title: Loneliness, social isolation, and behavioral and biological health indicators in older adults.
abstract: OBJECTIVE
  A number of mechanisms have been proposed through which social isolation and loneliness may affect health, including health-related behavioral and biological factors. However, it is unclear to what extent isolation and loneliness are independently associated with these pathways. The objective of the present analysis was to determine the impact of social isolation and loneliness, individually as well as simultaneously, on health-related behavioral and biological factors using data from the English Longitudinal Study of Ageing (ELSA).
  
  
  METHODS
  Data on health behaviors (smoking and physical activity) were analyzed from 8,688 participants and data on blood pressure, cholesterol, and inflammatory markers were analyzed from over 5,000 of these participants who were eligible for a nurse visit and blood sampling. Loneliness was measured using the short form of the Revised UCLA scale and an index of social isolation was computed incorporating marital status; frequency of contact with friends, family, and children; and participation in social activities.
  
  
  RESULTS
  Fewer than 2% of participants reported being lonely all the time, while nearly 7% had the highest possible scores on social isolation. Both social isolation and loneliness were associated with a greater risk of being inactive, smoking, as well as reporting multiple health-risk behaviors. Social isolation was also positively associated with blood pressure, C-reactive protein, and fibrinogen levels.
  
  
  CONCLUSIONS
  Loneliness and social isolation may affect health independently through their effects on health behaviors. In addition, social isolation may also affect health through biological processes associated with the development of cardiovascular disease.
authors.affiliation: Department of Epidemiology & Public Health, University College London, London, UK. aparna.shankar@ucl.ac.uk
authors.forename: Aparna
authors.initials: A
authors.lastname: Shankar
authors.forename: Anne
authors.initials: A
authors.lastname: McMunn
authors.forename: James
authors.initials: J
authors.lastname: Banks
authors.forename: Andrew
authors.initials: A
authors.lastname: Steptoe
mesh_terms: D000368:Aged; D002318:Cardiovascular Diseases; D002648:Child; D002675:Child, Preschool; D004739:England; D005260:Female; D015438:Health Behavior; D006304:Health Status; D006801:Humans; D008132:Loneliness / Q000523:psychology*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D012309:Risk-Taking; D012907:Smoking / Q000523:psychology; D012934:Social Isolation / Q000523:psychology*