title: Physical and social activities mediate the associations between social network types and ventilatory function in Chinese older adults.
abstract: OBJECTIVE
  This study examined the associations between social network types and peak expiratory flow (PEF), and whether these associations were mediated by social and physical activities and mood.
  
  
  METHODS
  Nine hundred twenty-four community-dwelling Chinese older adults, who were classified into five network types (diverse, friend-focused, family-focused, distant family, and restricted), provided data on demographics, social and physical activities, mood, smoking, chronic diseases, and instrumental activities of daily living. PEF and biological covariates, including blood lipids and glucose, blood pressure, and height and weight, were assessed. Two measures of PEF were analyzed: the raw reading in L/min and the reading expressed as percentage of predicted normal value on the basis of age, sex, and height. Diverse, friend-focused, and distant family networks were hypothesized to have better PEF values compared with restricted networks, through higher physical and/or social activities. No relative advantage was predicted for family-focused networks because such networks tend to be associated with lower physical activity.
  
  
  RESULTS
  Older adults with diverse, friend-focused, and distant family networks had significantly better PEF measures than those with restricted networks. The associations between diverse network and PEF measures were partially mediated by physical exercise and socializing activity. The associations between friend-focused network and PEF measures were partially mediated by socializing activity. No significant PEF differences between family-focused and restricted networks were found.
  
  
  CONCLUSIONS
  Findings suggest that social network types are associated with PEF in older adults, and that network-type differences in physical and socializing activity is partly responsible for this relationship.
authors.affiliation: Department of Psychological Studies, Hong Kong Institute of Education.
authors.forename: Sheung-Tak
authors.initials: ST
authors.lastname: Cheng
authors.affiliation: Department of Medicine and Geriatrics, United Christian Hospital.
authors.forename: Edward M F
authors.initials: EM
authors.lastname: Leung
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University.
authors.forename: Trista Wai Sze
authors.initials: TW
authors.lastname: Chan
mesh_terms: D000339:Affect; D000368:Aged; D000369:Aged, 80 and over; D002681:China; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity; D010366:Peak Expiratory Flow Rate / Q000502:physiology*; D012919:Social Behavior; D012944:Social Support