Diabetes mellitus and obesity: The bidirectional pathophysiological relationship

Diabetes mellitus and obesity are two closely interconnected metabolic disorders that represent a major global public health challenge. Obesity, particularly the accumulation of visceral adipose tissue, is a major risk factor for the development of type 2 diabetes mellitus (T2DM). Conversely, diabetes-related metabolic disturbances, changes in body composition, and certain glucose-lowering treatments may contribute to weight gain, creating a complex bidirectional relationship. The underlying mechanisms involve insulin resistance, chronic low-grade inflammation, adipose tissue dysfunction, altered adipokine secretion, ectopic lipid accumulation, mitochondrial dysfunction, and progressive pancreatic beta-cell impairment. These processes disrupt glucose and lipid homeostasis and increase the risk of cardiovascular disease, chronic kidney disease, metabolic dysfunction-associated steatotic liver disease, and other long-term complications. Advances in understanding the relationship between obesity and diabetes have led to more comprehensive approaches to prevention and treatment, including lifestyle modification, nutritional therapy, physical activity, anti-obesity medications, glucose-lowering agents with weight-reducing effects, and metabolic surgery. This article examines the epidemiology, molecular mechanisms, clinical consequences, diagnostic strategies, and contemporary management of the relationship between diabetes mellitus and obesity, emphasizing the importance of individualized, long-term metabolic care.