Background and objective: Polycystic ovary syndrome (PCOS), with an incidence of 5% in women of reproductive age, is defined as the presence of oligo- or amenorrhea in combination with hyperandrogenism. Most patients also suffer from impaired insulin action (insulin resistance). PCOS thus resembles the metabolic syndrome (type 2 diabetes mellitus, hypertension, lipid disorders, atherosclerosis). International studies showed a beneficial effect of metformin treatment on biochemical and reproductive parameters in PCOS. The aim of our study is the evaluation of metformin treatment in a German PCOS sample.
Patients and methods: 103 PCOS women (age 18-40) were treated, according to their body weight, with either 1000 mg or 1700 mg metformin per day after assessment of insulin resistance. Clinical features as well as endocrine and metabolic parameters were recorded at baseline and at 1, 6, and 12 months of treatment. Additionally, baseline data were compared with those of 98 control subjects (age 18-38).
Results: PCOS women showed significantly higher body mass index, body fat mass and androgen levels, as well as an impaired glucose- and insulin metabolism compared to controls. Metformin treatment ameliorated acne (36% to 4%), hirsutism-score (11.2 to 9.7) and restarted normal menstrual cycles in 66.7% of PCOS-women. Sixteen of 48 patients with unfulfilled wish to conceive became pregnant during therapy. Metformin restored menses in all previously amenorrheic women. Comparing post-metformin versus baseline levels, HOMA-IR (4.6 to 2.3), AUC-I (379 to 225) and 2-h glucose (117 to 90 mg/dl) decreased significantly. Furthermore, metformin decreased testosterone (2.9 to 1.8 nmol/l), free androgen index (9.1 to 5.3) and dehydroepiandrosterone levels (5.1 to 3.9 mg/l).
Conclusion: Metformin improves significantly hyperandrogenism and insulin resistance in PCOS patients and appears to be an efficacious mode of therapy.