Endocrinology Practice Questions

Q: Primary hyperparathyroidism is suggested by all of the following, except which of the following?

Low urinary calcium levels. ***Low urinary calcium*** - In primary hyperparathyroidism, **urinary calcium levels are typically elevated** due to increased calcium reabsorption in the kidneys [2]. - **Low urinary calcium levels** would suggest a different condition, such as **hypoparathyroidism** or a renal issue affecting calcium excretion [5]. *Increased PTH* - Primary hyperparathyroidism is characterized by **elevated parathyroid hormone (PTH)** levels, as the parathyroid glands are overactive [1][3]. - High PTH contributes to increased serum calcium and bone resorption [2]. *Increased serum calcium* - A hallmark of primary hyperparathyroidism is **hypercalcemia**, resulting from increased bone resorption and renal tubular reabsorption of calcium [1][2]. - The condition often leads to symptoms such as **kidney stones** and **bone pain** due to elevated serum calcium levels [3][4]. *Increased C-AMP* - Elevated levels of **cyclic AMP (C-AMP)** in urine are observed in primary hyperparathyroidism due to the stimulatory effect of PTH on renal tubular reabsorption of calcium. - Increased C-AMP correlates with the action of PTH in promoting calcium release from the bones [2].

Q: Hypophosphatemia is seen in:

Hyperparathyroidism. ***Hyperparathyroidism*** - In **primary hyperparathyroidism**, the excess **parathyroid hormone (PTH)** leads to increased phosphate excretion by the kidneys [1], [4]. - This results in **hypophosphatemia** as the body attempts to maintain **calcium-phosphate balance**, often at the expense of phosphate levels [1]. *Hyperthyroidism* - While hyperthyroidism can affect **bone metabolism**, it is typically associated with **normal or slightly elevated phosphate levels**, not hypophosphatemia [3]. - The main electrolyte disturbances are usually related to **calcium** (e.g., hypercalcemia) due to increased bone turnover [3]. *Hypoparathyroidism* - **Hypoparathyroidism** is characterized by **low or absent PTH**, leading to decreased renal phosphate excretion. - This results in **hyperphosphatemia**, along with **hypocalcemia** [2]. *Pseudohypoparathyroidism* - In **pseudohypoparathyroidism**, there is **PTH resistance** at target tissues, even with high or normal PTH levels [2]. - This leads to symptoms resembling hypoparathyroidism, including **hyperphosphatemia** and **hypocalcemia** [2].

Q: What is a significant cause of male pseudohermaphroditism?

Androgen insensitivity syndrome. ***Cytogenetic abnormalities*** - Male pseudohermaphroditism is most commonly caused by **isolated androgen insensitivity syndrome**, resulting from **androgen receptor gene mutations** [3]. - It leads to **male chromosomal composition (46,XY)** but with female phenotype due to lack of response to male hormones [3]. *Chromosomal abnormalities* - While chromosomal abnormalities can lead to **disorders of sexual development**, they are not the primary cause of pseudohermaphroditism [2], [3]. - Conditions like **Turner syndrome** affect development primarily in female individuals [1]. *Congenital adrenal hyperplasia* - More commonly leads to **female pseudohermaphroditism** due to excess androgen exposure during fetal life [3]. - In male infants, it typically presents as **salt-wasting**, affecting the adrenal glands rather than causing male pseudohermaphroditism [3]. *Adrenocortical tumor* - This condition can cause excess secretion of adrenal hormones, potentially leading to **precocious puberty**, but it does not typically cause pseudohermaphroditism. - It primarily affects adrenal function rather than sexual differentiation at the chromosomal level.

Q: What is the initial drug of choice for a suspected case of acute adrenal insufficiency?

Hydrocortisone. ***Hydrocortisone*** - This is the initial drug of choice due to its **combined mineralocorticoid and glucocorticoid activity**, which effectively replaces the deficient hormones in acute adrenal insufficiency. - It also has a **rapid onset of action** crucial for stabilizing patients in an adrenal crisis. *Norepinephrine* - This is a **vasopressor** used to manage **severe hypotension or shock** by increasing peripheral vascular resistance. - While hypotension is a feature of adrenal insufficiency, norepinephrine does not address the underlying hormonal deficiency directly and is not the primary treatment. *Dexamethasone* - Dexamethasone is a **potent glucocorticoid** and can be used in adrenal insufficiency, but it lacks significant **mineralocorticoid activity**. - Its longer half-life might make it less ideal for immediate, titratable replacement compared to hydrocortisone in an acute setting. *Fludrocortisone* - Fludrocortisone is a **pure mineralocorticoid** primarily used for long-term replacement therapy to manage sodium and potassium balance in adrenal insufficiency. - It does not have sufficient glucocorticoid activity to address the immediate, life-threatening aspects of acute adrenal crisis.

Q: Among the following, most reliable test for screening of diabetes mellitus?

Fasting sugar. ***Fasting sugar*** - A **fasting plasma glucose** (FPG) test is the most common and reliable initial test for screening for **diabetes mellitus** because it measures blood glucose after an overnight fast (typically 8-12 hours), providing a baseline level unaffected by recent food intake [1]. - A fasting glucose level of **≥ 126 mg/dL** (7.0 mmol/L) on two separate occasions is diagnostic of diabetes, making it an excellent screening tool for identifying individuals with impaired glucose metabolism [1]. *Random sugar* - A random plasma glucose test can be used to diagnose diabetes if the level is **≥ 200 mg/dL** (11.1 mmol/L) in a symptomatic individual, but it is less reliable for screening asymptomatic individuals due to its variability depending on recent food intake [1]. - Because it can be measured at any time of day without regard to the last meal, it has a **lower sensitivity** for detecting early stages of diabetes compared to fasting glucose. *Glucose tolerance test* - An **oral glucose tolerance test** (OGTT) is highly sensitive and specific for diagnosing diabetes and impaired glucose tolerance, but it is more cumbersome and time-consuming, involving multiple blood draws over two hours after consuming a sugary drink. - While it is a definitive diagnostic test, its complexity makes it **less practical for routine screening** in large populations compared to simpler tests like fasting plasma glucose. *Urine sugar* - The presence of glucose in urine (glycosuria) indicates that blood glucose levels have exceeded the **renal threshold** (typically around 180 mg/dL), meaning the kidneys are unable to reabsorb all the glucose. - This is a **less sensitive and specific** method for screening, as it only becomes positive once blood glucose is significantly elevated, and it does not detect milder forms of impaired glucose metabolism or early diabetes.

Q: What condition is caused by the intake of exogenous steroids?

Cushing's syndrome. ***Cushing's syndrome*** - **Exogenous steroid intake** is the most common cause of Cushing's syndrome, leading to symptoms associated with **excess cortisol** [1]. - This occurs because the steroids mimic the effects of **cortisol**, suppressing the body's natural production and leading to its characteristic signs and symptoms [2]. *Addison's disease* - This condition is characterized by **adrenal insufficiency**, meaning the adrenal glands produce too little **cortisol** and often **aldosterone**. - It is typically caused by autoimmune destruction of the adrenal glands, not by exogenous steroid intake. *Pheochromocytoma* - This is a rare tumor of the **adrenal medulla** that causes the overproduction of **catecholamines** (epinephrine and norepinephrine). - Symptoms include sudden, severe episodes of hypertension, palpitations, and sweating, unrelated to steroid intake. *Conn's syndrome* - Also known as **primary hyperaldosteronism**, this condition involves the overproduction of **aldosterone** by the adrenal glands. - It typically results in hypertension and hypokalemia and is not directly caused by exogenous steroid administration.

Q: Madarosis is seen in ?

Hypothyroidism. ***Hypothyroidism*** - **Madarosis**, specifically the loss of the **outer third of the eyebrows**, is a classic sign of **hypothyroidism** due to decreased thyroid hormone levels affecting hair follicle growth [1]. - Other common symptoms include **fatigue**, **weight gain**, **cold intolerance**, and **dry skin**. *Addison's disease* - This condition involves **adrenal insufficiency**, primarily causing symptoms like **hyperpigmentation**, low blood pressure, and fatigue. - **Hair loss** is generally not a prominent feature, and madarosis is not typically seen. *Acromegaly* - Characterized by excessive **growth hormone** production, leading to enlargement of hands, feet, and facial features. - While it can cause some changes in hair texture, **madarosis** is not a common clinical manifestation. *None of the options* - This option is incorrect because **Hypothyroidism** is a direct cause of madarosis due to its impact on **hair follicle metabolism** [1]. - The other conditions listed do not typically present with this specific type of eyebrow hair loss.

Q: A 50-year-old woman, who is 5 feet 7 inches tall and weighs 185 pounds, has a family history of diabetes mellitus. Her fasting blood glucose levels are 160 mg/dL and 155 mg/dL on two occasions, and her HbA1c level is 7.9%. After being educated on medical nutrition therapy, she returns for reevaluation in 8 weeks, reporting that she has followed diet and exercise recommendations, but her fasting blood glucose levels remain between 140 and 150 mg/dL, and her HbA1c level is 7.7%. She is asymptomatic, and physical examination reveals no abnormalities. Which of the following treatments is the most appropriate for her condition?

Metformin. ***Metformin*** - **Metformin** is the **first-line pharmacological treatment** for type 2 diabetes mellitus when lifestyle modifications are insufficient, as seen in this patient whose blood glucose and HbA1c remain elevated after 8 weeks of diet and exercise [1]. - It works by **decreasing hepatic glucose production** and **improving insulin sensitivity**, and it has a favorable safety profile, including no risk of hypoglycemia and potential for weight neutrality or modest weight loss [1]. *A thiazolidinedione* - **Thiazolidinediones** (e.g., pioglitazone) are effective in improving insulin sensitivity but are typically considered **second-line agents** or used in patients who cannot tolerate metformin. - They are associated with side effects such as **weight gain**, **fluid retention**, and an increased risk of heart failure, which might not be ideal for initial therapy. *A dipeptidyl ppetidase-4 (DPP-4) inhibitor* - **DPP-4 inhibitors** (e.g., sitagliptin) enhance insulin secretion and suppress glucagon secretion in a glucose-dependent manner, offering good glycemic control with a low risk of hypoglycemia. - However, they are **less potent** than metformin in lowering HbA1c and are generally used as **second-line therapy** or in combination with metformin. *Insulin therapy* - **Insulin therapy** is indicated for patients with **markedly elevated glucose levels** (e.g., HbA1c > 10% or fasting plasma glucose > 250 mg/dL), significant symptoms of hyperglycemia, or when other oral agents have failed. - This patient's HbA1c of 7.7% and asymptomatic status suggest that oral agents should be attempted first before resorting to insulin.

Q: Which of the following is the MOST characteristic feature of insulinoma?

Hypoglycemic attacks. Hypoglycemic attacks - **Insulinoma** is a tumor of the pancreatic beta cells that secretes excessive insulin, leading to recurrent episodes of **hypoglycemia** [1]. - These attacks often occur during fasting or after exercise and are relieved by glucose intake [2]. Weight gain - While patients with insulinoma may experience some **weight gain** due to increased caloric intake to prevent hypoglycemic symptoms, it is not the most defining or characteristic feature. - Weight gain is a non-specific symptom that can be associated with many other conditions. Usually Solitary tumour - While many insulinomas are solitary (about 90%), this is a pathological characteristic rather than a clinical feature. - The patient's presentation is dominated by the **functional consequences** of insulin overproduction. Mostly benign tumour - Approximately 90% of insulinomas are benign, but this is a pathological classification. - The most characteristic clinical manifestation from a patient's perspective remains the recurrent **hypoglycemia** caused by excessive insulin secretion.

Q: What is the most common adrenal incidentaloma?

Endocrine inactive tumors. ***Endocrine inactive tumors*** - The majority, about **70-85%**, of adrenal incidentalomas are **benign, non-secretory adenomas**, which are often referred to as endocrine inactive tumors. [1] - These tumors do not produce excess hormones and are typically discovered incidentally on imaging performed for other reasons. *Cortisol producing* - While **cortisol-producing adenomas** are a type of functional adrenal tumor, they represent a smaller percentage of incidentalomas, usually less than 10%. - These can lead to **Cushing's syndrome**, but most incidentalomas causing hypercortisolism are subclinical. *Aldosterone producing* - **Aldosterone-producing adenomas**, which cause primary aldosteronism, are also less common than inactive tumors, accounting for about 1-5% of incidentalomas. [1] - They are typically associated with **hypertension** and **hypokalemia**. *Pheochromocytoma* - **Pheochromocytomas**, which secrete catecholamines, are rare adrenal incidentalomas, making up less than 5% of cases. - These tumors can cause **hypertension**, **tachycardia**, and other symptoms related to catecholamine excess. [1]

Question 1

Primary hyperparathyroidism is suggested by all of the following, except which of the following?

Accepted Answer

Low urinary calcium levels

Answer

Increased serum calcium

Answer

Increased urinary calcium

Answer

Decreased PTH levels

Question 2

Hypophosphatemia is seen in:

Accepted Answer

Hyperparathyroidism

Answer

Hyperthyroidism

Answer

Hypoparathyroidism

Answer

Pseudohypoparathyroidism

Question 3

What is a significant cause of male pseudohermaphroditism?

Accepted Answer

Androgen insensitivity syndrome

Answer

Adrenocortical tumor

Answer

Cytogenetic abnormalities

Answer

Congenital adrenal hyperplasia (CAH)

Question 4

What is the initial drug of choice for a suspected case of acute adrenal insufficiency?

Accepted Answer

Hydrocortisone

Answer

Norepinephrine

Answer

Dexamethasone

Answer

Fludrocortisone

Question 5

Among the following, most reliable test for screening of diabetes mellitus?

Accepted Answer

Fasting sugar

Answer

Urine sugar

Answer

Random sugar

Answer

Glucose tolerance test

Question 6

What condition is caused by the intake of exogenous steroids?

Accepted Answer

Cushing's syndrome

Answer

Addison's disease

Answer

Pheochromocytoma

Answer

Conn's syndrome

Question 7

Madarosis is seen in ?

Accepted Answer

Hypothyroidism

Answer

None of the options

Answer

Addison's disease

Answer

Acromegaly

Question 8

A 50-year-old woman, who is 5 feet 7 inches tall and weighs 185 pounds, has a family history of diabetes mellitus. Her fasting blood glucose levels are 160 mg/dL and 155 mg/dL on two occasions, and her HbA1c level is 7.9%. After being educated on medical nutrition therapy, she returns for reevaluation in 8 weeks, reporting that she has followed diet and exercise recommendations, but her fasting blood glucose levels remain between 140 and 150 mg/dL, and her HbA1c level is 7.7%. She is asymptomatic, and physical examination reveals no abnormalities. Which of the following treatments is the most appropriate for her condition?

Accepted Answer

Metformin

Answer

A thiazolidinedione

Answer

A dipeptidyl peptidase-4 (DPP-4) inhibitor

Answer

Insulin therapy

Question 9

Which of the following is the MOST characteristic feature of insulinoma?

Accepted Answer

Hypoglycemic attacks

Answer

Usually Solitary tumour

Answer

Mostly benign tumour

Answer

Weight gain

Question 10

What is the most common adrenal incidentaloma?

Accepted Answer

Endocrine inactive tumors

Answer

Aldosterone producing

Answer

Pheochromocytoma

Answer

Cortisol producing

Endocrinology — MCQs

Endocrinology — MCQs

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