Obesity in Adults with Type 1 Diabetes Mellitus

The prevalence of overweight and obesity in individuals with type 1 diabetes mellitus (T1DM) has increased significantly due to multifactorial causes, paralleling global trends. Beyond known causes of obesity, pathophysiological and biopsychosocial causes specific to T1DM also have a role in the development of obesity. Obesity in T1DM may arise from treatment-related factors (intensive insulin therapy and defensive carbohydrate intake), behavioral aspects (reduced physical activity due to fear of hypoglycemia), and pathophysiological mechanisms such as adipose tissue dysfunction. Clinically, obesity in T1DM is associated with increased risk of cardiovascular disease, nephropathy, retinopathy, and psychosocial burden. Weight gain and increased insulin dependence have created a vicious cycle in the management of obesity in T1DM. Recent clinical studies have shown that incretin-based therapies, particularly glucagon-like peptide-1 (GLP-1) receptor agonists and dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 agonists, can reduce body weight and insulin requirements without significant safety concerns. Similarly, sodium-glucose cotransporter 2 inhibitors offer metabolic benefits but carry a risk of diabetic ketoacidosis. The lack of regulatory approval for obesity treatment agents in these patients highlights the importance of further research. In this review, we address the pathophysiology of obesity in T1DM, its clinical implications, and therapeutic approaches using an evidence-based approach.