Endocrinology Practice Questions

Q: A 60-year-old man is diagnosed with Conn's syndrome. What is the expected effect on his serum potassium levels?

Hypokalemia. ***Hypokalemia*** - **Conn's syndrome** (primary hyperaldosteronism) leads to excessive **aldosterone** secretion, which promotes potassium excretion in the kidneys [1]. - This increased renal potassium wasting results in **decreased serum potassium levels**, commonly presenting as hypokalemia [1], [2]. *Hyperkalemia* - **Hyperkalemia** (high potassium) is the opposite of what occurs in Conn's syndrome; conditions like **adrenal insufficiency** (Addison's disease) or renal failure are associated with hyperkalemia due to decreased aldosterone effect or inability to excrete potassium. - Conn's syndrome causes increased **aldosterone** activity, actively moving potassium out of the body [1]. *Normokalemia* - While some patients with primary hyperaldosteronism can initially present with **normokalemia**, sustained oversecretion of **aldosterone** typically leads to some degree of **potassium depletion** as the kidneys continue to excrete it [2]. - **Normokalemia** would not be the *expected* long-term effect in untreated Conn's syndrome. *Hypernatremia* - Conn's syndrome is characterized by increased **aldosterone** secretion, which primarily causes **sodium retention** and **potassium excretion** [1]. - While sodium retention occurs, it often leads to **volume expansion** and **suppression of ADH**, preventing significant **hypernatremia**; instead, patients often have normal or mildly elevated serum sodium levels [2].

Q: A 45-year-old woman is experiencing night sweats and tremors. Her laboratory results reveal elevated T3 and T4 levels. What is the most likely diagnosis?

Primary hyperthyroidism. ***Primary hyperthyroidism*** - The combination of **night sweats**, **tremors**, and **elevated T3 and T4 levels** is highly indicative of hyperthyroidism [3]. - In primary hyperthyroidism, the thyroid gland itself overproduces thyroid hormones, leading to increased levels of **T3** and **T4** and typically suppressed TSH (not provided, but implied) [2]. *Primary hypothyroidism* - This condition is characterized by **low T3 and T4 levels** and **elevated TSH**, which directly contradicts the patient's lab results [2]. - Clinical symptoms often include **fatigue**, **weight gain**, and **cold intolerance**, not night sweats and tremors [1]. *Secondary hypothyroidism* - This condition involves **low T3 and T4 levels** due to a pituitary or hypothalamic dysfunction, leading to low TSH, which is opposite to the patient's elevated thyroid hormones [4]. - Clinical presentation would also involve symptoms of thyroid hormone deficiency. *Secondary hyperthyroidism* - While this also causes **elevated T3 and T4**, it is due to an **overproduction of TSH** from the pituitary gland [4]. - This is a much rarer cause of hyperthyroidism compared to primary hyperthyroidism, and the lack of TSH information makes primary hyperthyroidism the most likely initial diagnosis given the common clinical presentation.

Q: Which of the following is the most appropriate initial management for a patient with diabetic ketoacidosis (DKA)?

Intravenous insulin infusion. ***Intravenous insulin infusion*** - **Intravenous insulin** is crucial in DKA to reverse gluconeogenesis, glycogenolysis, and ketogenesis, rapidly lowering blood glucose and resolving acidosis [1]. - An initial **bolus** followed by a continuous infusion ensures a steady and predictable reduction in glucose and ketone levels. *Oral metformin* - **Metformin** works by decreasing hepatic glucose production and increasing insulin sensitivity, which is too slow and ineffective in the acute crisis of DKA. - It is contraindicated in conditions leading to **renal impairment** or metabolic acidosis, both of which can be present or exacerbated in DKA. *Subcutaneous long-acting insulin* - **Long-acting insulin**, while essential for basal insulin replacement in diabetes management, acts too slowly to address the acute metabolic derangements of DKA. - Starting with long-acting insulin alone would **delay correction** of severe hyperglycemia and ketosis [2]. *Oral sulfonylureas* - **Sulfonylureas** stimulate insulin secretion from pancreatic beta cells, which are already severely dysfunctional or exhausted in DKA [3]. - These medications can also cause **hypoglycemia** and are not designed for the magnitude of hyperglycemia seen in DKA [3].

Q: A 60-year-old woman with type 2 diabetes presents with peripheral neuropathy. Which medication is the most appropriate for symptomatic treatment?

Gabapentin. ***Gabapentin*** - **Gabapentin** is a **first-line agent** (per ADA/NICE guidelines) for **diabetic peripheral neuropathy** (DPN) pain. - It works by binding to **voltage-gated calcium channels** and modulating **neurotransmitter release**, providing effective relief from **neuropathic pain**. - Other first-line options include **duloxetine**, **pregabalin**, and **tricyclic antidepressants**. *Metformin* - **Metformin** is a **first-line oral medication** for **type 2 diabetes** that **lowers blood glucose** by reducing hepatic glucose production and improving insulin sensitivity. - It does **not directly treat neuropathic pain** symptoms, though optimal glycemic control may slow neuropathy progression. *Insulin* - **Insulin** is used to **control blood glucose levels** by facilitating cellular glucose uptake. - While **good glycemic control** can prevent progression of neuropathy, insulin itself does **not provide symptomatic relief** for established neuropathic pain. *Lisinopril* - **Lisinopril** is an **ACE inhibitor** used for **hypertension**, **heart failure**, and **renal protection** in diabetic patients. - It has **no role** in the **symptomatic management of neuropathic pain**.

Q: A 70-year-old woman presents with a severe headache and visual disturbances. An MRI shows a pituitary mass that stains positive for ACTH. Which endocrine disorder is consistent with this presentation?

Corticotroph adenoma. ***Corticotroph adenoma*** - A pituitary mass that stains positive for **ACTH (adrenocorticotropic hormone)** is characteristic of a corticotroph adenoma. - This type of adenoma leads to **Cushing's disease** due to excessive ACTH production, which stimulates the adrenal glands to produce cortisol [1]. - The most common local complication of a large pituitary tumour is compression of the optic pathway, often resulting in visual disturbances [1]. *Prolactinoma* - A prolactinoma would stain positive for **prolactin**, not ACTH. - Clinical symptoms typically include **galactorrhea** and **amenorrhea** in women, or **hypogonadism** in men. *Somatotroph adenoma* - A somatotroph adenoma would stain positive for **growth hormone (GH)**, not ACTH. - It causes **acromegaly** in adults or gigantism in children, presenting with distinct physical changes rather than features of cortisol excess. *Thyrotroph adenoma* - A thyrotroph adenoma would stain positive for **thyroid-stimulating hormone (TSH)**, not ACTH. - This condition is rare and can lead to **hyperthyroidism** due to excess TSH production, with symptoms related to thyroid hormone excess.

Q: In a patient with diabetic ketoacidosis, which of the following biochemical markers is most significantly elevated?

Blood glucose. ***Blood glucose*** - **Diabetic ketoacidosis (DKA)** is characterized by **severe hyperglycemia** due to insufficient insulin, leading to glucose accumulation in the blood. - Blood glucose levels are typically **above 250 mg/dL** in DKA, often much higher (300-800 mg/dL), making it the most significantly elevated marker **among the given options**. - Note: While **beta-hydroxybutyrate (ketones)** is the hallmark marker of DKA and would be the most significantly elevated if included, glucose is the highest among the options presented. *Blood urea nitrogen* - **Blood urea nitrogen (BUN)** may be elevated in DKA due to **dehydration** and impaired renal perfusion, but it is not the primary or most significantly elevated marker compared to glucose. - The elevation is usually moderate and secondary to the **fluid imbalance** rather than a direct consequence of ketoacidosis itself. *Serum potassium* - **Serum potassium levels** can be variable in DKA; initially, they may appear normal or even elevated due to **extracellular shift** from acidosis, but total body potassium is typically depleted. - During treatment, potassium levels typically **fall** as insulin drives potassium back into cells, requiring careful monitoring and replacement. - While important for monitoring, **hyperkalemia** is not the defining or most significant biochemical elevation in DKA. *Serum sodium* - **Serum sodium levels** are often **artificially lowered** (pseudohyponatremia) in DKA due to the osmotic effect of severe hyperglycemia, drawing water from the intracellular to extracellular space. - Corrected sodium may be normal or elevated, but significant elevation of serum sodium is not a characteristic feature of DKA.

Q: Which outcome best evaluates the effect of a new antidiabetic medication on patient health?

Measured decrease in HbA1c levels. ***Measured decrease in HbA1c levels*** - **HbA1c** provides an average measure of blood glucose control over the past 2-3 months, directly reflecting the medication's effectiveness in managing **hyperglycemia** [1]. - A significant decrease in HbA1c levels indicates improved **long-term glycemic control**, reducing the risk of diabetes-related complications [4]. *Patient reports of improved well-being* - While important, **patient reports of well-being** are subjective and can be influenced by various factors beyond glycemic control, such as the **placebo effect** or concurrent lifestyle changes. - They do not offer a **quantitative, objective measure** of the medication's direct impact on controlling blood sugar. *Weight loss* - **Weight loss** can be a beneficial side effect of some antidiabetic medications, but it is not the primary measure of their effectiveness in controlling **hyperglycemia** [2], [3]. - Many effective antidiabetic medications do not cause weight loss, and some can even cause weight gain, yet they still improve **glycemic control** [3]. *Decreased frequency of urination* - **Decreased frequency of urination** can be a symptom improvement in some diabetic patients, particularly those with severe hyperglycemia causing **polyuria**. - However, it is a **symptomatic outcome** and not a direct, objective measure of the medication's effectiveness in maintaining stable blood glucose levels over time, unlike HbA1c.

Q: A 45-year-old woman presents with episodes of severe headache, palpitations, and sweating, with consistently high blood pressure during these episodes. What is the most likely diagnosis?

Pheochromocytoma. ***Pheochromocytoma*** - The classic triad of **severe headache, palpitations, and sweating**, especially when episodic and associated with **hypertensive crises**, is highly suggestive of a pheochromocytoma. - This tumor often secretes **catecholamines**, leading to these paroxysmal symptoms and sustained or episodic hypertension. *Migraine* - While migraines cause severe headaches, they are usually **unilateral** and often accompanied by **photophobia, phonophobia, and aura**, not episodic hypertension, palpitations, or profuse sweating. [1] - **Blood pressure changes** during a migraine are typically secondary and not the prominent, paroxysmal elevations seen here. *Cluster headache* - Characterized by **excruciating, unilateral pain** around the eye or temple, often accompanied by **lachrymation, ptosis, and rhinorrhea**, and occurs in clusters [2]. - It does **not typically present with hypertension, palpitations, or generalized sweating** as primary symptoms. *Temporal arteritis* - This condition presents with a **new-onset headache in an older adult**, often with **scalp tenderness, jaw claudication, and visual disturbances**. - It is an **inflammatory vasculitis** and does not cause episodic palpitations, sweating, or paroxysmal hypertension. [1]

Q: A 65-year-old woman with a history of osteoporosis presents with a vertebral compression fracture. Which of the following is the most appropriate long-term management?

Imaging assessment (MRI/CT). ***Imaging assessment (MRI/CT)*** - **MRI or CT imaging** is crucial for long-term management to precisely determine the extent of the **vertebral compression fracture**, identify the **number of affected vertebrae**, and detect any potential **spinal cord compression** or instability. - This information guides further interventions, including **vertebroplasty**, **kyphoplasty**, or **surgical stabilization**, and helps monitor the progression or healing of the fracture, especially in cases of **osteoporosis** [1]. *Neurological assessment* - While important in the **acute phase** to rule out immediate neurological compromise, a neurological assessment alone is not a long-term management strategy for the fracture itself [1]. - It helps guide initial treatment but does not address the underlying bone health or fracture mechanics. *Early mobilization as tolerated* - **Early mobilization** is crucial for preventing deconditioning and complications, but it is a rehabilitation strategy, not a primary long-term management for the fracture itself without prior assessment. - The type and extent of mobilization need to be guided by imaging and further medical assessment to prevent further damage [1]. *Pain management with analgesics* - **Pain management** is a symptomatic treatment and an important part of the immediate and ongoing care. - However, it does not address the underlying **pathology (osteoporosis)** or the **structural integrity of the spine**, which is critical for long-term management [1].

Q: A 62-year-old male with a history of hypertension and type 2 diabetes presents with fatigue and weight loss. His blood pressure is 160/100 mmHg. Laboratory tests show elevated aldosterone and low plasma renin activity. What is the most likely diagnosis?

Primary hyperaldosteronism. ***Primary hyperaldosteronism*** - The combination of **hypertension**, **elevated aldosterone**, and **low plasma renin activity** [2] is characteristic of primary hyperaldosteronism, where the adrenal glands produce excessive aldosterone independently of the renin-angiotensin system. - While fatigue and weight loss are non-specific, persistent hypertension unresponsive to usual treatments and associated with electrolyte imbalances (though not explicitly mentioned here) further points to this diagnosis. *Cushing's syndrome* - This condition is characterized by **excess cortisol**, leading to symptoms like **central obesity**, **moon facies**, **buffalo hump**, and **striae**, which are not described in the patient's presentation. - While hypertension can occur, the key lab findings of **elevated aldosterone and low renin** are not primary features of Cushing's syndrome [3]. *Pheochromocytoma* - A pheochromocytoma is a tumor that secretes **catecholamines**, causing **paroxysmal hypertension**, **tachycardia**, **palpitations**, **sweating**, and **headaches** [1]. - The characteristic laboratory findings would be **elevated plasma metanephrines or normetanephrines**, not elevated aldosterone or low renin. *Secondary hypertension* - This is a broad category, but the specific lab findings of **elevated aldosterone and low renin** in this patient precisely identify the *cause* of the secondary hypertension as primary hyperaldosteronism. - Without these specific findings, other causes of secondary hypertension (e.g., renal artery stenosis, thyroid dysfunction) would need to be considered [4], but the current data points to a specific etiology.

Question 1

A 60-year-old man is diagnosed with Conn's syndrome. What is the expected effect on his serum potassium levels?

Accepted Answer

Hypokalemia

Answer

Hyperkalemia

Answer

Normokalemia

Answer

Hypernatremia

Question 2

A 45-year-old woman is experiencing night sweats and tremors. Her laboratory results reveal elevated T3 and T4 levels. What is the most likely diagnosis?

Accepted Answer

Primary hyperthyroidism

Answer

Primary hypothyroidism

Answer

Secondary hypothyroidism

Answer

Secondary hyperthyroidism

Question 3

Which of the following is the most appropriate initial management for a patient with diabetic ketoacidosis (DKA)?

Accepted Answer

Intravenous insulin infusion

Answer

Oral metformin

Answer

Subcutaneous long-acting insulin

Answer

Oral sulfonylureas

Question 4

A 60-year-old woman with type 2 diabetes presents with peripheral neuropathy. Which medication is the most appropriate for symptomatic treatment?

Accepted Answer

Gabapentin

Answer

Metformin

Answer

Insulin

Answer

Lisinopril

Question 5

A 70-year-old woman presents with a severe headache and visual disturbances. An MRI shows a pituitary mass that stains positive for ACTH. Which endocrine disorder is consistent with this presentation?

Accepted Answer

Corticotroph adenoma

Answer

Prolactinoma

Answer

Somatotroph adenoma

Answer

Thyrotroph adenoma

Question 6

In a patient with diabetic ketoacidosis, which of the following biochemical markers is most significantly elevated?

Accepted Answer

Blood glucose

Answer

Blood urea nitrogen

Answer

Serum potassium

Answer

Serum sodium

Question 7

Which outcome best evaluates the effect of a new antidiabetic medication on patient health?

Accepted Answer

Measured decrease in HbA1c levels

Answer

Patient reports of improved well-being

Answer

Weight loss

Answer

Decreased frequency of urination

Question 8

A 45-year-old woman presents with episodes of severe headache, palpitations, and sweating, with consistently high blood pressure during these episodes. What is the most likely diagnosis?

Accepted Answer

Pheochromocytoma

Answer

Migraine

Answer

Cluster headache

Answer

Temporal arteritis

Question 9

A 65-year-old woman with a history of osteoporosis presents with a vertebral compression fracture. Which of the following is the most appropriate long-term management?

Accepted Answer

Imaging assessment (MRI/CT)

Answer

Early mobilization as tolerated

Answer

Neurological assessment

Answer

Pain management with analgesics

Question 10

A 62-year-old male with a history of hypertension and type 2 diabetes presents with fatigue and weight loss. His blood pressure is 160/100 mmHg. Laboratory tests show elevated aldosterone and low plasma renin activity. What is the most likely diagnosis?

Accepted Answer

Primary hyperaldosteronism

Answer

Cushing's syndrome

Answer

Pheochromocytoma

Answer

Secondary hypertension

Endocrinology — MCQs

Endocrinology — MCQs

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