Sex differences in the association between positional blood pressure and mortality

Sex-related discrepancies in mortality risk may be better elucidated and have greater clinical utility if body position and positional changes are considered. Thus, the aim of this study was to determine if supine, standing and the change in supine-to-standing BP have predictive value for all-cause mortality in a sex-dependent manner.

Participants consisted of 2121 apparently healthy males (51%) and females (49%) without known disease from the Ball State Adult Fitness Longitudinal Lifestyle Study (BALL ST) cohort. Resting supine and standing BP were acquired and the supine-to-standing BP change was calculated. Kaplan-Meier survival curves were created along with Cox proportional hazard models adjusting for traditional risk factors and hypertension medications were performed to assess the association of positional BP and all-cause mortality.

Supine and standing systolic BP (SBP) and pulse pressure (PP) in males and females, and supine diastolic BP (DBP) in females predicted mortality in unadjusted models ( P  < 0.05). Supine-to-standing SBP change in females, but not males, predicted mortality in the fully adjusted models ( P  < 0.05), and supine-to-standing DBP change predicted mortality in the unadjusted model only for males ( P  < 0.05). Compared to the low and medium tertiles, the high tertile for change in supine-to-standing SBP ( P  < 0.05) and PP ( P  =0.059) had the lowest survival probability in females, and lowest survival probability for DBP change for males ( P  ≤   0.05).

The change in supine-to-standing SBP predicts mortality in apparently healthy females independent of traditional risk factors and hypertension medications. Sex-specific differences in positional BP may provide additional diagnostic insight on all-cause mortality risk.