Association of overweight and obesity with cardiovascular disease morbidity and adverse outcomes in older adults: a retrospective cohort study

Background: The effect of baseline overweight and obesity status on cardiovascular disease(CVD) morbidity and adverse outcomes remains unclear. The aim of this study was to examine the association between overweight, obesity and CVD morbidity, mortality, and all-cause mortality in Chinese older individuals. Methods: This retrospective cohort study analyzed data from electronic health examination records of 86,049 older individuals aged ≥ 60 years in Xinzheng City, Henan Province, China, from January 2011 to December 2019. Cox proportional risk regression models and competing risk models were utilized to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for CVD morbidity and mortality, as well as all-cause mortality, in overweight and obese individuals. Restricted cubic splines were employed to evaluate dose-response associations. Results: During a median follow-up of 5.96 years, 35,731 older individuals were diagnosed with CVD. The total number of participant deaths was 17,029, with 7,605 deaths from CVD. The morbidity of CVD was higher in the overweight and obese groups compared to the normal BMI group, with HRs of 1.06(95%CI, 1.02-1.10) and 1.23(95%CI, 1.16-1.30), respectively. Competing risk models controlling for fatal events showed an increased morbidity of CVD in the overweight and obese groups, with HRs of 1.15(95%CI, 1.11-1.18) and 1.31(95%CI, 1.26-1.37), respectively. In contrast, the overweight group had a reduced risk of all-cause mortality and CVD mortality compared to the normal BMI group, with HRs of 0.91(95%CI, 0.88-0.94) and 0.89(95%CI, 0.82-0.97), respectively. The study found that the risk of all-cause mortality was lower in the obese group, with HRs of 0.89(95%CI, 0.82-0.97). Participants had the lowest risk of all-cause mortality and CVD mortality when their BMI was between 26 and 28 kg/m². The restricted cubic spline plots showed a J-shaped association between BMI and CVD morbidity and an inverse J-shaped association with CVD mortality and all-cause mortality. Conclusion: Overweight and obesity are positively correlated with the morbidity of CVD and negatively correlated with all-cause mortality in Chinese older individuals. However, it cannot be assumed that there is a negative correlation between obesity and CVD mortality. Therefore, obese individuals should aim to reduce weight appropriately, and overweight individuals should take appropriate measures to prevent obesity.