Metformin administration is more effective when non-obese patients with polycystic ovary syndrome show both hyperandrogenism and hyperinsulinemia.
BACKGROUND
Polycystic ovary syndrome (PCOS) is a common endocrine disease that is frequently observed to be related to increased insulin resistance independent of body weight. The use of insulin-sensitizer compounds, such as metformin, permits great improvement of such metabolic abnormality, restoring ovarian function and gonadal steroid synthesis and reducing insulin resistance.


OBJECTIVE
On this basis we aimed to evaluate a group of non-obese amenorrheic PCOS patients before and after 6 months of metformin administration (500 mg orally twice daily) to better understand upon which basis of clinical and endocrine parameters metformin administration might be chosen as a putative therapeutic tool.


METHODS
A group of non-obese PCOS patients (n = 42) was enrolled after informed consent. They underwent an oral glucose tolerance test for insulin, glucose and C-peptide levels and provided blood samples for determination of plasma levels of luteinizing hormone (LH), follicle-stimulating hormone, prolactin, estradiol, androstenedione, 17-hydroxyprogesterone, insulin, cortisol and testosterone levels on two occasions: before and on day 7 of the first menstrual cycle occurring after the 5th month of treatment.


RESULTS
Plasma LH, estradiol, insulin and C-peptide were decreased significantly by metformin treatment in the entire group of PCOS patients. When subdividing PCOS patients according to insulin sensitivity (i.e. hyper- and normoinsulinemic subjects), a greater rate of positive endocrine changes was observed in hyperinsulinemic patients and the highest rate was observed in hyperinsulinemic hyperandrogenic subjects. Menstrual cyclicity was recovered in all patients under treatment.


CONCLUSIONS
Our data show that metformin modulates ovarian function and greatly affects LH secretion through reduction of the hyperandrogenic condition. The highest rate of endocrine changes was observed in the hyperinsulinemic hyperandrogenic non-obese PCOS patients. Our study demonstrates that metformin administration is more appropriate in hyperinsulinemic hyperandrogenic non-obese PCOS patients.
Genazzani
Alessandro D
AD
Department of Obstetrics and Gynecology, University of Modena and Reggio Emilia, Modena, Italy. algen@unimo.it
Lanzoni
Chiara
C
Ricchieri
Federica
F
Baraldi
Enrica
E
Casarosa
Elena
E
Jasonni
Valerio M
VM
D000293:Adolescent; D000328:Adult; D000568:Amenorrhea / Q000188:drug therapy; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D017588:Hyperandrogenism / Q000188:drug therapy*; D006946:Hyperinsulinism / Q000188:drug therapy*; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D008687:Metformin / Q000627:therapeutic use*; D009839:Oligomenorrhea / Q000188:drug therapy; D010636:Phenols; D011085:Polycystic Ovary Syndrome / Q000188:drug therapy*; D011743:Pyrimidines; D012720:Severity of Illness Index; D016896:Treatment Outcome
C480542:BMI 1026; D007004:Hypoglycemic Agents; D010636:Phenols; D011743:Pyrimidines; D008687:Metformin