Endocrinology & Diabetes — MCQs
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A 71-year-old woman with type 2 diabetes for 18 years, hypertension, and previous myocardial infarction attends for medication review. Current medications include metformin 1g twice daily, empagliflozin 10mg once daily, and atorvastatin 80mg once daily. Her HbA1c is 69 mmol/mol (target <53 mmol/mol), eGFR is 42 ml/min, and urinary albumin:creatinine ratio is 45 mg/mmol. Blood pressure is 142/86 mmHg. Considering her cardiovascular and renal risk, what is the most appropriate addition to optimize her diabetes management?
A 38-year-old woman presents with a thyroid nodule. Ultrasound shows a 2.8cm solid hypoechoic nodule with irregular margins, microcalcifications, and taller-than-wide shape. There is no lymphadenopathy. Thyroid function tests are normal. Fine needle aspiration cytology is reported as 'Thy3f - follicular lesion/follicular neoplasm.' Which factor most significantly increases the probability of malignancy in this scenario?
A 54-year-old man with type 2 diabetes presents with a painless ulcer on the plantar aspect of his right first metatarsal head. The ulcer probes to bone. The surrounding skin is warm with mild erythema extending 2cm from the ulcer edge. He is systemically well with temperature 37.2°C. Foot pulses are palpable. X-ray shows soft tissue swelling but no obvious bony changes. What is the most appropriate next step in management?
A 47-year-old woman presents to the emergency department with confusion and agitation. She has a history of type 2 diabetes. Her capillary glucose is 48.2 mmol/L. Blood tests show sodium 152 mmol/L, potassium 4.8 mmol/L, urea 18.2 mmol/L, creatinine 156 μmol/L, and serum osmolality 348 mOsm/kg. Venous blood gas shows pH 7.38, bicarbonate 22 mmol/L. Urinalysis shows glucose 4+ but ketones are negative. What is the most critical difference in initial fluid management compared to diabetic ketoacidosis?
A 59-year-old man with type 2 diabetes for 8 years presents for diabetic eye screening. Fundoscopy reveals multiple microaneurysms and dot-blot haemorrhages in both eyes, with venous beading and intraretinal microvascular abnormalities in the left eye. No cotton wool spots or new vessels are seen. Visual acuity is 6/9 in both eyes. What is the most appropriate classification and management of this retinopathy?
A 22-year-old woman with type 1 diabetes for 10 years attends for review. She uses an insulin pump with continuous glucose monitoring. Her glucose profile shows frequent nocturnal hypoglycaemia at 3-4am, followed by elevated glucose readings at 7am (ranging 12-16 mmol/L). Her HbA1c is 68 mmol/mol. What is the most likely explanation for the morning hyperglycaemia?
A 76-year-old woman with type 2 diabetes, chronic kidney disease stage 4 (eGFR 22 ml/min), and heart failure is reviewed in clinic. Her current medications include metformin 500mg twice daily, gliclazide 80mg twice daily, and bisoprolol 2.5mg once daily. Her HbA1c is 75 mmol/mol and she has had two episodes of hypoglycaemia in the past month. What is the most appropriate modification to her diabetes management?
A 41-year-old woman presents with a 3-month history of anxiety, tremor, heat intolerance, and weight loss of 6 kg. Examination reveals a pulse of 104 bpm, fine tremor, and a smooth, non-tender, symmetrically enlarged thyroid gland with no nodules. TSH is <0.01 mU/L and free T4 is 38 pmol/L. TPO antibodies are negative. What is the most appropriate next investigation to determine the underlying cause?
A 35-year-old man with type 1 diabetes presents to the emergency department with vomiting and abdominal pain. Blood glucose is 22.4 mmol/L, venous pH 7.28, bicarbonate 14 mmol/L, and ketones 4.2 mmol/L. He is alert and orientated. He weighs 70 kg. Following initial fluid resuscitation with 0.9% sodium chloride, what is the most appropriate initial insulin regimen?
A 29-year-old woman with type 1 diabetes for 15 years is planning pregnancy. Her current HbA1c is 64 mmol/mol. She takes insulin glargine and insulin aspart, and also takes ramipril 5mg daily for microalbuminuria. What is the most important medication change required before conception?
Endocrinology & Diabetes UK Medical PG Practice Questions and MCQs
Question 91: A 71-year-old woman with type 2 diabetes for 18 years, hypertension, and previous myocardial infarction attends for medication review. Current medications include metformin 1g twice daily, empagliflozin 10mg once daily, and atorvastatin 80mg once daily. Her HbA1c is 69 mmol/mol (target <53 mmol/mol), eGFR is 42 ml/min, and urinary albumin:creatinine ratio is 45 mg/mmol. Blood pressure is 142/86 mmHg. Considering her cardiovascular and renal risk, what is the most appropriate addition to optimize her diabetes management?
- A. Add sitagliptin 50mg once daily (DPP-4 inhibitor) dose-adjusted for renal function
- B. Add semaglutide (GLP-1 receptor agonist) with proven cardiovascular benefit (Correct Answer)
- C. Increase empagliflozin to 25mg once daily for enhanced glucose lowering
- D. Add gliclazide MR 30mg once daily for additional glucose control
- E. Add pioglitazone 15mg once daily given cardiovascular disease
Explanation: ***Add semaglutide (GLP-1 receptor agonist) with proven cardiovascular benefit*** - In patients with **established cardiovascular disease** (previous MI) and CKD, a **GLP-1 receptor agonist** with proven benefit is recommended to reduce the risk of major adverse cardiovascular events (MACE). - Semaglutide is safe and effective to use at an **eGFR of 42 ml/min**, providing both glycaemic control and significant **cardioprotective and renoprotective** benefits. *Add sitagliptin 50mg once daily (DPP-4 inhibitor) dose-adjusted for renal function* - While sitagliptin is weight-neutral and safe in renal impairment, it has demonstrated **cardiovascular neutrality** rather than the superiority needed for this high-risk patient. - **GLP-1 agonists** are preferred over DPP-4 inhibitors in this clinical scenario due to the patient's history of **myocardial infarction**. *Increase empagliflozin to 25mg once daily for enhanced glucose lowering* - The **glucose-lowering efficacy** of SGLT2 inhibitors decreases significantly as **eGFR** declines below 45-60 ml/min; therefore, increasing the dose is unlikely to reach the HbA1c target. - The **cardiovascular and renal protection** offered by SGLT2 inhibitors is already being achieved at the 10mg dose and is not significantly enhanced by up-titration. *Add gliclazide MR 30mg once daily for additional glucose control* - Sulfonylureas like gliclazide increase the risk of **hypoglycemia** and weight gain, which is undesirable in a patient with **cardiovascular disease**. - They provide no specific **cardiovascular or renal protection**, making them a lower-priority choice compared to GLP-1 receptor agonists. *Add pioglitazone 15mg once daily given cardiovascular disease* - Pioglitazone is associated with **fluid retention** and an increased risk of **heart failure**, which is a significant concern in a patient with a previous **myocardial infarction**. - Although it has some secondary stroke prevention data, the risk-to-benefit ratio in **chronic kidney disease** and ischemic heart disease is less favorable than GLP-1 therapy.
Question 92: A 38-year-old woman presents with a thyroid nodule. Ultrasound shows a 2.8cm solid hypoechoic nodule with irregular margins, microcalcifications, and taller-than-wide shape. There is no lymphadenopathy. Thyroid function tests are normal. Fine needle aspiration cytology is reported as 'Thy3f - follicular lesion/follicular neoplasm.' Which factor most significantly increases the probability of malignancy in this scenario?
- A. The size of the nodule being greater than 2cm diameter
- B. The Thy3f cytology result indicating indeterminate follicular lesion
- C. The ultrasound features showing microcalcifications and irregular margins (Correct Answer)
- D. The patient's age being under 40 years old
- E. The presence of a solid rather than cystic nodule
Explanation: ***The ultrasound features showing microcalcifications and irregular margins***- High-risk ultrasound features such as **microcalcifications**, **irregular margins**, and a **taller-than-wide shape** are highly specific for thyroid malignancy, particularly **papillary thyroid carcinoma**.- These features significantly increase the **U-classification** (e.g., U4/U5 or TIRADS 4/5), indicating a high probability of cancer regardless of nodule size or a Thy3f cytology result.*The size of the nodule being greater than 2cm diameter*- While larger nodules (especially >4cm) may have a slightly increased risk, **size alone** (2.8cm in this case) is not as strong a predictor of malignancy as specific morphological characteristics.- Many large nodules are **benign multinodular goiters**, whereas small nodules with suspicious ultrasound signs are more concerning.*The Thy3f cytology result indicating indeterminate follicular lesion*- A **Thy3f (follicular neoplasm/suspicious for follicular neoplasm)** result has a malignancy risk of approximately **15-30%**, which is significant but less predictive than highly suspicious ultrasound morphology.- Cytology cannot definitively distinguish between a **follicular adenoma** (benign) and a **follicular carcinoma** (malignant), often necessitating diagnostic surgery rather than confirming malignancy.*The patient's age being under 40 years old*- While extremes of age (<20 or >60) are generally considered higher risk, being **under 40** (the patient is 38) is not as strong a predictor of malignancy compared to ultrasound characteristics.- In differentiated thyroid cancer, younger age is often associated with a **better prognosis** and lower mortality rates.*The presence of a solid rather than cystic nodule*- **Solid nodules** are more frequently malignant than purely cystic ones, but many benign nodules are also solid.- This feature is **less specific** for malignancy compared to the highly suspicious combination of microcalcifications and irregular margins seen on ultrasound.
Question 93: A 54-year-old man with type 2 diabetes presents with a painless ulcer on the plantar aspect of his right first metatarsal head. The ulcer probes to bone. The surrounding skin is warm with mild erythema extending 2cm from the ulcer edge. He is systemically well with temperature 37.2°C. Foot pulses are palpable. X-ray shows soft tissue swelling but no obvious bony changes. What is the most appropriate next step in management?
- A. Arrange MRI of the foot to assess for osteomyelitis and commence intravenous antibiotics (Correct Answer)
- B. Commence oral flucloxacillin and arrange urgent vascular surgery referral
- C. Debride the ulcer, take wound swab for culture, and commence oral broad-spectrum antibiotics
- D. Refer for urgent surgical debridement and amputation of affected toe
- E. Apply offloading device and arrange routine podiatry follow-up in 2 weeks
Explanation: ***Arrange MRI of the foot to assess for osteomyelitis and commence intravenous antibiotics*** - The **probe-to-bone test** is a highly accurate clinical sign for diagnosing **osteomyelitis** in diabetic foot ulcers, indicating the need for aggressive management. - **MRI** is the gold standard for diagnosing osteomyelitis, offering superior sensitivity and specificity in detecting early **bone marrow edema** and infection before X-ray changes become apparent. *Commence oral flucloxacillin and arrange urgent vascular surgery referral* - **Oral antibiotics** are typically insufficient for confirmed or highly suspected osteomyelitis, which requires parenteral (intravenous) administration for adequate bone penetration. - An **urgent vascular surgery referral** is not immediately indicated as foot pulses are palpable, suggesting that significant macrovascular ischemia is not the primary issue at this stage. *Debride the ulcer, take wound swab for culture, and commence oral broad-spectrum antibiotics* - **Wound swabs** from chronic ulcers are often contaminated with colonizing bacteria and may not accurately reflect the causative organisms of **deep bone infection**, making a bone biopsy more reliable. - Starting **oral broad-spectrum antibiotics** without confirming osteomyelitis and with limited penetration for bone infection is suboptimal given the high clinical suspicion. *Refer for urgent surgical debridement and amputation of affected toe* - **Amputation** is a definitive treatment and typically considered after failed conservative management or in cases of severe, irreversible tissue necrosis or limb-threatening infection, which is not described here. - While **surgical debridement** may be necessary, it's usually performed after confirming osteomyelitis with imaging and initiating appropriate antibiotic therapy. *Apply offloading device and arrange routine podiatry follow-up in 2 weeks* - While **offloading** is crucial for ulcer healing, waiting two weeks for follow-up is inappropriate and potentially dangerous given the strong suspicion of **osteomyelitis**, which requires urgent intervention. - This approach significantly delays definitive diagnosis and treatment, increasing the risk of **infection progression** and potential complications.
Question 94: A 47-year-old woman presents to the emergency department with confusion and agitation. She has a history of type 2 diabetes. Her capillary glucose is 48.2 mmol/L. Blood tests show sodium 152 mmol/L, potassium 4.8 mmol/L, urea 18.2 mmol/L, creatinine 156 μmol/L, and serum osmolality 348 mOsm/kg. Venous blood gas shows pH 7.38, bicarbonate 22 mmol/L. Urinalysis shows glucose 4+ but ketones are negative. What is the most critical difference in initial fluid management compared to diabetic ketoacidosis?
- A. Colloid solutions should be used initially due to severe hypovolaemia
- B. 0.9% sodium chloride should be avoided; 0.45% sodium chloride is preferred initially
- C. Fluid replacement should be more gradual over 48 hours rather than 24 hours to avoid cerebral oedema (Correct Answer)
- D. Potassium supplementation should be started immediately regardless of serum level
- E. Larger fluid volumes of 1000 ml/hour are required due to more severe dehydration
Explanation: ***Fluid replacement should be more gradual over 48 hours rather than 24 hours to avoid cerebral oedema*** - In **Hyperosmolar Hyperglycaemic State (HHS)**, patients have significant **hyperosmolality** and a large fluid deficit, often greater than in DKA. - Rapid correction of this high osmolality can lead to dangerous **cerebral oedema**, necessitating a slower, more controlled rehydration strategy over **48 hours**. *Colloid solutions should be used initially due to severe hypovolaemia* - **Crystalloids**, particularly **0.9% sodium chloride**, are the standard initial fluid of choice for restoring intravascular volume in HHS. - **Colloid solutions** are not routinely recommended for initial resuscitation in HHS unless there are specific indications like profound shock unresponsive to crystalloids. *0.9% sodium chloride should be avoided; 0.45% sodium chloride is preferred initially* - **Isotonic 0.9% sodium chloride** is essential for initial volume expansion and improving renal perfusion in HHS. - **Hypotonic 0.45% sodium chloride** is typically introduced later in treatment once the patient is hemodynamically stable and serum sodium is either stable or decreasing too slowly. *Potassium supplementation should be started immediately regardless of serum level* - Potassium management in HHS is similar to DKA, where supplementation is guided by **serum potassium levels** and renal function. - With a serum potassium of 4.8 mmol/L, immediate aggressive supplementation regardless of the level is not indicated and could cause dangerous **hyperkalaemia**. *Larger fluid volumes of 1000 ml/hour are required due to more severe dehydration* - While patients with HHS are severely dehydrated, aggressive fluid rates like **1000 ml/hour** are generally reserved for those in **hypovolaemic shock**. - The primary goal in HHS is a **slower, more controlled rate** of fluid administration to safely correct hyperosmolality and avoid **cerebral oedema** and fluid overload.
Question 95: A 59-year-old man with type 2 diabetes for 8 years presents for diabetic eye screening. Fundoscopy reveals multiple microaneurysms and dot-blot haemorrhages in both eyes, with venous beading and intraretinal microvascular abnormalities in the left eye. No cotton wool spots or new vessels are seen. Visual acuity is 6/9 in both eyes. What is the most appropriate classification and management of this retinopathy?
- A. Moderate non-proliferative retinopathy; routine annual screening adequate
- B. Severe non-proliferative retinopathy; urgent ophthalmology referral within 2 weeks (Correct Answer)
- C. Moderate non-proliferative retinopathy; ophthalmology referral within 6-13 weeks
- D. Proliferative retinopathy; immediate same-day ophthalmology referral required
- E. Mild non-proliferative retinopathy; repeat screening in 6 months
Explanation: ***Severe non-proliferative retinopathy; urgent ophthalmology referral within 2 weeks***- The presence of **venous beading** and **intraretinal microvascular abnormalities (IRMA)** in the left eye, alongside microaneurysms and dot-blot hemorrhages, fulfills the criteria for severe non-proliferative diabetic retinopathy (NPDR) under the **4-2-1 rule**.- Severe NPDR has a high risk of progression to **proliferative retinopathy** and warrants an urgent **ophthalmology referral** within 2 weeks for close monitoring and potential intervention like panretinal photocoagulation to prevent vision loss.*Moderate non-proliferative retinopathy; routine annual screening adequate*- Moderate NPDR is characterized by multiple **microaneurysms** and **dot-blot hemorrhages**, but it lacks the high-risk features of **venous beading** or **IRMA** observed in this patient.- Routine **annual screening** is inadequate for severe NPDR, which requires prompt specialist assessment due to its elevated risk of progression.*Moderate non-proliferative retinopathy; ophthalmology referral within 6-13 weeks*- The presence of **IRMA** and **venous beading** exceeds the diagnostic criteria for moderate NPDR, making this classification inaccurate.- A referral timeframe of **6-13 weeks** is typically reserved for stable moderate NPDR or maculopathy without immediate sight-threatening features, which does not apply to this patient's condition.*Proliferative retinopathy; immediate same-day ophthalmology referral required*- **Proliferative retinopathy (PDR)** is defined by the presence of **neovascularization** (new vessels on the disc or elsewhere) or **pre-retinal/vitreous hemorrhage**, which are explicitly noted as absent in this case.- An **immediate same-day ophthalmology referral** is typically reserved for acute complications of PDR, such as acute vitreous hemorrhage or tractional retinal detachment, which are not present here.*Mild non-proliferative retinopathy; repeat screening in 6 months*- **Mild NPDR** is characterized by the presence of only **microaneurysms**, without other significant retinal changes like hemorrhages, cotton wool spots, or IRMA/venous beading.- The finding of **venous beading** and **IRMA** signifies substantial retinal ischemia, making a mild classification and a **6-month follow-up** inadequate and potentially harmful.
Question 96: A 22-year-old woman with type 1 diabetes for 10 years attends for review. She uses an insulin pump with continuous glucose monitoring. Her glucose profile shows frequent nocturnal hypoglycaemia at 3-4am, followed by elevated glucose readings at 7am (ranging 12-16 mmol/L). Her HbA1c is 68 mmol/mol. What is the most likely explanation for the morning hyperglycaemia?
- A. Dawn phenomenon due to physiological nocturnal growth hormone and cortisol surge
- B. Somogyi effect with counter-regulatory response to nocturnal hypoglycaemia (Correct Answer)
- C. Insufficient basal insulin throughout the night requiring overall rate increase
- D. Dietary protein from evening meal causing delayed glucose rise
- E. Psychological insulin restriction due to fear of hypoglycaemia
Explanation: ***Somogyi effect with counter-regulatory response to nocturnal hypoglycaemia*** - The **Somogyi effect** is characterized by an initial episode of **nocturnal hypoglycaemia** (as documented at 3-4 am) which triggers a counter-regulatory response, involving the release of hormones like **glucagon, cortisol, and growth hormone**. - This hormonal surge leads to **rebound hyperglycaemia** in the morning (elevated glucose readings at 7 am), perfectly explaining the patient's observed glucose profile. *Dawn phenomenon due to physiological nocturnal growth hormone and cortisol surge* - The **Dawn phenomenon** also results in morning hyperglycaemia but is distinctly characterized by the **absence of preceding hypoglycaemia** during the night. - Glucose levels would typically show a **gradual rise** from stable or slightly elevated nocturnal levels, not a dip to 3-4 mmol/L followed by a surge. *Insufficient basal insulin throughout the night requiring overall rate increase* - **Insufficient basal insulin** would typically lead to a **progressive and sustained rise** in glucose levels throughout the night, without any preceding hypoglycaemia. - Increasing basal insulin in this scenario would be inappropriate as it would likely **exacerbate the nocturnal hypoglycaemia** at 3-4 am, leading to potential severe adverse events. *Dietary protein from evening meal causing delayed glucose rise* - While high **dietary protein** or fat can cause a delayed postprandial glucose increase, it typically manifests within a few hours of the meal and **would not explain** the observed pattern of nocturnal **hypoglycaemia** followed by a sharp rebound. - This mechanism does not account for the distinct dip in glucose levels that precedes the morning hyperglycaemia. *Psychological insulin restriction due to fear of hypoglycaemia* - **Psychological insulin restriction** (under-dosing insulin) would typically lead to **persistently elevated** glucose levels throughout the night and morning, as insufficient insulin is consistently administered. - This explanation does not fit the pattern of distinct **nocturnal hypoglycaemia** followed by a counter-regulatory rise, which suggests a physiological rather than behavioral issue.
Question 97: A 76-year-old woman with type 2 diabetes, chronic kidney disease stage 4 (eGFR 22 ml/min), and heart failure is reviewed in clinic. Her current medications include metformin 500mg twice daily, gliclazide 80mg twice daily, and bisoprolol 2.5mg once daily. Her HbA1c is 75 mmol/mol and she has had two episodes of hypoglycaemia in the past month. What is the most appropriate modification to her diabetes management?
- A. Stop metformin; continue gliclazide at reduced dose of 40mg twice daily
- B. Stop metformin and gliclazide; commence SGLT2 inhibitor for renal and cardiac benefits
- C. Stop metformin and gliclazide; commence DPP-4 inhibitor with dose adjustment for renal function (Correct Answer)
- D. Continue current therapy but reduce gliclazide to 40mg once daily only
- E. Stop metformin and gliclazide; commence insulin therapy for better glycaemic control
Explanation: ***Stop metformin and gliclazide; commence DPP-4 inhibitor with dose adjustment for renal function*** - **Metformin** is contraindicated in patients with an **eGFR <30 ml/min**, as seen in this patient with **CKD stage 4 (eGFR 22 ml/min)**, due to the significant risk of **lactic acidosis**. - **Gliclazide**, a sulfonylurea, should be stopped due to the patient's history of **hypoglycemia** and **advanced CKD**, which increases the risk of drug accumulation and further hypoglycemic events. **DPP-4 inhibitors** are a suitable alternative as they have a **low risk of hypoglycemia** and are safe in CKD, requiring dose adjustment (except linagliptin). *Stop metformin; continue gliclazide at reduced dose of 40mg twice daily* - While stopping metformin is appropriate, continuing **gliclazide** (a sulfonylurea) at any dose is risky given the patient's **eGFR of 22 ml/min** and recent **hypoglycemia**, as it remains a high-risk medication for severe hypoglycemia in this context. - The reduced renal clearance of gliclazide in **CKD stage 4** means that even a lower dose still carries an unacceptable risk of drug accumulation and recurrent hypoglycemic episodes. *Stop metformin and gliclazide; commence SGLT2 inhibitor for renal and cardiac benefits* - Most **SGLT2 inhibitors** are generally not initiated for **glycemic control** when the **eGFR is <30 ml/min** due to significantly reduced glucose-lowering efficacy at this stage of kidney disease. - Although SGLT2 inhibitors provide **cardiac and renal protection**, they would be insufficient to adequately address the patient's **HbA1c of 75 mmol/mol** and achieve satisfactory glycemic control in this specific clinical scenario. *Continue current therapy but reduce gliclazide to 40mg once daily only* - Continuing **metformin** with an **eGFR of 22 ml/min (CKD stage 4)** is a major safety breach and strongly contraindicated due to the high risk of **lactic acidosis**. - This option fails to address the contraindication of metformin and only partially mitigates the risk of hypoglycemia from gliclazide, which should ideally be discontinued entirely. *Stop metformin and gliclazide; commence insulin therapy for better glycaemic control* - While insulin can effectively lower blood glucose, commencing **insulin therapy** significantly increases the risk of further **hypoglycemic episodes**, which the patient has already experienced recently. - **DPP-4 inhibitors** offer a safer, less complex, and less invasive initial therapeutic modification with a lower risk of hypoglycemia compared to insulin, especially in an elderly patient with renal impairment.
Question 98: A 41-year-old woman presents with a 3-month history of anxiety, tremor, heat intolerance, and weight loss of 6 kg. Examination reveals a pulse of 104 bpm, fine tremor, and a smooth, non-tender, symmetrically enlarged thyroid gland with no nodules. TSH is <0.01 mU/L and free T4 is 38 pmol/L. TPO antibodies are negative. What is the most appropriate next investigation to determine the underlying cause?
- A. TSH receptor antibodies (TRAb) measurement
- B. Fine needle aspiration cytology of the thyroid gland
- C. Thyroid ultrasound scan to assess gland vascularity and nodules
- D. Thyroid uptake scan with radioactive iodine or technetium (Correct Answer)
- E. Repeat thyroid function tests in 6 weeks to confirm persistent hyperthyroidism
Explanation: ***Thyroid uptake scan with radioactive iodine or technetium*** - A **thyroid uptake scan** is the most appropriate next step to differentiate between functional causes like **Graves' disease** (diffuse high uptake) and inflammatory causes like **thyroiditis** (low/absent uptake). - In this patient with **overt hyperthyroidism** and a smooth goiter, determining if there is *de novo* hormone synthesis or release of preformed hormone is critical for guiding therapy. *TSH receptor antibodies (TRAb) measurement* - While **TRAb** is highly specific for **Graves' disease**, a negative result would still require further investigation to differentiate other causes of thyrotoxicosis, such as thyroiditis. - An **uptake scan** provides broader diagnostic utility by assessing the *functional activity* of the thyroid gland, which is essential to distinguish between causes of hyperthyroidism. *Fine needle aspiration cytology of the thyroid gland* - **Fine needle aspiration (FNA)** is used to evaluate for **malignancy** in suspicious thyroid nodules and is not indicated for a smooth, symmetrically enlarged thyroid without nodules. - FNA has no role in the diagnosis of **hyperthyroidism** or differentiating between the various causes of thyrotoxicosis. *Thyroid ultrasound scan to assess gland vascularity and nodules* - **Ultrasound** is excellent for detecting **nodal anatomy** and overall gland structure but is less definitive than an uptake scan for assessing the *biochemical function* of the thyroid tissue. - Although increased **vascularity (Doppler)** can suggest Graves' disease, it is generally considered a secondary modality to nuclear medicine scans for definitively categorizing the etiology of thyrotoxicosis. *Repeat thyroid function tests in 6 weeks to confirm persistent hyperthyroidism* - Repeating **thyroid function tests** would unnecessarily delay treatment for a patient who is already **symptomatic** with significantly elevated **free T4** and suppressed **TSH**. - The diagnosis of **thyrotoxicosis** is already established; the current clinical priority is identifying the specific **underlying cause** to start appropriate management.
Question 99: A 35-year-old man with type 1 diabetes presents to the emergency department with vomiting and abdominal pain. Blood glucose is 22.4 mmol/L, venous pH 7.28, bicarbonate 14 mmol/L, and ketones 4.2 mmol/L. He is alert and orientated. He weighs 70 kg. Following initial fluid resuscitation with 0.9% sodium chloride, what is the most appropriate initial insulin regimen?
- A. Fixed rate intravenous insulin infusion at 0.1 units/kg/hour (7 units/hour) (Correct Answer)
- B. Intravenous insulin bolus of 10 units followed by 6 units/hour infusion
- C. Subcutaneous insulin aspart 15 units immediately then hourly blood glucose monitoring
- D. Fixed rate intravenous insulin infusion at 0.05 units/kg/hour (3.5 units/hour)
- E. Continue usual subcutaneous insulin and add intravenous insulin at 2 units/hour
Explanation: ***Fixed rate intravenous insulin infusion at 0.1 units/kg/hour (7 units/hour)***- This is the **standard initial management** for **Diabetic Ketoacidosis (DKA)**, as per **Joint British Diabetes Societies (JBDS)** guidelines, focusing on reversal of acidosis and ketogenesis.- The dose of **0.1 units/kg/hour** (7 units/hour for a 70 kg patient) is specifically calculated to effectively **suppress ketogenesis**, resolve acidosis, and gradually lower blood glucose by a target of **3 mmol/L/hour**.*Intravenous insulin bolus of 10 units followed by 6 units/hour infusion*- **Insulin boluses** are generally **not recommended** in DKA management, as they can increase the risk of **hypokalemia** and potentially **cerebral edema**, especially in children.- The priority is a steady, controlled reduction in glucose and ketones achieved through a continuous infusion, rather than a rapid and potentially dangerous drop.*Subcutaneous insulin aspart 15 units immediately then hourly blood glucose monitoring*- **Subcutaneous insulin** is **contraindicated** in the initial management of DKA due to **poor peripheral perfusion** and dehydration, leading to unpredictable absorption and delayed action.- **Intravenous insulin** is mandatory to ensure rapid onset of action, reliable delivery, and the ability to immediately titrate or stop delivery if necessary.*Fixed rate intravenous insulin infusion at 0.05 units/kg/hour (3.5 units/hour)*- A fixed-rate infusion of **0.05 units/kg/hour** is generally considered **insufficient** to adequately suppress the high levels of counter-regulatory hormones and stop **ketone production** in typical DKA.- This lower rate might be considered in very specific circumstances, such as in patients with extreme **insulin sensitivity** or children, but the standard adult starting dose is higher.*Continue usual subcutaneous insulin and add intravenous insulin at 2 units/hour*- While **long-acting basal insulin** can be continued in some DKA protocols, **short-acting subcutaneous insulin** must be stopped once a fixed-rate intravenous infusion is commenced to avoid insulin stacking.- An additional **intravenous insulin** rate of only 2 units/hour is far too low to adequately address the metabolic requirements needed to switch off **lipolysis** and ketogenesis in an acute DKA presentation for a 70 kg patient.
Question 100: A 29-year-old woman with type 1 diabetes for 15 years is planning pregnancy. Her current HbA1c is 64 mmol/mol. She takes insulin glargine and insulin aspart, and also takes ramipril 5mg daily for microalbuminuria. What is the most important medication change required before conception?
- A. Switch from insulin glargine to NPH insulin as it has better pregnancy safety data
- B. Discontinue ramipril and commence alternative blood pressure medication if needed (Correct Answer)
- C. Add metformin to improve glycaemic control and reduce insulin requirements
- D. Change to twice-daily mixed insulin regimen for more stable glucose control
- E. Increase insulin doses by 50% in anticipation of increased requirements in pregnancy
Explanation: ***Discontinue ramipril and commence alternative blood pressure medication if needed*** - **ACE inhibitors** like **ramipril** are strictly **contraindicated** in pregnancy due to their association with **fetal renal dysgenesis**, skull hypoplasia, and **oligohydramnios**. - Women planning pregnancy must switch to safer alternatives such as **labetalol**, **nifedipine**, or **methyldopa** before conception to prevent teratogenicity. *Switch from insulin glargine to NPH insulin as it has better pregnancy safety data* - Modern **long-acting insulin analogues** like **glargine** and **detemir** are now considered safe for use during pregnancy according to major clinical guidelines. - Switching to **NPH** is not a priority and may destabilize glycemic control in a patient already established on a stable basal-bolus regimen. *Add metformin to improve glycaemic control and reduce insulin requirements* - While **metformin** is used in Type 2 diabetes or GDM, it is not standard management for **Type 1 diabetes** preconception care. - The primary focus for improving her **HbA1c** should be optimizing her established **basal-bolus insulin** doses and frequent monitoring. *Change to twice-daily mixed insulin regimen for more stable glucose control* - **Biphasic (mixed) insulin** regimens generally provide less flexibility and poorer glycemic control compared to **basal-bolus** regimens in Type 1 diabetes. - Maintaining a **basal-bolus** or **insulin pump** therapy is preferred during pregnancy to achieve tight glycemic targets safely. *Increase insulin doses by 50% in anticipation of increased requirements in pregnancy* - Insulin requirements typically **decrease** in the first trimester before increasing significantly in the second and third trimesters. - Prophylactically increasing doses pre-conception would cause dangerous **hypoglycemia**; doses should be adjusted reactively based on frequent blood glucose monitoring.
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