ASSOCIATION BETWEEN TRAJECTORIES OF SYSTOLIC BLOOD PRESSURE AND FRAILTY OUTCOME IN MIDDLE-AGED AND OLDER ADULTS

Abstract

Objective: The association between blood pressure and frailty outcome in the middle-aged and older population remains controversial. This study aimed to examine the relationship between trajectories of systolic blood pressure (SBP) and new-onset frailty. Design and method: From the China Health and Retirement Longitudinal Study, 6168 subjects were recruited in 2011 with follow ups in 2013, 2015 and 2018. The frailty index (FI) was constructed based on 40 scored items, with FI more than or equal to 0.25 defined as frailty. We identified the 5-year trajectory of SBP by latent class trajectory modeling. The association between SBP trajectories and frailty was explored based on hazard ratios (HR) by four Cox proportional hazards models. Restricted cubic splines were used to clarify the relationship between SBP and systolic blood pressure variability (SBPV) and frailty. Results: 6168 participants were included in this study with a mean age of 59 years. We identified five trajectories based on SBP, which are maintained low-stable SBP (T0), moderate-stable SBP (T1), remitting then increasing SBP (T2), increasing then remitting SBP (T3), and remaining stable at high SBP levels (T4). During the 7-year follow-up period, frailty outcome occurred in 1415 participants. After adjusting for other confounders, the two trajectories labeled “T2” and “T4” were associated with a higher risk of frailty compared with T0. In addition, elevated SBP and increased SBPV were associated with risk of frailty. Conclusions: Higher risk of frailty occurred in two trajectories, remitting then increasing and remaining stable at high SBP levels, were associated with a relatively higher risk of frailty.