INS and obesity due to melanocortin 4 receptor deficiency: The potential links between diabetes mellitus and GCa may involve the interactions with shared risk factors (e.g., obesity, hyperglycemia, hyperinsulinemia, insulin resistance, high salt intake, smoking, etc.), Helicobacter pylori (HP) infection, medications (e.g., insulin, metformin, statins, aspirin, proton pump inhibitors, antibiotics, etc.)and comorbidities (e.g., hypertension, dyslipidemia, vascular complications, heart failure, renal failure, etc.).