Impact of Overweight and Obesity on the Metabolic Presentation of Type 1 Diabetes Mellitus Among Iraqi Children

Abstract

Background: The increasing prevalence of childhood overweight and obesity has raised concerns regarding their influence on the clinical and metabolic presentation of type 1 diabetes mellitus (T1DM). Excess body weight may contribute to insulin resistance, alter disease manifestations, and increase the risk of metabolic complications at diagnosis. This study aimed to evaluate the impact of overweight and obesity on the metabolic presentation of newly diagnosed T1DM among Iraqi children. Methods: A cross-sectional study was conducted at Al-Zahra Teaching Hospital, Kut, Iraq, between January 2021 and January 2026. Ninety-two children newly diagnosed with T1DM were included. Demographic, anthropometric, clinical, and laboratory data were obtained from medical records. Participants were classified as normal weight, overweight, or obese according to the World Health Organization BMI-for-age Z-score criteria. Metabolic parameters, including blood pH, serum bicarbonate (HCO₃⁻), pCO₂, blood glucose, HbA1c, C-peptide levels, and the severity of diabetic ketoacidosis (DKA), were compared across BMI categories using appropriate nonparametric statistical tests. Results: Overweight children presented with significantly more severe metabolic disturbances at diagnosis, including lower blood pH, bicarbonate, and pCO₂ levels compared with children of normal weight. Obese children demonstrated significantly higher C-peptide concentrations, indicating greater residual pancreatic beta-cell function. However, both overweight and obese children showed a higher prevalence of DKA than their normal-weight counterparts. The combined prevalence of overweight and obesity among children with newly diagnosed T1DM was 20.6%. Conclusion: Overweight is associated with a more severe metabolic presentation of newly diagnosed T1DM in Iraqi children, while obesity is characterized by relatively preserved residual beta-cell function despite an increased frequency of DKA. Early recognition of T1DM symptoms in overweight and obese children may facilitate timely diagnosis and reduce the risk of severe metabolic complications.