Endocrine Abstracts

Introduction

Exenatide may provide weight loss in type 2 diabetes mellitus (T2D) via agonistic effect on GLP1 receptor. There is no study showing associations between free T4(fT4) and exenatide-related weight loss in T2D. We aimed to reveal the association between fT4 and exenatide-related weight loss, and change in thyroid functions with exenatide in euthyroid adult patients with T2D and obesity.

Materials and Methods

We included euthyroid adult patients with T2D and obesity under metformin, SGLT2 inhibitor and/or insulin treatment, whom exenatide was indicated. We excluded those < 18-year-old, with contraindication to exenatide, or history of thyroid dysfunction, or under levothyroxine or antithyroid medications. We analyzed baseline demographic features, chronic illnesses (hypertension, hyperlipidemia), AntiTPO and lipid parameters. We evaluated change (level at 6th month of exenatide – baseline level) in body weight, body mass index (BMI), TSH, fT4, fasting blood glucose (FBG), HbA1c. We grouped them as weight gain vs weight loss (absent vs < 10% vs ≥ 10% weight loss).

Results

TSH change and fT4 change were –0.077(1.10) and –0.0123(0.20) in total (n = 106), respectively (P = 0.229 and P = 0.908, respectively). TSH was increased in weight loss group, but decreased in weight gain group (P = 0.018). fT4 at baseline and at 6th month of treatment were higher in weight loss group than weight gain group (P = 0.010 and P = 0.004, respectively). The ratio of patients having fT4 in upper-range was higher in weight loss group (P = 0.042). Decrease in BMI was positively correlated with fT4 level at 6th month of exenatide (r = 0.234 and P = 0.016) but not with baseline fT4.

Conclusion

Higher fT4, even in normal range, was associated with higher weight loss in the patients with T2D after initiation of exenatide. Thyroid function seems not to be affected by exenatide. Baseline fT4 may be considered when selecting exenatide in T2D especially if weight loss is targeted.