ABSTRACT
OBJECTIVE: Glucagon-like peptide-1 (GLP-1) analogues are now widely used for the treatment of type 2 diabetes mellitus (DM). Many binding sites for GLP-1 have been demonstrated in the specific tissue compartments of organs in-cluding the brain and thyroid. The aim of this study was to investigate the effect of exenatide treatment on thyroid-stimulating hormone (TSH) and thyroid volume in diabetic patients without thyroid disease. MATERIAL AND METHODS: The study included 46 diabetic patients without thyroid disease who were receiving exenatide treatment. Comparisons were made of total thyroid volume and serum concentrations of TSH at baseline and after 6 months of follow-up. RESULTS: Of the 46 patients, 13 were excluded from the study, as they were unable to complete the treatment or left the follow-up process. After 6 months of exenatide treatment, the serum TSH concentration decreased significantly (from 2.3 [0.7-5.4] to 1.8 mIU/L [0.3-4.2], p= 0.007). There were no significant differences in thyroid volume (11.6 ± 9.0 vs. 12.1 ± 8.8 cm3, p = 0.19), free thyroxine (fT4), free tri-iodothyronine (fT3), and calcitonin levels before and after treatment. Thyroid volume was not affected by decreased TSH level (p:= 0.141) or a reduction in body mass index (BMI) (p > 0.05), and no correlation was detected between variation in TSH level and change in BMI (p > 0.05). CONCLUSIONS: Exenatide treatment for 6 months significantly decreased serum TSH concentration but did not affect thyroid volume in diabetic patients without thyroid disease.
ABSTRACT
OBJECTIVE: The aim of this study was to evaluate the effect of hyperprolactinemia on body fat, insulin sensitivity, inflammatory markers, and cardiovascular risk in patients with prolactinoma. METHODS: The study included 35 untreated hyperprolactinemic patients with pituitary adenomas, and 36 age-, gender-, and body mass index (BMI)-matched healthy controls without any known disease. Serum glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR, lipid profile, high-sensitivity C-reactive protein (hs-CRP), and heart-type fatty acid binding protein (H-FABP) levels were measured. Waist and hip circumference (WC and HC) were measured in all the participants. The body fat percentage was measured, and the visceral fat and abdominal fat percentages were measured via bioelectrical impedance (BIA). In addition, carotid intima media thickness (CIMT) was measured using high-resolution B-mode ultrasound. RESULTS: The serum glucose level, HOMA-IR, triglyceride level, and SC were significantly higher in the patient group than in the control group. The hs-CRP level and CIMT were significantly higher in the hyperprolactinemic patients. Visceral and truncal fat percentages were significantly higher in the patients with prolactinoma. H-FABP levels were similar in the 2 groups, and there was a positive correlation between the prolactin (PRL) and H-FABP protein levels. CONCLUSIONS: Based on the present findings, hyperprolactinemia is associated with preclinical atherosclerosis and metabolic abnormalities. Patients with hyperprolactinemia might experience cardiovascular disease in the long term. Metabolic control should be achieved in addition to the control of hyperprolactinemia in the clinical management of patients diagnosed with prolactinoma.
