Leptin, adiponectin levels and their ratios in women with polyendocrine metabolic ovarian syndrome: a systematic review and meta-analysis.

BACKGROUND

Polyendocrine metabolic ovarian syndrome (PMOS, formerly polycystic ovary syndrome [PCOS]) is a common endocrine and metabolic disorder. The global burden of PMOS shows an overall increasing trend. Recent studies have revealed significant alterations in serum leptin and adiponectin levels in patients with PMOS. However, the results are inconsistent.

OBJECTIVE

To compare the serum leptin and adiponectin levels, as well as the adiponectin-to-leptin (A/L) ratio, between women with PMOS (diagnosed according to the Rotterdam criteria) and healthy controls aged 18-49 years and to provide evidence for future screening strategies and the investigation of the pathogenesis of PMOS.

METHODS

A comprehensive search of "PubMed," "Web of Science," "Embase," and "Cochrane Library" was conducted from January 1, 2015, to March 31, 2026. The authors independently reviewed all relevant clinical trials via systematic evaluation of abstracts and titles.

RESULTS

A total of 62 studies met the inclusion criteria. The pooling analysis of all relevant studies revealed that adult women with PMOS had higher serum leptin levels (standardized mean difference (SMD): 0.83; 95% confidence interval (CI): 0.59 to 1.07; p < 0.0001) and lower adiponectin levels (SMD: -1.06; 95% CI: -1.47 to -0.66; p < 0.0001) than women without PMOS. Heterogeneity across studies was considerable and not eliminated in subgroup analyses. The A/L ratio was statistically significantly lower in PMOS (SMD: -2.31; 95% CI: -4.02 to -0.55; p = 0.010).

CONCLUSION

Women with PMOS aged 18-49 exhibit higher leptin levels, lower adiponectin levels and a lower A/L ratio. Further well-designed adequately powered prospective studies are needed to clarify the association between these markers and PMOS, including assessments of their sensitivity, specificity, and optimal cutoff values for predicting PMOS risk.

SYSTEMATIC REVIEW REGISTRATION: The protocol was registered on https://www.crd.york.ac.uk/PROSPERO/view/CRD420261364408 (CRD420261364408).