(29) The Impact of Antidepressant Treatment on Insulin Commencement in Type 2 Diabetes: A UK Electronic Health Record Nested Case-Control Study

Sunday, August 28, 2022

8:00 AM – 1:45 PM CEST

Location: Hall C

Publication Number: 1074

Presenting Author(s)

Annie Jeffery
– UCL School of Pharmacy

Co-Author(s)

Kate Walters
– Research Department of Primary Care and Population Health, University College London, United Kingdom
David Osborn
– Epidemiology and Applied Clinical Research Department, Division of Psychiatry, University College London (UCL), United Kingdom
Ian Wong
– Professor, Centre for Safe Medication Practice and Research, Department of Pharmacology and Pharmacy, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China, Hong Kong
Joseph F F. Hayes
– Principal Research Fellow, Division of Psychiatry, University College London, London, UK, United Kingdom

Background: Antidepressant treatment has been shown to have a small effect in the short-term on controlling HbA1C. However, there is no long-term evidence.

Objectives: We aimed to investigate the association between antidepressant prescription and commencing insulin therapy, as a marker of long-term diabetic decline, in adults with comorbid depression and T2DM, specifically:
i) The prescription of any antidepressant prescription
ii) The difference between recent (previous 6 months) and past antidepressant prescription
iii) The cumulative duration of antidepressant treatment
iv) The difference between different antidepressant agents

Methods: We performed a nested case-control study using UK primary care data from the Clinical Practice Research Datalink (CPRD) in the years 2000-2018. Our cohort consisted of individuals with comorbid depression and T2DM. Participants entered the study at the date of their first oral antidiabetic prescription, and were excluded if they had a prescription for insulin less than 6 months after the date of the first oral antidiabetic. We identified 11,862 cases as participants who received a prescription for insulin during the their electronic health record (EHR) follow-up. We matched these to 43,452 controls who had not yet received any prescription for insulin, based on age, gender, GP practice and length of follow-up. We used conditional logistic regression to describe the association between antidepressant prescribing during follow-up and starting insulin. We adjusted for demographic and health characteristics, and previous medication use.

Results: Cases who commenced insulin were similar to controls who had not yet commenced insulin, with regards to demographic characteristics and previous medication use. Cases had higher prevalence at study entry of all comorbidities. After adjusting for all covariates: Any antidepressant use was associated with almost 4x higher rate of starting insulin therapy (rate ratio 3.78, 3.53-4.04). There was no evidence of a difference between recent and past antidepressant use. Higher cumulative durations of antidepressant use (24+ months - RR 5.61, 5.23-6.03) were associated with further increased rate of insulin commencement, compared to shorter durations ( < 6 months - RR 3.94, 3.64-4.27). SSRIs were associated with the highest rate of commencing insulin (RR 3.14, 2.98-3.31) and mirtazapine with the lowest increased rate (RR 1.87, 1.74-2.01).

Conclusions: Antidepressant prescribing is associated with a large increase in the rate of commencing insulin having started oral antidiabetic treatment in people with comorbid depression and T2DM. The effect may be due in part to antidepressant users being individuals with more severe depression, as we were unable to sufficiently control for this.