Endocrine Hypertension — MCQs
Which of the following is NOT a criterion for the diagnosis of Primary Hyperaldosteronism?
Which of the following is NOT a feature of Cushing's triad?
Hyperaldosteronism is associated with all, except:
Which test is essential in a patient with suspected Cushing's syndrome for diagnosis confirmation?
Which of the following is a classic feature of pheochromocytoma?
Which drug is generally considered the first-line treatment for pheochromocytoma?
Which of the following is the most prominent clinical manifestation of primary hyperaldosteronism (Conn's syndrome)?
All are seen in pheochromocytoma except which of the following?
Which of the following statements about pheochromocytoma is true?
What is the primary effect of beta blockers in the management of thyroid storm?
Endocrine Hypertension Indian Medical PG Practice Questions and MCQs
Question 1: Which of the following is NOT a criterion for the diagnosis of Primary Hyperaldosteronism?
- A. Diastolic Hypertension without edema
- B. Low Plasma Renin Activity
- C. Hyperkalemia (Correct Answer)
- D. Hyperaldosteronism which is not suppressed by volume expansion
Explanation: Primary hyperaldosteronism is typically characterized by **hypokalemia** due to excessive aldosterone-mediated potassium excretion in the urine, not hyperkalemia [1]. Hyperkalemia would suggest other conditions, such as **adrenal insufficiency** or kidney disease, rather than primary hyperaldosteronism [2]. *Diastolic Hypertension without edema* - **Diastolic hypertension** is a common presentation of primary hyperaldosteronism due to increased **sodium and water retention**, leading to expanded extracellular volume. - The absence of significant edema is also common, as the body often develops an **"escape phenomenon"** where natriuresis occurs despite high aldosterone, preventing overt fluid overload [3]. *Low Plasma Renin Activity* - In primary hyperaldosteronism, the high aldosterone levels **suppress renin secretion** through negative feedback mechanisms. - Therefore, a **low plasma renin activity** (PRA) or plasma renin concentration (PRC) is a key diagnostic feature [4]. *Hyperaldosteronism which is not suppressed by volume expansion* - Normally, volume expansion would suppress aldosterone secretion. However, in primary hyperaldosteronism, aldosterone production is **autonomous** and remains elevated even after volume expansion. - This lack of suppression is a critical diagnostic criterion, often assessed through various **confirmatory tests** like saline infusion or oral sodium loading.
Question 2: Which of the following is NOT a feature of Cushing's triad?
- A. Hypertension
- B. Bradycardia
- C. Irregular breathing
- D. Hypotension (Correct Answer)
Explanation: ***Hypotension*** - Cushing's triad is an indicator of **increased intracranial pressure (ICP)** and classically presents with **hypertension**, not hypotension. - Hypotension would suggest a different problem, such as **spinal shock** or **hypovolemia**, which are not directly associated with Cushing's triad. *Bradycardia* - **Bradycardia** is a key component of Cushing's triad, resulting from vagal stimulation due to increased intracranial pressure. - This reflex reduces heart rate in an attempt to maintain cerebral perfusion. *Hypertension* - **Hypertension**, specifically a widened pulse pressure, is a cardinal feature of Cushing's triad, caused by systemic vasoconstriction to overcome increased ICP and maintain **cerebral perfusion pressure**. - It is a compensatory mechanism to push blood into the brain. *Irregular breathing* - **Irregular breathing patterns**, such as Cheyne-Stokes respiration or ataxic breathing, are characteristic of Cushing's triad, indicating brainstem compression [1]. - This irregular respiratory effort is due to direct pressure on the **respiratory centers** in the medulla [1].
Question 3: Hyperaldosteronism is associated with all, except:
- A. Hypernatremia
- B. Hypertension
- C. Hypokalemia
- D. Metabolic acidosis (Correct Answer)
Explanation: ***Metabolic acidosis*** - **Hyperaldosteronism** leads to increased **potassium and hydrogen ion excretion** in the kidneys [1], resulting in **metabolic alkalosis**, not acidosis [2]. - The increased loss of hydrogen ions causes a rise in blood pH and bicarbonate levels [2]. *Hypernatremia* - Aldosterone promotes **sodium reabsorption** in the renal tubules, leading to increased plasma sodium concentration [1], [3]. - This increased sodium reabsorption contributes to the expansion of extracellular fluid volume and **hypertension** [3]. *Hypokalemia* - Aldosterone stimulates the **secretion of potassium ions** into the renal tubules, leading to excessive potassium loss in the urine [1]. - This sustained potassium excretion often results in **low serum potassium levels**. *Hypertension* - The increased reabsorption of **sodium and water** due to aldosterone action expands the extracellular fluid volume [3]. - This volume expansion directly contributes to elevated blood pressure, making hypertension a hallmark feature of **hyperaldosteronism** [2].
Question 4: Which test is essential in a patient with suspected Cushing's syndrome for diagnosis confirmation?
- A. Serum aldosterone
- B. Serum renin
- C. Plasma ACTH
- D. 24-hour urine cortisol (Correct Answer)
Explanation: ***24-hour urine cortisol*** - This test measures the **total amount of cortisol excreted** in the urine over a 24-hour period, reflecting the average daily cortisol production. [1] - An **elevated 24-hour urine free cortisol** is a primary diagnostic test to confirm hypercortisolism in suspected Cushing's syndrome. [1] *Serum aldosterone* - This test is primarily used in the diagnosis of **hyperaldosteronism**, such as Conn's syndrome, which causes hypertension and hypokalemia. - While related to the adrenal glands, **aldosterone levels are not directly used to diagnose Cushing's syndrome**. *Serum renin* - This test is part of the workup for **hypertension** and is used in conjunction with aldosterone to assess the **renin-angiotensin-aldosterone system**. - It is **not a direct or essential test** for the diagnosis of Cushing's syndrome. *Plasma ACTH* - While **plasma ACTH** is crucial for differentiating between different causes of Cushing's syndrome (e.g., ACTH-dependent vs. ACTH-independent), it is **not the initial diagnostic test to confirm the presence of hypercortisolism**. [2] - **Confirmation of cortisol excess** typically precedes ACTH measurement to determine the etiology. [2]
Question 5: Which of the following is a classic feature of pheochromocytoma?
- A. Headache (Correct Answer)
- B. Hyperkalemia
- C. Bradycardia
- D. Hypoglycemia
Explanation: ***Headache*** - Severe, pounding **headaches** are a classic symptom due to the paroxysmal release of **catecholamines** causing extreme hypertension. - This symptom is often one of the "P's" associated with pheochromocytoma: palpitations, perspiration, pallor, and paroxysmal hypertension. *Hyperkalemia* - **Hyperkalemia** is not typically associated with pheochromocytoma; rather, the excessive catecholamine release can sometimes cause stress-induced hypokalemia due to increased intracellular potassium shift. - The primary electrolyte imbalance to watch for is related to severe hypertension complications. *Bradycardia* - **Bradycardia** is generally not a feature of pheochromocytoma; instead, patients frequently experience **tachycardia** and **palpitations** due to the stimulatory effects of catecholamines on the heart. - The sympathetic nervous system activation leads to an increased heart rate. *Hypoglycemia* - **Hypoglycemia** is uncommon in pheochromocytoma; the excess catecholamines typically lead to **hyperglycemia** by promoting glycogenolysis and gluconeogenesis, and inhibiting insulin release. - This elevation in blood sugar can mimic diabetes, sometimes requiring insulin therapy.
Question 6: Which drug is generally considered the first-line treatment for pheochromocytoma?
- A. Prazosin
- B. Phentolamine
- C. Phenoxybenzamine (Correct Answer)
- D. Propranolol
Explanation: ***Phenoxybenzamine (Correct Answer)*** - **Phenoxybenzamine** is a **non-competitive, non-selective alpha-adrenergic blocker** and is considered the **first-line treatment for pheochromocytoma** to prevent hypertensive crises during surgery. - It **irreversibly blocks** both alpha-1 and alpha-2 adrenergic receptors, leading to **vasodilation** and prevention of catecholamine-induced vasoconstriction. - Its **long duration of action** and irreversible binding make it ideal for pre-operative preparation. *Propranolol (Incorrect)* - **Propranolol** is a **beta-blocker** that should **never be used first** in pheochromocytoma as primary treatment. - Blocking beta-2 receptors can lead to **unopposed alpha-adrenergic vasoconstriction**, potentially causing a **hypertensive crisis**. - Beta-blockers are only introduced **after adequate alpha-blockade** to manage tachycardia and arrhythmias. *Prazosin (Incorrect)* - **Prazosin** is a **selective alpha-1 blocker** and competitive antagonist that may not provide sufficient protection against the massive surge of catecholamines during surgery. - While it can lower blood pressure, its effect is **reversible** and **selective**, making it less reliable than non-selective, irreversible blockers in this critical setting. *Phentolamine (Incorrect)* - **Phentolamine** is a **short-acting, non-selective alpha blocker** typically used for acute management of **hypertensive crises** (e.g., during surgery or in critical care) rather than for pre-operative preparation. - Its **shorter duration of action** requires frequent dosing and makes it less suitable for the sustained alpha-blockade needed in the days leading up to pheochromocytoma surgery.
Question 7: Which of the following is the most prominent clinical manifestation of primary hyperaldosteronism (Conn's syndrome)?
- A. Hyperkalemia
- B. Hypertension (Correct Answer)
- C. Hypokalemia
- D. Expansion of Extracellular and Plasma volume
Explanation: ** Hypertension** - **Hypertension** is the most prominent and consistent clinical manifestation of primary hyperaldosteronism, present in nearly all patients. - The excessive aldosterone leads to increased **sodium reabsorption** and water retention, directly causing elevated blood pressure [2], [3]. *Hypokalemia* - While **hypokalemia** is common in primary hyperaldosteronism due to increased renal potassium excretion, it is not universally present and can be absent in a significant portion of patients (up to 30-50%). - Therefore, hypertension is a more reliable and prominent symptom for initial suspicion [3]. *Hyperkalemia* - **Hyperkalemia** is inconsistent with primary hyperaldosteronism; the hallmark of the condition is **potassium wasting** and **hypokalemia**, not elevated potassium levels [2]. - Aldosterone's primary role includes promoting potassium excretion, so hyperkalemia would indicate a different underlying pathology, such as adrenal insufficiency [2]. *Expansion of Extracellular and Plasma volume* - While increased aldosterone does lead to **expansion of extracellular and plasma volume** due to sodium and water retention, this is a physiological consequence that contributes to hypertension rather than being the most prominent *clinical manifestation* itself [1]. - Hypertension is the direct observable and measurable clinical symptom that drives investigation [3].
Question 8: All are seen in pheochromocytoma except which of the following?
- A. Headaches
- B. Weight loss
- C. Sweating attacks
- D. Hypotension (Correct Answer)
Explanation: ***Hypotension*** - Pheochromocytoma is characterized by the **overproduction of catecholamines** (epinephrine and norepinephrine), which typically cause **hypertension** rather than hypotension. - The classic symptoms of pheochromocytoma, often described as the "5 Ps," are **pain (headache)**, **palpitations**, **perspiration**, **pallor**, and **paroxysmal hypertension**. *Headaches* - **Severe, throbbing headaches** are a very common symptom in pheochromocytoma due to the **vasospastic effects** of high circulating catecholamines. - These headaches are often sudden in onset and can be debilitating. *Weight loss* - The **hypermetabolic state** induced by excessive catecholamines can lead to **increased caloric expenditure** and subsequently, **weight loss**. - Catecholamines increase **basal metabolic rate** and breakdown of fat stores. *Sweating attacks* - **Diaphoresis** or profuse sweating attacks are a hallmark symptom, caused by **sympathetic nervous system activation** due to high catecholamine levels. - These attacks are often paroxysmal and can be accompanied by an exacerbation of other symptoms.
Question 9: Which of the following statements about pheochromocytoma is true?
- A. Arises from chromaffin cells of adrenal medulla (Correct Answer)
- B. Bilateral in 20% of all cases
- C. Hypotension rules out pheochromocytoma
- D. Almost always a malignant tumor
Explanation: ***Arises from chromaffin cells of adrenal medulla*** - **Pheochromocytomas** are rare neuroendocrine tumors that develop from **chromaffin cells** found in the adrenal medulla. - These cells are responsible for synthesizing and secreting **catecholamines**, explaining the characteristic symptoms of pheochromocytoma. *Bilateral in 20% of all cases* - While pheochromocytomas can be bilateral, this occurs in about **10% of cases**, mostly associated with genetic syndromes like **MEN 2**. - A higher percentage of bilaterality is seen in **familial forms** of the disease, but not in all cases. *Hypotension rules out pheochromocytoma* - Although **hypertension** is a hallmark symptom, **hypotension** can occur, particularly **orthostatic hypotension** due to volume depletion and impaired vasoconstriction. - Rarely, **pheochromocytoma crisis** can present with **shock** due to massive catecholamine release and subsequent myocardial dysfunction or vasoplegia. *Almost always a malignant tumor* - Most pheochromocytomas are **benign**; only about **10-15%** are malignant. - Malignancy is suggested by the presence of **metastatic disease**, as histology alone cannot reliably differentiate between benign and malignant forms.
Question 10: What is the primary effect of beta blockers in the management of thyroid storm?
- A. Increases metabolism of thyroxine
- B. Blocks thyroxine receptors
- C. Decreases synthesis of thyroxine
- D. Provides rapid relief of symptoms (Correct Answer)
Explanation: Detailed management of thyrotoxic crisis (thyroid storm) is a medical emergency where patients should be given propranolol, either oral or intravenous, to manage life-threatening symptoms [1]. ***Provides rapid relief of symptoms*** - Beta blockers primarily address the **adrenergic manifestations** of thyroid storm, such as **tachycardia**, **tremors**, anxiety, and palpitations [1]. - By blocking **beta-adrenergic receptors**, they provide rapid symptomatic relief and reduce cardiovascular stress, without affecting hormone levels [2]. Thyroid hormones normally increase the expression of genes for beta-adrenergic receptors and G-proteins, leading to increased heart rate and force of contraction [2]. *Increases metabolism of thyroxine* - Beta blockers do not increase the **metabolism** or breakdown of thyroxine; their action is primarily on the **peripheral effects** of thyroid hormones. - While some beta blockers like **propranolol** can inhibit the peripheral conversion of T4 to T3, this is a secondary effect and not their primary role in providing rapid symptomatic relief [1]. *Blocks thyroxine receptors* - Beta blockers do not block **thyroxine receptors**; thyroid hormones exert their effects by binding to intracellular receptors, not adrenergic receptors [2]. - Their action is on the **adrenergic system**, which is overstimulated by the high levels of thyroid hormones. *Decreases synthesis of thyroxine* - Beta blockers do not directly decrease the **synthesis of thyroxine** by the thyroid gland. - That action is performed by **antithyroid drugs** like methimazole and propylthiouracil, which inhibit hormone production [1].
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