Abstract Body: Background: Recent studies show that the risk of cardiovascular disease (CVD) increases from a lower level of systolic blood pressure (SBP) in women than men, and increases at a steeper rate. This has led to a suggestion for sex-based SBP thresholds for hypertension diagnosis.
Aims: To investigate sex differences in the association of SBP and incident CVD.
Methods: The UK Biobank recruited over 500,000 participants aged 40-70 years between 2006 and 2010, with follow up until May-October 2022. The present study included 420,649 participants with no prior history of CVD. The primary outcome was incident CVD, defined as a first diagnosis of fatal or non-fatal coronary heart disease (CHD) or stroke. Age-adjusted sex-specific risks, relative risks and risk differences relating SBP to CVD were estimated using Poisson and Cox regression.
Results: The mean (SD) age among 235,556 (56.0%) women was 56.1 (8.0) years and among 185,093 men was 56.1 (8.2) years. Over a mean follow-up of 13.2 years, there were 28,628 CVD events. CVD risks across SBP levels showed a “J-shape”, and were higher in men than women at all BP levels. The lowest risk for CVD among women was at SBP 100-<105 mmHg (15.6 [95% CI 11.8-23.1] events per 10,000 person-years) and SBP 110-<115 among men (47.2 [95% CI 41.8-53.0]). Compared with SBP 100-<110 mmHg, sex-specific relative risks at SBP above 120 mmHg were higher in women than men, but risk differences were higher in men than women at all levels of SBP. Furthermore, compared to men at SBP100-<110 mmHg (i.e. the men with least risk), risks in women were lower at all levels of SBP below 170 mmHg, and the relative risk at the highest SBP (≥180 mmHg) in women (1.3 [95% CI 1.1-1.5]) remained lower than men (2.4 [95% CI 2.0-2.7]) at the same SBP level.
Conclusions: Consideration of the risks and sex-combined analyses do not support that women should have lower BP thresholds than men.