Social isolation exacerbates diet-induced obesity and peripheral inflammation in young male mice under thermoneutrality

Social isolation (SI) is associated with an increased risk of mortality and various chronic diseases-including obesity-in humans. Murine studies probing SI meta-bolic outcomes remain inconsistent, due in part to a lack of consideration for housing temperature. Such experiments typically occur at room temperature, subjecting mice to chronic cold stress. Single housing prevents social thermoreg-ulation, further exacerbating cold stress and obscuring psychosocial influences on metabolism at room temperature. In this study, C57BL/6 and BALB/c male mice were group-and single-housed under thermoneutral conditions to determine whether SI affects the development of high-fat diet-induced obesity. We report SI promotes weight gain, increases food intake, increases adiposity, worsens gly-cemic control, reduces insulin signaling, exacerbates systemic and adipose inflam-matory responses, and induces a molecular signature within the hypothalamus. This study establishes a murine model that recapitulates the SI-induced propen-sity for obesity, which may further our understanding of SI's influence on health and disease.

Automated summary

Social isolation is associated with increased risk of mortality and chronic diseases, including obesity, in humans. However, studies on mice have been inconsistent, partly due to a lack of consideration for housing temperature. This study establishes a mouse model that demonstrates the propensity for obesity induced by social isolation, providing insights into the influence of social isolation on health and disease.