title: Social Integration and Reduced Risk of Coronary Heart Disease in Women: The Role of Lifestyle Behaviors.
abstract: BACKGROUND
  Higher social integration is associated with lower cardiovascular mortality; however, whether it is associated with incident coronary heart disease (CHD), especially in women, and whether associations differ by case fatality are unclear.
  
  
  OBJECTIVE
  This study sought to examine the associations between social integration and risk of incident CHD in a large female prospective cohort.
  
  
  RESULTS
  Seventy-six thousand three hundred and sixty-two women in the Nurses' Health Study, free of CHD and stroke at baseline (1992), were followed until 2014. Social integration was assessed by a simplified Berkman-Syme Social Network Index every 4 years. End points included nonfatal myocardial infarction and fatal CHD. Two thousand three hundred and seventy-two incident CHD events occurred throughout follow-up. Adjusting for demographic, health/medical risk factors, and depressive symptoms, being socially integrated was significantly associated with lower CHD risk, particularly fatal CHD. The most socially integrated women had a hazard ratio of 0.55 (95% confidence interval, 0.41-0.73) of developing fatal CHD compared with those least socially integrated (Pfor trend <0.0001). When additionally adjusting for lifestyle behaviors, findings for fatal CHD were maintained but attenuated (Pfor trend =0.02), whereas the significant associations no longer remained for nonfatal myocardial infarction. The inverse associations between social integration and nonfatal myocardial infarction risk were largely explained by health-promoting behaviors, particularly through differences in cigarette smoking; however, the association with fatal CHD risk remained after accounting for these behaviors and, thus, may involve more direct biological mechanisms.
  
  
  CONCLUSIONS
  Social integration is inversely associated with CHD incidence in women, but is largely explained by lifestyle/behavioral pathways.
authors.affiliation: From the Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (S.-C.C., E.B.R.); Department of Social and Behavioral Sciences (S.-C.C., M.G., S.W., I.K., L.D.K.), Department of Nutrition (E.B.R.), Department of Biostatistics (E.T.T.), and Department of Epidemiology (E.B.R.), Harvard T.H. Chan School of Public Health, Boston, MA; Department of Epidemiology and Biostatistics, University of California, San Francisco (M.G., S.W.); and Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL (M.C.). nhshc@channing.harvard.edu.
authors.forename: Shun-Chiao
authors.initials: SC
authors.lastname: Chang
authors.affiliation: From the Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (S.-C.C., E.B.R.); Department of Social and Behavioral Sciences (S.-C.C., M.G., S.W., I.K., L.D.K.), Department of Nutrition (E.B.R.), Department of Biostatistics (E.T.T.), and Department of Epidemiology (E.B.R.), Harvard T.H. Chan School of Public Health, Boston, MA; Department of Epidemiology and Biostatistics, University of California, San Francisco (M.G., S.W.); and Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL (M.C.).
authors.forename: Maria
authors.initials: M
authors.lastname: Glymour
authors.affiliation: From the Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (S.-C.C., E.B.R.); Department of Social and Behavioral Sciences (S.-C.C., M.G., S.W., I.K., L.D.K.), Department of Nutrition (E.B.R.), Department of Biostatistics (E.T.T.), and Department of Epidemiology (E.B.R.), Harvard T.H. Chan School of Public Health, Boston, MA; Department of Epidemiology and Biostatistics, University of California, San Francisco (M.G., S.W.); and Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL (M.C.).
authors.forename: Marilyn
authors.initials: M
authors.lastname: Cornelis
authors.affiliation: From the Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (S.-C.C., E.B.R.); Department of Social and Behavioral Sciences (S.-C.C., M.G., S.W., I.K., L.D.K.), Department of Nutrition (E.B.R.), Department of Biostatistics (E.T.T.), and Department of Epidemiology (E.B.R.), Harvard T.H. Chan School of Public Health, Boston, MA; Department of Epidemiology and Biostatistics, University of California, San Francisco (M.G., S.W.); and Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL (M.C.).
authors.forename: Stefan
authors.initials: S
authors.lastname: Walter
authors.affiliation: From the Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (S.-C.C., E.B.R.); Department of Social and Behavioral Sciences (S.-C.C., M.G., S.W., I.K., L.D.K.), Department of Nutrition (E.B.R.), Department of Biostatistics (E.T.T.), and Department of Epidemiology (E.B.R.), Harvard T.H. Chan School of Public Health, Boston, MA; Department of Epidemiology and Biostatistics, University of California, San Francisco (M.G., S.W.); and Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL (M.C.).
authors.forename: Eric B
authors.initials: EB
authors.lastname: Rimm
authors.affiliation: From the Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (S.-C.C., E.B.R.); Department of Social and Behavioral Sciences (S.-C.C., M.G., S.W., I.K., L.D.K.), Department of Nutrition (E.B.R.), Department of Biostatistics (E.T.T.), and Department of Epidemiology (E.B.R.), Harvard T.H. Chan School of Public Health, Boston, MA; Department of Epidemiology and Biostatistics, University of California, San Francisco (M.G., S.W.); and Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL (M.C.).
authors.forename: Eric
authors.initials: E
authors.lastname: Tchetgen Tchetgen
authors.affiliation: From the Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (S.-C.C., E.B.R.); Department of Social and Behavioral Sciences (S.-C.C., M.G., S.W., I.K., L.D.K.), Department of Nutrition (E.B.R.), Department of Biostatistics (E.T.T.), and Department of Epidemiology (E.B.R.), Harvard T.H. Chan School of Public Health, Boston, MA; Department of Epidemiology and Biostatistics, University of California, San Francisco (M.G., S.W.); and Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL (M.C.).
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kawachi
authors.affiliation: From the Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (S.-C.C., E.B.R.); Department of Social and Behavioral Sciences (S.-C.C., M.G., S.W., I.K., L.D.K.), Department of Nutrition (E.B.R.), Department of Biostatistics (E.T.T.), and Department of Epidemiology (E.B.R.), Harvard T.H. Chan School of Public Health, Boston, MA; Department of Epidemiology and Biostatistics, University of California, San Francisco (M.G., S.W.); and Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL (M.C.).
authors.forename: Laura D
authors.initials: LD
authors.lastname: Kubzansky
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003327:Coronary Disease / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D015438:Health Behavior / Q000502:physiology; D000070497:Healthy Lifestyle / Q000502:physiology; D006801:Humans; D007398:Interpersonal Relations; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D040242:Risk Reduction Behavior; D012944:Social Support; D011795:Surveys and Questionnaires
keywords: coronary heart disease risk; epidemiology; marginal structural model; mediation; prospective cohort study; social integration; women and minorities