A diabetic patient reports weight loss. Are they more likely to have Type 1 diabetes or Type 2 diabetes?

• A. Type 2 diabetes
• B. Gestational diabetes
• C. Type 1 diabetes
• D. Prediabetes

Answer: (C)

Weight loss at presentation points to insulin deficiency. In Type 1 diabetes, autoimmune destruction of pancreatic beta cells leads to little or no endogenous insulin. Without insulin, glucose cannot enter cells, so the body shifts to breaking down fat and muscle for energy, causing weight loss even if appetite is normal or increased. Hyperglycemia also causes osmotic diuresis, contributing to dehydration and further weight loss. In Type 2 diabetes, insulin resistance with relative insulin deficiency is more typical, and patients are usually overweight; weight loss can occur but is not the classic presenting feature. Gestational diabetes occurs during pregnancy, and prediabetes is not full diabetes. Hence, the presentation fits Type 1 diabetes.