Social relationships and physiological determinants of longevity across the human life span

Abstract

Two decades of research indicate causal associations between social relationships and mortality, but important questions remain as to how social relationships affect health, when effects emerge, and how long they last. Drawing on data from four nationally representative longitudinal samples of the US population, we implemented an innovative life course design to assess the prospective association of both structural and functional dimensions of social relationships (social integration, social support, and social strain) with objectively measured biomarkers of physical health (C-reactive protein, systolic and diastolic blood pressure, waist circumference, and body mass index) within each life stage, including adolescence and young, middle, and late adulthood, and compare such associations across life stages. We found that a higher degree of social integration was associated with lower risk of physiological dysregulation in a doseresponse manner in both early and later life. Conversely, lack of social connections was associated with vastly elevated risk in specific life stages. For example, social isolation increased the risk of inflammation by the same magnitude as physical inactivity in adolescence, and the effect of social isolation on hypertension exceeded that of clinical risk factors such as diabetes in old age. Analyses of multiple dimensions of social relationships within multiple samples across the life course produced consistent and robust associations with health. Physiological impacts of structural and functional dimensions of social relationships emerge uniquely in adolescence and midlife and persist into old age.social relationships | physiological dysregulation | longevity | life course | biomarker

Invited Commentary: Integrating Genomics and Social Epidemiology—Analysis of Late-Life Low Socioeconomic Status and the Conserved Transcriptional Response to Adversity

“…Social disadvantage in childhood and adulthood predict increased systemic inflammation and chronic infection (17)(18)(19)(20). The present study by Levine et al, combined with others (21,22), suggests differential regulation of gene expression as a potential mechanism in this social gradient.…”

Empirical redefinition of comprehensive health and well-being in the older adults of the United States

“…Members of Diabetes, Hypertension, and Immobility (CM5) were less likely to feel isolated (17%) and as socially engaged as the general population, whereas 45% of the most vulnerable Extensive Multimorbidity and Frailty (CM6) felt isolated, were not socially engaged (35%), and lived alone (32%). The marked differences in social characteristics captured by the CM are clinically relevant, because social connections affect not only well-being but also, access to health care and compliance (46)(47)(48).…”

A Longitudinal Analysis of Stepfamily Relationship Quality and Adolescent Physical Health

“…It is especially notable that stepparent-child relationship quality is associated with youths’ physical health, as most extant research has examined the emotional and behavioral health of youth in stepfamilies. Our findings suggest that stepfamily relationships might “get under the skin” to impact the physical health of youth [36]. …”