Association of obesity with cardiovascular disease in the absence of traditional risk factors

Background The association between obesity and cardiovascular disease (CVD) in people without traditional CVD risk factors is unclear. This study aimed to investigate the association of obesity with CVD and its subtypes in people without traditional CVD risk factors. Methods Based on the Kailuan cohort study, the included participants were divided into different groups according to levels of body mass index (BMI) and waist height ratio (WHtR), respectively. Multivariate Cox proportional hazard models were used to evaluate the associations. Results This study included 31,955 participants [men 63.99%; mean age (48.14 ± 3.33) years]. During a median follow-up period of 12.97 (interquartile range: 12.68–13.17) years, 1298 cases of CVD were observed. Compared with the normal BMI group, the hazard ratios (HRs) for CVD, stroke, and myocardial infarction (MI) in the BMI obese group were 1.31 (95% confidence interval [CI] 1.11–1.55), 1.21 (95%CI 1.01–1.46), 1.62 (95%CI 1.13–2.33), respectively. Compared with the WHtR non-obese group, the HRs for CVD, stroke, and MI in the obese group were 1.25(95%CI 1.11–1.41), 1.18 (95%CI 1.03–1.34), 1.57 (95%CI 1.18–2.09), respectively. There was an interaction between age and WHtR ( P for interaction was 0.043). The association between WHtR and CVD was stronger in people under 60 years old, with a HR of 1.44 (95%CI 1.24–1.67). Conclusion We found that obesity increased the risk of CVD in people without traditional CVD risk factors. The association of WHtR with CVD was stronger in people under 60 years old.