Endocrinology — MCQs

Endocrinology Indian Medical PG Practice Questions and MCQs

Question 1461: A patient presents with muscle weakness and fatigue. Laboratory results show hyperkalemia. Which hormone is most likely deficient in this patient?

A. Aldosterone (Correct Answer)
B. Cortisol
C. Insulin
D. Thyroxine (T4)

Explanation: ***Aldosterone*** - **Aldosterone deficiency** leads to impaired renal potassium excretion, resulting in **hyperkalemia** [1]. - It also causes **sodium wasting** and **hypotension**, contributing to symptoms like fatigue and weakness due to **volume depletion** [1]. *Cortisol* - **Cortisol deficiency** (e.g., in Addison's disease) often presents with **hyponatremia**, **hypotension**, and generalized weakness, but typically does not cause hyperkalemia directly [1]. - While fatigue and weakness are prominent, severe hyperkalemia is not its primary metabolic derangement related to electrolyte balance. *Insulin* - **Insulin deficiency** (e.g., in Type 1 Diabetes) primarily leads to **hyperglycemia** and metabolic acidosis [1]. - Although it can cause electrolyte imbalances like **hypokalemia** (due to intracellular shift during treatment), it does not directly cause hyperkalemia via its primary mechanism of action. *Thyroxine (T4)* - **Thyroxine deficiency** (hypothyroidism) presents with symptoms such as fatigue, weight gain, cold intolerance, and bradycardia. - It does not directly cause **hyperkalemia**; electrolyte disturbances are not a prominent feature of primary hypothyroidism.

Question 1462: A patient with a history of type 2 diabetes and peripheral neuropathy presents with a red, swollen left foot, with no open wounds present. What is the most appropriate treatment?

A. Blood sugar optimization and routine follow-up
B. Oral antibiotics and close monitoring
C. Immediate immobilization and non-weight bearing with urgent imaging (Correct Answer)
D. Topical anti-inflammatory cream and elevation

Explanation: **_Immediate immobilization and non-weight bearing with urgent imaging_** - The presentation of a **red, swollen foot** in a diabetic patient with **peripheral neuropathy** and no open wounds is highly suggestive of acute **Charcot neuroarthropathy** [1]. - **Urgent immobilization** and **non-weight bearing** are essential to prevent further joint destruction, and imaging (e.g., X-ray, MRI) is crucial for diagnosis and assessing severity. *Oral antibiotics and close monitoring* - While diabetic foot infections are common, the absence of **open wounds** and the primary presentation as diffuse swelling and redness make infection less likely as the sole immediate diagnosis [1]. - Initiating antibiotics without evidence of infection or Charcot diagnosis could delay appropriate management and potentially contribute to antibiotic resistance. *Blood sugar optimization and routine follow-up* - **Blood sugar optimization** is vital for long-term diabetes management and prevention of complications, but it does not address the acute, destructive process of Charcot neuroarthropathy. - **Routine follow-up** is insufficient for an acute condition that can rapidly progress to severe deformity and disability if not managed urgently. *Topical anti-inflammatory cream and elevation* - **Topical anti-inflammatory creams** and **elevation** are insufficient for managing the significant inflammation and bone/joint changes associated with Charcot neuroarthropathy. - This approach would lead to inadequate treatment, allowing for continued joint destruction and worsening of the condition.

Question 1463: A 28-year-old male presents with muscle weakness and a history of difficulty climbing stairs. His serum potassium level is elevated. Which of the following conditions is most likely associated with hyperkalemia?

A. Addison's disease (Correct Answer)
B. Hypothyroidism
C. Primary hyperaldosteronism
D. Cushing's syndrome

Explanation: **Addison's disease** - Addison's disease (primary adrenal insufficiency) leads to decreased production of **aldosterone**, a hormone responsible for sodium reabsorption and potassium excretion [2]. - The resulting **aldosterone deficiency** causes **hyperkalemia** (elevated potassium) and hyponatremia [1]. *Cushing's syndrome* - Cushing's syndrome is characterized by **excess cortisol** production, which often has mineralocorticoid effects, leading to **hypokalemia** (low potassium). - It typically presents with muscle weakness, but the serum potassium level would be low, not elevated [3]. *Primary hyperaldosteronism* - This condition involves **excessive aldosterone** production, causing increased sodium reabsorption and significant **potassium excretion** [1]. - This leads to **hypokalemia**, often with hypertension, which is the opposite of the patient's presentation [3]. *Hypothyroidism* - Severe hypothyroidism can sometimes cause mild electrolyte disturbances, but it is **not typically associated with significant hyperkalemia**. - Muscle weakness in hypothyroidism is common, but the underlying mechanism for hyperkalemia is not directly related to thyroid hormone deficiency.

Question 1464: A 60-year-old female with hypothyroidism complains of increased lethargy and constipation. Her TSH level is elevated. What is the best management approach?

A. Reduce levothyroxine dose
B. Increase levothyroxine dosage (Correct Answer)
C. Start liothyronine therapy
D. Check TSH in 3 months

Explanation: ***Increase levothyroxine dosage*** - An **elevated TSH level** indicates that the thyroid gland is understimulated, despite the patient being on thyroid hormone replacement, implying **hypothyroidism** is not adequately controlled [1]. - Symptoms like **increased lethargy** and **constipation** are classic signs of persistent or worsening hypothyroidism, necessitating an increase in the **levothyroxine dose** [1] to achieve euthyroid status. *Reduce levothyroxine dose* - **Reducing levothyroxine** would worsen the underlying hypothyroidism, leading to a further increase in TSH and exacerbation of symptoms. - This action is appropriate only if the TSH were suppressed (low) or the patient showed signs of **hyperthyroidism** [1]. *Start liothyronine therapy* - **Liothyronine (T3)** is typically reserved for patients who do not respond adequately to levothyroxine (T4) therapy alone or in specific situations like myxedema coma. - In this case, optimizing the **levothyroxine dose** is the first-line and most effective approach; there is no indication that the patient requires T3. *Check TSH in 3 months* - While regular monitoring of TSH is crucial, simply waiting for 3 months without any intervention is inappropriate given the patient's existing **symptoms** and currently **elevated TSH**. - An immediate adjustment in the dose is needed [1], followed by re-evaluation of TSH and clinical status, typically within 6-8 weeks [1], to ensure therapeutic effectiveness.

Question 1465: A 34-year-old woman presents with palpitations, weight loss, and heat intolerance. Physical examination reveals a diffusely enlarged thyroid. The initial laboratory test to confirm the diagnosis would be:

A. Thyroid-stimulating hormone (TSH) level (Correct Answer)
B. Thyroid ultrasound
C. Radioactive iodine uptake
D. Serum thyroglobulin

Explanation: Thyroid-stimulating hormone (TSH) level - A **suppressed TSH level** is the most sensitive and specific initial screening test for **hyperthyroidism**, which is suggested by the patient's symptoms of palpitations, weight loss, and heat intolerance [2]. - In primary hyperthyroidism, the excessive production of thyroid hormones (T3 and T4) by the thyroid gland causes negative feedback on the pituitary, leading to a **decrease in TSH secretion** [1]. *Thyroid ultrasound* - A thyroid ultrasound provides information about the **structure** and **morphology** of the thyroid gland, such as nodularity or diffuse enlargement. - While it can confirm diffuse enlargement, it does not directly assess thyroid function or confirm the diagnosis of hyperthyroidism, which requires **biochemical testing** [1]. *Radioactive iodine uptake* - This test is used to determine the **etiology of hyperthyroidism** by measuring the thyroid gland's ability to take up iodine, helping differentiate between conditions like Graves' disease and thyroiditis [1]. - It is typically performed **after** hyperthyroidism has been biochemically confirmed (e.g., with TSH and free T4 levels) to guide treatment. *Serum thyroglobulin* - **Serum thyroglobulin** is primarily used as a tumor marker for monitoring patients with **differentiated thyroid cancer** after thyroidectomy. - Although it can be elevated in various thyroid conditions, it is not a direct measure of thyroid function and is therefore not the initial test to confirm hyperthyroidism.

Question 1466: A patient with a history of radiation exposure presents with fatigue and weight loss. Which hormone deficiency is most commonly associated with cranial radiation therapy?

A. Growth hormone deficiency (Correct Answer)
B. Prolactin deficiency
C. Gonadotropin deficiency
D. ACTH deficiency

Explanation: **Growth hormone deficiency** - The **somatotrophs** in the pituitary gland, which produce growth hormone, are the most sensitive to the effects of **radiation therapy**, making growth hormone deficiency the earliest and most common endocrine abnormality to develop after cranial radiation. - Symptoms such as **fatigue** and **weight loss** can be manifestations of growth hormone deficiency, although they are nonspecific and require further investigation. *Prolactin deficiency* - While prolactin-producing cells (lactotrophs) can be affected by radiation, **prolactin deficiency** is less common than growth hormone deficiency and typically presents with symptoms related to lactation failure. - There is no strong direct association between prolactin deficiency and the presented symptoms of fatigue and weight loss. *Gonadotropin deficiency* - Deficiency of gonadotropins (LH and FSH) can occur due to radiation damage to the **gonadotrophs**, leading to hypogonadism. - Symptoms often include **sexual dysfunction**, **infertility**, and changes in secondary sexual characteristics, which are not the primary complaints here. *ACTH deficiency* - **ACTH deficiency** due to radiation damage to the **corticotrophs** is possible but typically occurs later than growth hormone deficiency. - It can lead to **adrenal insufficiency** with symptoms like severe fatigue, weakness, hypotension, and electrolyte disturbances, which are more critical than the general symptoms described.

Question 1467: A 63-year-old female with a history of osteoporosis presents with worsening back pain and weight loss. MRI shows multiple vertebral fractures and compression deformities. Which treatment option is most appropriate for this patient?

A. Calcium and vitamin D supplementation, defer further treatment
B. Initiate bisphosphonates to reduce further bone loss (Correct Answer)
C. Spinal surgery, then reassess bone health
D. Start anabolic agents like teriparatide to build bone mass

Explanation: ***Initiate bisphosphonates to reduce further bone loss*** - Bisphosphonates are **first-line therapy** for osteoporosis, especially in patients with **vertebral fractures**, as they reduce bone resorption and the risk of future fractures [1]. - While weight loss and multiple fractures might raise concern for other etiologies, addressing the established **osteoporosis** with proven anti-resorptive therapy is the immediate and most appropriate step. *Calcium and vitamin D supplementation, defer further treatment* - While essential for bone health, **calcium and vitamin D supplementation alone** is insufficient to treat severe osteoporosis with existing vertebral fractures [1]. - Deferring further specific treatment for osteoporosis would leave the patient at **high risk for additional fractures** and worsening pain and disability [1]. *Spinal surgery, then reassess bone health* - **Spinal surgery** is considered for specific indications such as **spinal instability**, neurological compromise, or intractable pain not responding to conservative management, which are not explicitly mentioned as primary concerns. - Addressing the underlying **osteoporosis** with medication is crucial regardless of surgical intervention, as surgery does not treat the systemic bone disease. *Start anabolic agents like teriparatide to build bone mass* - **Anabolic agents like teriparatide** are potent therapies that stimulate bone formation and are highly effective; however, they are typically reserved for patients with very severe osteoporosis, those who have failed bisphosphonate therapy, or those with very high fracture risk. - Given the established osteoporosis and new fractures, initiating **bisphosphonates** is the more common and generally recommended initial approach before considering more specialized anabolic agents.

Question 1468: Which treatment option would be most effective in managing a patient with hypoaldosteronism?

A. Sodium restriction
B. Potassium supplements
C. Fludrocortisone administration (Correct Answer)
D. Increased water intake

Explanation: ***Fludrocortisone administration*** - **Fludrocortisone** is a synthetic **mineralocorticoid** that mimics the action of **aldosterone**, effectively replacing the deficient hormone in hypoaldosteronism. - It helps to **retain sodium** and water, and excrete potassium, thereby correcting the electrolyte imbalances associated with the condition [1]. *Sodium restriction* - Patients with **hypoaldosteronism** already have difficulty retaining sodium due to the lack of aldosterone, leading to **hyponatremia** and fluid loss [1]. - **Restricting sodium** intake would worsen these symptoms and is contraindicated. *Potassium supplements* - **Hypoaldosteronism** typically causes **hyperkalemia** (high potassium levels) because aldosterone normally promotes potassium excretion [1]. - Therefore, **potassium supplements** would exacerbate the existing hyperkalemia and are harmful. *Increased water intake* - While patients may experience some degree of dehydration due to sodium and water loss, simply **increasing water intake** without addressing the underlying sodium deficiency can lead to **dilutional hyponatremia** [2]. - This approach does not correct the core problem of mineralocorticoid deficiency and its electrolyte imbalances.

Question 1469: A patient presents with signs of Cushing's syndrome. Which hormone is primarily responsible for this condition?

A. Aldosterone
B. Cortisol (Correct Answer)
C. Thyroxine
D. Insulin

Explanation: ***Cortisol*** - **Cushing's syndrome** is primarily caused by prolonged exposure to **high levels of cortisol**, leading to a characteristic set of signs and symptoms [1]. - **Cortisol** is a glucocorticoid hormone involved in stress response, metabolism, and immune function, and its excess disrupts these processes [1]. *Aldosterone* - **Aldosterone** is a mineralocorticoid hormone involved in **sodium and potassium balance**, and its excess leads to conditions like Conn's syndrome (**hyperaldosteronism**), not Cushing's syndrome [2]. - Symptoms of **hyperaldosteronism** include hypertension and hypokalemia, which differ from the classic features of Cushing's syndrome. *Thyroxine* - **Thyroxine** is a thyroid hormone that regulates metabolism; its excess causes **hyperthyroidism**, characterized by weight loss, tachycardia, and heat intolerance. - **Hyperthyroidism** symptoms are distinct from the weight gain, central obesity, and hyperglycemia seen in **Cushing's syndrome**. *Insulin* - **Insulin** is a pancreatic hormone responsible for glucose uptake by cells; its deficiency or resistance causes **diabetes mellitus**. - While **hyperglycemia** can occur in Cushing's syndrome due to cortisol's effects, **insulin itself is not the primary hormone** responsible for the syndrome's overall pathogenesis.

Question 1470: A 30-year-old female presents with difficulty swallowing and a sensation of a lump in her throat. Examination reveals a large, non-tender thyroid mass. What is the most appropriate next step in management?

A. Thyroid function tests
B. CT scan of the neck
C. Ultrasound of the neck (Correct Answer)
D. Fine needle aspiration biopsy

Explanation: ***Ultrasound of the neck*** - An **ultrasound** is the most appropriate initial imaging study for evaluating a **thyroid mass**, as it can characterize the size, number, and features of nodules, identifying suspicious characteristics [1]. - It helps distinguish between **cystic** and **solid lesions** and guides further procedures like **fine needle aspiration (FNA)** [1]. *Thyroid function tests* - While important for assessing **thyroid hormone levels** and identifying hyper- or hypothyroidism, they do not characterize the **mass itself** or its potential for malignancy [1]. - An abnormal thyroid function test does not negate the need for anatomical evaluation of the mass. *CT scan of the neck* - A **CT scan** is typically reserved for evaluating the **extent of a large or complex thyroid mass** once malignancy is suspected, particularly for assessing tracheal compression or metastatic disease [2]. - It exposes the patient to **radiation** and is not the first-line imaging modality for initial characterization of a palpable thyroid nodule. *Fine needle aspiration biopsy* - **FNA biopsy** is crucial for obtaining tissue for **histopathological analysis** to determine if a nodule is benign or malignant [1]. - However, it should be performed **after an ultrasound** has characterized the nodule and identified features that warrant biopsy.

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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