ContextCentral obesity in polycystic ovary syndrome (PCOS) is associated with increased inflammatory markers and increased risk for type 2 diabetes.ObjectiveTo evaluate if improved body composition during treatment with metformin (M) vs. oral contraceptive pills (OCP) was associated with changes in circulating adiponectin, interleukin (IL)-6, and monocyte chemoattractant protein (MCP)-1.Patients and interventionsNinety patients with PCOS were randomized to 12-month treatment with M (2 g/day), M + OCP (150 mg desogestrel + 30 microgram ethinylestradiol) or OCP. Adiponectin, IL-6, MCP-1, whole body DXA scans, and clinical evaluations were performed before and after the intervention period in the 65 study completers.Main outcome measuresChanges in inflammatory markers and changes in total and regional fat mass estimates.ResultsAdiponectin, IL-6, and MCP-1 levels were unchanged during the three types of medical intervention. Treatment with M and M + OCP was superior to OCP regarding decreased regional fat mass. Baseline adiponectin and IL-6 were associated with BMI, waist, and trunk fat mass. Changes in trunk fat were significantly associated with changes in IL-6 and MCP-1 during M + OCP.ConclusionsLong-term treatment with M alone or in combination with OCP was associated with improved body composition compared to OCP, whereas inflammatory markers were unchanged. OCP was not associated with increased inflammatory markers despite a small but significant weight gain.