Prevention of insulin resistance in adolescents at risk for type 2 diabetes with depressive symptoms: 1-year follow-up of a randomized trial

Abstract

Background: Depression is associated with poor insulin sensitivity. We evaluated the long-term effects of a cognitive behavioral therapy (CBT) program for prevention of depression on insulin sensitivity in adolescents at risk for type 2 diabetes (T2D) with depressive symptoms.

Methods: One-hundred nineteen adolescent females with overweight/obesity, T2D family history, and mild-to-moderate depressive symptoms were randomized to a 6-week CBT group (n = 61) or 6-week health education (HE) control group (n = 58). At baseline, posttreatment, and 1 year, depressive symptoms were assessed, and whole body insulin sensitivity (WBISI) was estimated from oral glucose tolerance tests. Dual energy X-ray absorptiometry assessed fat mass at baseline and 1 year. Primary outcomes were 1-year changes in depression and insulin sensitivity, adjusting for adiposity and other relevant covariates. Secondary outcomes were fasting and 2-hr insulin and glucose. We also evaluated the moderating effect of baseline depressive symptom severity.

Results: Depressive symptoms decreased in both groups (P < .001). Insulin sensitivity was stable in CBT and HE (ΔWBISI: .1 vs. .3) and did not differ between groups (P = .63). However, among girls with greater (moderate) baseline depressive symptoms (N = 78), those in CBT developed lower 2-hr insulin than those in HE (Δ-16 vs. 16 μIU/mL, P < .05). Additional metabolic benefits of CBT were seen for this subgroup in post hoc analyses of posttreatment to 1-year change.

Conclusions: Adolescent females at risk for T2D decreased depressive symptoms and stabilized insulin sensitivity 1 year following brief CBT or HE. Further studies are required to determine if adolescents with moderate depression show metabolic benefits after CBT.

Keywords: T2D mellitus; child/adolescent; clinical trials; depression; insulin resistance.

Figure 1

Study flow from initial assessment to one-year follow-up; six-week follow-up, immediate post-treatment results have been published elsewhere (11).

Figure 2

Time course over the study of adolescent depressive symptoms, as assessed on the Center for Epidemiologic Studies-Depression Scale (CES-D), and of whole body insulin sensitivity (WBISI), with greater values reflecting better insulin sensitivity and lower values reflecting poorer insulin sensitivity. Panels A and C characterize the total sample; panels B and D describe the subset with baseline moderate depressive symptoms (CES-D >20) only. Values displayed are derived from multiply imputed data and are adjusted for covariates.