Higher Blood Pressure, Greater Mortality
A sizable body of evidence indicates that raised blood pressure correlates with increased mortality. There are good reasons for this relationship to exist. Excessive blood pressure damages small vessels and delicate tissues in organs throughout the body, and that damage adds up. It also contributes to harmful remodeling of the heart, making it larger and weaker, and accelerates the growth of atherosclerotic plaque in arterial walls. Excessively low blood pressure in later life is also indicative of conditions that tend to lead to raised mortality, of course. As this study shows, there is a safest range somewhere in the middle.
We aimed to determine survival probabilities to age 90 for various systolic blood pressure (SBP) levels among women aged ≥ 65 years with or without blood pressure (BP) medication. 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 2020.
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 120 mmHg 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 woman 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% absolute survival probability. For those with 20% time in range, the probability was 21%.
In conclusion, 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.