Endocrinology Module 2

A 52-year-old woman with rheumatoid arthritis has been treated with prednisone 5 mg per day for the last 4 years. She has recently commenced biologic therapy with the intention of tapering off her steroid therapy. A 9am cortisol level is measured and is found to be 350 nmol/L.

What is the most appropriate next step in managing this patient’s steroid therapy?

All of the following drugs are known to cause hyperthyroidism except?

All of the following drugs are known to cause low serum TBG except?

What is the most specific test for Graves disease?

A patient presents with fever, malaise, neck pain, and odynophagia. Blood tests show low TSH and high T4.

What is the most likely diagnosis?

Which of the following does NOT cross the placenta from mother to foetus?

Which of the following lipid-lowering drugs works primarily by the upregulation of low density lipoprotein (LDL) receptor activity?

Hypoglycemia unawareness is predominantly due to failure of secretion of which one of the following hormones?

A 28-year-old woman presents five weeks postpartum with new-onset headaches, fatigue, and sudden cessation of lactation. Her delivery was complicated by a significant postpartum hemorrhage requiring transfusion. Her blood pressure is 85/60 mmHg.

The first step that you would take is:

An asymptomatic patient presents for investigation of hypercalcemia. His mother had a similar diagnosis three years ago. She had a parathyroidectomy that was unsuccessful in treating her raised calcium level.

Serum calcium: 2.8 mmol/L (2.1–2.6)

Phosphate: 0.8 mmol/L (0.75–1.45)

PTH: Normal

What is the most appropriate investigation?

A 38 year old woman presents with a two year history of weight gain, hypertension and easy bruising. Clinical examination reveals thin skin, facial hirsutism and proximal muscle weakness. Cushing’s syndrome is suspected. The results of a 1 mg dexamethasone suppression test demonstrated a plasma cortisol of 296 nmol/L at 0800 hours the following morning (normal < 100 nmol/L). 24 hour urinary free cortisol is 1523 nmol/24 h (normal < 350 nmol/24h).

The most appropriate investigation to perform NEXT is:

A 27-year-old woman with type 1 diabetes presents for review and reports frequent unexplained hypoglycemic episodes in the past three weeks.

The MOST important test to request is:

A 72-year old woman presents with back pain and is found to have a vertebral fracture at T7. Bone mineral densitometry shows that she has osteoporosis. You write out a prescription for a bisphosphonate and counsel her about the potential side-effects of this medication.

Which ONE of the following is NOT a recognised potential side effect of a bisphosphonate?

A 31-year old woman with a body mass index of 42 kg/m2 is attending for ante-natal care.

Because of her obesity, the pregnancy has an increased risk of all of the following, EXCEPT:

A 65-year old man presents with a ten year history of hypertension. His current medications are metoprolol, irbesartan, ramipril and hydrochlorothiazide. On examination, his BP is 160/90 and his heart rate is 60 bpm. His BMI is 34 kg/m2.

Investigations showed:

• Serum Na+ 145 mmol/L
• Serum K+ 3.0 mmol/L
• Plasma aldosterone 499 pmol/L (55 – 250)
• Plasma renin activity < 0.16 ng/L/hr
• Elevated plasma aldosterone concentration (PAC) to plasma renin activity (PRA) ratio.
• Measurement of urinary aldosterone on a high salt diet confirmed the presence of primary hyperaldosteronism.
• A CT abdomen shows a left adrenal mass.

The NEXT best step in the management of this patient is:

A 61-year-old man with type 2 diabetes attends your clinic for an annual review. He was discharged from hospital one week ago following an NSTEMI. He takes metformin 500 mg twice daily for glycemic control, irbesartan for hypertension, and low-dose aspirin. He has recently had fundal screening with no evidence of retinopathy.

His investigations show:

• HbA1c: 6.5%
• Urinary albumin/creatinine ratio: 4.6
• Total cholesterol: 4.2 mmol/L
• Triglycerides: 2.3 mmol/L
• Carotid Doppler: bilateral stenoses of 15–30% (asymptomatic)

With respect to his lipid profile, what is your next step?

A 41-year-old university professor presents with discomfort on swallowing and tenderness in the right anterior neck for the past month. Over the past 2 weeks, he has developed shooting pain radiating to the angle of the jaw on the left and into the left ear.

On examination: heart rate 92 bpm; he has a stare but no signs of ophthalmopathy; fine tremor of outstretched fingers; thyroid is asymmetrically enlarged, firm, nodular, and tender; reflexes are brisk.

• Free T4: 42.5 pmol/L (elevated)
• TSH: <0.1 mU/L (suppressed)
• Full blood count and electrolytes: normal

Which one of the following tests would most specifically confirm your clinical diagnosis?

A 21-year-old Anglo-Celtic woman presents with new-onset diabetes mellitus. She has a sibling and one parent who also have diabetes. Her BMI is normal and she has no evidence of acanthosis nigricans. Her pancreatic autoantibodies are negative. Her C-peptide is 0.95 nmol/L at a time when her blood glucose is 8.5 mmol/L. She is subsequently diagnosed as having monogenic diabetes due to a mutation of the gene that encodes for the transcription factor HNF1A.

Which one of the following statement is FALSE?

A 64-year-old woman with a history of thyroidectomy for Graves’ disease has been taking thyroxine 150 μg per day for many years. She recently sustained head injuries in a motor vehicle accident. She now has seizures for which she takes phenytoin.

Her recent tests showed:

• T4: 8.0 pmol/L (9–26)
• T3: 3.9 pmol/L (3.5–6.5)
• TSH: 1.5 mU/L (0.5–4.0)

The NEXT best step is:

A 76-year-old woman being treated for bacterial meningitis has a tonic-clonic seizure. She has been treated with intravenous vancomycin and is on a glucose/saline drip. She has no relevant past medical history. After investigation of the seizure, she is found to have hyponatremia.

Her lab results are as follows:

• Na⁺: 114 mmol/L
• Glucose: 38 mmol/L
• Creatinine: 130 μmol/L
• TSH: 7.0 mU/L
• Cortisol: 800 nmol/L
• Plasma osmolality: 262 mOsmol/kg (280–296)
• Urinary osmolality: 380 mOsmol/kg
• Urinary Na⁺: 45 mEq/L

Which ONE of the following best explains her hyponatremia?

A 16-year-old girl is referred with primary amenorrhea. She has short stature and Hashimoto’s thyroiditis for which she takes thyroxine.

On examination, her height is 1.48 m and her weight is 48 kg. She has small-volume breast tissue. Pubic hair is present. There is no palpable goiter.

Investigation results:

• Karyotype: 45,X/46,XX
• TSH: 2.0 mU/L
• IGF-1: normal
• Prolactin: 300 mIU/L (50–500)
• FSH: 35 IU/L (elevated)
• Bone age: 15 years

A diagnosis of Turner syndrome is made. The NEXT step is:

A 42-year-old woman returned from a holiday in Greece in September. She is perplexed that her tan has not yet faded. She has also noticed discoloration of her gums. She is on thyroxine for autoimmune thyroiditis and is fatigued despite being optimally replaced.

You suspect that she has Addison’s disease.

The BEST test to perform to confirm the diagnosis is:

A 65-year old man with CLL has recently been diagnosed with type 2 diabetes. Random BG levels range from 12 to 16 mmol/L. He is currently being treated with fludarabine for the leukaemia. On examination, he has a BMI of 25 kg/m2. He has no diabetic complications. He has a 2/6 ejection systolic murmur and mild peripheral oedema.

Laboratory results show:

• HBA1c 5.6 %
• Glucose 13.3 mmol/L
• Hb 80 g/L
• Haematocrit 24%
• WBC 105,000 mm3
• Creatinine 80 μmol/L

Which of the following is the single BEST answer?

A 51-year old man presents to your clinic because he noticed that his hands have increased in size. He has had his wedding ring cut off because it was too tight.

He also reports increasing tiredness and sensory changes in both hands typical of carpal tunnel syndrome.

Which of the following test would be most helpful?

Approximately 50% of blood calcium is free (ionized) calcium. The remainder is bound to plasma proteins (primarily albumin) or complexed with anions such as citrate, lactate, and phosphate.

What is the major determinant of calcium binding in the blood?

Which of the following cell types does NOT express the calcium-sensing receptor (CaSR), a receptor that responds to changes in serum calcium and amino acid levels?

In response to hypercalcemia, what is an important effect of calcium-sensing receptor activation in the kidney?

Which of the following feature is not consistent with the diagnosis of autosomal dominant hypocalcemia?

What is the mechanism of action of cinacalcet?

Which of the following is the strongest indication for surgery in a patient with asymptomatic primary hyperparathyroidism?

A patient presents with mucosal neuromas.

What should this patient be investigated for?