The impact of major depressive disorder on glycaemic control in type 2 diabetes: a longitudinal cohort study using UK Biobank primary care records

• Published in: BMC medicine Vol. 22; no. 1; p. 211
• Main Authors: Gillett, Alexandra C, Hagenaars, Saskia P, Handley, Dale, Casanova, Francesco, Young, Katherine G, Green, Harry, Lewis, Cathryn M, Tyrrell, Jess
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 29.05.2024; BioMed Central; BMC
• Subjects: Adult; Aged; Analysis; Biobanks; Biological Specimen Banks; Biomarkers; Blood pressure; Body mass index; Care and treatment; Cohort Studies; Complications and side effects; Depressive Disorder, Major - blood; Depressive Disorder, Major - epidemiology; Diabetes; Diabetes mellitus (non-insulin dependent); Diabetes Mellitus, Type 2 - blood; Diabetes therapy; Diagnosis; Epidemiology; Ethnicity; Female; Glycated Hemoglobin - analysis; Glycemic Control; Glycosylated hemoglobin; HbA1c; Health aspects; Humans; Longitudinal; Longitudinal Studies; Major depressive disorder; Male; Measurement; Medical records; Mental depression; Middle Aged; Primary care; Primary Health Care; Risk factors; Self report; Type 2 diabetes; UK Biobank; United Kingdom - epidemiology; United Kingdom; United Kingdom > UK; Type 2 diabetes; Longitudinal; Epidemiology; HbA1c; Major depressive disorder
• ISSN: 1741-7015; 1741-7015
• DOI: 10.1186/s12916-024-03425-9

This study evaluates longitudinal associations between glycaemic control, measured by mean and within-patient variability of glycated haemaglobin (HbA1c) levels, and major depressive disorder (MDD) in individuals with type 2 diabetes (T2D), focusing on the timings of these diagnoses. In UK Biobank, T2D was defined using self-report and linked health outcome data, then validated using polygenic scores. Repeated HbA1c measurements (mmol/mol) over the 10 years following T2D diagnosis were outcomes in mixed effects models, with disease duration included using restricted cubic splines. Four MDD exposures were considered: MDD diagnosis prior to T2D diagnosis (pre-T2D MDD), time between pre-T2D MDD diagnosis and T2D, new MDD diagnosis during follow-up (post-T2D MDD) and time since post-T2D MDD diagnosis. Models with and without covariate adjustment were considered. T2D diagnostic criteria were robustly associated with T2D polygenic scores. In 11,837 T2D cases (6.9 years median follow-up), pre-T2D MDD was associated with a 0.92 increase in HbA1c (95% CI: [0.00, 1.84]), but earlier pre-T2D MDD diagnosis correlated with lower HbA1c. These pre-T2D MDD effects became non-significant after covariate adjustment. Post-T2D MDD individuals demonstrated increasing HbA1c with years since MDD diagnosis ( , 95% CI: [0.17, 0.86]). Retrospectively, across study follow-up, within-patient variability in HbA1c was 1.16 (95% CI: 1.13-1.19) times higher in post-T2D MDD individuals. The timing of MDD diagnosis is important for understanding glycaemic control in T2D. Poorer control was observed in MDD diagnosed post-T2D, highlighting the importance of depression screening in T2D, and closer monitoring for individuals who develop MDD after T2D.