Endocrinology Practice Questions

Q: An individual has a fasting blood glucose concentration of 115 mg/dL on three occasions. What is your conclusion?

Impaired glucose tolerance. ### Explanation The diagnosis of glycemic status is based on standardized criteria set by the WHO and ADA. This question tests your knowledge of the **Fasting Plasma Glucose (FPG)** thresholds. **1. Why "Impaired Glucose Tolerance" (Prediabetes) is correct:** According to current guidelines, the classification for Fasting Plasma Glucose is: * **Normal:** < 100 mg/dL * **Impaired Fasting Glucose (IFG):** 100–125 mg/dL * **Diabetes Mellitus:** ≥ 126 mg/dL A value of **115 mg/dL** falls squarely within the 100–125 mg/dL range. Since this was confirmed on three separate occasions, it consistently indicates a state of "Prediabetes." While the technical term for fasting elevation is "Impaired Fasting Glucose," in the context of many exams (including NEET-PG), this is often grouped under the broader clinical umbrella of **Impaired Glucose Tolerance (IGT)** or Prediabetes. **2. Analysis of Incorrect Options:** * **A. Normal:** Incorrect, as the upper limit for normal fasting glucose is 99 mg/dL. * **B. Diabetic:** Incorrect, as the diagnostic cutoff for diabetes is ≥ 126 mg/dL on two separate occasions. * **D. Needs further evaluation:** While an Oral Glucose Tolerance Test (OGTT) or HbA1c might be done clinically to further assess risk, the *conclusion* based on the provided data is already defined by the diagnostic criteria. **3. High-Yield Clinical Pearls for NEET-PG:** * **HbA1c Cutoffs:** Normal (< 5.7%), Prediabetes (5.7–6.4%), Diabetes (≥ 6.5%). * **2-hour Post-Prandial (OGTT):** Normal (< 140 mg/dL), IGT (140–199 mg/dL), Diabetes (≥ 200 mg/dL). * **Random Blood Sugar:** ≥ 200 mg/dL + classic symptoms of hyperglycemia (polyuria, polydipsia, weight loss) is diagnostic for Diabetes. * **Note:** Always look for "two separate occasions" for a definitive diagnosis unless the patient is in a clear hyperglycemic crisis.

Q: Which of the following is NOT a sign of pituitary apoplexy?

Hypertension. **Explanation:** **Pituitary apoplexy** is a medical emergency caused by sudden hemorrhage or infarction of the pituitary gland, usually within an existing macroadenoma. **Why Hypertension is the correct answer:** Hypertension is **not** a feature of pituitary apoplexy. In fact, the condition typically leads to **hypotension or shock** [1]. This occurs due to the sudden destruction of the anterior pituitary, resulting in **acute secondary adrenal insufficiency** (ACTH deficiency) [1]. Without cortisol, the body cannot maintain vascular tone, leading to a precipitous drop in blood pressure [1]. **Analysis of Incorrect Options:** * **Shock:** As explained above, acute adrenal crisis leads to circulatory collapse and shock [1]. This is the most life-threatening complication of apoplexy. * **Loss of consciousness:** Increased intracranial pressure, meningeal irritation from extravasated blood, or severe hypotension can lead to altered sensorium or coma [4]. * **Headache:** This is the most common presenting symptom (seen in >95% of cases). It is typically sudden, "thunderclap" in nature, and retro-orbital, caused by the rapid expansion of the gland stretching the dura mater [4]. **Clinical Pearls for NEET-PG:** * **Classic Triad:** Sudden severe headache [4], visual field defects (bitemporal hemianopia) [2], and ophthalmoplegia (CN III, IV, VI palsy due to cavernous sinus involvement). * **Diagnosis:** **MRI Brain** (Pituitary protocol) is the investigation of choice [2]; it shows T1 hyperintensity in cases of hemorrhage. * **Management:** Immediate administration of **high-dose intravenous corticosteroids** (Hydrocortisone) is the priority to treat adrenal crisis [1], followed by surgical decompression if vision is threatened [3].

Q: Canagliflozin acts by:

Increasing urinary glucose excretion. **Explanation:** **Mechanism of Action:** Canagliflozin is a member of the **SGLT-2 (Sodium-Glucose Co-transporter 2) inhibitors** class. Under normal physiological conditions, approximately 90% of glucose filtered by the renal glomeruli is reabsorbed in the S1 segment of the proximal convoluted tubule via SGLT-2. By inhibiting this transporter, Canagliflozin reduces the renal threshold for glucose and prevents its reabsorption, leading to **increased urinary glucose excretion (glucosuria)**. This results in a reduction of plasma glucose levels in an insulin-independent manner. **Analysis of Incorrect Options:** * **Option A:** Decreasing hepatic glucose production is the primary mechanism of **Metformin** (Biguanides). * **Option C:** Increasing insulin secretion is the mechanism of **Sulfonylureas** and **Meglitinides** (secretagogues). * **Option D:** Prolonging endogenous GLP-1 action is the mechanism of **DPP-4 inhibitors** (Gliptins), which prevent the degradation of GLP-1. **High-Yield Clinical Pearls for NEET-PG:** * **Weight & BP:** SGLT-2 inhibitors promote weight loss (due to calorie loss via urine) and have a mild diuretic effect that lowers blood pressure. * **Cardio-Renal Protection:** These drugs are highly favored in exams for their proven benefits in reducing hospitalization for **Heart Failure** and slowing the progression of **Chronic Kidney Disease (CKD)**. * **Side Effects:** The most common side effect is **Genitourinary infections** (e.g., Vulvovaginal candidiasis) due to high glucose in the urine. A rare but serious complication is **Euglycemic Diabetic Ketoacidosis (eDKA)**. * **Suffix:** All drugs in this class end in **"-gliflozin"** (Dapagliflozin, Empagliflozin).

Q: A 17-year-old male presents with a 3-month history of headache, weight gain, decreased concentration, polyuria, and polydipsia. His headaches are mostly in the morning and involve the frontal region. On examination, he was found to have a bitemporal visual field defect and no facial hair. An MRI scan revealed a suprasellar partially calcified cystic lesion with displacement of the optic chiasm. What is the most likely pathology?

Craniopharyngioma. **Explanation:** The clinical presentation is classic for a **Craniopharyngioma**, a benign but locally aggressive tumor derived from remnants of **Rathke’s pouch** [1]. **Why Craniopharyngioma is correct:** 1. **Age & Symptoms:** It has a bimodal distribution (5–14 years and >50 years) [1]. In this 17-year-old, the tumor causes mass effect (morning headaches, bitemporal hemianopia due to optic chiasm compression) and endocrine dysfunction (delayed puberty/lack of facial hair due to GH/LH/FSH deficiency). 2. **Diabetes Insipidus (DI):** Polyuria and polydipsia indicate central DI, a hallmark of craniopharyngiomas due to hypothalamic-pituitary axis disruption [1]. 3. **Imaging:** The description of a **suprasellar, cystic, and calcified lesion** is pathognomonic [1]. Calcification is seen in ~90% of pediatric cases. **Why other options are incorrect:** * **Giant aneurysm:** While it can cause mass effect, it would not typically present with a cystic, calcified appearance on MRI or cause DI in a teenager. * **Pituitary macroadenoma:** These are rare in adolescents. While they cause bitemporal hemianopia [2], they are usually solid and **rarely calcified**. * **Glioblastoma multiforme:** This is a high-grade intraparenchymal malignancy, not a suprasellar cystic/calcified lesion, and is rare in this age group. **High-Yield Pearls for NEET-PG:** * **Histology:** Look for "Adamantinomatous" type (machinery oil fluid, wet keratin, stellate reticulum) in children. * **Imaging Triad:** Suprasellar location, Cystic components, and Calcification. * **Most common cause** of hypopituitarism in children. * **Visual field defect:** Bitemporal hemianopia (starts in the **inferior** quadrants because the tumor compresses the chiasm from above).

Q: Treatment of thyroid storm includes all of the following EXCEPT?

Radioactive iodine. **Explanation:** Thyroid storm is a life-threatening medical emergency characterized by extreme hypermetabolism. The management strategy focuses on inhibiting thyroid hormone synthesis, blocking hormone release, preventing peripheral conversion of T4 to T3, and controlling sympathetic overactivity. **Why Radioactive Iodine (RAI) is the Correct Answer:** Radioactive iodine (I-131) is **contraindicated** in the acute management of thyroid storm. Its mechanism involves the destruction of thyroid parenchyma, which initially causes a massive release of stored thyroid hormones into the circulation. In a patient already in thyroid storm, this "leakage" can worsen the thyrotoxicosis and prove fatal. RAI is reserved for definitive therapy only after the patient has reached a stable, euthyroid state. **Analysis of Other Options:** * **Propranolol (Option A):** Used to control life-threatening sympathetic symptoms (tachycardia, palpitations, tremors). It also uniquely inhibits the peripheral conversion of T4 to T3. * **Hydrocortisone (Option C):** Corticosteroids are used to treat relative adrenal insufficiency associated with severe stress and to inhibit the peripheral conversion of T4 to T3. * **Lugol’s Iodine (Option D):** High doses of stable iodine inhibit the release of thyroid hormones via the **Wolff-Chaikoff effect**. Note: It must be administered *after* starting antithyroid drugs (like PTU) to prevent the iodine from being used as a substrate for new hormone synthesis (Jod-Basedow effect). **NEET-PG High-Yield Pearls:** * **Drug of Choice:** **Propylthiouracil (PTU)** is preferred over Methimazole in thyroid storm because it inhibits both hormone synthesis and the peripheral conversion of T4 to T3. * **Sequence of Treatment:** Always give PTU/Methimazole at least 1 hour **before** giving Lugol’s iodine. * **Supportive Care:** Aggressive cooling (avoiding salicylates as they displace T4 from TBG) and IV fluids are essential.

Q: In which condition is mucocutaneous candidiasis an important clinical feature?

Autoimmune hypoparathyroidism. **Explanation:** The correct answer is **Autoimmune hypoparathyroidism**. This condition is a hallmark component of **Autoimmune Polyendocrine Syndrome Type 1 (APS-1)**, also known as **APECED** (Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy). **1. Why Autoimmune Hypoparathyroidism is Correct:** APS-1 is caused by a mutation in the **AIRE (Autoimmune Regulator) gene**. The classic clinical triad includes: * **Chronic Mucocutaneous Candidiasis (CMC):** Usually the first sign, appearing in early childhood. * **Autoimmune Hypoparathyroidism:** The most common endocrine manifestation. * **Addison’s Disease:** Typically develops later. The presence of CMC in this context is due to the production of autoantibodies against Th17 cytokines (IL-17 and IL-22), which are essential for fungal mucosal immunity. **2. Why Other Options are Incorrect:** * **DiGeorge Syndrome:** While it involves hypocalcemia and T-cell deficiency (which can lead to infections), the classic triad involves thymic aplasia, cardiac defects, and cleft palate. It is not primarily defined by the specific CMC-hypoparathyroidism association seen in APS-1. * **Pseudohypoparathyroidism:** This is a genetic resistance to PTH (end-organ resistance). It is characterized by Albright’s Hereditary Osteodystrophy (short stature, round face, short 4th/5th metacarpals) but does not involve autoimmune candidiasis. * **Post-surgical Hypoparathyroidism:** This is an acquired mechanical complication (e.g., after thyroidectomy) and lacks any autoimmune or immunological component. **High-Yield Clinical Pearls for NEET-PG:** * **APS-1 Triad:** Candidiasis + Hypoparathyroidism + Addison’s Disease. * **Inheritance:** Autosomal Recessive (AIRE gene mutation on Chromosome 21). * **Dermatological Clue:** CMC in APS-1 often presents as persistent oral thrush, nail dystrophy, or angular cheilitis that is refractory to standard treatment.

Question 1

Which of the following antibodies is involved in the tissue destructive process associated with hypothyroidism in Hashimoto's and atrophic thyroiditis?

Accepted Answer

Thyroperoxidase antibody

Answer

Thyroglobulin antibody

Answer

TSH receptor antibody

Answer

Thyroid stimulating antibody

Question 2

A 40-year-old alcoholic man is being treated for tuberculosis with intermittent compliance. He complains of increasing weakness, fatigue, weight loss, and nausea over the preceding 3 weeks. His blood pressure is 80/50 mm Hg, and there is increased pigmentation over the elbows and in the palmar creases. Cardiac examination is normal. What is the best next step in his evaluation?

Accepted Answer

Early morning serum cortisol and cosyntropin stimulation test

Answer

Complete blood count with iron and iron-binding capacity

Answer

Erythrocyte sedimentation rate (ESR)

Answer

Blood cultures

Question 3

Hypothyroidism is associated with which of the following clinical problems, except?

Accepted Answer

Thromboembolism

Answer

Menorrhagia

Answer

Early abortions

Answer

Galactorrhea

Question 4

Which of the following is the best intervention to reduce the incidence of macrovascular complications in type 2 diabetes?

Accepted Answer

Strict blood pressure control

Answer

HbA1c less than 6.5%

Answer

Urine microalbumin measurement

Answer

Fasting capillary blood glucose values below 180 mg/dL

Question 5

An individual has a fasting blood glucose concentration of 115 mg/dL on three occasions. What is your conclusion?

Accepted Answer

Impaired glucose tolerance

Answer

Normal

Answer

Diabetic

Answer

Needs further evaluation by other biochemical tests

Question 6

Which of the following is NOT a sign of pituitary apoplexy?

Accepted Answer

Hypertension

Answer

Shock

Answer

Loss of consciousness

Answer

Headache

Question 7

Canagliflozin acts by:

Accepted Answer

Increasing urinary glucose excretion

Answer

Decreasing hepatic glucose production

Answer

Increasing insulin secretion

Answer

Prolonging endogenous GLP-1 action

Question 8

A 17-year-old male presents with a 3-month history of headache, weight gain, decreased concentration, polyuria, and polydipsia. His headaches are mostly in the morning and involve the frontal region. On examination, he was found to have a bitemporal visual field defect and no facial hair. An MRI scan revealed a suprasellar partially calcified cystic lesion with displacement of the optic chiasm. What is the most likely pathology?

Accepted Answer

Craniopharyngioma

Answer

Giant aneurysm of the carotid artery

Answer

Pituitary macroadenoma

Answer

Glioblastoma multiforme

Question 9

Treatment of thyroid storm includes all of the following EXCEPT?

Accepted Answer

Radioactive iodine

Answer

Propranolol

Answer

Hydrocortisone

Answer

Lugol's iodine

Question 10

In which condition is mucocutaneous candidiasis an important clinical feature?

Accepted Answer

Autoimmune hypoparathyroidism

Answer

DiGeorge syndrome

Answer

Pseudohypoparathyroidism

Answer

Post-surgical hypoparathyroidism

Endocrinology — MCQs

Endocrinology — MCQs

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