Biomedicine: 2023; 43(4): 1177-1182 July-August 2023 DOI: https://doi.org/10.51248/.v43i4.3106 Biomedicine- Vol. 43 No. 4: 2023 Research article Levels of leptin, irisin, oxytocin and insulin in obese and normal weight Iraqi young men Alaa Subhi Hammoud, Maryam I. Salman Department of Biology, University of Anbar, College of Science, Anbar, Iraq (Received: June 2023 Revised: July 2023 Accepted: August 2023) Corresponding author: Alaa Subhi Hammoud. Email: alaasubhihammoud@gmail.com ABSTRACT Introduction and Aim: Obesity is a serious, life-threatening health condition that is prevalent in Iraq and the world as a whole. Since Leptin, irisin, oxytocin and insulin are proposed to play main roles in energy expenditure, glucose homeostasis, regulating body weight, reducing obesity and improving life expectancy so the aim of this study was to evaluate the concentrations of these anti-obesity hormones plus insulin resistance Materials and Methods: The study was conducted on 100 obese young men with a mean age of 29.95 years and fifty normal weight young men with a mean age of 28.44. Results: In obese men, the mean leptin concentration was 24.08±9.91 ng/ml which was significantly higher than in normal weight men 5.48 ng/ml. Serum irisin levels in obese men and normal weight were 8.9 ng/ml, 2.4 ng/ml respectively, and it was significantly higher in obese group in comparison to the normal weight group. The mean serum oxytocin concentration was significantly lower in obese group 6.41pg/ml in comparison to normal weight 29.55 pg/ml. Serum insulin levels in obese and normal weight were 19.55±5.56 and 3.64 micro lU/ml respectively and it was significantly higher in obese men. The mean fasting blood glucose concentration in obese men was 98.67mg/dl and it was significantly higher than in normal weight 84±9.85 mg/ml. Insulin resistance (HOMA IR) was significantly higher in obese men 6.6 than in normal weight 0.68. Conclusion: Serum levels of leptin, irisin, insulin, and insulin resistance are higher in obese young men, while oxytocin levels were noticeably low. Our study also shows that obesity increases the likelihood of insulin resistance. Keywords: Obesity; leptin; irisin; oxytocin; insulin resistance. INTRODUCTION besity is a multifaceted condition that exhibits strong associations with several significant diseases, including hypertension, type 2 diabetes mellitus, dyslipidemia, heart disease, fatty liver disease, and various forms of cancer (1,2). In the year 2016, the phenomenon under consideration was found to be accountable for the mortality of more than 3.4 billion individuals of mature age on a global scale. Based on data provided by the World Health Organization (WHO), it is estimated that approximately 1.9 billion individuals are classified as overweight, while approximately 650 million individuals are categorized as obese (3,4). Given the severity and potential fatality associated with obesity, it is imperative to conduct an investigation into the hormones implicated in the regulation of metabolism and energy balance among individuals who are obese. Specifically, the hormones of interest include leptin, irisin, and oxytocin. Leptin, a polypeptide hormone with a molecular weight of 16-KDa, is primarily synthesized and secreted into the bloodstream by white adipocytes and small intestinal cells (5). Leptin regulates food intake, body mass, energy balance, and body weight by its influence on hypothalamic receptors, resulting in appetite inhibition, in addition to playing a role in metabolic rate stimulation and thermogenesis (5). Irisin, a newly identified myokine which converts the white adipose tissues to brown adipose tissues, so this hormone also participates in energy expenditure, thermogenesis, and glucose homeostasis (6). Irisin a recently discovered myokine, secreted by both muscle and adipose tissues, is involved in functions such as energy expenditure, thermogenesis, and glucose homeostasis (6, 7). Myokine levels have been suggested to play a vital role in improving obesity, diabetes and life expectancy (8, 9). The production of oxytocin, a neuropeptide hormone consisting of nine amino acids, primarily occurs in the hypothalamus. Subsequently, it is stored and released into the bloodstream through the pituitary gland (10). Oxytocin is known to control key aspects of reproduction including childbirth and lactation as well as in many neuropsychiatric activities such as social behavior, learning, memory, sexual behavior, and food intake (11). In addition to food intake, oxytocin has also been demonstrated to regulate metabolic and energy balance (12). Insulin, a hormone, is accountable for regulating the levels of glucose in the bloodstream. Insulin resistance is a pathological state characterized by the diminished capacity of body cells to uptake glucose from the bloodstream, consequently leading to elevated levels of blood glucose. This condition is associated with various disorders, including diabetes and obesity (13). The aim of this study was to assess and compare the O 1177