Objective: To investigate if changes in depressive symptoms would be associated with changes in glycemic control over a 12-month period in patients with Type 1 and Type 2 diabetes.
Methods: Ninety (Type 1 diabetes, n = 28; Type 2 diabetes, n = 62) patients having Beck Depression Inventory (BDI) levels of >10 were enrolled in the study. Of those 90 patients, 65 patients completed a 12-week cognitive behavioral therapy intervention. BDI was assessed at baseline and thereafter biweekly during 12 months. Hemoglobin (HbA1c) and fasting blood glucose levels were assessed at baseline and at four quarterly in-hospital follow-up visits. Linear mixed-model analysis was applied to determine the effects of time and diabetes type on depressive symptoms, HbA1c levels, and fasting glucose levels.
Results: Mean and standard deviation baseline BDI and HbA1c levels were 17.9 +/- 5.8 and 7.6 +/- 1.6, respectively, with no significant difference between patients with Type 1 and Type 2 diabetes. Mixed-model regression analysis found no difference between the groups with Type 1 and Type 2 diabetes in the within-subject effect of BDI score on HbA1c or fasting glucose levels during the study. Depressive symptoms decreased significantly (p = .0001) and similarly over a 12-month period in both patients with Type 1 and Type 2 diabetes, whereas HbA1c and fasting glucose levels did not change significantly over time in either group.
Conclusion: Changes in depressive symptoms were not associated with changes in HbA1c or fasting glucose levels over a 1-year period in either patients with Type 1 or Type 2 diabetes.