Impact of metformin monotherapy versus metformin with oestrogen-progesterone on lipids in adolescent girls with polycystic ovarian syndrome

Objective Hyperinsulinaemia is an important determinant of the polycystic ovarian syndrome (PCOS). In addition to lifestyle measures, therapeutic strategies include the use of oestrogen-progesterone combination pills (EP), and insulin sensitizers such as metformin, either alone or in combination. Data are limited regarding the impact of metformin alone vs metformin with EP on cardiometabolic risk in overweight adolescents with PCOS. We hypothesized that metformin alone would lead to an improvement in HbA1C and lipid levels in overweight adolescent girls with PCOS compared with meformin with EP. Study design Retrospective clinic-based therapy. Patients and measurements We examined the effects of therapy with metformin alone (n = 14) vs metformin with EP (n = 13) on HbA1C and lipid parameters over 10-14 months in 27 overweight girls, drawn from a clinic population of adolescents with PCOS. Results The groups did not differ for age, body mass index (BMI), HbA1C or baseline lipids. After at least 10 months, the metformin only group compared with the metformin and EP group had a decrease in total cholesterol (-0.605 +/- 0.100 vs 0.170 +/- 0.348 mM, P = 0.02, nonparametric test) and triglycerides (-0.342 +/- 0.184 vs 0.262 +/- 0.133 mM, P = 0.02), despite similar changes in BMI (-1.6 +/- 0.7 vs 0.6 +/- 2.1 kg/m(2), P = 0.25) and HbA1C (0.03 +/- 0.06 vs 0.03 +/- 0.13%, P = 0.99). Differences between groups remained significant after controlling for baseline parameters and for changes in BMI. Conclusion Metformin alone more effectively improves lipid parameters than metformin with EP in adolescent PCOS, as indicated by a decrease in total cholesterol and triglycerides. This effect is not related to BMI changes.