The effects of ketogenic diet on metabolic and hormonal parameters in patients with polycystic ovary syndrome: a systematic review and meta-analysis of clinical trials

In recent years, using the ketogenic diet (KD) as a potential intervention for polycystic ovary syndrome (PCOS) has gained attention. Therefore, this study aimed to conduct a meta-analysis to determine the effects of KD on sexual hormones, glycemic and lipid parameters in women diagnosed with PCOS.

A comprehensive literature search was performed using online databases such as Medline/PubMed, Scopus, Web of Science (ISI), Embase, and the Cochrane Library and clinical trials were selected based on the inclusion criteria. Data extraction and quality assessment were conducted independently by two investigators using appropriate tools. The effects of a KD on metabolic biomarkers and hormonal parameters were pooled using a random-effects model and were considered as the weighted mean difference (WMD) with corresponding 95% confidence intervals (CIs). Heterogeneity across studies was assessed using Cochran's Q test and the I-square test.

Ten studies including 408 women were analyzed in this analysis. Findings showed that KD significantly decreased triglycerides levels (WMD = -44.03 mg/dL; 95% CI, -56.29, -31.76), total cholesterol (-18.95 mg/dL; -29.06, -8.83), and low-density lipoprotein cholesterol (LDL) (-18.11 mg/dL; -29.56, -6.67) compared to the control groups. KD also led to a notable reduction in fasting glucose (-10.30 mg/dL; -14.10, -6.50) and HOMA-IR (-1.93; -3.66, -0.19). Also, this diet led to a significant decrease in luteinizing hormone (LH) levels (-3.75 mIU/mL; -3.84, -3.65) and total testosterone levels (-7.71 ng/dL); -12.08, -3.35), while follicle-stimulating hormone (FSH) increased (0.43 mIU/mL; 0.29, 0.57).

The KD demonstrated promising outcomes in improving metabolic and hormonal parameters in women diagnosed with PCOS.