Longitudinal changes in depression symptoms and glycemia in adults with type 1 diabetes

OBJECTIVE This study assessed longitudinal change in depression symptoms over ≥4 years in adults with type 1 diabetes and examined the association between change in depression symptom status and glycemia. RESEARCH DESIGN AND METHODS Adults in the T1D Exchange registry with HbA1c and Patient Health Questionnaire (PHQ-8) at 1 year (baseline) and 5 years post-enrollment (follow-up; n = 2,744, mean age, 42 years; 57% female, 92% white; mean HbA1c, 7.6% [58 mmol/mol]) were included. Depression status was defined as Persistent Elevated Depression Symptoms (EDS) (EDS at baseline and follow-up), Resolved EDS (EDS at baseline, no EDS at follow-up), New Onset EDS (no EDS at baseline, EDS at follow-up), and Not Depressed (no EDS at baseline or follow-up). RESULTS Overall, 131 (5%) had Persistent EDS, 122 (4%) had Resolved EDS, 168 (6%) had New Onset EDS, and 2,323 (85%) were Not Depressed. Of those with EDS (PHQ ≥ 10) at baseline, 53% had EDS at follow-up; of those not depressed at baseline, 7% had EDS at follow-up. An increase in PHQ-8 was associated with an increase in HbA1c (P < 0.001). Although HbA1c increased in all groups, the increase was less in the Resolved EDS and Not Depressed groups (P = 0.001). Persistent EDS and New Onset EDS groups were more likely to experience diabetic ketoacidosis (DKA) (P < 0.001). CONCLUSIONS T1D Exchange registry data provide evidence for relationships over time between persistently, and newly developing EDSs and worsening glycemic control, and suggest relationships between depression symptoms and the occurrence of severe hypoglycemia and DKA. Successful treatment of depression symptoms may lead to better long-term diabetes outcomes.