Common mental disorders associated with 2-year diabetes incidence: the Netherlands Study of Depression and Anxiety (NESDA).

BACKGROUND

Few prospective cohort studies describe the risk of type 2 diabetes mellitus associated with depression or anxiety. The aim of this study was to determine the 2-year diabetes incidence and pattern of explanatory factors associated with depressive and/or anxiety disorders.

METHODS

A prospective cohort of 2981 participants (aged 18-65 years, 66% women) recruited in the Netherlands Study of Depression and Anxiety (NESDA) from community, primary care and outpatient psychiatric clinics were followed-up for two years. Complete data were analyzed from 2460 participants without baseline diabetes. Lifetime or current (past 6-month) depressive and/or anxiety disorders at baseline were assessed using the Composite Interview Diagnostic Instrument (CIDI) and classified by the DSM-IV. Diabetes was classified by either self-report, medications, or fasting plasma glucose ≥ 7.0 mmol/L. Baseline covariates included age, gender, lifestyle factors, and medical conditions. Odds ratios (OR [95% confidence intervals]) for diabetes were determined using exact logistic regression.

RESULTS

The unadjusted 2-year diabetes incidence was 0.2% (1/571), 1.1% (6/548), and 1.8% (24/1340) for no, remitted, and current depressive and/or anxiety disorders, respectively. In comparison to those without psychopathology, current depressive and/or anxiety disorders was associated with diabetes incidence in unadjusted (OR 10.4 [1.7, 429.0]) and age-adjusted (OR 11.9 (1.9, 423.0]) analyses. The strength of this association (beta coefficient) was slightly changed after further adjustments for impaired fasting glucose (11.4%), high triglycerides (-7.8%), and lifestyle cumulative risk score (-5.0%), in contrast to other covariates when assessed in separate models.

LIMITATIONS

The low incidence of diabetes resulted in considerable uncertainty for the odds ratios and low statistical power that limited covariate adjustments.

CONCLUSIONS

The relative odds of developing diabetes within two years was increased for persons with current depressive and/or anxiety disorders, which was partially explained by, but remained independent of, lifestyle cumulative risk factors.