Moderating Effect of Sex on the Relationship Between Physical Activity and Quality of Life in Coronary Heart Disease Patients in China

Purpose:The aim of this study was to investigate the moderating effect of sex on the relationship between physical activity (PA) and quality of life (QoL) in Chinese patients with coronary heart disease (CHD) not participating in cardiac rehabilitation.Methods:Chinese patients with CHD (aged 18-80 yr) were selected 12 mo after discharge from three Hebei Province tertiary hospitals. The International Physical Activity Questionnaire was used to assess PA in metabolic equivalents of energy (METs) and the Chinese Questionnaire of Quality of Life in Patients With Cardiovascular Disease was used to assess QoL. Data were analyzed using Student's t test and the chi 2 test, multivariant and hierarchical regression analysis, and simple slope analysis.Results:Among 1162 patients with CHD studied between July 1 and November 30, 2017, female patients reported poorer QoL and lower total METs in weekly PA compared with male patients. Walking (beta= .297), moderate-intensity PA (beta= .165), and vigorous-intensity PA (beta= .076) positively predicted QoL. Hierarchical regression analysis showed that sex moderates the relationship between walking (beta= .195) and moderate-intensity PA (beta= .164) and QoL, but not between vigorous-intensity PA (beta=-.127) and QoL. Simple slope analysis revealed the standardized coefficients of walking on QoL were 0.397 (female t = 8.210) and 0.338 (male t= 10.142); the standardized coefficients of moderate-intensity PA on QoL were 0.346 (female, t = 7.000) and 0.175 (male, t= 5.033).Conclusions:Sex moderated the relationship between PA and QoL among patients with CHD in China. There was a greater difference in QoL for female patients reporting higher time versus those with lower time for both walking and moderate-intensity PA than for male patients.