title: Social network characteristics and body mass index in an elderly Korean population.
abstract: OBJECTIVE
  Research has shown that obesity appears to spread through social ties. However, the association between other characteristics of social networks and obesity is unclear. This study aimed to identify the association between social network characteristics and body mass index (BMI, kg/m(2)) in an elderly Korean population.
  
  
  METHODS
  This cross-sectional study analyzed data from 657 Koreans (273 men, 384 women) aged 60 years or older who participated in the Korean Social Life, Health, and Aging Project. Network size is a count of the number of friends. Density of communication network is the number of connections in the social network reported as a fraction of the total links possible in the personal (ego-centric) network. Average frequency of communication (or meeting) measures how often network members communicate (or meet) each other. The association of each social network measure with BMI was investigated by multiple linear regression analysis.
  
  
  RESULTS
  After adjusting for potential confounders, the men with lower density (<0.71) and higher network size (4-6) had the higher BMI (β=1.089, p=0.037) compared to the men with higher density (>0.83) and lower size (1-2), but not in the women (p=0.393). The lowest tertile of communication frequency was associated with higher BMI in the women (β=0.885, p=0.049), but not in the men (p=0.140).
  
  
  CONCLUSIONS
  Our study suggests that social network structure (network size and density) and activation (communication frequency and meeting frequency) are associated with obesity among the elderly. There may also be gender differences in this association.
authors.affiliation: Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Won Joon
authors.initials: WJ
authors.lastname: Lee
authors.affiliation: Department of Sociology, Yonsei University College of Social Sciences, Seoul, Korea.
authors.forename: Yoosik
authors.initials: Y
authors.lastname: Youm
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Yumie
authors.initials: Y
authors.lastname: Rhee
authors.affiliation: Division of Silver Industry, Kangnam University, Yongin, Korea.
authors.forename: Yeong-Ran
authors.initials: YR
authors.lastname: Park
authors.affiliation: Department of Clinical Nursing Science, Yonsei University College of Nursing, Seoul, Korea.
authors.forename: Sang Hui
authors.initials: SH
authors.lastname: Chu
authors.affiliation: Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyeon Chang
authors.initials: HC
authors.lastname: Kim
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D015897:Comorbidity; D003863:Depression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D056910:Republic of Korea / Q000453:epidemiology; D012649:Self Concept; D012907:Smoking; D060756:Social Networking
keywords: Aged; Body mass index; Social support