Depressed mood is a factor in glycemic control in type 1 diabetes

Objective: The diabetes literature contains conflicting evidence on the rel ationship between depression and glycemic control. This may be due, in part , to the fact that past studies failed to distinguish between patients with , pe 1 and type 2 diabetes. Because these are actually completely different diseases that are often treated differently tv and consequently make diffe rent demands on patients, the relationship between glycemic control and dep ressed mood in type 1 and type 2 diabetes was examined separately. Methods: The relationship between Beck Depression Inventory (BDI) scores and HbA(1C ), as an index of long-term glycemic control, was measured in samples of 30 patients with type 1 and 34 patients with type 2 diabetes. Results: Groups of patients with type 1 and type 2 diabetes did not differ in mean BDI sco re or HbA(1C) level. Correlation analysis revealed a significant positive r elationship between BDI scores and HbA(1C) in the type 1 group (r =.44, p < .02) but not in the type 2 group (r = -0.06, p > .05). This relationship w as evident throughout the entire range of BDI scores and was not restricted to scores indicative of clinical depression. Patients with type 1 diabetes who had higher HbA(1C) and BDI scores reported a lower frequency of home b lood glucose monitoring. Conclusions: Variations in depressive mood, below the level of clinical depression, are associated with meaningful difference s in glycemic control in type 1 but not type 2 diabetes. Preliminary data a nalysis suggests that this effect may be mediated, at least in part, by dec reased self-care behaviors in patients with more depressed mood.