Social relations, depressive symptoms, and incident type 2 diabetes mellitus: The English Longitudinal Study of Ageing

AIMS: We examined whether social relations are associated with the risk of developing type 2 diabetes mellitus (T2DM) and furthermore, whether social relations modify the association between depressive symptoms and incident T2DM. We hypothesized that the risk of developing T2DM would be lower for individuals with stronger social relations compared to those with weaker social relations, and that the association between depressive symptoms and incident T2DM would be attenuated for those with stronger social relations.

METHODS: Non-diabetic participants (n=7662) of the "English Longitudinal Study of Ageing" (3398 men) aged 50-91years were followed until 2012/2013, after baseline assessment of depressive symptoms, social support, relational strain, and network size. Hazard ratios (HR) for incident diabetes were calculated using Cox proportional hazard models, adjusting for relevant confounders.

RESULTS: Age and sex adjusted HRs showed that social relations were associated with incident diabetes (Support: HR 0.98 95% CI 0.97; 0.99, Strain: HR 1.02 95% CI 1.01; 1.04, Networklimited: HR 1.19 95% CI 0.98; 1.44), however, when adjusted for age, sex, ethnicity, marital status, household wealth, health behaviour, and body mass index the associations were attenuated and were no longer statistically significant. Depressive symptoms were associated with higher diabetes risk. This effect was not modified by any of the social variables.

CONCLUSIONS: People with stronger social relations are at lower risk of developing T2DM; however, this effect is largely explained by known diabetes risk factors. No evidence was found that stronger social relations reduce the association between depressive symptoms and incident T2DM.