[A cohort study on body mass index and risk of all-cause mortality among hypertensive population]

Objective: To investigate the relationship between body mass index (BMI) and all-cause mortality in hypertensive population. Methods: All participants were selected from a prospective cohort study based on a rural population from Henan province, China. Cox proportional hazards regression models were used to estimate the associations of different levels of BMI stratification with all-cause mortality. Restricted cubic spline models were used to detect the dose-response relation. Results: Among the 5 461 hypertensive patients, a total of 31 048.38 person-years follow-up was conducted. The median of follow-up time was 6 years, and 589 deaths occurred during the follow-up period. Compared to normal weight group (18.5 kg/m(2)%CI: 0.37-1.87), 0.81 (95%CI: 0.67-0.97), and 0.72 (95%CI: 0.56-0.91), respectively. The dose-response analysis showed a nonlinear, reverse "S" shaped relationship (non-linearity P<0.001). Conclusion: Overweight or obese might have a protective effect on all-cause mortality in hypertensive population, which supports the "obesity paradox" phenomenon.