**Question:** Increased glucose is due to-

A. Insulin resistance
B. Diabetes mellitus
C. Hyperaldosteronism
D. Cushing's syndrome

**Core Concept:**

Glucose is a crucial molecule essential for providing energy to cells throughout the body. In the context of the question, elevated glucose levels can be attributed to either increased production or decreased elimination. The question implies that we should focus on conditions that directly affect glucose homeostasis or indirectly impact it through hormonal imbalances.

**Why the Correct Answer is Right:**

**B. Diabetes mellitus:** Diabetes mellitus (DM) is a group of disorders characterized by hyperglycemia (high blood glucose levels) due to defects in insulin production, insulin action, or both. The primary cause of increased glucose in diabetes is insulin resistance (A), which is a condition where cells do not respond effectively to insulin, leading to elevated glucose levels. Insulin is a hormone produced by the pancreas that regulates glucose uptake by cells, and in insulin resistance, the body's cells do not respond to insulin as they should, causing glucose to remain in the bloodstream.

**Why Each Wrong Option is Incorrect:**

**A. Insulin resistance:** Although insulin resistance is a crucial aspect of diabetes, the question specifically asks for conditions causing elevated glucose levels. Diabetes mellitus is the correct answer since insulin resistance is a feature of the disease rather than a direct cause of elevated glucose.

**C. Hyperaldosteronism:** Hyperaldosteronism refers to increased production of aldosterone, a hormone that regulates electrolyte balance and blood pressure. While it can lead to secondary hyperglycemia, it is not directly responsible for elevated glucose levels.

**D. Cushing's syndrome:** Cushing's syndrome is caused by excess cortisol production, often due to adrenal gland tumors or external factors like prolonged corticosteroid use. Although Cushing's syndrome can lead to hyperglycemia, the question asks for conditions causing elevated glucose levels, making diabetes mellitus the correct answer.

**Clinical Pearl:** Understanding the underlying causes of elevated glucose levels is essential for diagnosing and managing diabetes mellitus, as well as recognizing its potential complications. Proper management of diabetes includes lifestyle modifications, oral medications, and, if needed, insulin therapy to maintain blood glucose levels within the normal range and prevent long-term complications.