2007 HSR&D National Meeting Abstract
1021 — Longitudinal Effects of Depression on Glycemic Control in Veterans with Type 2 Diabetes
Egede LE (Charleston TREP) , Mueller M
(Charleston TREP), Mauldin P
(Charleston TREP), Durkalski V
(Charleston TREP), Chen J
(Charleston TREP), Moran W
To examine the longitudinal effects of depression on glycemic control in veterans with type 2 diabetes.
Data on a cohort of 11,531 veterans with type 2 diabetes were analyzed. The cohort included subjects with type 2 diabetes from January 8, 1996 to March 2, 2006 using established algorithms for identifying type 2 diabetes in VA administrative data. For each subject, the first outpatient visit with a hemoglobin A1C (HBA1C) value was used as the baseline visit, and then subjects were followed forward in time until the last available HBA1C. Subjects were classified as depressed based on ICD-9 codes for depression at the baseline visit using validated algorithms. A mixed linear regression model was used to examine the change in HBA1C over time in the depressed and non-depressed groups. HBA1C was entered as the dependent variable and depression was entered as the primary independent variable. The model was adjusted for baseline HBA1C, baseline age, and time from baseline HBA1C, to account for unequal time intervals between consecutive A1C values. SAS was used for statistical analysis.
4.4% of the sample had diagnosed depression. Mean age was 64 years. 97% were men. 49% were non-Hispanic whites, 27% were non-Hispanic Blacks, 0.4% were Hispanic, 0.4% were non-Hispanic “Other”, and 23% had missing race/ethnicity information. 66% were married and 48% were unemployed. Mean follow-up period was 3.2 years. Mean HBA1C at baseline were not significantly different (depressed: 7.41 [sd 2.14]; non-depressed: 7.32 [sd 1.91], p=0.369). Over the follow-up period, HBA1C among depressed veterans increased over time, while those for non-depressed veterans declined in year 1 and then increased in subsequent years. After adjusting for covariates, HBA1C in depressed veterans were significantly higher than those in non-depressed veterans with a mean difference in HBA1C over time of 0.17 (95% CI: [0.07; 2.13], p<0.0001).
Depression worsens glycemic control over time and the effect of depression on glycemic control persists over time in veterans with type 2 diabetes.
Comorbid depression is deleterious to the health of veterans with diabetes. Studies are needed to better understand how depression influences glycemic control and determine interventions that improve glycemic control in this sub-group of veterans.