Endocrinology Practice Questions

Q: Which of the following is NOT a cause of fasting hypoglycemia?

Chronic pancreatitis. ***Chronic pancreatitis*** - This condition primarily affects the **exocrine function of the pancreas**, leading to malabsorption and, in later stages, often **diabetes mellitus** due to islet cell destruction [1]. - While it can lead to **pancreatic insufficiency**, it is not typically a cause of **fasting hypoglycemia**; rather, it often causes hyperglycemia [1]. *Alcohol intake* - **Ethanol metabolism** can inhibit gluconeogenesis in the liver, especially when **glycogen stores are depleted**, leading to **hypoglycemia**. - This is a common cause of **fasting hypoglycemia**, particularly in individuals with poor nutrition. *Pentamidine therapy* - **Pentamidine**, used to treat *Pneumocystis jiroveci* pneumonia, can cause **direct toxicity to pancreatic beta cells**, leading to acute **insulin release** and subsequent hypoglycemia. - While long-term use can lead to **beta-cell destruction** and diabetes, its acute effect is often **severe hypoglycemia**. *Renal insufficiency* - **Kidney failure** can lead to hypoglycemia through several mechanisms, including **reduced renal gluconeogenesis** and decreased insulin clearance. - The kidneys play a significant role in **insulin degradation** and glucose production, so impaired function can result in **prolonged insulin levels** and lower blood glucose.

Q: In case of hypothyroidism, which investigation is most informative and commonly used?

Serum TSH Level. ***Serum TSH Level*** - **Thyroid-stimulating hormone (TSH)** is the most sensitive and specific biomarker for primary hypothyroidism, as even small changes in thyroid hormone levels cause significant reciprocal changes in TSH [1]. - A **high TSH level** indicates that the pituitary gland is working harder to stimulate a underactive thyroid gland [1]. *Serum T3, T4 Level* - While **low T3 and T4 levels** are characteristic of hypothyroidism, TSH is a more reliable initial test due to its greater sensitivity as a first-line screen [1]. - T4 levels may be affected by various conditions like malnutrition, non-thyroidal illness, and medication, which might complicate interpretation. *Serum Calcitonin assay* - **Calcitonin** is a hormone involved in calcium regulation and is primarily used as a tumor marker for medullary thyroid cancer. - It has no role in diagnosing hypothyroidism. *Serum T3 level* - **Triiodothyronine (T3)** levels can be maintained within the normal range even in early hypothyroidism due to increased peripheral conversion of T4 to T3 [1]. - T3 measurement is generally more useful in **hyperthyroidism** diagnosis or in assessing the severity of thyrotoxicosis rather than hypothyroidism [1].

Q: Which of the following is a common presentation of acute adrenal insufficiency?

Abdominal pain, fatigue, and hypotension. ***Abdominal pain, fatigue, and hypotension*** - **Acute adrenal insufficiency** often presents with a constellation of symptoms including **severe abdominal pain**, profound **fatigue**, and **hypotension** due to the sudden lack of cortisol and aldosterone [1]. - The abdominal pain can be mimic an **acute abdomen**, while profound fatigue and **hypotension** are directly linked to the body's inability to maintain vascular tone and electrolyte balance without proper adrenal hormones [1]. *Severe fatigue and weakness* - While **severe fatigue** and **weakness** are prominent symptoms of adrenal insufficiency, this option is incomplete as it misses other critical clinical signs like **hypotension** and **GI symptoms** that characterize the acute presentation. - These symptoms alone could be indicative of numerous other conditions, making them not specific enough for **acute adrenal insufficiency** compared to the more comprehensive answer choice. *Hypotension and shock* - **Hypotension** and progression to **shock** are indeed critical and life-threatening features of **acute adrenal insufficiency** [1]. - However, this option does not include other key clinical manifestations such as **abdominal pain** and **fatigue**, which are commonly present and help in diagnosis before full shock develops [1]. *None of the options* - This option is incorrect because the first option accurately describes the **common and critical presentation** of acute adrenal insufficiency by including the most salient symptoms. - The combination of **abdominal pain**, **fatigue**, and **hypotension** is highly characteristic of this medical emergency [1].

Q: What is the average time period that HbA1c reflects blood glucose control?

2 - 3 months. ***2 - 3 months*** - **Hemoglobin A1c (HbA1c)** reflects the average blood glucose levels over the preceding **2-3 months** due to the typical lifespan of red blood cells [1]. - Glucose molecules bind irreversibly to hemoglobin within red blood cells, and the level of glycosylation directly correlates with the average plasma glucose concentration during and after the red cell's formation [1], [2]. *1 - 2 months* - This timeframe is too short to accurately represent the full lifespan of red blood cells, which is the basis for HbA1c measurement. - While some red blood cells are younger, a significant portion reflecting the earlier part of the 3-month period would be missed, providing an incomplete picture. *3 - 4 months* - This period is generally considered too long, as the contribution of red blood cells older than approximately 3 months to the overall HbA1c value becomes negligible due to their natural turnover [1]. - Focusing on this longer duration might incorporate data from red blood cells that have already been replaced, potentially overestimating or underestimating recent glucose control. *4 - 5 months* - This timeframe would be significantly inaccurate for HbA1c measurement. - The vast majority of red blood cells from 4-5 months prior would have been replaced, leading to a poor reflection of actual blood glucose control.

Q: Which drug is used for the medical management of acromegaly due to small pituitary tumors?

Octreotide. ***Octreotide*** - **Octreotide** is a **somatostatin analog** and the **first-line medical therapy** for acromegaly. - It effectively suppresses **growth hormone (GH)** and **IGF-1** secretion by binding to somatostatin receptors (especially SSTR2 and SSTR5) on pituitary adenomas. - Normalizes IGF-1 levels in **50-70%** of patients and can reduce tumor size. - Used for small or large tumors when surgery is not feasible, has failed, or as primary medical management. *Cabergoline* - **Cabergoline** is a **dopamine agonist** with limited efficacy in acromegaly. - Controls GH/IGF-1 in only **10-20%** of patients, primarily those with **co-secretion of prolactin** (mixed GH-PRL adenomas). - May be used as **adjunctive therapy** with somatostatin analogs but is not first-line treatment. *Pegvisomant* - **Pegvisomant** is a **GH receptor antagonist** that blocks GH action at the tissue level. - Highly effective at normalizing **IGF-1** levels (**>90%** of patients). - Used as **second-line therapy** when somatostatin analogs fail or are insufficient. - Does not reduce tumor size or GH secretion directly. *Vigabatrin* - **Vigabatrin** is an **antiepileptic drug** that inhibits GABA transaminase. - Has no role in the treatment of acromegaly or pituitary tumors.

Q: Patchy hair loss with velvety skin points to the diagnosis of which of the following conditions?

Cushing's syndrome. Cushing's syndrome - Patchy hair loss (alopecia) and velvety skin (acanthosis nigricans) are characteristic cutaneous manifestations seen in Cushing's syndrome due to excess glucocorticoids [2]. - Hyperandrogenism, often associated with Cushing's, can contribute to hair thinning in affected areas [2]. Alopecia areata - Characterized by well-demarcated, smooth patches of hair loss on the scalp or body [1], but typically does not present with velvety skin. - It is an autoimmune condition where the immune system attacks hair follicles. Trichotillomania - Involves compulsive hair pulling, leading to irregular patches of hair loss with hairs of varying lengths [1]. - The skin beneath the affected areas is typically normal and does not exhibit a velvety texture. Adenoma sebaceum - These are angiofibromas (small, red bumps) primarily found on the face, particularly around the nose and cheeks, and are associated with tuberous sclerosis. - They do not typically cause widespread patchy hair loss or generalized velvety skin.

Q: Which of the following syndromes is least likely to be associated with obesity?

Sipple syndrome. ***Sipple syndrome*** - Sipple syndrome, also known as **multiple endocrine neoplasia type 2**, is primarily associated with **medullary thyroid carcinoma** and does not typically correlate with obesity. - It includes signs like **pheochromocytoma** and **hyperparathyroidism**, but obesity is not a prominent feature. *Cushing syndrome* - Cushing syndrome leads to **excess cortisol**, commonly resulting in weight gain and central obesity [1]. - Characteristic features include **moon facies**, **buffalo hump**, and easy bruising, all associated with obesity [1]. *Pickwinian syndrome* - Pickwinian syndrome, characterized by **severe obesity**, is a condition primarily affecting physical stature and weight. - It is linked to **hypoventilation** and sleep apnea, reinforcing the presence of obesity. *Prader willi syndrome* - Prader-Willi syndrome is marked by **insatiable hunger** leading to **obesity** due to hypothalamic dysfunction [2]. - Individuals with this condition also demonstrate **hypotonia** and developmental delays, commonly accompanied by obesity [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1127-1129. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Central Nervous System Synapse, pp. 454-455.

Q: In which condition are hung-up reflexes typically observed?

Hypothyroidism. ***Hypothyroidism*** - **Hung-up reflexes** (or **Woltman's sign**) are characterized by a **slow relaxation phase** of deep tendon reflexes, a classic finding in hypothyroidism. - This delayed relaxation is due to altered muscle contraction and relaxation kinetics caused by **deficient thyroid hormones**. *Chorea* - Chorea is characterized by **brief, abrupt, irregular, unpredictable, non-stereotyped movements** that flow from one body part to another [1]. - Reflexes themselves are not typically "hung up" but may be difficult to elicit or appear irregular due to the involuntary movements. *Cerebral palsy* - Cerebral palsy is a group of permanent movement disorders that appear in early childhood and are typically characterized by **spasticity**, **ataxia**, or **dystonia**. - While reflex abnormalities are common, including **hyperreflexia** and sustained clonus, the specific finding of "hung-up reflexes" (slow relaxation) is not typical. *Cerebellar ataxia* - Cerebellar ataxia primarily affects **coordination, balance, and gait**, leading to dysmetria, dysdiadochokinesia, and intention tremor [2]. - Reflexes in cerebellar ataxia are often **normal** or can exhibit **pendular reflexes**, where the limb swings back and forth several times after being struck, rather than a delayed relaxation.

Q: The Z score measures bone mineral density compared to the average of which group of individuals?

Individuals matched for age, race, and sex. ***Individuals matched for age, race, and sex*** - A **Z-score** compares a patient's **bone mineral density (BMD)** to the average BMD of a healthy, age-matched, sex-matched, and race-matched population. - It is particularly useful in premenopausal women, men under 50 years of age, and children to help diagnose **secondary osteoporosis**. *Individuals matched for race and sex* - This definition is incomplete as it omits matching for **age**, which is a crucial demographic factor influencing bone density. - Without age-matching, the comparison would not accurately reflect expected bone density for the patient's specific life stage. *Individuals matched for sex* - This is an insufficient comparison for **bone mineral density**, as it excludes critical demographic factors like **age** and **race**. - Bone density naturally varies significantly with age and can also differ across racial groups. *None of the options* - This option is incorrect because the first option accurately describes the reference population for a **Z-score**. - The **Z-score** is a clearly defined metric in bone densitometry with a specific reference group.

Question 1

Diabetes insipidus is diagnosed when:

Accepted Answer

Urine output exceeds 3 liters per day and urine osmolarity is less than 300 mOsm/L

Answer

Urine output exceeds 2 liters per day and urine osmolarity is less than 250 mOsm/L

Answer

Urine output exceeds 5 liters per day and urine osmolarity is less than 320 mOsm/L

Answer

Urine output exceeds 4 liters per day and urine osmolarity is less than 280 mOsm/L

Question 2

Which of the following is NOT a cause of fasting hypoglycemia?

Accepted Answer

Chronic pancreatitis

Answer

Pentamidine therapy

Answer

Renal insufficiency

Answer

Alcohol intake

Question 3

In case of hypothyroidism, which investigation is most informative and commonly used?

Accepted Answer

Serum TSH Level

Answer

Serum T3, T4 Level

Answer

Serum Calcitonin assay

Answer

Serum T3 level

Question 4

Which of the following is a common presentation of acute adrenal insufficiency?

Accepted Answer

Abdominal pain, fatigue, and hypotension

Answer

Severe fatigue and weakness

Answer

Hypotension and shock

Answer

None of the options

Question 5

What is the average time period that HbA1c reflects blood glucose control?

Accepted Answer

2 - 3 months

Answer

3 - 4 months

Answer

4 - 5 months

Answer

1 - 2 months

Question 6

Which drug is used for the medical management of acromegaly due to small pituitary tumors?

Accepted Answer

Octreotide

Answer

Vigabatrin

Answer

Pegvisomant

Answer

Cabergoline

Question 7

Patchy hair loss with velvety skin points to the diagnosis of which of the following conditions?

Accepted Answer

Cushing's syndrome

Answer

Trichotillomania

Answer

Adenoma sebaceum

Answer

Alopecia areata

Question 8

Which of the following syndromes is least likely to be associated with obesity?

Accepted Answer

Sipple syndrome

Answer

Cushing syndrome

Answer

Prader willi syndrome

Answer

Pickwickian syndrome

Question 9

In which condition are hung-up reflexes typically observed?

Accepted Answer

Hypothyroidism

Answer

Cerebral palsy

Answer

Chorea

Answer

Cerebellar ataxia

Question 10

The Z score measures bone mineral density compared to the average of which group of individuals?

Accepted Answer

Individuals matched for age, race, and sex

Answer

Individuals matched for race and sex

Answer

Individuals matched for sex

Answer

None of the options

Endocrinology — MCQs

Endocrinology — MCQs

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