A. M. Ajeed¹ (https://orcid.org/0009-0005-6924-9503)
R. J. Kadhim² (https://orcid.org/0009-0000-7574-1899)
N. J. Abbas³ (https://orcid.org/0009-0007-1787-4758)
N. A. Nasser⁴* (https://orcid.org/0000-0003-3047-9967)

¹Al-Turath University, College of Pharmacy, Baghdad, Iraq;
²Department of Biotechnology, College of Science,
University of Baghdad, Baghdad, Iraq;
³Department of Clinical Laboratory Sciences, College of Pharmacy,
Al-Nahrain University, Baghdad, Iraq;
⁴Department of Chemistry and Biochemistry, College of Medicine,
Al-Nahrain University, Baghdad, Iraq
*e-mail: Nesreen.ahmed@nahrainuniv.edu.iq

Received: 13 January 2026; Revised: 05 March 2026;
Accepted: 29 May 2026; Available on-line: June 2026

Background. Polycystic ovary syndrome (PCOS) is an endocrine-metabolic disease with reproductive dysfunction, intricate hormonal imbalance, elevated risk of cardiovascular disease and obesity in women of reproductive age. Apelin, an adipokine, and corin, a serine protease which activates natriuretic peptide as a cardiovascular regulator, could be involved in the connection between reproductive endocrine imbalance and cardiometabolic regulation in this condition. Objective. To determine apelin and corin levels in the blood of women with polycystic ovary syndrome and to evaluate whether they can be useful biochemical predictors for characterizing the disease and stratifying risks. Methods. The case-control study was conducted on 60 women, comprising 30 patients with PCOS and 30 healthy age- and demographically-matched controls. The levels of serum apelin and corin were evaluated with ELISA, that of hormones, 25-hydroxyvitamin D and B₁₂ were analyzed with the help of a Finecare analyser. Results. Much higher apelin and corin levels, increased luteinizing hormone (LH) level and LH/follicle-stimulating hormone ratio, and lower 25-hydroxyvitamin D level in the serum of PCOS patients compared to healthy group were detected. Conclusions. The analysis of ROC curves showed significantly positive relationship between hormonal disturbance and the levels of circulating apelin and corin, indicating their higher PCOS diagnostic accuracy compared to the traditional hormonal markers.

Keywords: 25-hydroxyvitamin D, apelin, corin, luteinizing hormone, polycystic ovary syndrome