Overweight in mediating the association between depression and new-onset diabetes: A population-based research from Health and Retirement Study.

BACKGROUND: Several studies have suggested a close link between depression, overweight, and new-onset diabetes, particularly among middle-aged and older populations; however, the causal associations remain poorly understood.

AIM: To investigate the role of overweight in mediating the association between depression and new-onset diabetes in middle-aged and older populations.

METHODS: Data of 9426 individuals aged ≥ 50 years from the 1998-2016 Health and Retirement Study database were analyzed. Weighted logistic regression was employed to obtain odds ratios (ORs) and 95% confidence intervals (95%CIs) for depression and new-onset diabetes in the middle-aged and older populations. Mediation analysis and the Sobel test were used to test the mediating effects of overweight between depression and the risk of new-onset diabetes.

RESULTS: New-onset diabetes was identified in 23.6% of the study population. Depression was significantly associated with new-onset diabetes (OR: 1.18, 95%CI: 1.03-1.35, value: 0.014). Further adjustment for overweight attenuated the effect of depression on new-onset diabetes to 1.14 (95%CI: 1.00-1.30, = 0.053), with a significant mediating effect ( of Sobel test = 0.003). The mediation analysis demonstrated that overweight accounted for 61% in depression for the risk of new-onset diabetes, with overweight having a partially mediating role in the depression-to-diabetes pathway.

CONCLUSION: New-onset diabetes was not necessarily a direct complication of depression; rather, depression led to behaviors that increase the risk of overweight and, consequently, new-onset diabetes.