Association between body mass index changes and short- and long-term outcomes of hypertension in a Chinese rural cohort study.

Abstract

This study aimed to investigate the effect of body mass index (BMI) changes on hypertension among rural areas of China. A population-based sample of 13,263 and 5944 rural Chinese people aged ≥35 years and without hypertension at baseline was included in our analysis of BMI changes (from (2004-2006) to 2008) and short- and long-term outcomes of hypertension (from 2008 to 2010 and 2010 to 2017). The participants were divided into four groups by a comprehensive cross-sectional combination according to baseline BMI (18.5-24 vs. ≥24 kg/m2) and follow-up changes (decreased vs. increased). Adjusted Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs). During a median follow-up period of 4.8 (short-term) and 11.7 (long-term) years, 2299 (17.33%) and 2020 (33.98%) participants developed hypertension, respectively. For participants with a baseline BMI ≥ 24 kg/m2, when BMI decreased in follow-ups, the multivariable-adjusted HRs (95% CI) of short-term hypertension were 0.898 (0.857-0.942). For baseline 18.5 kg/m2 ≤ BMI < 24 kg/m2, when BMI increased in follow-ups, the risks of short-term hypertension were 1.103 (1.068-1.139). We detected that BMI changes had a lower impact on the incidence of hypertension in long-term than short-term. Our study indicated that BMI changes were significantly associated with the incidence of hypertension for the short-term, and it had a stronger impact on short-term outcomes than long-term. Managing weight by lifestyle modification was particularly important for the primary prevention of hypertension in rural Chinese population.