MONTREAL, May 13 — Major depression doubles the risk of incident diabetic foot ulcers, according to the results of a large, prospective, population-based cohort study.

The findings strongly suggest screening for and treating depression to prevent this complication, said Lisa Williams, M.D., from the University of Washington, Seattle.

“Depression is twice as common in patients with diabetes,” she said at the annual meeting of the Society for Investigative Dermatology.

“At any time, 11% to 12% of patients with diabetes have major depression, and 31% have significant depressive symptoms, which include major and minor depression.”

Until now, it has not been known whether depression increases the incidence of diabetic foot ulcers, Dr. Williams said.

However, she said that “depression is associated with more severe and larger diabetic foot ulcers, and poor healing and recurrence. Depression is also associated with a threefold increase in mortality rate among patients with their first foot ulcer.”

Her analysis included data from 3,474 patients enrolled in the Pathways Epidemiologic Study — a prospective cohort of primary care diabetes patients from nine clinics in western Washington state.

Major and minor depression was assessed, using the Patient Health Questionnaire-9 (PHQ-9), and there was a mean follow-up of approximately four years.

New-onset foot ulcers were assessed during the course of the study, using ICD-9 codes, which were confirmed by chart review.

There were 401 diagnoses of major depression in the cohort, 290 diagnoses of minor depression, and 121 incident foot ulcers, said Dr. Williams.

Compared to patients with no depression, the study found a significant increase in the risk of foot ulcers among patients with major, but not minor depression (HR 2.0 and 1.3 respectively).

There was no difference between depressed and nondepressed patients in foot self-care, which was assessed using a validated diabetes questionnaire.

However, previous research has shown that depression in patients with diabetes is associated with poor self-care, low physical activity, unhealthy diet, nonadherence to medication regimens, nonadherence and missed doctor’s appointments — as well as hyperglycemia, smoking, and obesity, she said.

“In our study, we found that compared to nondepressed patients, depressed patients were older, unmarried, had higher BMIs, were more likely to smoke, and had more diabetes complications.”

The study was funded by the National Institutes of Mental Health. Dr. Williams reported no relevant financial conflicts.

Primary source: Society for Investigative Dermatology
Source reference:
Williams LH et al “Depression and incident diabetic foot ulcers: a prospective cohort study”SID 2009; Abstract 365.