Cognitive behavioural therapy (CBT) compared with blood glucose awareness training (BGAT) in poorly controlled Type 1 diabetic patients: long-term effects on HbA1c moderated by depression. A randomized controlled trial

Objective To test the effectiveness at 6 and 12 months' follow-up of group cognitive behavioural therapy (CBT) compared with blood glucose awareness training (BGAT) in poorly controlled Type 1 diabetic patients and to explore the moderating effect of baseline depression. Research design and methods Adults with Type 1 diabetes (n=86) with glycated haemoglobin (HbA(1c))>= 8% were randomized to CBT or BGAT. Primary outcome was HbA(1c) control. Secondary outcomes were: self-care, diabetes-related distress (Problem Areas in Diabetes scale; PAID), diabetes self-efficacy (Confidence in Diabetes Self-care scale; CIDS) and depressive symptoms (Centre for Epidemiological Studies-Depression scale; CES-D). Measurements were scheduled before CBT and BGAT, and at 3, 6 and 12 months after. Differential effects were analysed for the subgroup of patients reporting low vs. high baseline levels of depression. Results Neither CBT nor BGAT had a significant impact on HbA1c at 6 and 12 months' follow-up. Both interventions resulted in lower depressive symptoms (CES-D 15.7-13.3, P = 0.01) up to 12 months, but only CBT was effective in lowering HbA1c in patients with high baseline depression scores (HbA(1c) 9.5-8.8%) up to 1 year of follow-up ( P = 0.03). Conclusions Our findings suggest that group CBT can effectively help Type 1 diabetic patients with co-morbid depression achieve and maintain better glycaemic outcomes.