Measuring only sitting blood pressure without considering supine blood pressure underestimates cardiovascular risk in the elderly

Abstract

Abstract Background and Objective Elderly individuals exhibit greater variability in blood pressure (BP) readings between sitting and supine positions. Nocturnal hypertension (supine position) is closely associated with cardiovascular diseases and mortality. However, the relationship between supine BP and cardiovascular risk remains unclear. This study aims to investigate the association between the occurrence of major adverse cardiovascular events (MACEs) with BP in sitting and supine positions. Methodologies A total of 3363 participants aged 65 years or older from the Northern Shanghai Study were included. Each participant is given 3 consecutive sitting SBP readings (SBP1, SBP2, SBP3) at 2-minute intervals, we then calculated the SBP1-2 (average of SBP1 and SBP2), SBP2-3 (average of SBP2 and SBP3), SBP1-2-3 (average of SBP1, SBP2 and SBP3). we also collected two supine BP readings (S-SBP1, S-SBP2). Kaplan-Meier and Cox proportional hazard regression were used to investigate the association of sitting and supine BP with MACEs (composite of nonfatal myocardial infarction, nonfatal stroke, or death). Results The mean age of participants was 71.5 years, and 1467(43.6%) were men. After a median of 6.4-year follow-up, a total of 362 events were recorded. Among 3 successive BP readings, SBP2-3 had strongest association with MACEs incidence (hazard ratio, 1.12 [1.00-1.26] per SD). Multiple cox proportional hazard regression showed supine BP had significant value in predicting MACEs, acute myocardial infarction (AMI) and mortality compared to sitting BP. Kaplan-Meier revealed significant differences in MACEs rates among participants without hypertension (HTN) in both sitting and supine positions, with HTN in both positions, or those with HTN in either position (Log rank P < 0.01). Compared to participants without HTN in both sitting and supine positions, those with HTN in both positions had a 1.4-fold (hazard ratio,1.40[1.08-1.82]) higher risk of MACEs and 2-fold (hazard ratio,2.01[1.24-3.26]) higher risk of stroke. Conclusion Supine BP measurements are more valuable than sitting BP in predicting MACEs in elderly individuals. Hypertension in both positions significantly increases the risk of MACEs. Taken together, supine BP may also need to be emphasized in the elderly.central illustration