OBJECTIVE: To evaluate and compare the effect of treatment with orlistat vs. metformin on the hormonal and biochemical features of patients with polycystic ovarian syndrome (PCOS)

METHODS: 21 Caucasian women with PCOS (mean (± SEM) age 27 ± 0.9 yr, and body mass index 36.7 ± 3.3) participated in this prospective, randomized, open labeled, study. All subjects had an eight week run in period of dietary modification and then randomized to receive either metformin (500 mg TDS) or orlistat (120 mg TDS) for 3 months. Weight, blood pressure and fasting blood samples were taken at screening, randomization and on completion. Insulin resistance was calculated using the Homeostasis Model Assessment method (HOMA-IR = (Insulin x glucose)/22.5).

RESULTS: The results are expressed as mean ± SEM. When compared with baseline, treatment with both orlistat (93.5 ± 11.5 ng/dl (3.24 ± 0.4 nmol/L) vs. 114.5 ± 11.5 ng/dl (3.97 ± 0.4 nmol/L), P = 0.039) and metformin 97.2 ± 11.5 ng/dl (3.37 ± 0.4 nmol/L) vs. 120.0 ± 8.7 ng/dl (4.16 ± 0.3 nmol/L), P = 0.048) produced a significant reduction in total testosterone. Treatment with orlistat produced a 4.69% reduction in weight (99.0 ± 6.0 vs. 94.6 ± 6.1 Kg, P = 0.002) and this reduction was more significant than the reduction produced by metformin (4.69% vs. 1.02%, P = 0.006). There was no significant reduction seen following either treatment group for fasting insulin, HOMA-IR, SHBG or any of the lipid parameters studied.

CONCLUSIONS: In this study orlistat produced a significant reduction in weight and total testosterone. The reduction in total testosterone was similar to that seen following treatment with metformin. Orlistat may therefore prove to be a useful adjunct in the treatment of PCOS.