Loneliness and social isolation as risk factors for CVD: implications for evidence based patient care and scientific inquiry
A recent meta analysis has shown that loneliness and social isolation are risk factors for coronary heart disease and stroke.1 These latest findings, specific to cardiovascular outcomes, are consistent with substantial research indicating broad health risks (eg, immune functioning, cardiovascular functioning, cognitive decline) associated with the quantity and quality of social relationships including several meta analyses documenting mortality risk.2 ,3 In the most comprehensive of these,3 the overall odds for mortality was 1.50, similar to the risk from light smoking and exceeding the risks conferred by hypertension and obesity. Thus, the epidemiological data suggest that having more and better quality social relationships is linked to decreased health risks and having fewer and poorer quality relationships increased risk.2 ,3 Research has also documented the influence of social connections (including measures specific to loneliness and isolation) on multiple pathways involved in both the development and progression of coronary heart disease and stroke. As depicted in figure 1, these include lifestyle (eg, nutrition, physical activity, sleep),4 treatment adherence and cooperation,5 and direct effects on surrogate biological markers.6 ,7 Recent longitudinal data from four nationally representative US samples revealed a dose response effect of social integration on several surrogate biomarkers of cardiovascular disease including hypertension, body mass index, waist circumference and inflammation (hs CRP).6 Moreover, most epidemiological studies control for lifestyle factors (eg, smoking, physical activity) documenting an independent influence of social relationships on mortality. Taken together, these latest findings specific to loneliness and isolation1 bolster the already robust evidence documenting that social connections significantly predict morbidity and mortality, supporting the case for inclusion as a risk factor for cardiovascular disease (CVD) Figure 1 Simplified model of possible direct and indirect pathways by which social connections influence disease morbidity and mortality. How should these data inform clinical practice?
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