Examining the Correlation Between Antidepressant Target Dose Optimization and Achievement of Glycemic Control

Stephanie Walek, Pharm.D., Allina Health

Background: Patients with comorbid diabetes and depression are shown to have lower levels of self-care, lower chances of achieving glycemic control, and incur higher medical costs. Consequent to these findings, the American Diabetes Association (ADA) recommends screening and addressing depression for all diabetic patients at least annually. It has been well documented that glycemic control improves when depression is addressed by clinicians in this subset of patients. However, there is little available evidence concerning the achievement of optimal antidepressant dosing and its effect on reducing hemoglobin A1c (HbA1c) in patients with comorbid diabetes and depression.

Objective: To assess the effect of antidepressant target dose optimization on glycemic control in patients with comorbid diabetes and depression.

Study Design: The CommUnityCare Health Centers in Texas conducted an electronic health record-based cohort study of patients with comorbid diabetes and depression who were initiated on first-line antidepressants between January 1, 2015 and September 30, 2015. Patients aged 18-89 years old were included if they had uncontrolled diabetes (defined as HbA1c >7%) within the previous 4 months and kept at least 2 office visits during the study period. Patients were excluded if they had an active prescription for an antipsychotic or lithium. First-line antidepressant therapy included selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and bupropion; which were the most commonly prescribed antidepressants by CommUnityCare primary care providers. Twelve months after therapy initiation, patients were separated into one of two groups: those who met target dose and those who did not. Target doses were defined prior to the study, using the Primary Psychiatry website as a reference. There were 723 patients initiated on a low antidepressant dose during the study period. Only 178 of these patients fit the inclusion criteria;76 patients achieved an optimal dose (target group) and 102 patients did not (control group).

Results: Patients in both the target and control groups had similar baseline HbA1c values (9.29% and 9.24%, respectively). At the end of the study period, only 48 patients in the target group and 23 patients in the control group had all the required follow-up data. Those who met HbA1c goal of <7% in the target and control groups were 22.9% and 4.3% of patients, respectively (P<0.05). The average HbA1c was 8.4% in the target group, compared to 8.96% in the control group, and deemed non-significant by the authors. No relationship between HbA1c and PHQ-9 could be established due to inadequate PHQ-9 reporting.

Conclusions: The results of the study suggest that antidepressant dose optimization in patients with diabetes may lead to an increased likelihood of achieving an HbA1c goal <7%. There was insufficient evidence to draw conclusions regarding reaching HbA1c goal and improvement in depression.

Key Point: When treating patients with comorbid diabetes and depression, it is important to screen for and address depression at least annually. Optimizing antidepressant therapy may aid in the achievement of glycemic control.

Reference:

  1. Grisham-Takac C, Lai P, Srinivasa M, Vasquez L, Rascati KL. Correlation of antidepressant target dose optimization and achievement of glycemic control. Ment Health Clin. 2019;9(1):12-7. DOI: 10.9740/mhc.2019.01.012.