Endocrinology Practice Questions

Q: A 65-year-old woman with a history of type 2 diabetes mellitus for the last 8 years dies in a hospital. She had no other significant medical history. Which of the following is the most likely cause of her death?

Myocardial infarction. In patients with Type 2 Diabetes Mellitus (T2DM), **cardiovascular disease (CVD)** is the leading cause of morbidity and mortality [2]. Approximately 65–70% of deaths in diabetic patients are attributed to macrovascular complications, with **Myocardial Infarction** being the single most common cause [2], [3]. Diabetes is considered a **"Coronary Artery Disease (CAD) equivalent,"** meaning a diabetic patient without a prior MI has the same cardiovascular risk as a non-diabetic patient who has already suffered one. **2. Why the other options are incorrect:** * **Diabetic Ketoacidosis (DKA):** This is an acute metabolic complication more common in Type 1 DM. While it can occur in T2DM (especially during severe stress), it is rarely the primary cause of death in an elderly patient with long-standing T2DM compared to vascular events. * **Renal Failure:** While diabetic nephropathy is the leading cause of End-Stage Renal Disease (ESRD) globally, most diabetic patients with chronic kidney disease actually die from cardiovascular events *before* they reach the stage of terminal renal failure [2]. * **Stroke:** Cerebrovascular accidents are a significant macrovascular complication of DM, but statistically, they occur less frequently as a cause of death than ischemic heart disease [2]. **3. Clinical Pearls for NEET-PG:** * **Silent MI:** Diabetic patients often present with "painless" or silent MI due to **autonomic neuropathy**, leading to delayed diagnosis and higher mortality [1]. * **Leading cause of death in T1DM:** In young patients (<30 years), it is often acute complications (DKA) or renal disease; however, as they age, CVD becomes the leading cause here as well. * **The "Legacy Effect":** Early intensive glycemic control reduces long-term macrovascular risks (UKPDS study).

Q: Which condition is associated with pNET?

Zollinger Ellison syndrome. **Explanation:** **Zollinger-Ellison Syndrome (ZES)** is the correct answer because it is caused by a **gastrinoma**, which is a type of **pancreatic neuroendocrine tumor (pNET)**. Gastrinomas secrete excessive amounts of gastrin, leading to gastric acid hypersecretion and refractory peptic ulcer disease. Approximately 25% of ZES cases occur as part of **Multiple Endocrine Neoplasia type 1 (MEN1)** syndrome, which is characterized by the triad of Parathyroid hyperplasia, Pituitary adenomas, and Pancreatic islet cell tumors (pNETs). **Analysis of Incorrect Options:** * **Intestinal Metaplasia:** This is a precancerous transformation of the gastric or esophageal mucosa (e.g., Barrett’s esophagus) usually due to chronic irritation (H. pylori or GERD). It is associated with adenocarcinoma, not pNETs. * **Peutz-Jeghers Syndrome:** An autosomal dominant disorder characterized by hamartomatous polyps in the GI tract and mucocutaneous hyperpigmentation. While it increases the risk of various cancers (breast, pancreas, colon), it is not primarily defined by pNETs. * **Familial Polyposis Coli (FAP):** Caused by a mutation in the APC gene, this condition leads to hundreds of adenomatous colorectal polyps. It is strongly associated with colorectal carcinoma and extracolonic manifestations like desmoid tumors and osteomas (Gardner syndrome), but not pNETs. **High-Yield Clinical Pearls for NEET-PG:** * **Most common pNET in MEN1:** Insulinoma (overall), but Gastrinoma is the most common *symptomatic* malignant pNET. * **Gastrinoma Triangle (Passaro’s Triangle):** Boundaries are the junction of the cystic and common bile duct, the junction of the 2nd and 3rd parts of the duodenum, and the neck of the pancreas. * **Diagnostic Test for ZES:** Elevated fasting serum gastrin levels (>1000 pg/mL) and a positive **Secretin Stimulation Test** (paradoxical rise in gastrin).

Q: Which of the following is not a clinical feature of hypothyroidism?

Atrial fibrillation. **Explanation:** In hypothyroidism, the metabolic rate and sympathetic activity are significantly decreased. **Atrial Fibrillation (AF)** is a classic feature of **hyperthyroidism** (thyrotoxicosis) [1], where excess thyroid hormone increases the expression of beta-adrenergic receptors in the heart, leading to tachycardia and arrhythmias. In contrast, hypothyroidism is typically associated with **sinus bradycardia** and low-voltage complexes on ECG. **Analysis of Options:** * **Edema:** Hypothyroidism leads to the accumulation of glycosaminoglycans (like hyaluronic acid) in the interstitial space, which traps water. This results in non-pitting edema, classically termed **myxedema**. * **Cold skin:** Decreased thermogenesis and peripheral vasoconstriction (to conserve heat) result in skin that is characteristically cold, dry, and rough. * **Diastolic hypertension:** While hyperthyroidism causes systolic hypertension (due to increased stroke volume), hypothyroidism often causes **diastolic hypertension** due to increased systemic vascular resistance and stiffness of the arterial wall. **Clinical Pearls for NEET-PG:** * **Wolff-Chaikoff Effect:** Autoregulatory inhibition of thyroid hormone synthesis after ingestion of a large amount of iodine. * **Most common cause:** Globally, iodine deficiency; in iodine-sufficient areas, **Hashimoto’s Thyroiditis** (associated with anti-TPO antibodies). * **Hoffman’s Syndrome:** A rare form of hypothyroid myopathy characterized by muscle stiffness and pseudohypertrophy. * **Hungry Bone Syndrome** is a complication of parathyroid surgery, but **Delayed relaxation of deep tendon reflexes** (Woltman sign) is a pathognomonic physical finding in hypothyroidism.

Q: Cardiac manifestations of Grave's disease would include all of the following except?

Aortic insufficiency. Explanation: Graves' disease (Hyperthyroidism) induces a hyperdynamic circulatory state due to the direct effects of thyroid hormones on the myocardium and the upregulation of beta-adrenergic receptors. Why Aortic Insufficiency is the correct answer: Aortic insufficiency (AI) is a structural valvular abnormality. While Graves' disease causes functional murmurs due to increased flow [3], it does not cause structural damage to the aortic valve leaflets. Therefore, AI is not a manifestation of thyrotoxicosis. Analysis of other options: * Wide pulse pressure: Thyroid hormones decrease systemic vascular resistance (vasodilation) and increase systolic blood pressure (increased stroke volume), leading to a characteristic wide pulse pressure [4]. * Atrial fibrillation: This is the most common rhythm disturbance in hyperthyroidism, occurring in approximately 10–15% of patients, especially in the elderly [1]. * Pleuropericardial scratch (Means-Lerman scratch): This is a high-yield clinical sign. It is a systolic scratchy sound heard over the left second intercostal space during expiration. It is thought to result from the rubbing of the hyperdynamic heart against the pleura, not from pericarditis. NEET-PG High-Yield Pearls: 1. Most common arrhythmia: Sinus tachycardia [1]; however, Atrial Fibrillation is the most significant supraventricular tachyarrhythmia. 2. Means-Lerman Scratch: A classic physical sign of hyperthyroidism mimicking a friction rub. 3. Heart Failure: Graves' can lead to "High-Output Heart Failure." 4. Treatment of choice for cardiac symptoms: Propranolol (Beta-blockers) to control adrenergic overactivity [2].

Q: Obesity is not a feature of which of the following conditions?

Adrenal insufficiency. ### Explanation The correct answer is **Adrenal insufficiency**. **1. Why Adrenal Insufficiency is the correct answer:** Adrenal insufficiency (Addison’s disease) is characterized by a deficiency of cortisol and, in primary cases, aldosterone [1]. Cortisol is a glucocorticoid essential for metabolic homeostasis. Its absence leads to decreased gluconeogenesis and increased insulin sensitivity, often resulting in **weight loss** and anorexia rather than obesity. Weight loss is a hallmark clinical feature of chronic adrenal insufficiency, often accompanied by hyperpigmentation (in primary cases) and hypotension. **2. Why the other options are incorrect:** * **Hypothyroidism:** Low levels of thyroid hormones (T3/T4) lead to a decreased Basal Metabolic Rate (BMR) and accumulation of glycosaminoglycans (myxedema), which causes fluid retention and weight gain. * **Hypogonadism:** Testosterone and estrogen play roles in body fat distribution and muscle mass. Deficiency in these hormones (especially testosterone in males) leads to increased adiposity and decreased lean body mass. * **Cushing’s Syndrome:** This is characterized by chronic glucocorticoid excess [3]. It causes "centripetal obesity" (trunk, buffalo hump, and moon facies) due to the redistribution of fat and stimulation of adipogenesis [3]. **3. NEET-PG High-Yield Pearls:** * **Weight Loss Triad in Endocrinology:** Adrenal insufficiency, Hyperthyroidism, and Type 1 Diabetes Mellitus. * **Secondary Adrenal Insufficiency:** Unlike primary Addison’s, there is **no hyperpigmentation** (due to low ACTH) and **no mineralocorticoid deficiency** (regulated by the RAAS, not ACTH) [2]. * **Cushing’s vs. Simple Obesity:** In Cushing’s, the obesity is typically "central" with thin extremities (due to muscle wasting), whereas simple obesity is usually generalized [3].

Q: A 64-year-old man presents with severe polyuria and polydipsia, consuming 3 to 4 glasses of water and producing over 0.5 liters of urine each hour. After overnight water restriction, the following test results were obtained: Plasma sodium concentration: 155 mEq/L; Urine osmolarity: 90 mOsmol/L; Urine glucose concentration: 0 mg/dL. Which of the following is the most likely diagnosis?

Diabetes insipidus. ### Explanation **1. Why Diabetes Insipidus (DI) is the Correct Answer:** The clinical hallmark of DI is the inability to concentrate urine despite rising plasma osmolality. This patient presents with the classic triad: **polyuria** (>3L/day), **polydipsia**, and **hypernatremia** (155 mEq/L). [4] * **Water Restriction Test:** In a normal individual, water restriction triggers ADH release, leading to concentrated urine. Here, the urine remains significantly dilute (**90 mOsmol/L**), which is far below the normal response (>600 mOsmol/L) and even below the plasma osmolality. [1] * The absence of glycosuria rules out osmotic diuresis from glucose, confirming that the polyuria is due to a lack of ADH effect (either Central or Nephrogenic DI). **2. Why the Other Options are Incorrect:** * **Addison’s Disease:** Typically presents with **hyponatremia** (due to aldosterone deficiency) and hyperkalemia, not hypernatremia and dilute polyuria. [3] * **Fanconi Syndrome:** While it can cause polyuria due to proximal tubule dysfunction, it is characterized by **glycosuria** (at normal blood glucose levels), phosphaturia, and aminoaciduria. This patient has 0 mg/dL urine glucose. * **Diabetes Mellitus:** Causes osmotic diuresis due to hyperglycemia. The urine would show a **high glucose concentration** and a higher osmolarity than 90 mOsmol/L. **3. NEET-PG High-Yield Clinical Pearls:** * **Diagnostic Cut-off:** DI is suspected when urine osmolarity is ** 295 mOsmol/L). [2] * **Differentiation:** To distinguish Central from Nephrogenic DI, administer **Desmopressin (dDAVP)**. A >50% increase in urine osmolarity indicates Central DI; little to no response indicates Nephrogenic DI. [2] * **Common Causes:** Central DI is often post-neurosurgery or idiopathic; Nephrogenic DI is commonly caused by **Lithium** or hypercalcemia. [2]

Q: Which of the following conditions is a common cause of hypercalcemia?

Hyperthyroidism. **Explanation:** Hypercalcemia is a common clinical finding in endocrinology, primarily driven by increased bone resorption or decreased renal excretion [1]. **Why Hyperthyroidism is Correct:** Thyroid hormones (T3 and T4) have a direct stimulatory effect on osteoclasts, leading to increased bone turnover and resorption. In approximately 15-20% of patients with thyrotoxicosis, this accelerated bone breakdown exceeds the rate of bone formation, resulting in mild hypercalcemia [1]. Additionally, the increased calcium load suppresses Parathyroid Hormone (PTH), leading to hypercalciuria. **Analysis of Incorrect Options:** * **A. Adrenocortical insufficiency:** While Addison’s disease can cause hypercalcemia (due to decreased renal calcium clearance and increased bone resorption), it is considered an **uncommon** cause compared to the metabolic impact of hyperthyroidism [1]. * **B. Amyloidosis:** This is a restrictive/infiltrative disease. While it can lead to renal failure (which causes *hypocalcemia* due to phosphate retention and low Vitamin D) [2], it is not a recognized cause of hypercalcemia. * **D. Vitamin C intoxication:** Vitamin C (Ascorbic acid) is not involved in calcium metabolism. It is **Vitamin D** intoxication (increased intestinal absorption) [1] or **Vitamin A** intoxication (increased bone resorption) that causes hypercalcemia. **High-Yield NEET-PG Pearls:** * **Most common cause overall:** Primary Hyperparathyroidism (outpatient) and Malignancy (inpatient) [1]. * **Mnemonic for Hypercalcemia (CHIMPANZEES):** **C**alcium supplements, **H**yperparathyroidism, **I**atrogenic/Immobilization, **M**ilk-alkali syndrome, **P**aget’s disease, **A**ddison’s/Acromegaly, **N**eoplasia, **Z**ollinger-Ellison (MEN1), **E**xcess Vitamin D, **E**xcess Vitamin A, **S**arcoidosis [1]. * **ECG Finding:** Shortened QT interval is the classic sign of hypercalcemia.

Question 1

What is the most common cause of death in acromegaly?

Accepted Answer

Cardiovascular causes

Answer

Obstructive Sleep Apnea

Answer

Impaired glucose Tolerance

Answer

Colonic malignancy

Question 2

A 65-year-old woman with a history of type 2 diabetes mellitus for the last 8 years dies in a hospital. She had no other significant medical history. Which of the following is the most likely cause of her death?

Accepted Answer

Myocardial infarction

Answer

Diabetic ketoacidosis

Answer

Renal failure

Answer

Stroke

Question 3

A 60-year-old male patient exhibits excessive sleepiness, slowing of movements, mild depression, and proximal muscle weakness. Serology shows normal blood calcium and increased creatinine with reduced creatinine clearance. The patient has had joint swellings and abdominal discomfort for several months. What is the most likely diagnosis?

Accepted Answer

Hyperparathyroidism

Answer

Hypermagnesemia

Answer

Hepatolenticular degeneration

Answer

Akinetic mutism

Question 4

Which condition is associated with pNET?

Accepted Answer

Zollinger Ellison syndrome

Answer

Intestinal metaplasia

Answer

Peutz Jeghers syndrome

Answer

Familial polyposis coli

Question 5

Which of the following is not a clinical feature of hypothyroidism?

Accepted Answer

Atrial fibrillation

Answer

Edema

Answer

Cold skin

Answer

Diastolic hypertension

Question 6

Cardiac manifestations of Grave's disease would include all of the following except?

Accepted Answer

Aortic insufficiency

Answer

Wide pulse pressure

Answer

Atrial fibrillation

Answer

Pleuropericardial scratch

Question 7

All of the following are true about acromegaly except:

Accepted Answer

Excessive growth occurs before fusion of the epiphyses of the long bones

Answer

Increased IGF-1 levels

Answer

Somatostatin analogues can be used

Answer

Growth hormone levels are increased

Question 8

Obesity is not a feature of which of the following conditions?

Accepted Answer

Adrenal insufficiency

Answer

Hypothyroidism

Answer

Hypogonadism

Answer

Cushing's syndrome

Question 9

A 64-year-old man presents with severe polyuria and polydipsia, consuming 3 to 4 glasses of water and producing over 0.5 liters of urine each hour. After overnight water restriction, the following test results were obtained: Plasma sodium concentration: 155 mEq/L; Urine osmolarity: 90 mOsmol/L; Urine glucose concentration: 0 mg/dL. Which of the following is the most likely diagnosis?

Accepted Answer

Diabetes insipidus

Answer

Addison's disease

Answer

Fanconi syndrome

Answer

Diabetes mellitus

Question 10

Which of the following conditions is a common cause of hypercalcemia?

Accepted Answer

Hyperthyroidism

Answer

Adrenocortical insufficiency

Answer

Amyloidosis

Answer

Vitamin C intoxication

Endocrinology — MCQs

Endocrinology — MCQs

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