Sex Differences in Blood Pressure and Cardiovascular Risk: What the Evidence Does and Does Not Support

The question of whether hypertension guidelines should incorporate sex-specific blood pressure thresholds has moved from academic debate to clinical urgency. The European Society of Cardiology’s recent assertion that women’s cardiovascular risk begins at lower blood pressure levels than in men1 has intensified calls for revising diagnostic criteria. Yet the fundamental tension lies in reconciling three observations: women develop hypertension at lower absolute blood pressure levels,2 experience steeper increases in relative risk as blood pressure rises, yet maintain lower absolute cardiovascular disease (CVD) risk than men across the blood pressure spectrum.3 How should clinicians navigate this paradox? Kelly et al4 provide a rigorous examination on this question through analysis of over 420,000 UK Biobank participants across narrow 5-mmHg blood pressure intervals over a median 13.6 years of follow-up. Their key methodological contribution, presenting results using both sex-specific and common reference groups, exposes why relative risk metrics alone cannot guide clinical decisions. Women exhibit cardiovascular risk elevation at systolic blood pressure (SBP) levels of 100-105 mmHg, below the 110-115 mmHg nadir observed in men. The steeper slope of relative risk increase among women at higher blood pressure levels aligns with prior observations.2,5 However, when anchored to a common reference, women’s relative risks never surpass those of the lowest-risk male group, even at SBP levels up to 175 mmHg. Men maintain higher absolute CVD risk across all blood pressure categories. These findings highlight a critical tension: relative risk patterns differ by sex, but absolute risk—arguably the more relevant metric for treatment decisions—remains higher in men. Whether this pattern justifies maintaining unified diagnostic criteria or calls for a more nuanced approach remains an open question.