Exp Clin Endocrinol Diabetes 2018; 126(10): 645-650
DOI: 10.1055/a-0584-0006
Article
© Georg Thieme Verlag KG Stuttgart · New York

The Effect of Metformin on Serum Gonadotropin Levels in Postmenopausal Women with Diabetes and Prediabetes: A Pilot Study

Robert Krysiak
1   Department of Internal Medicine and Clinical Pharmacology, Medical University of Silesia, Medyków 18, 40-752 Katowice, Poland
,
Witold Szkróbka
1   Department of Internal Medicine and Clinical Pharmacology, Medical University of Silesia, Medyków 18, 40-752 Katowice, Poland
,
Bogusław Okopień
1   Department of Internal Medicine and Clinical Pharmacology, Medical University of Silesia, Medyków 18, 40-752 Katowice, Poland
› Author Affiliations
Further Information

Publication History

received 21 December 2017
revised 22 February 2018

accepted 27 February 2018

Publication Date:
12 March 2018 (online)

Abstract

Background Metformin was found to decrease serum levels of prolactin and thyrotropin. The aim of this study was to investigate the effect of this drug on hypothalamic-pituitary-ovarian axis activity in postmenopausal women with recently diagnosed and untreated glucose metabolism abnormalities.

Methods The study included three matched groups of postmenopausal women: patients with type 2 diabetes (group A, n=16), women with prediabetes (group B, n=14), and individuals with normal glucose metabolism (group C, n=14). Women with diabetes were then treated with high-dose metformin (3 g daily), while women with prediabetes received moderate doses of this agent (1.7 g daily). Glucose homeostasis markers, as well as serum levels of FSH, LH, thyrotropin, prolactin, estradiol and creatinine were measured at baseline and after 16 weeks of metformin treatment.

Results In both groups of metformin-treated women, the drug improved glucose homeostasis. High-dose metformin treatment reduced circulating levels of FSH and tended to reduce serum levels of LH, and these effects correlated with an improvement in insulin sensitivity. No changes in gonadotropin levels were observed in prediabetic women receiving moderate doses of metformin. Serum levels of thyrotropin, prolactin and estradiol, as well as the estimated glomerular filtration rate remained at a similar level throughout the study.

Conclusions Our study shows that the effect of metformin on hypothalamic-pituitary-ovarian axis activity in postmenopausal women depends on its dose and the magnitude of insulin resistance.