Impact of Muscarinic M3 Receptor Antagonism on the Risk of Type 2 Diabetes in Antidepressant-Treated Patients: A Case-Controlled Study

Yen-Hao Tran, Catharina C. M. Schuiling-Veninga, Jorieke E. H. Bergman, Henk Groen, Bob Wilffert

M3 muscarinic receptor antagonism has been associated with glucose intolerance and disturbance of insulin secretion. Our objective was to examine the risk of type 2 diabetes mellitus (T2DM) in patients using antidepressants with and without M3 muscarinic receptor antagonism (AD_antaM3 and AD_nonantaM3, respectively). We designed a case-control study using a pharmacy prescription database. We selected a cohort of patients who initiated antidepressant use between the ages of 20 and 40 years and who did not receive any anti-diabetic prescriptions at baseline. Cases were defined as those who developed T2DM [i.e., receiving oral anti-diabetic medication, Anatomical Therapeutic Chemical (ATC) code A10B] during the follow-up period (1994-2014), and ten random controls were picked for each case from the cohort of patients who did not develop T2DM. A total of 530 cases with incident T2DM and 5300 controls were included. Compared with no use of antidepressants during the previous 2 years, recent (within the last 6 months) exposure to AD_antaM3 was associated with a moderately increased risk of T2DM: adjusted odds ratio 1.55 (95% confidence interval 1.18-2.02). In the stratified analyses, this association was dose dependent (>365 defined daily doses) and significant for patients who were in the younger age group (<45 years at the end of follow-up), were female and had no co-morbidity. On the other hand, recent exposure to AD_nonantaM3 was not associated with a risk for T2DM in any of our analyses. Our results suggest that exposure to AD_antaM3 was associated with the development of T2DM among antidepressant users.