Endocrinology — MCQs

A 31-year-old woman presents with new-onset headaches and elevated blood pressure. She also reports episodic symptoms including palpitations, anxiety, and marked blood pressure elevation. Workup for secondary causes of hypertension reveals elevated urinary free catecholamines. What is the typical cardiovascular involvement in a patient with this systemic disease?

Q1266Easy

Obesity is associated with all of the following except?

Q1267Medium

Syndrome of Inappropriate secretion of Anti-Diuretic hormone (SIADH) may be seen in all of the following conditions except?

Q1268Easy

Diabetic neuropathy is a type of:

Q1269Medium

If a normal individual receives an insulin injection that lowers plasma glucose to 30 mg/dl, which of the following hormones will NOT be released?

Q1270Easy

Which of the following is seen in Vitamin D deficiency?

Endocrinology Indian Medical PG Practice Questions and MCQs

Question 1261: What is the most common ophthalmic complication of diabetes mellitus?

A. Retinopathy (Correct Answer)
B. Cataract
C. Rubeosis iridis
D. Vitreous hemorrhage

Explanation: **Explanation:** **1. Why Retinopathy is the Correct Answer:** Diabetic Retinopathy (DR) is the most common microvascular complication of diabetes mellitus and the leading cause of blindness in the working-age population [1]. It occurs due to chronic hyperglycemia leading to basement membrane thickening, pericyte loss, and microaneurysm formation. Epidemiologically, nearly all patients with Type 1 Diabetes and >60% of patients with Type 2 Diabetes will develop some degree of retinopathy after 20 years of disease duration. **2. Analysis of Incorrect Options:** * **B. Cataract:** While diabetics develop cataracts earlier and more frequently (due to sorbitol accumulation in the lens via the polyol pathway), it is less common than the baseline incidence of retinopathy. * **C. Rubeosis iridis:** This refers to neovascularization of the iris. It is a late-stage complication usually secondary to severe proliferative diabetic retinopathy (PDR) and is much rarer than retinopathy itself [1]. * **D. Vitreous hemorrhage:** This is a specific complication of Proliferative Diabetic Retinopathy (PDR) caused by the rupture of fragile new vessels [1]. It is a consequence of advanced disease, not the most common finding. **3. High-Yield Clinical Pearls for NEET-PG:** * **Earliest Clinical Sign:** Microaneurysms (seen as red dots on fundoscopy) [1]. * **Earliest Pathological Sign:** Loss of pericytes and basement membrane thickening. * **Classification:** Divided into Non-Proliferative (NPDR) and Proliferative (PDR). The hallmark of PDR is **Neovascularization** [1]. * **Screening Guidelines:** * Type 1 DM: 5 years after diagnosis. * Type 2 DM: At the time of diagnosis (as the duration of hyperglycemia is often unknown). * **Most common cause of vision loss in DM:** Macular Edema (can occur at any stage of NPDR or PDR) [1].

Question 1262: What is a subtle presentation of hyperparathyroidism?

A. Psychiatric manifestation
B. Nephrocalcinosis
C. Abdominal pain
D. Asymptomatic hypercalcemia (Correct Answer)

Explanation: **Explanation:** Primary Hyperparathyroidism (PHPT) is most commonly caused by a solitary parathyroid adenoma. In the modern era of routine biochemical screening, the clinical profile of the disease has shifted significantly. **Why D is the correct answer:** **Asymptomatic hypercalcemia** is now the most common presentation of PHPT (found in >80% of cases). Most patients are identified incidentally during routine blood tests (e.g., a comprehensive metabolic panel) showing elevated serum calcium and inappropriately high or normal PTH levels. These patients lack the classic "bones, stones, abdominal groans, and psychic moans" and are clinically "subtle" or asymptomatic. **Why other options are incorrect:** * **B (Nephrocalcinosis) & C (Abdominal pain):** These represent the "Stones" and "Groans" of the classic tetrad. Nephrocalcinosis and peptic ulcer disease/pancreatitis are late-stage, overt complications of chronic, severe hypercalcemia, rather than subtle presentations. * **A (Psychiatric manifestation):** Known as "Psychic moans" (depression, fatigue, or confusion), these occur in symptomatic disease. While they can be vague, they are considered part of the established clinical syndrome rather than the most common subtle finding. **NEET-PG High-Yield Pearls:** * **Most common cause:** Solitary Adenoma (85-90%). * **Classic X-ray finding:** Subperiosteal bone resorption (most common in the radial aspect of middle phalanges) and "Salt and pepper" skull. * **Brown Tumors:** Also known as Osteitis Fibrosa Cystica; these are non-neoplastic lesions due to increased osteoclast activity. * **Biochemical Hallmark:** ↑ Serum Calcium, ↓ Serum Phosphate, ↑ PTH, and ↑ Urinary cAMP. * **Hungry Bone Syndrome:** A common post-operative complication after parathyroidectomy characterized by severe hypocalcemia.

Question 1263: Which of the following tests is best for differentiating an ACTH-secreting pituitary tumor from ectopic ACTH production?

A. 24-hour urinary free cortisol
B. Overnight dexamethasone suppression test
C. Low-dose dexamethasone suppression test
D. High-dose dexamethasone suppression test (Correct Answer)

Explanation: ### Explanation The diagnostic approach to Cushing’s syndrome follows a stepwise protocol: first, confirming hypercortisolism, and second, determining the etiology (ACTH-dependent vs. independent) [1]. **Why Option D is Correct:** The **High-Dose Dexamethasone Suppression Test (HDDST)** is used to differentiate between ACTH-dependent causes [3]. Pituitary adenomas (Cushing’s Disease) retain some degree of negative feedback sensitivity. Therefore, a high dose of dexamethasone (8 mg) is sufficient to suppress cortisol levels (usually by >50%). In contrast, **Ectopic ACTH production** (e.g., small cell lung cancer) is autonomous and does not respond to negative feedback, resulting in no cortisol suppression. **Why Other Options are Incorrect:** * **Options A, B, and C:** These are **screening tests** used to establish the diagnosis of Cushing’s syndrome (hypercortisolism) [1]. They cannot differentiate the source of ACTH [2]. * **24-hour Urinary Free Cortisol (UFC):** Measures integrated cortisol excretion [1]. * **Overnight/Low-Dose DST (LDDST):** Demonstrates the loss of normal negative feedback; failure to suppress cortisol confirms Cushing’s syndrome but not the cause [1]. **NEET-PG High-Yield Pearls:** * **Gold Standard:** The most accurate test to differentiate pituitary vs. ectopic ACTH is **Inferior Petrosal Sinus Sampling (IPSS)** with CRH stimulation. * **CRH Stimulation Test:** Pituitary tumors respond with a rise in ACTH/cortisol; ectopic sources do not. * **Imaging:** Once HDDST suggests a pituitary source, an MRI brain is the next step [3]. If it suggests ectopic, CT Chest/Abdomen is indicated. * **Classic Association:** Ectopic ACTH is frequently associated with profound hypokalemia and very high hyperpigmentation compared to Cushing’s disease.

Question 1264: What is true about diabetic nephropathy?

A. Microalbuminuria is not an indicator of long-term cardiovascular morbidity.
B. Strict glycemic control cannot prevent microalbuminuria.
C. Pancreatic transplantation can improve proteinuria in the early stage. (Correct Answer)
D. Angiotensin receptor blockers have no additive advantage over other drugs except for blood pressure control.

Explanation: ### Explanation **Correct Option: C. Pancreatic transplantation can improve proteinuria in the early stage.** Pancreatic transplantation is the only treatment that can achieve a truly euglycemic state. In the early stages of diabetic nephropathy (functional stage), achieving normoglycemia through transplantation can reverse glomerular hyperfiltration and significantly reduce or stabilize proteinuria. While it may not reverse established, advanced glomerulosclerosis, it effectively halts the progression of early-stage microvascular complications. **Analysis of Incorrect Options:** * **Option A:** Microalbuminuria (30–300 mg/day) is a potent independent predictor of **cardiovascular morbidity and mortality** [3] in both Type 1 and Type 2 diabetics. It reflects generalized endothelial dysfunction. * **Option B:** Large-scale trials like **DCCT (Type 1)** and **UKPDS (Type 2)** [2] have conclusively proven that strict glycemic control (maintaining HbA1c <7%) significantly reduces the risk of developing microvascular complications and slows the progression of albuminuria [1]. * **Option D:** ACE inhibitors and ARBs are the **drugs of choice** for diabetic nephropathy. Beyond blood pressure control, they provide a specific **renoprotective effect** [4] by dilating the efferent arteriole, thereby reducing intraglomerular pressure and decreasing protein excretion. **High-Yield Clinical Pearls for NEET-PG:** * **First clinical sign:** Microalbuminuria (Stage 3 of Mogensen’s classification) [1]. * **Earliest change (Histology):** Basement membrane thickening [1]. * **Most specific change (Histology):** Kimmelstiel-Wilson (KW) nodules (nodular glomerulosclerosis) [1]. * **Screening:** Annual screening for microalbuminuria should start 5 years after diagnosis in Type 1 DM and at the time of diagnosis in Type 2 DM [1]. * **Target BP:** Generally <130/80 mmHg in patients with proteinuria [4].

Question 1265: A 31-year-old woman presents with new-onset headaches and elevated blood pressure. She also reports episodic symptoms including palpitations, anxiety, and marked blood pressure elevation. Workup for secondary causes of hypertension reveals elevated urinary free catecholamines. What is the typical cardiovascular involvement in a patient with this systemic disease?

A. Focal myocardial necrosis (Correct Answer)
B. Proximal aortitis
C. Endothelial plaques
D. Systolic scratchy sound

Explanation: The clinical presentation of episodic hypertension, palpitations, anxiety, and elevated urinary catecholamines is classic for **Pheochromocytoma**. This catecholamine-secreting tumor (usually of the adrenal medulla) leads to significant cardiovascular morbidity. **1. Why Focal Myocardial Necrosis is correct:** Chronic or paroxysmal exposure to high levels of circulating catecholamines (epinephrine and norepinephrine) causes direct toxic effects on the myocardium. This leads to **"Catecholamine Myocarditis,"** characterized by focal myocardial necrosis, mononuclear cell infiltration, and interstitial fibrosis. This damage can manifest as Takotsubo-like cardiomyopathy, arrhythmias, or congestive heart failure. **2. Why the other options are incorrect:** * **Proximal aortitis:** This is typically associated with large-vessel vasculitides like Takayasu arteritis or Syphilis, not catecholamine excess. * **Endothelial plaques:** While hypertension accelerates atherosclerosis (plaque formation), it is a chronic, non-specific process [2]. Focal necrosis is the specific, "typical" pathological hallmark of pheochromocytoma-induced heart disease. * **Systolic scratchy sound:** This refers to a pericardial friction rub (pericarditis) or the Hamman sign (pneumomediastinum). Pheochromocytoma does not typically cause pericardial inflammation. **High-Yield Clinical Pearls for NEET-PG:** * **Rule of 10s:** 10% bilateral, 10% malignant, 10% extra-adrenal (Paraganglioma), 10% pediatric, and 10% familial. * **Diagnosis:** Best initial screening test is **Plasma free metanephrines**; most specific is **24-hour urinary metanephrines** [1]. * **Management:** Always start **Alpha-blockers first** (e.g., Phenoxybenzamine) for 10-14 days before Beta-blockers to avoid a hypertensive crisis (unopposed alpha-stimulation) [1]. * **Associated Syndromes:** MEN 2A, MEN 2B, von Hippel-Lindau (VHL), and NF-1.

Question 1266: Obesity is associated with all of the following except?

A. Osteoarthritis
B. Hypertension
C. Gall stones
D. Pancreatitis (Correct Answer)

Explanation: The correct answer is **Pancreatitis**. While obesity is a major risk factor for several metabolic and mechanical disorders, it is not a direct cause of pancreatitis. However, obesity can indirectly increase the risk of pancreatitis by predisposing individuals to **gallstones** (biliary pancreatitis) or **hypertriglyceridemia**. Furthermore, if pancreatitis occurs in an obese patient, it tends to follow a more severe clinical course with a higher risk of complications, but obesity itself is not listed as a primary etiology in standard classifications. **Analysis of Incorrect Options:** * **Osteoarthritis:** Obesity increases mechanical loading on weight-bearing joints (knees/hips). Additionally, adipose tissue releases pro-inflammatory cytokines (adipokines) that contribute to cartilage degradation [1]. * **Hypertension:** Obesity leads to increased sympathetic nervous system activity, activation of the Renin-Angiotensin-Aldosterone System (RAAS), and physical compression of the kidneys by visceral fat, all of which elevate blood pressure [1]. * **Gallstones:** Obesity increases the hepatic synthesis and biliary secretion of cholesterol, leading to supersaturation of bile and the formation of cholesterol stones. **NEET-PG High-Yield Pearls:** * **Pickwickian Syndrome:** Also known as Obesity Hypoventilation Syndrome; characterized by the triad of obesity, daytime hypercapnia, and sleep-disordered breathing. * **Metabolic Syndrome (ATP III Criteria):** Requires 3 out of 5: Abdominal obesity, High Triglycerides, Low HDL, Hypertension, and High Fasting Glucose [1]. * **Cancer Risk:** Obesity is strongly linked to cancers of the endometrium, breast (post-menopausal), colon, and esophagus (adenocarcinoma).

Question 1267: Syndrome of Inappropriate secretion of Anti-Diuretic hormone (SIADH) may be seen in all of the following conditions except?

A. Use of vincristine
B. Oat cell carcinoma of lung
C. Acute attack of porphyria
D. Primary pulmonary emphysema (Correct Answer)

Explanation: **Explanation:** SIADH is characterized by the excessive release of ADH (Vasopressin) from the posterior pituitary or an ectopic source, leading to water retention, dilutional hyponatremia, and concentrated urine [1]. **Why Primary Pulmonary Emphysema is the Correct Answer:** SIADH is commonly associated with pulmonary pathologies that disrupt normal physiology (like infections or tumors), but **Primary Pulmonary Emphysema** (a form of COPD) is typically **not** a cause. In fact, severe COPD can sometimes lead to compensatory mechanisms that differ from the unregulated water retention seen in SIADH. **Analysis of Incorrect Options:** * **Oat Cell Carcinoma (Small Cell Lung Cancer):** This is the most common cause of ectopic ADH production. The tumor cells directly secrete ADH, making it a classic paraneoplastic syndrome. * **Use of Vincristine:** Several drugs trigger SIADH by either increasing ADH release or enhancing the kidney's sensitivity to it. Vincristine (vinca alkaloid) is a high-yield causative agent, along with Cyclophosphamide and SSRIs. * **Acute Attack of Porphyria:** Acute Intermittent Porphyria (AIP) can cause hypothalamic damage during an attack, leading to the inappropriate release of ADH. **NEET-PG High-Yield Pearls:** 1. **Diagnostic Criteria:** Look for hyponatremia, low serum osmolality (<275 mOsm/kg), and inappropriately high urine osmolality (>100 mOsm/kg) in a **euvolemic** patient [1]. 2. **CNS Causes:** Stroke, trauma, and meningitis are frequent triggers. 3. **Treatment:** Fluid restriction is the first-line treatment. For severe cases, Vaptans (Vasopressin receptor antagonists) or hypertonic saline are used. 4. **Caution:** Rapid correction of hyponatremia can lead to **Osmotic Demyelination Syndrome (Central Pontine Myelinolysis).**

Question 1268: Diabetic neuropathy is a type of:

A. Distal symmetric sensory polyneuropathy
B. Mononeuritis
C. Autonomic neuropathy
D. All of the above (Correct Answer)

Explanation: Diabetic neuropathy is a common microvascular complication of diabetes mellitus, resulting from chronic hyperglycemia leading to nerve ischemia and metabolic derangement (polyol pathway). It is not a single entity but a spectrum of disorders affecting different parts of the nervous system [1]. **Explanation of Options:** * **A. Distal Symmetric Sensory Polyneuropathy (DSPN):** This is the most common clinical presentation [1]. It typically follows a "stocking-and-glove" distribution, starting in the toes and progressing proximally. It primarily involves sensory loss and paresthesia. * **B. Mononeuritis:** Diabetes can cause focal nerve damage. This includes cranial mononeuropathies (CN III is most common, typically pupil-sparing) or compression neuropathies like Carpal Tunnel Syndrome [3]. Mononeuritis multiplex can also occur. * **C. Autonomic Neuropathy:** This affects the involuntary nervous system, leading to resting tachycardia, orthostatic hypotension, gastroparesis, diabetic diarrhea, and erectile dysfunction [2]. Since diabetic neuropathy encompasses all these patterns, **Option D (All of the above)** is the correct answer. **High-Yield Clinical Pearls for NEET-PG:** * **Earliest Sign:** Loss of vibration sense (tested with a 128 Hz tuning fork) and loss of ankle jerk reflex [1]. * **Screening:** The 10g Semmes-Weinstein monofilament test is the gold standard for identifying a "foot at risk" for ulceration. * **Cranial Nerve III Palsy:** In diabetes, the pupillary reflex is usually **preserved** because the parasympathetic fibers are peripheral and receive a separate blood supply. * **Treatment:** First-line agents for painful neuropathy include Pregabalin, Duloxetine, or Amitriptyline. Tight glycemic control is the only way to prevent progression.

Question 1269: If a normal individual receives an insulin injection that lowers plasma glucose to 30 mg/dl, which of the following hormones will NOT be released?

A. ACTH
B. Epinephrine
C. Growth hormone
D. Aldosterone (Correct Answer)

Explanation: ### Explanation The physiological response to hypoglycemia involves the activation of the **counter-regulatory hormone system**, which aims to restore blood glucose levels [1]. **Why Aldosterone is the Correct Answer:** Aldosterone is a mineralocorticoid primarily regulated by the **Renin-Angiotensin-Aldosterone System (RAAS)** and plasma potassium levels [1], [2]. Its primary function is sodium retention and potassium excretion, not glucose homeostasis. Hypoglycemia does not stimulate the RAAS or the adrenal cortex to release aldosterone; therefore, it is the only hormone among the options that is not part of the acute counter-regulatory response. **Analysis of Incorrect Options:** * **Epinephrine (Option B):** This is the **first-line** rapid response hormone [1]. Hypoglycemia triggers the sympathetic nervous system, leading to adrenal medullary release of epinephrine, which promotes glycogenolysis and gluconeogenesis [3], [4]. * **ACTH (Option A):** Hypoglycemia is a potent stressor that activates the Hypothalamic-Pituitary-Adrenal (HPA) axis [3]. The anterior pituitary releases ACTH, which stimulates the adrenal cortex to produce **Cortisol**. Cortisol acts as a late-phase counter-regulatory hormone [1]. * **Growth Hormone (Option C):** GH is released from the anterior pituitary in response to falling glucose levels. It decreases peripheral glucose utilization and promotes lipolysis, helping to maintain blood sugar during prolonged hypoglycemia [1]. **NEET-PG High-Yield Pearls:** 1. **Hierarchy of Response:** The first defense against hypoglycemia is the suppression of endogenous insulin, followed by a rise in **Glucagon** (most important) and **Epinephrine** [1]. 2. **Whipple’s Triad:** Used for diagnosing hypoglycemia—symptoms of hypoglycemia, low plasma glucose (<55 mg/dl), and relief of symptoms after glucose administration. 3. **Growth Hormone & Cortisol:** These are "permissive" or delayed counter-regulatory hormones, typically acting 4–6 hours after the onset of hypoglycemia [1].

Question 1270: Which of the following is seen in Vitamin D deficiency?

A. Increased alkaline phosphatase (Correct Answer)
B. Decreased phosphate in urine
C. Hyperphosphatemia
D. Decreased alkaline phosphatase

Explanation: Vitamin D deficiency leads to decreased intestinal absorption of calcium and phosphate [1]. This triggers a physiological cascade essential for NEET-PG preparation: 1. **Why Option A is Correct:** Low serum calcium stimulates the parathyroid glands to secrete **Parathyroid Hormone (PTH)** (Secondary Hyperparathyroidism) [2]. PTH increases bone remodeling and osteoblastic activity to mobilize calcium. **Alkaline Phosphatase (ALP)** is a byproduct of osteoblastic activity; therefore, its levels rise significantly as the bone attempts to compensate for the mineral deficit. This is often the earliest biochemical marker of osteomalacia/rickets. 2. **Why Options B and C are Incorrect:** * **Hypophosphatemia (Not Hyperphosphatemia):** While Vitamin D deficiency reduces phosphate absorption, the secondary hyperparathyroidism further worsens this by causing **phosphaturia** (increased phosphate excretion in urine) by inhibiting the sodium-phosphate cotransporter in the proximal tubule [3, 4]. * **Increased Urine Phosphate (Not Decreased):** Due to the action of PTH on the kidneys, phosphate clearance increases, leading to low serum phosphate levels [2]. 3. **Why Option D is Incorrect:** Decreased ALP is rare and seen in conditions like hypophosphatasia or profound malnutrition, whereas Vitamin D deficiency characteristically shows elevated ALP [4]. **High-Yield Clinical Pearls for NEET-PG:** * **Biochemical Profile of Vitamin D Deficiency:** ↓ Serum Calcium (or normal in early stages) [1], ↓ Serum Phosphate, ↑ PTH, and **↑ Alkaline Phosphatase** [4]. * **Urinary Findings:** Increased phosphate and increased cAMP in urine. * **Radiological Sign:** Look for **Looser’s zones** (pseudofractures) in osteomalacia [4] and **cupping/fraying** of metaphyses in rickets [1]. * **Golden Rule:** In any metabolic bone disease involving high bone turnover (except Multiple Myeloma), ALP is typically elevated.

Practice by Chapter

Diabetes Mellitus

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Thyroid Disorders

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Adrenal Gland Disorders

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Pituitary Disorders

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Calcium and Bone Metabolism

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Reproductive Endocrinology

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Lipid Disorders

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Endocrine Hypertension

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Multiple Endocrine Neoplasia

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Obesity and Metabolic Syndrome

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Neuroendocrine Tumors

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Endocrine Emergencies

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