Association between social network structure and physical activity in middle-aged Korean adults

Evidence suggests that physical activity participation is shaped through a myriad of structural aspects of social relationships. We examined the relationship between social network structure based on egocentric social network and physical activity. From 6799 middle-aged Korean adults, we assessed the social network density and proportion of closed triads, using the name generator module. Self-reported physical activity for functional and leisure purposes was calculated in metabolic equivalent of task (MET)-min/week. We employed sex-stratified, multivariable linear regression to assess the association between each network structure variable and total physical activity, adjusting for age, network size, socioeconomic status, and comorbidities. We also examined the association with moderate-to-vigorous physical activity (MVPA) and wrist-worn accelerometer assessed physical activity. The network members of female participants were more likely to be of same sex and family member compared to those of males. There were no sex differences in average network size. Network density based on affiliation was sex-differentially associated with physical activity (male β −346.7, p 0.2221 and female β −528.6, p 0.0002). In parallel, the proportion of closed triads was negatively associated with physical activity only in females (male β −542.6, p 0.0551 and female β −641.51, p < 0.0001). However, network density and closed triads were insignificantly yet positively associated with MVPA in male (density β 229.7, p 0.3193 and closed triad β 109.21, p 0.6333). Network structure by contact frequency or emotional closeness and accelerometer-assessed physical activity showed inconsistent results. Understanding the role of social network structures can help to achieve ideal physical activity level in the context of primary prevention of cardiometabolic disorders.