5α-Reductase Activity in Women with Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis

In the 2017 meta-analysis by Wu et al., it was found that women with polycystic ovary syndrome (PCOS) had significantly higher 5α-reductase activity compared to controls, as evidenced by higher ratios of 5α-reduced tetrahydrocortisol to tetrahydrocortisol (5αTHF/THF) and androsterone to etiocholanolone (An/Et). The study included five articles with 356 cases and 236 controls. The standardized mean differences (SMD) for 5αTHF/THF and An/Et were 0.43 and 0.86, respectively. Significant heterogeneity was found between studies for An/Et. Subgroup analysis showed that the increased 5α-reductase activity was significantly associated with insulin resistance, measured by HOMA-IR, regardless of obesity. However, due to the small number of studies and potential publication bias, the results should be interpreted with caution and confirmed by future research. Increased 5α-reductase activity may be a key biochemical feature of PCOS, particularly in relation to insulin resistance.