Tehran University of Medical Sciences Acta Biochimica Iranica 0001-5261 3 1 2025 03 20 17 22 Asma Kheirollahi Department of Comparative Biosciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Akram Vatannejad Vatannejad Department of Comparative Biosciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Sara Bayat Department of Comparative Biosciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Maryam Teimouri Department of Clinical Biochemistry, School of Allied Medical Science, Shahroud University of Medical Sciences, Shahroud, Iran Molood Bagherieh Ramsar Campus, Mazandaran University of Medical Sciences, Ramsar, Iran Farzad Amiri Department of Endocrinology, Shahid Beheshti University of Medical Sciences, Tehran, Iran Faezeh Fattahi Department of Obstetrics and Gynecology Iran University of Medical sciences, Tehran, Iran Farah Jadidizadeh Department of Comparative Biosciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran 2025 07 27 Objectives: Polycystic ovarian syndrome (PCOS) is a prevalent endocrine disorder that significantly impacts women. It is closely associated with metabolic syndrome and obesity. However, the exact interplay between serum homocysteine levels and body mass index (BMI) in PCOS patients remains incompletely understood. In this study, we investigated the levels of homocysteine in normal weight and overweight/obese Iranian women with and without PCOS. Methods: 189 women with PCOS and 86 healthy and fertile women were entered in the study. The patients and controls were divided according to BMI into two groups as follow: BMI<25 Kg/m2 and BMI≥ 25 Kg/m2. Blood Samples were collected from all participants to assess fasting blood glucose, fasting insulin, lipid profile, free testosterone and homocysteine levels. Results: BMI, HOMA-IR, fasting insulin, TC, LDL and free testosterone levels were significantly elevated in the PCOS group when compared with controls. Homocysteine levels were increased in both overweight/obese and normal weight PCOS groups compared with controls. However, no significant association was observed between homocysteine levels in overweight/obese PCOS group vs. normal weight PCOS group. Conclusion: The results of this study showed that homocysteine levels were notably elevated in women with PCOS, regardless of their BMI. https://abi.tums.ac.ir/index.php/abi/article/view/144 https://abi.tums.ac.ir/index.php/abi/article/download/144/97