Depression and Anxiety Screens as Simultaneous Predictors of 10-Year Incidence of Diabetes Mellitus in Older Adults in Primary Care.

OBJECTIVES: To examine depression and anxiety screens and their individual items as simultaneous predictors of incident diabetes mellitus.

DESIGN: Ten-year follow-up study of individuals screened for the Improving Mood-Promoting Access to Collaborative Treatment (IMPACT) trial.

SETTING: Two large urban primary care clinics in Indianapolis, Indiana.

PARTICIPANTS: Diverse sample (53% African American, 80% of lower socioeconomic status) of 2,156 older adults initially free of diabetes mellitus.

MEASUREMENTS: Depression and anxiety screens were completed during routine primary care visits between 1999 and 2001. Incident diabetes mellitus data were obtained from an electronic medical record system and the Centers for Medicare and Medicaid Services analytical files though 2009.

RESULTS: Over the 10-year period, 558 (25.9%) participants had diabetes mellitus onset. Cox proportional hazards models adjusted for demographic and diabetes mellitus risk factors revealed that a positive screen for anxiety, but not for depression, predicted incident diabetes mellitus when entered into separate models (anxiety: hazard ratio (HR) = 1.36, 95% confidence interval (CI) = 1.15-1.61, P < .001; depression: HR = 1.18, 95% CI = 0.95-1.46, P = .13) and when entered simultaneously into one model (anxiety: HR = 1.35, 95% CI = 1.12-1.61, P < .001; depression: HR = 1.04, 95% CI = 0.83-1.31, P = .73). The feeling anxious (P = .03) and the worry (P = .02) items predicted incident diabetes mellitus independent of the depression screen.

CONCLUSION: These findings suggest that screening positive for anxiety is a risk factor for diabetes mellitus in older adults independent of depression and traditional diabetes mellitus risk factors. Anxiety requires greater consideration and awareness in the context of diabetes mellitus risk assessment and primary prevention.