Endocrinology — MCQs

Endocrinology Indian Medical PG Practice Questions and MCQs

Question 1631: Which of the following is seen in Conn's syndrome?

A. Hypokalemia (Correct Answer)
B. Metabolic alkalosis
C. Hypertension
D. Edema

Explanation: ***Hypokalemia*** - In Conn's syndrome (primary hyperaldosteronism), excessive **aldosterone** secretion leads to increased renal reabsorption of sodium and excretion of **potassium** and hydrogen ions, resulting in hypokalemia. - This persistent electrolyte imbalance can manifest clinically as muscle weakness, fatigue, and cardiac arrhythmias. *Hypertension* - While hypertension is a prominent feature of Conn's syndrome due to increased sodium reabsorption and water retention, it is a **symptom** or **consequence** of the condition, not the underlying biochemical derangement that defines the syndrome itself. - The elevated aldosterone causes volume expansion and increased vascular tone, leading to systemic hypertension. *Metabolic alkalosis* - Metabolic alkalosis can occur in Conn's syndrome due to the renal excretion of **hydrogen ions** in exchange for sodium reabsorption. - However, it is a **secondary effect** of the hyperaldosteronism and is not the primary defining biochemical abnormality like hypokalemia. *Edema* - Edema is generally **not a common or prominent** feature of Conn's syndrome despite the increased sodium reabsorption. - The body's "escape phenomenon" often limits significant fluid retention and overt edema, preventing gross fluid overload.

Question 1632: Which of the following clinical problems is NOT associated with hypothyroidism?

A. Early abortions are associated with hypothyroidism.
B. Galactorrhoea is associated with hypothyroidism.
C. Menorrhagia is associated with hypothyroidism.
D. Weight loss is associated with hypothyroidism. (Correct Answer)

Explanation: Weight loss is associated with hypothyroidism. - Hypothyroidism is characterized by a **decreased metabolic rate**, leading to common symptoms like **weight gain** and difficulty losing weight [1]. - Therefore, **weight loss** is not a typical clinical problem associated with hypothyroidism; rather, it is often seen in hyperthyroidism [1]. *Menorrhagia is associated with hypothyroidism.* - Hypothyroidism can lead to **menorrhagia** (heavy menstrual bleeding) due to impaired coagulation factor synthesis and altered estrogen metabolism. - The **slowed metabolism** can affect the breakdown of estrogen, leading to prolonged endometrial stimulation. *Early abortions are associated with hypothyroidism.* - **Untreated hypothyroidism** in pregnant individuals is associated with an increased risk of **early pregnancy loss** and recurrent miscarriages. - This is thought to be due to an inadequate uterine environment and hormonal imbalances critical for a viable pregnancy. *Galactorrhoea is associated with hypothyroidism.* - Hypothyroidism can cause **hyperprolactinemia** due to increased **thyrotropin-releasing hormone (TRH)**, which stimulates prolactin release. - Elevated prolactin levels can lead to **galactorrhoea** (milk production unrelated to childbirth or breastfeeding).

Question 1633: Which of the following is not a marker for hyperparathyroidism?

A. Increase in serum parathyroid hormone (PTH) levels
B. Subperiosteal bone resorption of phalanges
C. Increase in serum calcium
D. Alteration in serum calcitonin levels (Correct Answer)

Explanation: ***Alteration in serum calcitonin levels*** - While calcitonin plays a role in calcium regulation, its levels are generally **not directly altered** in primary hyperparathyroidism. - Calcitonin is secreted by **parafollicular C cells of the thyroid gland** and acts to lower plasma calcium, *Increase in serum calcium* - **Hypercalcemia** is a hallmark of primary hyperparathyroidism, as excess PTH mobilizes calcium from bones and increases renal reabsorption [2]. - Prolonged elevation can lead to symptoms like **"stones, bones, groans, and psychic overtones"** [1]. *Increase in serum parathyroid hormone (PTH) levels* - An **elevated PTH level** is the primary diagnostic criterion for primary hyperparathyroidism [1]. - This indicates an overactive parathyroid gland, which is responsible for **regulating calcium homeostasis**. *Subperiosteal bone resorption of phalanges* - This is a classic radiographic finding in advanced **primary hyperparathyroidism**, particularly in the **distal phalanges**. - It results from the continuous action of **excess PTH on osteoclasts**, leading to bone breakdown [1].

Question 1634: The commonest cause of primary hyperparathyroidism is what?

A. Parathyroid carcinoma
B. Solitary parathyroid adenoma (Correct Answer)
C. Chronic kidney disease
D. Parathyroid hyperplasia

Explanation: ***Solitary parathyroid adenoma*** - A **solitary parathyroid adenoma** is the cause of **80-85%** of primary hyperparathyroidism cases [2]. - This benign tumor leads to excessive parathyroid hormone (PTH) secretion, causing **hypercalcemia** [3]. *Parathyroid carcinoma* - **Parathyroid carcinoma** is a very rare cause of primary hyperparathyroidism, accounting for less than **1%** of cases. - While it also causes hypercalcemia, its clinical presentation is often more severe with significantly higher PTH and calcium levels, often with a palpable neck mass. *Chronic kidney disease* - **Chronic kidney disease** is a common cause of **secondary hyperparathyroidism**, not primary hyperparathyroidism [2]. - In secondary hyperparathyroidism, low calcium and vitamin D levels (due to impaired kidney function) stimulate the parathyroid glands to produce more PTH [1], [2]. *Parathyroid hyperplasia* - **Parathyroid hyperplasia**, involving enlargement of all four parathyroid glands, accounts for about **10-15%** of primary hyperparathyroidism cases. - It is the second most common cause after solitary adenomas, but still less frequent.

Question 1635: Which of the following is a common laboratory finding in hypothyroidism?

A. High TSH (Correct Answer)
B. Low T3
C. High cholesterol
D. High Triglycerides

Explanation: ### High TSH - In **primary hypothyroidism**, the thyroid gland fails to produce adequate thyroid hormones (**T3** and **T4**). [1] - This leads to a compensatory increase in **TSH** release from the pituitary gland, attempting to stimulate the thyroid. [1] *Low T3* - While **low T3** can be present in hypothyroidism, **low free T4** is generally a more sensitive and specific marker for the diagnosis of primary hypothyroidism. [1] - T3 levels can sometimes remain normal or only slightly reduced even in overt hypothyroidism, especially in the early stages. *High cholesterol* - **Elevated cholesterol**, particularly **LDL (low-density lipoprotein)**, is a common metabolic consequence of hypothyroidism due to decreased catabolism of lipids. [2] - However, it is a metabolic complication rather than a direct hormonal lab finding defining hypothyroidism. *High Triglycerides* - **High triglycerides** can also be observed in hypothyroidism due to impaired lipid metabolism and reduced lipoprotein lipase activity. - Similar to elevated cholesterol, it is a metabolic consequence, not a primary diagnostic marker for the thyroid hormone imbalance itself.

Question 1636: Middle-aged female with a mass in the sella turcica, what is the hormone level that is increased?

A. Prolactin (Correct Answer)
B. Thyroxine
C. ADH
D. Estrogen

Explanation: ***Prolactin*** - A mass in the **sella turcica** suggests a **pituitary adenoma**, and the most common type is a **prolactinoma** [1]. - **Prolactinomas** cause an elevation in **prolactin levels**, leading to symptoms like galactorrhea, amenorrhea, and infertility in women [1]. *Thyroxine* - An increase in **thyroxine** usually indicates **hyperthyroidism**, which results from thyroid gland dysfunction or a TSH-secreting pituitary adenoma, not typically a mass directly causing elevated thyroxine. - While TSH-secreting adenomas are rare causes of thyrotoxicosis, a non-functional or prolactin-secreting pituitary mass would not directly increase peripheral thyroxine levels [2]. *ADH* - **Antidiuretic hormone (ADH)**, also known as vasopressin, is primarily involved in water balance. - While ADH can be affected by pituitary lesions, an increase would typically lead to **syndrome of inappropriate ADH secretion (SIADH)**, causing hyponatremia, which is not the primary presentation for most sella turcica masses. *Estrogen* - **Estrogen** levels are regulated by the ovaries under the influence of FSH and LH from the pituitary. - While pituitary masses can affect gonadotropin secretion (FSH/LH), leading to changes in estrogen, the mass itself does not directly secrete estrogen.

Question 1637: Which of the following is NOT a feature of hypothyroidism?

A. Delayed puberty
B. Delayed bone age
C. Short metacarpals in hands (Correct Answer)
D. Altered upper and lower segment ratio

Explanation: Short metacarpals in hands - While other skeletal developmental issues like **delayed bone age** and altered proportions are seen in hypothyroidism, **short metacarpals** (brachydactyly) are not a typical feature. - Short metacarpals are more characteristic of conditions like **Turner syndrome** or **pseudohypoparathyroidism**, not primary hypothyroidism. *Delayed puberty* - **Hypothyroidism** can lead to significant delays in growth and development, including **delayed onset of puberty**, due to its impact on overall metabolic processes and hormonal regulation [1]. - Insufficient thyroid hormones are crucial for proper **gonadal development** and function. *Delayed bone age* - **Thyroid hormones** are essential for normal epiphyseal fusion and bone maturation; therefore, their deficiency in hypothyroidism leads to a **delayed skeletal maturation**, which is observed as a delayed bone age on X-rays [1]. - This delay indicates that the bones are less mature than expected for the chronological age of the individual. *Altered upper and lower segment ratio* - In children with **untreated hypothyroidism**, bone growth can be disproportionate, leading to an **altered upper to lower segment ratio**. - Specifically, they may have relatively **shortened legs** (lower segment) compared to their trunk (upper segment).

Question 1638: The best marker for hyperthyroidism is

A. T3
B. T4
C. TSH (Correct Answer)
D. Thyroglobulin

Explanation: ***TSH*** - **TSH (Thyroid-Stimulating Hormone)** is the most sensitive and specific initial test for evaluating thyroid function. - In **hyperthyroidism**, the thyroid gland produces excess thyroid hormones (T3 and T4), which suppresses TSH release from the pituitary gland, leading to **very low or undetectable TSH levels**. *T3* - While **elevated T3 levels** are diagnostic of hyperthyroidism, TSH is a more sensitive initial screen. - Some patients, particularly those with **T3 toxicosis**, may have elevated T3 but normal T4. *T4* - **Elevated T4 levels** are a key indicator of hyperthyroidism, but TSH often reflects changes in thyroid hormone status earlier and is more sensitive for screening. - **Free T4** is preferred over total T4 as it is not affected by protein binding changes. *Thyroglobulin* - **Thyroglobulin** is a protein produced by the thyroid gland and is primarily used as a **tumor marker** in patients with differentiated thyroid cancer after thyroidectomy. - It is **not a primary diagnostic marker for hyperthyroidism**, although it can be elevated in conditions causing thyroid destruction or inflammation.

Question 1639: In a patient presenting with diabetic ketoacidosis (DKA), what is the most appropriate immediate treatment?

A. Administration of an oral hypoglycemic agent
B. Administration of bicarbonate
C. Administration of insulin (Correct Answer)
D. Close observation only

Explanation: ***Administration of insulin*** - **Insulin therapy** is critical in DKA to reverse the underlying metabolic abnormalities by stopping ketogenesis and facilitating glucose uptake into cells [1]. - It is typically administered intravenously at a continuous rate, after initial **fluid resuscitation**, to gradually lower blood glucose and resolve acidosis [1]. *Administration of an oral hypoglycemic agent* - **Oral hypoglycemic agents** are ineffective in DKA because these patients typically have an absolute or relative **insulin deficiency** and **profound insulin resistance** due to stress hormones [3]. - Moreover, they are not suitable for acutely ill patients who may have impaired gastrointestinal absorption. *Administration of bicarbonate* - **Bicarbonate administration** is generally not recommended in DKA unless the **pH is extremely low** (e.g., < 6.9 or 7.0) due to potential risks like paradoxical central nervous system acidosis and fluid overload. - The acidosis usually resolves with **insulin therapy** and **fluid resuscitation** as ketone body production ceases and they are metabolized [1]. *Close observation only* - **Diabetic ketoacidosis** is a medical emergency requiring urgent and aggressive intervention, not just observation [2]. - Delaying treatment can lead to severe complications, including **cerebral edema**, **coma**, and **death** [2].

Question 1640: The triad of diabetes, gallstones, and steatorrhea is associated with which of the following?

A. Somatostatinomas (Correct Answer)
B. VIPomas
C. Gastrinomas
D. Glucagonomas

Explanation: ***Somatostatinomas*** - This **triad** is characteristic of a somatostatinoma, as somatostatin inhibits insulin release, gallbladder contraction, and pancreatic enzyme secretion. - The inhibition of **insulin release** leads to diabetes [1], blocked **cholecystokinin (CCK)** release causes gallstones, and reduced **pancreatic enzyme** secretion results in steatorrhea. *Gastrinomas* - Gastrinomas typically cause **Zollinger-Ellison syndrome**, characterized by severe peptic ulcers and diarrhea due to excessive acid production. - They are not directly associated with the specific triad of diabetes, gallstones, and steatorrhea. *VIPomas* - VIPomas are known for causing **Verner-Morrison syndrome** or pancreatic cholera, leading to severe watery diarrhea, hypokalemia, and achlorhydria. - Diabetes and gallstones are not prominent features of VIPomas. *Glucagonomas* - Glucagonomas primarily manifest with **diabetes** (due to elevated glucagon), a characteristic skin rash called **necrolytic migratory erythema**, and weight loss [1]. - While diabetes is present, gallstones and steatorrhea are not typical associations.

Practice by Chapter

Diabetes Mellitus

Practice Questions

Thyroid Disorders

Practice Questions

Adrenal Gland Disorders

Practice Questions

Pituitary Disorders

Practice Questions

Calcium and Bone Metabolism

Practice Questions

Reproductive Endocrinology

Practice Questions

Lipid Disorders

Practice Questions

Endocrine Hypertension

Practice Questions

Multiple Endocrine Neoplasia

Practice Questions

Obesity and Metabolic Syndrome

Practice Questions

Neuroendocrine Tumors

Practice Questions

Endocrine Emergencies

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free