Loneliness as a risk factor for metabolic syndrome: results from the HUNT study

Objective Metabolic syndrome (MetS) includes hyperglycaemia, hypertension, central adiposity, elevated triglyceride levels and low levels of high-density lipoprotein cholesterol. All factors are identified as risk factors for cardiovascular disease and mortality. This longitudinal study examined whether loneliness, which has been shown to predict a range of negative health outcomes, increases the risk for MetS. Methods We used data from 'the Nord-Trondelag Health Study' (HUNT) which is a large longitudinal health study based on a Mid-Norway county population (n=26 990). Self-reports, physical examinations and blood samples were analysed to evaluate the associations between loneliness and incidents of MetS after 10 years (follow-up survey conducted during 2006-2008). We also investigated the role of depression as a potential mediating factor. Results Individuals who reported higher levels of loneliness had a higher odds for MetS (adjusted OR 1.09 (95% CI 1.02 to 1.16); p=0.007). This effect was mediated through depression. Conclusions Findings suggest that loneliness may be an important factor that increases the risk for MetS. The effect of loneliness on MetS is mediated through depressive symptoms. Reducing loneliness may help prevent the incidence of MetS and related diseases.