Does loneliness ‘get under the skin’? Associations of loneliness with subsequent change in inflammatory and metabolic markers

Objectives: To expand existing knowledge about the associations of late-life loneliness with subsequent change in inflammation as well as with metabolic dysregulation, using national representative longitudinal data. The current analysis also explores age, gender, and race differences in these pre-disease pathways. Method: The analysis is based on data from the 2005–06 and 2010–11 waves of the National Social Life, Health, and Aging Project (NSHAP)–a longitudinal survey conducted among a representative sample of community-dwelling Americans aged 57–85. Adjusted logistic regression models were used to examine associations of loneliness with changes in C-reactive protein (CRP), Glycated hemoglobin (HbA1c), Body Mass Index (BMI), Waist Circumference (WC), and metabolic burden. Results: Loneliness was found to be associated with a change for the worse in most of the metabolic bio-markers. Specifically, lonely older adults had 39%–71% higher odds of developing prospective risk levels in three out of the four metabolic bio-markers that were measured: HbA1c, BMI, and metabolic burden. Salient differences by race were found in this regard. Whereas loneliness was not significantly associated with HbA1c risk levels and BMI among the Whites, the prospective risk of high HbA1c was more than five times greater and the risk of high BMI scores was three times greater among Hispanics who experienced loneliness than among the not-lonely Hispanic group. Conclusions: The robust impact of loneliness on prospective changes for the worse in levels of various metabolic bio-markers that are closely associated with morbidity highlights the need for prevention, coping with, and reducing loneliness.