Introduction: Polycystic ovary syndrome (PCOS) has shown to be associated with increased levels of pro-inflammatory cytokines. This study was undertaken to determine the changes of pro-inflammatory cytokines in patients with PCOS after rimonabant and/or metformin treatment.
Methods: A 3 month randomised open labelled parallel study of rimonabant or metformin in 20 patients with PCOS with a body mass index >30 kg/m2 was undertaken. Subsequently, patients who were on 3 months of rimonabant were changed over to metformin for 3 months, whereas those on 3 months of metformin were continued on metformin for another 3 months.
Results: After 3 months of rimonabant there was a significant reduction reduction in weight (104.6+4.6 vs 98.4+4.7 kg, P< 0.01) whilst there was no change in the metformin group. This weight loss with rimonabant was maintained after 3 months extension period with metformin. There were no significant changes in CRP in both groups. There was no significant change (mean+SD) in the levels of IL-1, IL-6 and TNFα after rimonabant treatment. IFN-α (86.22+27.14 vs 92.77+34.24 pg/ml, P=0.037) and IL-8 (7.3+11 vs 18.0+13.2 pg/ml, P=0.03) reduced significantly after 3 months of rimonabant treatment. There were no changes in any of these cytokines after 3 months extension phase with metformin. There was no correlation between weight loss and CRP with changes in cytokines. Insulin resistance measured by HOMA did not differ between rimonabant and metformin therapy. In the metformin group IL-7 (252.4+ 31.4 vs 230.9 + 35.9 pg/ml, P<0.05) and IL-13 (29.6+8.92 vs 27.6+10.6 pg/ml, P<0.05) decreased significantly after 6 months of metformin treatment.
Conclusion: It is unclear whether the weight reduction or a direct effect of rimonabant increased pro-inflammatory cytokines in these obese PCOS subjects. Conversely, whilst metformin was weight neutral and insulin resistance reduction equal to rimonabant, pro-inflammatory cytokines decreased.
Declaration of interest: There is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.
Funding: No specific grant from any funding agency in the public, commercial or not-for-profit sector.