Insulin Resistance Assessment in Relation to Obesity Levels Among Iraqi Type 2 Diabetics

Abstract

Diabetes mellitus (DM) represents a metabolic syndrome characterized by dysregulation of carbohydrate metabolism. Obesity is recognized as a principal modifiable risk factor predisposing individuals to type 2 DM (T2DM) and is defined by excessive adiposity. In the obese state, adipose tissue exhibits increased secretion of non-esterified fatty acids, glycerol, hormonal mediators, pro-inflammatory cytokines, and additional bioactive substances that collectively contribute to the pathogenesis of insulin resistance (IR). A robust and well-documented association exists between body mass index (BMI), IR, and the subsequent development of T2DM. The present investigation aimed to elucidate the relationship between degrees of obesity and IR among Iraqi patients diagnosed with T2DM. Specifically, the study sought to quantify the impact of IR relative to obesity severity within this population group. A case-control study design was employed, encompassing 300 participants (163 females and 137 males), aged between 30 and 60 years, over the period extending from July to December 2024 study subjects, including both cases and controls, were stratified into four categories based on BMI: normal weight, overweight, obese, and markedly obese. All participants provided informed consent consistent with World Health Organization ethical guidelines. Biochemical and anthropometric assessments comprised the homeostatic model assessment of IR (HOMA-IR), glycated hemoglobin (HbA1c), fasting blood glucose (FBG), comprehensive lipid profile, and BMI determination. Comparative analysis demonstrated that the case group exhibited significantly elevated levels of FBG, HbA1c, total cholesterol, triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and HOMA-IR compared to the control group (p = 0.001). Conversely, no statistically significant difference was observed between groups regarding high-density lipoprotein cholesterol (HDL-C) concentrations. Emerging evidence underscores that incremental increases in BMI are associated with progressive reductions in insulin sensitivity and amplification of IR, ultimately facilitating the onset and progression of T2DM.