Does Physical Activity Mediate the Effect of Loneliness on Inflammatory and Metabolic Processes?

The study to be presented in the chapter explores one potential behavioral mechanism by which loneliness affects inflammatory and metabolic processes in old age. Specifically, it addresses whether physical activity mediates the loneliness—inflammatory/metabolic dysregulation association. Multivariate linear regressions were applied to data derived from the Health and Retirement Study (HRS). The findings revealed that loneliness was prospectively associated with elevated values of log C-reactive protein (log-CRP) and with amplified levels of Glycated hemoglobin (HbA1c), Cystatin C (CysC), and Body Mass Index (BMI), after controlling for socio-demographics. Second, physical activity mediated the association between loneliness with prospective values of log-CRP and also mediated associations between loneliness and prospective levels of metabolic biomarkers. These findings affirm the contribution (i.e., the mediation), of physical activity to the associations between loneliness and immune and metabolic processes and provide insights concerning the mechanism by which this social—biological connection operates