Williams LH (COE, Seattle, WA), Miller DR
(COE, Bedford, MA), Raugi GJ
(COE, Seattle, WA), Etzioni R
(Fred Hutchinson Cancer Research Center, Seattle, WA), Maynard C
(COE, Seattle, WA), Fincke G
(COE, Bedford, MA), Lafrance JP
(COE, Bedford, MA), Reiber GE
(COE, Seattle, WA)
In patients with diabetes, depression appears to accelerate the development of macrovascular and microvascular complications, but the risk of foot complications is not well characterized. We studied the association of diagnosed depression with incident non-traumatic lower limb amputations in veterans with diabetes.
We conducted a retrospective cohort study in 531,973 VA patients with diabetes using the Diabetes Epidemiology Cohorts, a national VA diabetes registry. Based on previously developed methods, depression was identified using diagnosis codes and antidepressant prescriptions, and incident lower limb amputations were identified using diagnosis and procedure codes. Diabetes patients with and without diagnosed depression in 2000 were followed through 2004 for incident non-traumatic lower limb amputations. Risk of amputation, overall and for major (transtibial and above) and minor (ankle and below) subtypes, was estimated using Cox regression, with adjustment for demographics, health care utilization, diabetes severity, and medical and mental health conditions.
Mean follow-up was 4.1 years. During this period, 3,830 patients had an incident lower limb amputation, including 1,289 major amputations. Diagnosed depression was associated with an adjusted hazard ratio (95% confidence interval) of 1.12 (1.02, 1.22) for any lower limb amputation, 1.33 (1.15, 1.55) for major amputations, and 1.01 (0.90, 1.13) for minor amputations. The results did not change when depression was identified by diagnosis codes alone or antidepressant prescriptions alone. Among patients with diagnosed depression, there was no difference in amputation risk associated with receiving antidepressants in 2000.
Diagnosed depression was associated with an increased risk of incident major amputations in patients with diabetes.
These results support aggressive depression screening and treatment in patients with diabetes. Successful treatment of depression could reduce major amputation rates.