INS and obesity due to melanocortin 4 receptor deficiency: In this sense, patients with recently diagnosed type 2 diabetes mellitus could be grouped into seven subgroups: diabetes with pancreatic β-cell deficiency, insulin-resistant diabetes, patients with a combination of deficient insulin secretion and increased resistance, obesity-related diabetes, patients with obesity and a high level of insulin resistance, age-related diabetes, and diabetes with hereditary components.