Endocrinology Practice Questions

Q: A middle-aged woman presents with weight gain, cold intolerance, and painless enlargement of th e thyroid gland. Which of the following antibodies is most commonly associated with this condition?

Anti TPO. ***Anti TPO*** - This patient presents with classic signs of **hypothyroidism** (weight gain, cold intolerance, thyroid enlargement), highly suggestive of **Hashimoto's thyroiditis**, which is an **autoimmune disorder**. - **Anti-thyroid peroxidase (anti-TPO)** antibodies are the most sensitive and specific markers found in the vast majority of patients with Hashimoto's thyroiditis. *Anti mitochondrial ab* - These antibodies are the hallmark diagnostic marker for **Primary Biliary Cholangitis (PBC)**, an autoimmune liver disease. - Clinical features of PBC include **pruritus** and elevated **alkaline phosphatase**, which are distinct from the thyroid dysfunction described here. *Anti ds DNA ab* - These are highly specific antibodies associated with **Systemic Lupus Erythematosus (SLE)**. - SLE typically presents with multisystem involvement, such as a **malar rash**, **arthritis**, and **serositis**, rather than isolated thyroid autoimmunity. *Anti TSH Rc* - These antibodies (Thyroid-stimulating immunoglobulin) are characteristic of **Graves' disease**, which causes **hyperthyroidism** rather than hypothyroidism. - They act to stimulate the **TSH receptor**, resulting in an overactive thyroid, tachycardia, and weight loss, opposite to this patient's presentation.

Q: Which option correctly matches both thyroid conditions with their associated antibodies?

Both Hyperthyroidism - LATS and Hypothyroidism - Anti-TPO. ***Both Hyperthyroidism - LATS and Hypothyroidism - Anti-TPO*** - **Long-Acting Thyroid Stimulator (LATS)** is an autoantibody historically identified in **Graves' disease**, which acts as a thyroid-stimulating immunoglobulin (TSI) by activating the **TSH receptor**. - **Anti-thyroid peroxidase (Anti-TPO)** antibodies are the hallmark serological marker for **Hashimoto's thyroiditis**, which is the most common cause of autoimmune primary hypothyroidism. *Hyperthyroidism - LATS only* - While LATS is associated with hyperthyroidism (Graves' disease), this option is incomplete because the question asks for the correct match for *both* conditions, and LATS is not the exclusive antibody associated with hyperthyroidism (TSH receptor antibodies are the modern nomenclature). - This option ignores the accurate association of Anti-TPO with hypothyroidism, making it less comprehensive than the correct choice. *Hypothyroidism - Anti-TPO only* - Although Anti-TPO is correctly linked to hypothyroidism (Hashimoto's), this option is incomplete because it fails to acknowledge the LATS association with hyperthyroidism. - The premise of the question requires identifying both valid associations, rendering this option incorrect by omission. *Neither pair is correct* - This option is incorrect because both presented associations represent classic, well-established immunological markers for their respective thyroid pathologies. - Recognizing these specific autoantibodies is essential for the serological diagnosis of common autoimmune thyroid disorders.

Q: A known Type II DM, 70 year old patient was under medication. He aslo takes Telmisartan. Patients current lab values: HbA1c-8.5, eGFR-50 mL/min/1.73 m. Normal potassium levels. What is the next appropriate step to decrease the risk of further eGFR decrement?

Increase Telmisartan dose. ***Increase Telmisartan dose*** - In patients with **diabetic nephropathy** and chronic kidney disease, optimizing the dose of **Angiotensin Receptor Blockers (ARBs)** like telmisartan to maximum tolerated levels is crucial to achieve maximal **renoprotection** and reduce **albuminuria**. - Since the patient has normal potassium and an eGFR of 50 mL/min/1.73 m², there is room for dosage titration to further suppress the **renin-angiotensin-aldosterone system (RAAS)** and slow the progression of renal decline. *Shift to Ramipril* - This patient is already on an ARB; shifting to an **ACE inhibitor (ACEi)** like Ramipril does not provide superior **renoprotective benefits** compared to ARBs in the context of diabetic nephropathy. - Dual therapy with an ACEi and an ARB is contraindicated due to increased risks of **hyperkalemia** and acute kidney injury without added clinical benefit. *Increase the dose of antidiabetic meds* - While glycemic control is vital (targeting HbA1c < 7.0%), simply increasing the dose of non-specific antidiabetic medications does not directly address hemodynamics to prevent **hyperfiltration** in the way RAAS inhibition does. - Specific agents like **SGLT2 inhibitors** or **GLP-1 receptor agonists** should be preferred for renal protection, rather than focusing solely on increasing existing medication doses. *Start Carvedilol* - **Carvedilol**, a non-selective beta-blocker, is indicated for heart failure or hypertension control but does not provide primary renal protection for diabetic patients with stable blood pressure. - Introducing a beta-blocker does not address the underlying **glomerular hyperfiltration** mechanism causing the eGFR decline as effectively as maximizing RAAS blockade.

Q: A young patient presents with persistently elevated blood pressure despite adequate lifestyle measures. Laboratory evaluation reveals hypokalemia associated with metabolic alkalosis. There is no history of diuretic intake, and renal function tests are within normal limits. Which of the following is the most likely diagnosis?

Conn syndrome. ### ***Conn syndrome*** - This condition, also known as **primary hyperaldosteronism**, typically presents with **hypertension**, **hypokalemia**, and metabolic alkalosis, driven by autonomous aldosterone secretion from an adrenal adenoma. - The absence of diuretic use and normal renal function supports an endocrine cause of **secondary hypertension**, where inappropriate mineralocorticoid activity leads to sodium retention and renal potassium wasting. *Pheochromocytoma* - While this condition causes hypertension, it typically presents with **paroxysmal episodes** of headache, palpitations, and sweating. - It is not routinely associated with the classic triad of hypokalemia and metabolic alkalosis seen in **primary hyperaldosteronism**. *Liddle syndrome* - This is an **autosomal dominant** disorder caused by a gain-of-function mutation in the **epithelial sodium channel (ENaC)**, causing early-onset hypertension and hypokalemia. - Crucially, Liddle syndrome is characterized by **suppressed plasma aldosterone** and low renin levels, whereas Conn syndrome presents with high aldosterone levels. *Carcinoid syndrome* - This condition arises from **neuroendocrine tumors** and is defined by the triad of flushing, diarrhea, and wheezing, rather than hypertensive endocrine workups. - There is no direct pathophysiological link between carcinoid syndrome and the development of **hypokalemia** in the setting of hypertension.

Q: Eruptive xanthomas with a prominent chylomicron band on lipid electrophoresis are most commonly seen due to:

Lipoprotein lipase (LPL) deficiency. ***Lipoprotein lipase (LPL) deficiency*** - This condition, classified as **Familial Chylomicronemia Syndrome (Type I Hyperlipoproteinemia)**, is characterized by the accumulation of **chylomicrons** in the plasma due to defective hydrolysis of triglycerides. - Clinically, it presents with **eruptive xanthomas**, **pancreatitis**, and **hepatosplenomegaly**, often appearing in childhood with extremely high **serum triglyceride levels**. *LDL receptor defect* - This pathology causes **Familial Hypercholesterolemia (Type IIa Hyperlipoproteinemia)**, characterized by elevated **LDL cholesterol**. - It typically results in **tendon xanthomas** and **xanthelasma**, not eruptive xanthomas, and presents primarily with increased risk of premature **coronary artery disease**. *Apo B-100 deficiency* - This leads to **hypobetalipoproteinemia**, where there is an inability to assemble VLDL, resulting in very low levels of **LDL** and **VLDL**. - It does not cause hypertriglyceridemia or eruptive xanthomas; instead, it is associated with **fat malabsorption** and **vitamin E deficiency**. *Apo E deficiency* - This is associated with **Familial Dysbetalipoproteinemia (Type III Hyperlipoproteinemia)**, which results in the accumulation of **remnant particles** (IDL and chylomicron remnants). - Characteristic findings include **tuberoeruptive** and **palmar xanthomas**, rather than the acute eruptive xanthomas seen in classic Chylomicronemia syndrome.

Q: A 66-year-old female has normal calcium, elevated PTH, low phosphate, and raised ALP. What is the diagnosis?

Vitamin D deficiency. ***Vitamin D deficiency*** - In early or mild **Vitamin D deficiency**, the **parathyroid hormone (PTH)** is elevated (secondary hyperparathyroidism) to compensate for low calcium absorption, which often keeps serum **calcium** levels within the low-normal range. - The elevated **PTH** causes increased renal phosphate excretion (leading to **low phosphate**) and increased bone turnover (leading to **raised ALP**). *Primary hyperparathyroidism* - Typically characterized by **hypercalcemia** alongside elevated **PTH**, unlike the normal calcium seen here. - While elevated **ALP** and low **phosphate** can occur, the calcium profile is the primary differentiator. *Hypoparathyroidism* - Characterized by **low PTH** levels and **hypocalcemia**, which directly contradicts the lab findings presented. - It is usually due to surgical damage to the glands or autoimmune destruction, not a metabolic state of compensation. *Chronic kidney disease* - Often presents with **hyperphosphatemia** (high phosphate) due to impaired renal excretion, not the low phosphate seen in this patient. - While secondary hyperparathyroidism can occur, the typical profile is **low/normal calcium**, **high phosphate**, and **high PTH**.

Q: A 15-year-old boy presents with hypertension and salt-water retention. He is suspected to have 17-alpha hydroxylase deficiency. What is the expected serological profile?

High mineralocorticoid, low cortisol, low androgen. ***High mineralocorticoid, low cortisol, low androgen*** - In **17-alpha hydroxylase deficiency**, the conversion of pregnenolone and progesterone to 17-OH derivatives (cortisol precursors) is blocked, which shunts the substrate toward the **mineralocorticoid pathway**. - This leads to excessive production of **deoxycorticosterone** (a potent mineralocorticoid), causing hypertension and salt retention, while simultaneously causing **cortisol** and **androgen** deficiency due to downstream blockages. *High mineralocorticoid, high cortisol, high androgen* - This profile is not seen in 17-alpha hydroxylase deficiency; **high androgens** are typically seen in 21-hydroxylase deficiency (congenital adrenal hyperplasia). - High cortisol would contradict the block in the glucocorticoid synthesis pathway caused by the enzyme deficiency. *High mineralocorticoid, high cortisol, low androgen* - While the mineralocorticoid levels are correctly described as high, **cortisol** levels are typically low due to the enzymatic block. - The deficiency of cortisol leads to increased **ACTH** (adrenocorticotropic hormone) secretion via feedback, but the enzyme block prevents downstream cortisol production. *Low mineralocorticoid, low cortisol, low androgen* - This profile is more characteristic of **Addison's disease** (primary adrenal insufficiency) where total adrenal function is impaired. - In 17-alpha hydroxylase deficiency, the mineralocorticoid pathway is essentially hyperactive, so low mineralocorticoid is incorrect.

Q: A 28-year-old woman with severe anorexia is admitted for nutritional rehabilitation. Within 48 hours of initiating enteral feeding, she develops muscle weakness, cardiac arrhythmias, and respiratory distress. Which metabolic abnormality is most characteristically responsible?

Hypophosphatemia. ***Hypophosphatemia*** - This patient is presenting with classic signs of **refeeding syndrome**, which occurs when rapid insulin secretion after carbohydrate ingestion triggers intracellular uptake of electrolytes, depleting serum pools. - **Hypophosphatemia** is the hallmark metabolic abnormality, leading to **adenosine triphosphate (ATP) depletion** and subsequent muscle weakness, cardiomyopathy, arrhythmias, and respiratory failure due to diaphragmatic weakness. *Hyponatremia* - While electrolyte disturbances are common in anorexia, **hyponatremia** is typically associated with excessive water intake or volume depletion rather than the rapid physiological shift seen in refeeding. - It does not explain the specific constellation of profound muscular and respiratory failure seen shortly after the initiation of feeding in this clinical context. *Hypocalcemia* - Although **hypocalcemia** can occur in refeeding syndrome due to an influx into the intracellular space, it is usually secondary and less frequently the primary cause of the severe, acute respiratory and cardiac symptoms described. - It typically manifests with signs of **tetany**, **Chvostek's sign**, or **Trousseau's sign** rather than the primary respiratory distress pattern seen here. *Hyperkalemia* - In the context of refeeding, the risk is typically **hypokalemia** due to the insulin-stimulated shift of potassium into cells, not hyperkalemia. - **Hyperkalemia** would likely present with different ECG changes, such as peaked T-waves, which is contrary to the clinical presentation of refeeding syndrome.

Q: A patient on long-term steroid therapy presents with centripetal obesity, buffalo hump, and abdominal striae. Dexamethasone suppression test confirms the diagnosis. What is the next investigation to identify the source?

ACTH level. ***ACTH level*** - Measuring the plasma **ACTH level** is the crucial next step to differentiate between ACTH-dependent (e.g., Cushing's disease, ectopic ACTH syndrome) and ACTH-independent (e.g., adrenal adenoma, exogenous steroid use) causes of **Cushing's syndrome**. - If the ACTH is suppressed (undetectable), it points toward an adrenal source or exogenous steroid administration, whereas high or inappropriately normal levels suggest a pituitary or ectopic source. *CECT adrenal* - A **Contrast-Enhanced CT (CECT)** of the adrenal glands is typically reserved for later stages of the diagnostic algorithm, specifically after biochemical testing has confirmed an ACTH-independent cause. - While it can visualize adrenal masses, it is not the primary discriminatory test for determining the etiology (pathophysiology) of the hypercortisolism. *Non-contrast CT adrenal* - **Non-contrast CT** is generally less sensitive than dedicated adrenal CT protocols for characterizing adrenal lesions, and therefore is not the immediate test of choice. - Similar to CECT, this is an anatomical imaging modality that should only be ordered after the biochemical classification (ACTH-dependent vs. independent) is established. *MRI pituitary gland* - **MRI of the pituitary gland** is the imaging modality of choice for suspected **Cushing's disease** (pituitary adenoma). - This investigation should only be ordered if the biochemical workup confirms an **ACTH-dependent** cause, as imaging early in the diagnostic process can lead to misinterpretation due to incidentalomas.

Q: A 45-year-old male with type 2 diabetes mellitus on metformin 1000 mg twice daily presents with HbA1c of 8.5%. His serum creatinine is 2.8 mg/dL (eGFR 28 mL/min/1.73m²) and he has a history of two episodes of heart failure in the past year. His BMI is 32 kg/m². Which of the following would be the most appropriate addition to his current therapy?

Empagliflozin. ***Empagliflozin*** - **SGLT2 inhibitors** like empagliflozin are now recommended down to an **eGFR ≥20 mL/min/1.73m²** for **cardiorenal protection**, making this patient with an eGFR 28 an appropriate candidate. - This patient has a history of **heart failure**, which is a **Class I indication** for SGLT2 inhibitor therapy due to proven mortality benefits and **reduction in HF hospitalizations**. *Sitagliptin* - **DPP-4 inhibitors** like sitagliptin are considered **cardiovascularly neutral** and do not provide the specific benefits for **heart failure** required by this patient. - While they can be used in **chronic kidney disease** with dose adjustments, their glycemic efficacy is moderate compared to other agents. *Pioglitazone* - **Pioglitazone** is strictly contraindicated in patients with symptomatic **heart failure** because it causes **fluid retention** and peripheral edema. - Adding this medication would significantly increase the risk of a **heart failure exacerbation** in a patient with two recent episodes. *Insulin glargine* - While **insulin** is effective for glycemic control and safe in renal impairment, it lacks the **organ-protective benefits** provided by SGLT2 inhibitors. - Current guidelines prioritize medications with proven **cardiovascular and renal outcome benefits** over insulin in patients with established HF and CKD.

Question 1

A middle-aged woman presents with weight gain, cold intolerance, and painless enlargement of th e thyroid gland. Which of the following antibodies is most commonly associated with this condition?

Accepted Answer

Anti TPO

Answer

Anti mitochondrial ab

Answer

Anti ds DNA ab

Answer

Anti TSH Rc

Question 2

Which option correctly matches both thyroid conditions with their associated antibodies?

Accepted Answer

Both Hyperthyroidism - LATS and Hypothyroidism - Anti-TPO

Answer

Hyperthyroidism - LATS only

Answer

Hypothyroidism - Anti-TPO only

Answer

Neither pair is correct

Question 3

A known Type II DM, 70 year old patient was under medication. He aslo takes Telmisartan. Patients current lab values: HbA1c-8.5, eGFR-50 mL/min/1.73 m. Normal potassium levels. What is the next appropriate step to decrease the risk of further eGFR decrement?

Accepted Answer

Increase Telmisartan dose

Answer

Shift to Ramipril

Answer

Increase the dose of antidiabetic meds

Answer

Start Carvedilol

Question 4

A young patient presents with persistently elevated blood pressure despite adequate lifestyle measures. Laboratory evaluation reveals hypokalemia associated with metabolic alkalosis. There is no history of diuretic intake, and renal function tests are within normal limits. Which of the following is the most likely diagnosis?

Accepted Answer

Conn syndrome

Answer

Pheochromocytoma

Answer

Liddle syndrome

Answer

Carcinoid syndrome

Question 5

Eruptive xanthomas with a prominent chylomicron band on lipid electrophoresis are most commonly seen due to:

Accepted Answer

Lipoprotein lipase (LPL) deficiency

Answer

LDL receptor defect

Answer

Apo B-100 deficiency

Answer

Apo E deficiency

Question 6

A 66-year-old female has normal calcium, elevated PTH, low phosphate, and raised ALP. What is
the diagnosis?

Accepted Answer

Vitamin D deficiency

Answer

Primary hyperparathyroidism

Answer

Hypoparathyroidism

Answer

Chronic kidney disease

Question 7

A 15-year-old boy presents with hypertension and salt-water retention. He is suspected to have
17-alpha hydroxylase deficiency. What is the expected serological profile?

Accepted Answer

High mineralocorticoid, low cortisol, low androgen

Answer

High mineralocorticoid, high cortisol, high androgen

Answer

High mineralocorticoid, high cortisol, low androgen

Answer

Low mineralocorticoid, low cortisol, low androgen

Question 8

A 28-year-old woman with severe anorexia is admitted for nutritional rehabilitation. Within 48
hours of initiating enteral feeding, she develops muscle weakness, cardiac arrhythmias, and
respiratory distress. Which metabolic abnormality is most characteristically responsible?

Accepted Answer

Hypophosphatemia

Answer

Hyponatremia

Answer

Hypocalcemia

Answer

Hyperkalemia

Question 9

A patient on long-term steroid therapy presents with centripetal obesity, buffalo hump, and
abdominal striae. Dexamethasone suppression test confirms the diagnosis. What is the next
investigation to identify the source?

Accepted Answer

ACTH level

Answer

CECT adrenal

Answer

Non-contrast CT adrenal

Answer

MRI pituitary gland

Question 10

A 45-year-old male with type 2 diabetes mellitus on metformin 1000 mg twice daily presents with HbA1c of 8.5%. His serum creatinine is 2.8 mg/dL (eGFR 28 mL/min/1.73m²) and he has a history of two episodes of heart failure in the past year. His BMI is 32 kg/m². Which of the following would be the most appropriate addition to his current therapy?

Accepted Answer

Empagliflozin

Answer

Sitagliptin

Answer

Pioglitazone

Answer

Insulin glargine

Endocrinology — MCQs

Endocrinology — MCQs

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