**Question:** A 34 years old male presents with a history of thirst, polyuria and recent 3.2 kg weight loss. His urine contains a small amount of ketones. Which of the following would suggest he is most likely to have type 2 diabetes than type 1?

A. Insulin resistance
B. Absence of ketosis
C. Absence of weight loss
D. Rapid onset of symptoms

**Core Concept:** Diabetes mellitus is a group of disorders characterized by hyperglycemia due to insulin production, secretion, or action defects. Type 1 diabetes is caused by absolute insulin deficiency, usually due to autoimmune destruction of pancreatic beta cells, leading to ketosis and rapid onset of symptoms. Type 2 diabetes results from insulin resistance, where the body does not use insulin effectively, often combined with relative insulin deficiency. Type 2 diabetes typically presents with polyuria, polydipsia, polyphagia, and weight loss, which is less common compared to type 1 diabetes.

**Why the Correct Answer is Right:** The presence of ketones in urine indicates impaired gluconeogenesis and glycogenolysis, which is more commonly seen in type 1 diabetes due to absolute insulin deficiency. In contrast, type 2 diabetes is characterized by insulin resistance, and the presence of ketones in urine is less likely.

**Why Each Wrong Option is Incorrect:**

**A. Absence of ketosis:** Even though type 2 diabetes is more likely, the presence of a small amount of ketones suggests that the patient is not entirely insulin deficient. Ketosis is more common in type 1 diabetes, indicating absolute insulin deficiency.

**B. Absence of weight loss:** Weight loss is a common presentation in type 2 diabetes due to hyperglycemia-induced osmotic diuresis and increased energy expenditure.

**C. Absence of weight loss:** As explained above, weight loss is a common presentation in type 2 diabetes. In this case, the patient presents with weight gain, further supporting a more probable diagnosis of type 2 diabetes.

**D. Rapid onset of symptoms:** Type 2 diabetes is typically slower in onset compared to type 1 diabetes due to its gradual progression caused by insulin resistance.

**Clinical Pearl:** A thorough understanding of the clinical features of both types of diabetes is essential to differentiate between them. This helps in appropriate management and timely intervention.