Longitudinal Changes in Depression and Glycemia in Adults with Type 1 Diabetes

To assess change in depression over ≥4 years in adults with type 1 diabetes (T1D) and the association between change in depression and glycemic outcomes, we examined PHQ-8 data in adults in the T1D Exchange Clinic Registry with T1D duration ≥ 1 year (N= 2547; 57% female, 92% non-Hispanic white, year 1 age 43±16 years). PHQ-8 score ≥10 defined “depressed.” Linear regression was used to assess association of continuous outcomes and depression; logistic regression was used for categorical outcomes. At year 1/year 5, 9%/11% were depressed. In this sample, 126 (5%) had Persistent Depression (depressed at year 1 and year 5), 112 (4%) Resolved Depression (depressed at year 1, not at year 5), 148 (6%) New Year 5 Depression (not depressed at year 1, depressed at year 5), and 2161 (85%) Not Depressed at year 1/year 5. Of those depressed at year 1, 53% were depressed at year 5; of those not depressed at year 1, 6% were depressed at year 5. Participants with persistent depression/new year 5 depression had a significant increase (↑) in A1c [adj mean ↑ 0.5± 0.2/0.5± 0.2; adj mean 8.1±0.1 for both; adj P’s=0.001]; those not depressed at year 1/year 5 showed a trend in ↑A1c [0.3±0.1; adj mean 7.8±0.1; adj P=0.04]. Those with resolved depression did not show change in A1c [0.2±0.2; adj mean 7.7±0.2; adj P=0.28]. Those with persistent depression/new year 5 depression were more likely to report new year 5 DKA (DKA year 5 | no DKA year 1) than those not depressed at year 1/year 5 (adj P’s=0.03/0.04). There were trends for those with persistent depression to be more likely to report new year 5 severe hypoglycemia (SH) than those not depressed (11.1% vs. 4.8%); and for those with resolved depression to be less likely to report new year 5 SH (3.6 vs. 4.8%, adj P’s=0.09/0.11). Depression category was not associated with change in BMI (adj P=0.80). As a continuous variable, ↑in PHQ-8 was associated with ↑ in A1c (adj P<0.001), but not with new year 5 SH or BMI change (adj P>0.50). Depression (persistent or new year 5) has a negative impact on glycemic control over time. Adults with T1D should be screened and treated for depression.