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Association between glycine levels and insulin resistance in women with polycystic ovary syndrome: A case-control study

Solin Rafiq Hussein
Department of Clinical Biochemistry , College of Health Science, Hawler Medical University, Kurdistan Region, Iraq.
Sardar Nouri Ahmed
Department of Clinical Biochemistry, College of Medicine, Hawler Medical University, Kurdistan Region, Iraq.
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Copyright (c) 2026 Solin Rafiq Hussein , Sardar Nouri Ahmed (Author)

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Abstract

Background and objective: Polycystic Ovary Syndrome (PCOS) is an endocrine disorder with multi-factorial origins characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology. Its pathogenesis is complex, but one of the leading contributors to hyperandrogenism is insulin resistance (IR) which leads to a greater likelihood of developing type 2 diabetes mellitus (T2DM). This study aims to analyze the association between PCOS and T2DM, with a focus on IR and the potential moderating role of glycine.

Methods: This case-control study included 100 women (50 PCOS and 50 controls) aged 18–35 years. Women with PCOS showed significantly higher glycated hemoglobin (HbA1c) (6.014% ± 0.042 vs. 4.372% ± 0.071), fasting blood glucose (FBG) (97.25 ± 0.285 vs. 85.48 ± 0.755 mg/dL), insulin levels (20.24 ± 0.581 vs. 4.624 ± 0.087 µU/mL), and HOMA-IR (4.929 ± 0.125 vs. 0.982 ± 0.026) compared to controls (all P <0.001). Glycine levels were significantly lower in PCOS (125.76 ± 1.868 vs. 294.28 ± 8.754 µmol/L, P <0.001).

Results: COS women also had significantly higher insulin, fasting glucose, homeostasis model assessment for (HOMA-IR), and HbA1c levels but lower glycine levels compared with controls. Glycine was negatively correlated with insulin and HOMA-IR, while there were significant positive correlations between insulin and HOMA-IR (P <0.001).

Conclusion: These findings demonstrate that IR is a key factor in the metabolic dysfunction associated with PCOS and the potential development of T2DM.

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How to Cite
Rafiq Hussein , S., & Nouri Ahmed , S. (2026). Association between glycine levels and insulin resistance in women with polycystic ovary syndrome: A case-control study. Zanco Journal of Medical Sciences (ZJMS), 30(1), 288–298. https://doi.org/10.15218/zjms.2026.020

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