The Impact of Diet-Induced Weight Loss on Inflammatory Status and Hyperandrogenism in Women with Polycystic Ovarian Syndrome (PCOS)—A Systematic Review and Meta-Analysis

Background: Currently, the primary strategy for addressing polycystic ovarian syndrome (PCOS) involves lifestyle modifications, with a focus on weight loss. The purpose of this meta-analysis was to assess the impact of weight loss through dietary interventions on inflammatory status and hyperandrogenism in PCOS women. Methods: A comprehensive search was conducted to identify randomised controlled trials (RCTs) and cohort studies assessing the impact of diet-induced weight loss on circulating inflammatory markers (CRP, IL-6, IL-1β, TNF-α), androgens (testosterone, androstenedione), SHBG, and luteinising hormone (LH) in PCOS women. The quality and risk of bias of the included studies were assessed using the Cochrane Collaboration’s tool for RCTs and the Newcastle–Ottawa Scale for cohort studies. Data were entered into RevMan software v5.9 for the calculation of standard mean difference (SMD) and the 95% confidence interval (95%CI) of circulating inflammatory markers, androgens, and LH between baseline and post-weight loss values. Results: Eleven studies (n = 323) were eligible for the systematic review, of which nine (n = 286) were included in the meta-analysis. Pooled analysis of data revealed a statistically significant decrease in circulating CRP (SMD 0.39, 95%CI 0.22, 0.56; 9 studies, n = 286), IL-6 (SMD 0.37, 95%Cl, 0.12, 0.61; 3 Studies, n = 140), TNF-α (SMD 0.30, 95%Cl, 0.07, 0.53; 4 Studies, n = 162), androstenedione (SMD 0.36, 95%Cl, 0.13, 0.60; 4 studies, n = 147) and LH (SMD 0.30, 95% Cl, 0.09, 0.51; 5 studies, n = 197) after weight loss compared to baseline levels among PCOS women. A meta-analysis of five studies (n = 173) showed a statistically significant increase in circulating SHBG after weight loss compared to baseline levels (SMD −0.43, 95%Cl, −0.65, −0.21). Conclusions: These findings suggest that weight loss induced by dietary interventions seems to improve PCOS-related chronic inflammation and hyperandrogenism. The possible causative relationship between the improvement in inflammation and hyperandrogenism remains to be determined.