Association between body mass index and risk of cardiovascular disease-specific mortality among adults with hypertension in Shanghai, China.

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.