Sedentary lifestyle is independently associated with higher fat mass index regardless of physical activity level in patients with coronary artery disease

Cardiac rehabilitation (CR) after a coronary artery disease (CAD) event is recommended to improve risk factor control, as some of them remain poorly controlled (e.g. obesity, physical activity), while new ones are emerging (e.g. sedentary behavior). The aim of our study was to investigate the associations between physical activity, sedentary behavior, and traditional risk factors with body fat mass index (FMI) in patients with CAD. In this cross-sectional study, CAD patients entering phase III CR (2016–2023) were assessed for FMI by dual-energy X-ray absorptiometry, cardiorespiratory fitness by cardiopulmonary exercise testing, 7-day accelerometer-measured physical activity and sedentary behavior, and cardiovascular risk factors. There were 111 CAD patients, their average age was 61.7 ± 9.8 years, 15 (13.5%) were female. Patients were divided into three groups, based on the FMI: normal (n = 19), overweight (n = 62) and obese (n = 30). Obese patients, compared to patients with normal FMI, had significantly higher systolic blood pressure, total sedentary time, non-HDL and triglycerides levels, and lower exercise capacity. On the contrary, there were no significant differences in physical activity level, diastolic blood pressure, total cholesterol, HDL and LDL cholesterol. In a multivariate linear regression analysis, sedentary time showed an independent association with FMI, whereas physical activity did not. Obese CAD patients exhibit poorer control of blood pressure, lipid levels, and sedentary behavior compared with normal-weight and overweight patients. Effective strategies are needed to curb sedentary behavior in this population, which may directly reduce body fat.