Rising Glucagon-Like Peptide 1 Concentrations After Parathyroidectomy in Patients With Primary Hyperparathyroidism Vasiliki Antonopoulou, MD, MSc, a Spyridon N. Karras, MD, PhD, a Theocharis Koufakis, MD, PhD, a Maria Yavropoulou, MD, PhD, a Niki Katsiki, MD, PhD, a Spyridon Gerou, MD, PhD, b Theodosios Papavramidis, MD, PhD, c and Kalliopi Kotsa, MD, MMedSci, PhD a, * a Division of Endocrinology and Metabolism, First Department of Internal Medicine, AHEPA Hospital, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece b Laboratories “Analysi Iatriki S.A.”, Thessaloniki, Greece c 1st Department of Surgery, AHEPA Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece article info Article history: Received 3 January 2019 Received in revised form 26 May 2019 Accepted 11 July 2019 Available online 7 August 2019 Keywords: Primary hyperparathyroidism Parathyroidectomy Parathyroid hormone Glucose metabolism Insulin resistance Glucagon-like peptide 1 abstract Background: Although primary hyperparathyroidism has been associated with insulin resistance, potential optimal effects of parathyroidectomy (PTX) on glucose homeostasis remain controversial. Accordingly, the impact of PTX on glucose-stimulated incretin (glucagon-like peptide 1 [GLP-1] and gastric inhibitory peptide) secretion has not been evaluated. The aim of this pilot study was to compare glucose-stimulated incretin secre- tion (GSIS) in patients with asymptomatic primary hyperparathyroidism with normal glucose homeostasis, before and after PTX. Methods: Fourteen patients were included in the study. Fasting calcium, parathyroid hor- mone, glucose, insulin, GLP-1, and gastric inhibitory peptide were measured pre- and post- operatively. Homeostasis Model Assessment 2, QUICKI, and Matsuda indexes were used as markers of insulin sensitivity and resistance before and after PTX. Preoperatively, a 75 g oral glucose tolerance test (OGTT) was performed to evaluate the response of glucose, insulin, and GSIS. OGTT measurements were repeated 6  2 wk post-PTX. Results: Patients had a mean age of 52.93  9.96 y, and female-to-male ratio was 12:2. Pre- and post-operatively, a positive correlation between parathyroid hormone and Homeo- stasis Model Assessment 2 for b-cell function was evident (r ¼ 0.74, P ¼ 0.002 and r ¼ 0.55, P ¼ 0.04, respectively). After PTX, a significant increase in GSIS for GLP-1 during OGTT was observed (in 60 min: 63.06  44.78 versus 102.64  40.19 pg/mL, P ¼ 0.02; and in 120 min: 71.20  35.90 versus 102.49  40.02 pg/mL, P ¼ 0.03). Conclusions: The increase of GLP-1 response following oral glucose load after PTX may reflect an initial recovery phase of glucose homeostasis. Long-term studies are required to elucidate the physiological interplay between the normalization of calciotropic axis and the rising GLP-1 concentrations post-PTX. ª 2019 Elsevier Inc. All rights reserved. * Corresponding author. Division of Endocrinology and Metabolism, First Department of Internal Medicine, AHEPA Hospital, Medical School, Aristotle University of Thessaloniki, S. Kiriakidi Str. 1, Thessaloniki 54636, Greece. Tel.: þ302310994706; fax: þ302310994608. E-mail address: kkalli@auth.gr (K. Kotsa). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.JournalofSurgicalResearch.com journal of surgical research  january 2020 (245) 22 e30 0022-4804/$ e see front matter ª 2019 Elsevier Inc. All rights reserved. https://doi.org/10.1016/j.jss.2019.07.019