Endocrine Abstracts

Background: Liraglutide is a long-acting GLP-1 receptor (GLP-1R) agonist. GLP-1R is highly expressed in C-cells hyperplasia and in medullary thyroid cancer. We aimed to evaluate calcitonin levels stimulated by calcium test and possible development of C-cell hyperplasia during Liraglutide therapy in a case with obesity.

Case Report: A 50-year-old woman was referred to endocrinology policlinic with complaints of increased appetite and weight gain. There were no history and familial history about thyroidal diseases. In phsical examination, his wieght 92,7 kg, weight 171 cm, body mass index 31,7 kg/m2, waist circumferences 112 cm, blood pressures 114/92 mmHg and pulse rate 76 per minute were detected. The findings of the other systems were unremarkable. For the treatment of obesity, medical nutrition therapy, behavior change therapy and increased physical activity were started. Liraglutide was started when appetite control and weight loss were not sufficient. In third months, basal calcitonin level was 13.6 pg/ml (normal range, < 5 pg/ml), peak calcitonin value was 69.5 pg/ml during calcium stimulation test Thyroid function tests were in normal range, and sonographical evaluation of thyroid gland was shown normal. Liraglutid therapy were stopped because of possible C-cell hyperplasia. The patient was followed up with medical nutrition therapy, behavioral therapy and increased physical activity.

Discussion: Liraglutide leads to variations in both basal calcitonin and stimulated calcitonin. According to our case, the findings suggest the possible induction of the C cells and thus C-cell hyperplasia.

Keywords: Calcitonin, GLP-1R, Liraglutide, obesity