The aim of our study was to examine the association between body mass index (BMI) and the risk of cardiovascular disease (CVD)-specific mortality among Chinese adults with hypertension by sex. This study included 212,394 adult hypertensive patients aged 20-85 years registered in the records of Minhang District during 2007-2018. Cox proportional hazards regression was performed to evaluate the association between BMI and CVD-specific mortality among Chinese adults with hypertension. There were 14,029 deaths over an average of 8.24 years (range, 0.19-11.96 years). The multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) across BMI categories (< 18.5 kg/m2, 18.5-24.9 kg/m2 [reference group], 25.0-29.9 kg/m2, and ≥ 30 kg/m2) for CVD-specific mortality were 1.37 (1.22-1.53), 1.00 (reference), 0.95 (0.90-1.01), and 1.21 (1.04-1.40) in males, and 1.44 (1.31-1.59), 1.00 (reference), 0.96 (0.91-1.01), and 1.04 (0.92-1.17) in females. A U-shaped relationship was observed between BMI and CVD-specific mortality (overall association P< 0.001; non-linearity P< 0.001). This association was attenuated in old age. This study revealed a U-shaped relationship between BMI and CVD-specific mortality among hypertensive men and women. In older people, overweight and obesity are potential factors that reduce the risk of CVD death.
Keywords: adults; body mass index; cardiovascular disease; hypertension; mortality.