Comorbid Depressive and Anxiety Symptoms and the Risk of Type 2 Diabetes: Findings from the Lifelines Cohort Study.

Background:
Prior studies indicate that depression is a risk factor for type 2 diabetes (T2D), though there is considerable heterogeneity in reported estimates. Identifying homogeneous subgroups of depression strongly associated with T2D may be beneficial. This study examined associations between depression and anxiety comorbidity with the risk of T2D.

Methods:
78,025 participants from the Lifelines Cohort Study (age range=30–75 years) without diabetes at baseline were included in this study. The Mini-International Neuropsychiatric Interview assessed depressive and anxiety symptoms at baseline. Incident T2D was assessed by self-report or hemoglobin A1c levels during an approximately 3.8-year follow-up period. Risk of T2D was compared across four groups (no depressive or anxiety symptoms, depressive symptoms alone, anxiety symptoms alone, comorbid depressive/anxiety symptoms) using mixed effects logistic regression analyses adjusted for sociodemographic, lifestyle, and cardiometabolic characteristics.

Results:
1,096 participants developed diabetes. Compared to those without depressive or anxiety symptoms (n=74,467), those with comorbid depressive and anxiety symptoms (n=743) were more likely to develop T2D (n=28, OR=2.12, 95% CI=1.22–3.68). Depressive symptoms alone (n=650) and anxiety symptoms alone (n=2,165) were not significantly associated with T2D (n=23 and n=24, respectively, developed diabetes). Those with comorbid symptoms were also more likely to develop T2D compared to those with depressive symptoms alone (OR=2.86, 95% CI=1.25–6.54).

Limitations:
Depressive and anxiety symptom assessments were based on a screening tool. Hemoglobin A1c data were only available for a subset of participants.

Conclusions:
Depression with comorbid anxiety may be a subgroup of depression that is strongly associated with the risk of T2D.