Type 1 diabetes UK Medical PG Practice Questions and MCQs
Practice UK Medical PG questions for Type 1 diabetes. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Type 1 diabetes UK Medical PG Question 1: A 46-year-old man presents with recurrent episodes of severe flushing and diarrhea. CT shows liver metastases and a pancreatic mass. Chromogranin A is markedly elevated. What is the most likely primary tumor?
- A. Pancreatic adenocarcinoma
- B. Pancreatic neuroendocrine tumor (Correct Answer)
- C. Hepatocellular carcinoma
- D. Cholangiocarcinoma
- E. Gastrinoma
Type 1 diabetes Explanation: ***Pancreatic neuroendocrine tumor*** - The classic presentation of recurrent **flushing** and **diarrhea**, combined with a **pancreatic mass** and **liver metastases**, is highly characteristic of a functional **neuroendocrine tumor (NET)**, specifically a **carcinoid syndrome**. - Markedly elevated **Chromogranin A** is a widely used and sensitive biochemical marker for **neuroendocrine tumors**, confirming this diagnosis. *Pancreatic adenocarcinoma* - This tumor typically presents with symptoms such as **jaundice**, **weight loss**, and **abdominal pain**, not **flushing** and **diarrhea**. - **Chromogranin A** is not elevated in pancreatic adenocarcinoma; **CA 19-9** is a more common tumor marker. *Hepatocellular carcinoma* - While **liver metastases** are mentioned, the primary tumor is a **pancreatic mass**, not a primary liver tumor. - It does not typically cause **flushing** and **diarrhea**, nor is **Chromogranin A** a marker for hepatocellular carcinoma. *Cholangiocarcinoma* - This is a cancer of the **bile ducts** and usually presents with **jaundice**, **pruritus**, and **dark urine**, not **flushing** and **diarrhea**. - The primary mass is in the **pancreas**, not the bile ducts, and **Chromogranin A** is not elevated in cholangiocarcinoma. *Gastrinoma* - A **gastrinoma** is a type of pancreatic neuroendocrine tumor that primarily causes **Zollinger-Ellison syndrome**, characterized by severe **peptic ulcer disease** and **diarrhea** due to excessive gastrin. - While it's a NET, the prominent **flushing** is not a typical feature of gastrinoma; this symptom strongly points towards a tumor producing other vasoactive substances (e.g., serotonin, VIP) consistent with a broader **carcinoid syndrome** presentation.
Type 1 diabetes UK Medical PG Question 2: A 43-year-old man presents with recurrent episodes of severe sweating, palpitations, and headache. His BP during episodes is 240/130 mmHg. What is the most appropriate preoperative management?
- A. Beta-blockers only
- B. Alpha-blockers only
- C. Alpha-blockers then beta-blockers (Correct Answer)
- D. ACE inhibitors
- E. Calcium channel blockers
Type 1 diabetes Explanation: ***Alpha-blockers then beta-blockers***- The clinical presentation (paroxysmal **hypertension**, headache, palpitations, and sweating) is highly suggestive of a **pheochromocytoma**.- Preoperative stabilization requires adequate **alpha-adrenergic blockade** first (e.g., phenoxybenzamine or doxazosin) to control blood pressure and allow for volume expansion, followed by **beta-blockade** to manage tachycardia or arrhythmias.*Beta-blockers only*- Using beta-blockers alone is contraindicated as it causes **unopposed alpha-adrenergic stimulation**, leading to severe **vasoconstriction** and potentially a fatal hypertensive crisis or pulmonary edema.- Beta-blockers are only instituted *after* achieving complete alpha-blockade and adequate blood pressure control, typically to manage persistent tachycardia.*Alpha-blockers only*- While alpha-blockade is the essential first step, it is usually insufficient for full preoperative management, as patients often require subsequent **beta-blockade** to control catecholamine-induced tachycardia and arrhythmias.- Complete preparation requires both classes of medication to fully mitigate cardiovascular risk before surgery.*ACE inhibitors*- These medications target the **renin-angiotensin-aldosterone system** and are ineffective at blocking the direct severe vasoconstrictive effects of excessive circulating catecholamines.- They may also increase the risk of severe **hypotension** after tumor removal if the patient is relatively volume-depleted from prolonged vasoconstriction.*Calcium channel blockers*- While some CCBs (like nicardipine) can be used as **adjuncts** for blood pressure control, they cannot replace the mandatory initial step of **alpha-adrenergic blockade** and volume repletion.- They do not address the need for full adrenergic receptor blockade necessary to prevent cardiovascular catastrophe during surgical manipulation of the tumor.
Type 1 diabetes UK Medical PG Question 3: A 44-year-old woman presents with fatigue, muscle weakness, and weight loss. She has hyperpigmentation of palmar creases. Blood tests show Na+ 128 mmol/L, K+ 5.6 mmol/L. What is the most appropriate diagnostic test?
- A. Dexamethasone suppression test
- B. Synacthen stimulation test (Correct Answer)
- C. 24-hour urine cortisol
- D. Adrenal antibodies
- E. ACTH levels
Type 1 diabetes Explanation: ***Synacthen stimulation test*** - Also known as the **ACTH stimulation test**, this is the **gold standard** for diagnosing adrenal insufficiency, as the clinical signs (hyperpigmentation, hyponatremia, hyperkalemia) strongly suggest **Primary Adrenal Insufficiency** (Addison's disease). - The test assesses the adrenal gland's reserve capacity to produce cortisol; an insufficient rise in cortisol following the injection of synthetic **ACTH (Synacthen)** confirms the diagnosis. *Dexamethasone suppression test* - This test is primarily used to confirm or exclude **Cushing syndrome** (hypercortisolism) by checking if cortisol production can be suppressed by exogenous steroids. - It is inappropriate for suspected adrenal insufficiency, as it does not evaluate the maximum functional capacity of the adrenal glands. *24-hour urine cortisol* - This test measures the total amount of free cortisol excreted over a day and is typically used as a screening tool for **Cushing syndrome**. - While very low values might suggest adrenal failure, it is less sensitive and specific for diagnosing adrenal insufficiency compared to the **Synacthen test**. *Adrenal antibodies* - Detecting adrenal antibodies (e.g., against **21-hydroxylase**) is crucial for determining the **autoimmune etiology** of primary adrenal insufficiency. - However, measuring antibodies is a step in determining the *cause* of the disease, not the definitive *diagnostic test* for glandular failure. *ACTH levels* - Plasma **ACTH** measurement is essential for distinguishing between primary (high ACTH) and secondary (low ACTH) insufficiency *after* the diagnosis is confirmed by the Synacthen test. - It serves as a differentiation tool, but cannot confirm the initial diagnosis of adrenal insufficiency, which requires assessing the cortisol response to stimulation.
Type 1 diabetes UK Medical PG Question 4: A 64-year-old woman presents with bone pain and fatigue. Blood tests show calcium 3.1 mmol/L, phosphate 0.7 mmol/L, and suppressed PTH. She has a history of sarcoidosis. What is the most likely cause of hypercalcemia?
- A. Primary hyperparathyroidism
- B. Malignancy
- C. Granulomatous disease (Correct Answer)
- D. Vitamin D intoxication
- E. Milk-alkali syndrome
Type 1 diabetes Explanation: ***Granulomatous disease***
- Sarcoidosis, a common granulomatous disease, causes non-PTH mediated hypercalcemia due to the autonomous expression of **1-alpha-hydroxylase** by activated macrophages within the granulomas.
- This enzyme overproduces **1,25-dihydroxyvitamin D (calcitriol)**, leading to increased intestinal calcium absorption and subsequent **suppression of PTH**.
*Primary hyperparathyroidism*
- This condition is characterized by an elevated or inappropriately normal **parathyroid hormone (PTH)** level in the setting of hypercalcemia, typically due to a parathyroid adenoma.
- The patient's lab results show **suppressed PTH**, which effectively rules out primary hyperparathyroidism.
*Malignancy*
- Malignancy frequently causes hypercalcemia, often through osteolytic bone destruction or the secretion of **Parathyroid Hormone-related Protein (PTHrP)**, which also suppresses PTH.
- Although PTH is suppressed, the strong history of **sarcoidosis** (a known non-malignant cause of calcitriol-mediated hypercalcemia) makes granulomatous disease the most probable specific diagnosis.
*Vitamin D intoxication*
- This typically results from massive exogenous intake of vitamin D, leading to extremely high levels of serum **25-hydroxyvitamin D** and subsequent elevation of serum calcium.
- While it causes suppressed PTH and hypercalcemia, the known diagnosis of sarcoidosis provides a strong, intrinsic explanation that must be prioritized over exogenous intake.
*Milk-alkali syndrome*
- This syndrome is caused by the substantial intake of **calcium** and absorbable **alkali**, resulting in hypercalcemia, suppressed PTH, and often metabolic alkalosis.
- The history provided emphasizes sarcoidosis rather than excessive antacid or calcium supplementation, making this diagnosis less likely.
Type 1 diabetes UK Medical PG Question 5: A 47-year-old woman presents with fatigue, muscle weakness, and depression. She has purple striae and central obesity. 24-hour urine cortisol is elevated. What is the next most appropriate test?
- A. MRI pituitary
- B. Dexamethasone suppression test (Correct Answer)
- C. ACTH levels
- D. Adrenal CT
- E. CRH stimulation test
Type 1 diabetes Explanation: ***Dexamethasone suppression test***
- An elevated 24-hour urine cortisol confirms hypercortisolism; the next step is to determine the underlying cause, which the **dexamethasone suppression test** helps to differentiate.
- This test assesses the feedback control of the **hypothalamic-pituitary-adrenal axis** to differentiate among pituitary Cushing's disease, ectopic ACTH production, and adrenal tumors.
*MRI pituitary*
- **MRI pituitary** is primarily used for **localization** of a pituitary adenoma after ACTH-dependent Cushing's syndrome has been established.
- It is not the initial test to *determine the cause* of hypercortisolism after it has been confirmed.
*ACTH levels*
- **ACTH levels** are crucial to differentiate between **ACTH-dependent** (pituitary or ectopic) and **ACTH-independent** (adrenal) causes of Cushing's syndrome.
- While important, a **dexamethasone suppression test** is often performed first or concurrently to provide functional insight into cortisol suppressibility.
*Adrenal CT*
- **Adrenal CT** is performed to **localize an adrenal adenoma** or hyperplasia once ACTH-independent Cushing's syndrome (low ACTH) has been identified.
- It is a localization step, not the primary diagnostic test to determine the *type* of Cushing's syndrome after initial confirmation of hypercortisolism.
*CRH stimulation test*
- The **CRH stimulation test** is typically used to help differentiate between **pituitary Cushing's disease** and **ectopic ACTH production** in cases of ACTH-dependent Cushing's syndrome.
- It is a more specialized test performed after initial confirmation and differentiation steps like the dexamethasone suppression test and ACTH levels.
Type 1 diabetes UK Medical PG Question 6: A 29-year-old woman presents with episodes of severe anxiety, tremor, and palpitations. These occur mainly when fasting. Blood glucose during episodes is 2.1 mmol/L. Insulin and C-peptide are elevated. What is the most likely diagnosis?
- A. Panic disorder
- B. Insulinoma (Correct Answer)
- C. Factitious hypoglycemia
- D. Reactive hypoglycemia
- E. Adrenal insufficiency
Type 1 diabetes Explanation: ***Insulinoma*** - The presentation fulfills **Whipple's triad** (symptoms of hypoglycemia, low blood glucose, relief upon glucose administration) occurring specifically with **fasting**. - The key diagnostic findings are **fasting hypoglycemia** (2.1 mmol/L) combined with inappropriately **elevated insulin and C-peptide**, confirming excessive *endogenous* insulin secretion from a pancreatic **β-cell tumor**. *Panic disorder* - Although the symptoms (anxiety, tremor, and palpitations) mimic adrenergic symptoms of hypoglycemia, the coexisting **severe hypoglycemia** rules out pure panic disorder. - Panic disorder is a psychiatric diagnosis and does not cause underlying metabolic derangements like low blood glucose or hyperinsulinemia. *Factitious hypoglycemia* - If the patient were using **exogenous insulin**, the C-peptide level would be **suppressed or low**, as commercial insulin preparations do not typically contain C-peptide. - While sulfonylurea abuse (a form of factitious hypoglycemia) can raise both insulin and C-peptide, **insulinoma** remains the primary organic diagnosis when these findings occur spontaneously, especially with severe fasting symptoms. *Reactive hypoglycemia* - This condition is characterized by hypoglycemia occurring **postprandially** (2–4 hours after a meal) due to rapid glucose absorption and delayed insulin response, not during **fasting**. - It is often seen after gastric surgeries or in the initial stages of diabetes, and typically presents with milder symptoms. *Adrenal insufficiency* - Adrenal insufficiency causes hypoglycemia primarily through lack of **cortisol**, which is a counter-regulatory hormone to insulin. - Hypoglycemia secondary to this condition would present with **suppressed** or low insulin and C-peptide levels, as the pancreas is not producing excess insulin.
Type 1 diabetes UK Medical PG Question 7: A 67-year-old woman presents with bone pain and confusion. Serum calcium is 3.4 mmol/L, phosphate is low, and PTH is elevated. Parathyroid scan shows increased uptake. What is the most appropriate treatment?
- A. IV fluids and bisphosphonates
- B. Parathyroidectomy (Correct Answer)
- C. Cinacalcet
- D. High-dose vitamin D
- E. Corticosteroids
Type 1 diabetes Explanation: ***Parathyroidectomy*** - The presence of severe hypercalcemia (3.4 mmol/L), elevated PTH, and end-organ damage (bone pain, confusion) are clear indications for definitive surgical management of **Primary Hyperparathyroidism** (PHPT). - Parathyroidectomy is the curative treatment for PHPT, effectively removing the source of excess PTH production (likely an **adenoma**, localized by the scan) and normalizing calcium levels long-term. *IV fluids and bisphosphonates* - These agents are used for the initial, acute management of **hypercalcemic crisis** to rapidly reduce serum calcium, but they are not the definitive curative treatment for the underlying PHPT. - Bisphosphonates inhibit osteoclast activity, but the failure to address the sustained excess PTH means high calcium levels will recur shortly without definitive surgical intervention. *Cinacalcet* - Cinacalcet is a **calcimimetic** that increases the sensitivity of the calcium-sensing receptor, reducing PTH secretion and serum calcium. - It is typically reserved for PHPT patients who are poor surgical candidates or have intractable secondary hyperparathyroidism, not the **first-line curative treatment**. *High-dose vitamin D* - Vitamin D should be avoided as it would exacerbate the patient's hypercalcemia by increasing **intestinal calcium absorption** and mobilizing calcium from bone. - It is used to treat conditions causing **hypocalcemia** (like hypoparathyroidism or vitamin D deficiency), which is the opposite of this clinical scenario. *Corticosteroids* - Corticosteroids are primarily used to treat hypercalcemia associated with **malignancy** or **granulomatous diseases** (e.g., sarcoidosis) by reducing calcitriol production. - They are generally ineffective in managing the high calcium levels driven by increased PTH secretion caused by a **parathyroid adenoma**.
Type 1 diabetes UK Medical PG Question 8: A 49-year-old woman presents with recurrent episodes of severe flushing and diarrhea. CT shows multiple liver lesions and a pancreatic mass. Chromogranin A is elevated. What is the most likely diagnosis?
- A. Pancreatic adenocarcinoma
- B. Neuroendocrine tumor (Correct Answer)
- C. Hepatocellular carcinoma
- D. Cholangiocarcinoma
- E. Lymphoma
Type 1 diabetes Explanation: ***Neuroendocrine tumor***- The combination of **severe flushing** and secretory **diarrhea** (suggestive of **carcinoid syndrome**), coupled with a pancreatic mass and liver metastases, is highly specific for a functional Neuroendocrine Tumor (NET).- The elevated **Chromogranin A** confirms the neuroendocrine origin of the tumor, as this protein is stored and released by neurosecretory granules in NET cells.*Pancreatic adenocarcinoma*- This common pancreatic malignancy typically presents with **painless jaundice**, severe back pain, or weight loss, but **lacks the specific hormonal symptoms** of flushing and diarrhea.- The primary tumor marker for adenocarcinoma is usually **CA 19-9**, not Chromogranin A.*Hepatocellular carcinoma*- This primary liver cancer arises most often in the setting of chronic liver disease/cirrhosis and presents with mass effects or systemic decline, but **flushing and diarrhea are absent**.- The liver lesions in this case are likely **metastases** arising from the primary pancreatic neuroendocrine tumor, not primary HCC.*Cholangiocarcinoma*- This cancer of the bile ducts manifests primarily as **obstructive jaundice** and right upper quadrant pain.- It is not associated with the syndrome of flushing and diarrhea or the release of hormones that lead to elevated **Chromogranin A**.*Lymphoma*- Lymphoma typically presents with systemic **B symptoms** (**fever, night sweats, weight loss**) and significant lymphadenopathy.- It does not produce the hormones that cause flushing and diarrhea, nor is it associated with elevated serum **Chromogranin A**.
Type 1 diabetes UK Medical PG Question 9: A 28-year-old woman presents with amenorrhea and galactorrhea. Visual field testing shows bitemporal hemianopia. Prolactin is 8000 mU/L. What is the most likely diagnosis?
- A. Hypothyroidism
- B. Prolactinoma (Correct Answer)
- C. Craniopharyngioma
- D. Empty sella syndrome
- E. Sheehan syndrome
Type 1 diabetes Explanation: ***Prolactinoma***- The constellation of **amenorrhea** and **galactorrhea** is classical for hyperprolactinemia, directly correlated with the extremely high **prolactin level (8000 mU/L)**.- The presence of **bitemporal hemianopia** indicates a large tumor (**macroadenoma**) causing compression of the **optic chiasm**.*Hypothyroidism*- While severe **hypothyroidism** can cause modest prolactin elevation due to high **TRH** (Thyrotropin-releasing hormone), it rarely causes prolactin levels this high (typically < 3000 mU/L) or a significant mass effect.- Primary symptoms would include fatigue, weight gain, and cold intolerance, and TSH would be notably elevated.*Craniopharyngioma*- A **craniopharyngioma** is usually a suprasellar mass that causes visual field defects and features of central hypopituitarism.- It is **not** a prolactin-secreting tumor; if prolactin is elevated, it is due to pituitary stalk compression, which typically results in levels **below 2000 mU/L**.*Empty sella syndrome*- This condition results from herniation of the **arachnoid membrane** and CSF into the sella turcica, flattening the pituitary gland.- It typically causes *no* significant endocrine hyperfunction (like pronounced hyperprolactinemia) and is usually asymptomatic, rarely causing visual defects.*Sheehan syndrome*- **Sheehan syndrome** is **pituitary necrosis** following severe postpartum hemorrhage, leading to *hypopituitarism* (hormone deficiency).- While it causes amenorrhea (due to low gonadotropins), it **does not** cause galactorrhea or hyperprolactinemia, and no mass lesion is present.
Type 1 diabetes UK Medical PG Question 10: A 38-year-old woman presents with recurrent episodes of severe flushing triggered by alcohol and stress. CT shows multiple liver lesions and a small bowel mass. What is the most appropriate symptom control medication?
- A. Antihistamines
- B. Beta-blockers
- C. Octreotide (Correct Answer)
- D. Corticosteroids
- E. Proton pump inhibitors
Type 1 diabetes Explanation: ***Octreotide*** - The clinical presentation of recurrent severe flushing, especially when triggered by alcohol and stress, coupled with a small bowel mass and liver lesions, is highly suggestive of **carcinoid syndrome** from a metastatic neuroendocrine tumor. - **Octreotide**, a somatostatin analog, is the most appropriate medication for symptom control as it inhibits the release of vasoactive substances like **serotonin** from the tumor cells, thereby reducing flushing and diarrhea. *Antihistamines* - While histamine can contribute to flushing in some rare types of carcinoid (e.g., gastric), the predominant mediator of flushing in typical midgut carcinoid syndrome is **serotonin** and other kinins, against which antihistamines are largely ineffective. - Antihistamines are primarily used for allergic reactions or mast cell-related conditions, which have a different underlying pathophysiology than carcinoid flushing. *Beta-blockers* - Beta-blockers are primarily used to manage specific cardiac complications of carcinoid syndrome, such as **carcinoid heart disease**, or associated hypertension, not the acute flushing episodes themselves. - They do not directly inhibit the release of vasoactive mediators responsible for the flushing. *Corticosteroids* - Corticosteroids are powerful anti-inflammatory agents but do not address the root cause of carcinoid symptoms by inhibiting the synthesis or release of **serotonin** or other active amines from neuroendocrine tumors. - They are not indicated for the primary management of carcinoid-related flushing or hormonal symptoms. *Proton pump inhibitors* - Proton pump inhibitors (PPIs) are used to reduce gastric acid secretion, which is relevant in conditions like **Zollinger-Ellison syndrome** where there is gastrin hypersecretion. - They have no role in controlling the severe diarrhea or flushing characteristic of typical carcinoid syndrome, which are mediated by excess **serotonin** and other vasoactive peptides.
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