Systolic Blood Pressure and Survival to Very Old Age. Results from the Women's Health Initiative [preprint]

Abstract

Background: The association between systolic blood pressure (SBP) and longevity is not fully understood. We aimed to determine survival probabilities to age 90 for various SBP levels among women aged ≥ 65 years with or without BP medication.

Methods: We analyzed blood pressure data from participants in the Women's Health Initiative (n=16,570) who were aged 65 or older and without history of cardiovascular disease, diabetes or cancer. Blood pressure was measured at baseline (1993-1998) and then annually through 2005. The outcome was defined as survival to age 90 with follow-up until February 28, 2020.

Results: During a follow-up of 18 years, 9,723 (59%) of 16,570 women survived to age 90. The SBP associated with the highest probability of survival was about 120mmHg regardless of age. Compared to an SBP between 110 and 130 mmHg, women with uncontrolled SBP had a lower survival probability across all age groups and with or without BP medication. A 65-year-old women on BP medication with an interpolated SBP between 110 and 130 mmHg in 80% of the first 5 years of follow-up had a 31% (95% confidence interval, 24%, 38%) absolute survival probability. For those with 20% time in range, the probability was 21% (95% confidence interval, 16%, 26%).

Conclusions: An SBP level below 130 mmHg was found to be associated with longevity among older women. The longer SBP was controlled at a level between 110 and 130 mmHg, the higher the survival probability to age 90. Preventing age-related rises in SBP and increasing the time with controlled BP levels constitute important measures for achieving longevity.

Clinical perspective: What is new ?: The age-related rise in SBP is commonly regarded as inevitable and intensified SBP treatment in older adults is still controversial, as strict BP control in older adults has been related to a higher risk of mortality.Based on a real-world national cohort, an SBP level below 130 mmHg was associated with the highest survival probability to age 90 years in women with or without BP medication.The longer the time women had their SBP controlled at ≥ 110 and <130mmHg, the higher the probability of survival to age 90.What are the clinical implications ?: The age-related BP estimates in conjunction with survival probabilities to age 90 presented clearly emphasize the importance of maintaining well-controlled BP levels even at older age.Preventive measures and risk factor control to ensure a constant relatively low SBP pattern during ageing are warranted.