hypertension or use of antihypertensives at baseline.

At ages 65, 70, 75, and 80, there was a consistent trend toward increased probability of survival to age 90 with a systolic BP of 110 to 130 mm Hg. For 80-year-old women with a systolic BP 110 mm to 130 mm Hg, for example, the probability of reaching age 90 was 79% if they were not on an antihypertensive medication and 72% if they were. With diastolic BP, the highest probability of surviving to age 90 years occurred in those who maintained a range of 70 to 80 mm Hg.

When the researchers included the possibility of disease-free survival to age 90, a target systolic BP below 130 mm Hg was associated with better odds of CVD-free survival.

“Our findings are in line with results from the Blood Pressure Lowering Treatment Trialists’ Collaboration showing that BP medication should be viewed as an effective tool for preventing cardiovascular disease when an individual’s cardiovascular risk is elevated,” Haring and colleagues write.

While the harms of too-tight BP control also are an important consideration in elderly patients with limited life expectancy, Haring said the women in the study reflect “a very large part of the population for which the benefits of maintaining a systolic blood pressure level below 130 mm Hg clearly outweigh the risks.”

Since the study consisted of women in generally good health and with no history of severe illnesses such as cancer, he added that the findings may not be generalizable to women with a high chronic disease burden.