title: Social connectedness is associated with fibrinogen level in a human social network.
abstract: Socially isolated individuals face elevated rates of illness and death. Conventional measures of social connectedness reflect an individual's perceived network and can be subject to bias and variation in reporting. In this study of a large human social network, we find that greater indegree, a sociocentric measure of friendship and familial ties identified by a subject's social connections rather than by the subject, predicts significantly lower concentrations of fibrinogen (a biomarker of inflammation and cardiac risk), after adjusting for demographics, education, medical history and known predictors of cardiac risk. The association between fibrinogen and social isolation, as measured by low indegree, is comparable to the effect of smoking, and greater than that of low education, a conventional measure of socioeconomic disadvantage. By contrast, outdegree, which reflects an individual's perceived connectedness, displays a significantly weaker association with fibrinogen concentrations.
authors: Department of Emergency Medicine, Stanford University, 300 Pasteur Drive MC 5119, Stanford, CA 94305, USA.
authors: David A
authors: 0000-0003-0151-5121
authors: DA
authors: Kim
authors: The National Heart, Lung and Blood Institute & Boston University's Framingham Heart Study, 73 Mount Wayte Avenue, Framingham, MA 01702, USA.
authors: Emelia J
authors: EJ
authors: Benjamin
authors: Departments of Medicine and Political Science, University of California, San Diego, 9500 Gilman Drive #0521, La Jolla, CA 92093, USA.
authors: James H
authors: JH
authors: Fowler
authors: Departments of Medicine, Ecology and Evolutionary Biology, and Sociology, Yale University, PO Box 208263, New Haven, CT 06520, USA nicholas.christakis@yale.edu.
authors: Nicholas A
authors: NA
authors: Christakis
mesh_terms: D005340:Fibrinogen / Q000032:analysis*; D006304:Health Status; D006801:Humans; D007249:Inflammation; D012934:Social Isolation; D012944:Social Support
chemical_list: D005340:Fibrinogen
keywords: fibrinogen; social epidemiology; social hierarchy; social networks; stress response