Is higher systolic blood pressure linked to cardiovascular risk even within the normal range?

Details

The risk of atherosclerotic cardiovascular disease (ASCVD) at currently defined normal systolic blood pressure (SBP) levels is not well defined for people without ASCVD risk factors under current definitions. Researchers examined associations of SBP with coronary artery calcium and ASCVD in people without hypertension or other traditional ASCVD risk factors under those definitions.

This cohort study included 1,457 ASCVD-free participants from the Multi-Ethnic Study of Atherosclerosis with SBP between 90 and 129 mm Hg. They had no dyslipidemia, defined as low-density lipoprotein cholesterol of 160 mg/dL or higher or high-density lipoprotein cholesterol below 40 mg/dL; no diabetes, defined as fasting glucose of 126 mg/dL or higher; no treatment for hyperlipidemia or diabetes; and no current tobacco use. Participants taking hypertension medication were excluded.

The exposure was SBP. Researchers classified coronary artery calcium as present or absent and calculated adjusted hazard ratios (aHRs) for incident ASCVD events. The study was conducted from March 27, 2018, to February 12, 2020.

Of the 1,457 participants, 894 were women (61.4%). Mean age was 58.1 years (SD 9.8), and mean follow-up was 14.5 years (SD 3.9). Traditional ASCVD risk factors, coronary artery calcium, and incident ASCVD events increased with higher SBP. The aHR for ASCVD was 1.53 (95% CI 1.17–1.99) for each 10-mm Hg increase in SBP.

Compared with SBP of 90–99 mm Hg, the aHR for ASCVD was 3.00 (95% CI 1.01–8.88) at 100–109 mm Hg, 3.10 (95% CI 1.03–9.28) at 110–119 mm Hg, and 4.58 (95% CI 1.47–14.27) at 120–129 mm Hg.

The researchers concluded that, beginning at an SBP as low as 90 mm Hg, coronary artery calcium presence and incident ASCVD risk appeared to increase stepwise as SBP rose. They said the results highlight the importance of primordial prevention of increases in SBP and other traditional ASCVD risk factors, which generally appear to show similar graded increases in risk within values traditionally considered normal.