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 59-year-old woman presents with bone pain and fatigue. Blood tests show calcium 3.3 mmol/L, low albumin, and normal PTH. She has a history of breast cancer 5 years ago. What is the most likely mechanism?
- A. Parathyroid hormone excess
- B. PTH-related protein (Correct Answer)
- C. Vitamin D excess
- D. Bone metastases
- E. Sarcoidosis
Type 1 diabetes Explanation: ***PTH-related protein***- This is the most common cause of **Humoral Hypercalcemia of Malignancy (HHM)**, especially in solid tumors like breast cancer, where **PTHrP** acts as a systemic hormone, mimicking the effects of **parathyroid hormone** on bone and kidney.- The presentation of **severe hypercalcemia** (3.3 mmol/L) with normal or **suppressed PTH** strongly indicates a PTH-independent mechanism, making HHM due to PTHrP the primary diagnosis over primary hyperparathyroidism.*Parathyroid hormone excess*- **Primary Hyperparathyroidism** causes hypercalcemia due to an adenoma or hyperplasia resulting in *high* or *inappropriately normal* circulating levels of **PTH**.- In this patient, the PTH level is normal (implying suppression by the high calcium), which effectively rules out PTH excess as the direct cause of the hypercalcemia.*Vitamin D excess*- Causes hypercalcemia by increasing **intestinal calcium absorption** and promoting bone resorption, identifiable by significantly elevated levels of **25(OH)D** or active **1,25(OH)₂D**.- While possible, this mechanism is far less likely than malignancy-associated hypercalcemia in a patient with a known history of breast cancer.*Bone metastases*- Breast cancer commonly metastasizes to bone, causing **osteolytic lesions** that release calcium via local cytokine-mediated osteoclast activation.- Although common, hypercalcemia caused solely by local osteolysis tends to be less severe than the level seen here; pronounced hypercalcemia with suppressed PTH is the hallmark presentation of **humoral hypercalcemia (PTHrP)**.*Sarcoidosis*- This granulomatous disease causes hypercalcemia via ectopic production of **1-alpha-hydroxylase** by activated macrophages, leading to unregulated synthesis of active **1,25-dihydroxyvitamin D**.- This mechanism is not typically associated with breast cancer and is usually accompanied by other features of sarcoidosis, such as pulmonary symptoms or cutaneous lesions.
Type 1 diabetes UK Medical PG Question 3: 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 4: 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 5: 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 6: 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 7: A 45-year-old man presents with recurrent episodes of severe sweating, headache, and palpitations. His BP during attacks reaches 220/120 mmHg. 24-hour urine catecholamines are elevated. What is the most likely diagnosis?
- A. Essential hypertension
- B. Pheochromocytoma (Correct Answer)
- C. Panic disorder
- D. Hyperthyroidism
- E. Cocaine use
Type 1 diabetes Explanation: ***Pheochromocytoma*** - The highly suggestive clinical presentation includes the classic paroxysmal triad of severe **headache**, generalized **sweating**, and **palpitations** (tachycardia), often coinciding with **hypertensive crises** (220/120 mmHg).- The diagnosis is biochemically confirmed by finding significant evidence of excessive catecholamine production, such as **elevated 24-hour urine catecholamines** or metanephrines.*Essential hypertension*- Essential hypertension is a diagnosis of exclusion that typically does not present with severe, intermittent, and paroxysmal symptomatic crises.- It is not characterized by pathologically high levels of **catecholamines** or their metabolites in the urine or plasma.*Panic disorder*- Panic disorder can cause symptoms mimicking sympathetic overdrive (palpitations, sweating), but it rarely causes the severe, transient **hypertensive crises** seen in this patient (e.g., 220/120 mmHg).- Panic attacks are excluded as the primary cause by the finding of high levels of circulating and **urinary catecholamines**.*Hyperthyroidism*- While hyperthyroidism causes palpitations and sweating, the hypertension is usually predominantly **systolic** (leading to a wide pulse pressure), not spiking to 220/120 mmHg.- Diagnosis relies on elevated **thyroid hormone levels** (T3/T4) and a suppressed TSH, not elevated catecholamines.*Cocaine use*- Acute cocaine intoxication causes severe sympathetic hyperactivity and hypertension, but this is usually transient and related to recent drug ingestion.- If intoxication were the cause, laboratory findings would typically show evidence of drug use or metabolites, rather than chronic baseline elevation of **catecholamines** suggestive of a secreting tumor.
Type 1 diabetes UK Medical PG Question 8: 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 9: 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 10: 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**.
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