Endocrinology Module 1

A 33 year old nurse is admitted for prolonged fasting. She originally presented to clinic with a history of episodic sweating and light-headedness which had developed over a six month period with symptoms being entirely relieved by eating. She had developed one of these episodes whilst on the ward and a BM monitor showed a value of 2 mmol/l. She took some glucose tablets and had quickly recovered.

On examination, no specific abnormalities were found with a blood pressure of 118/74 mmHg, a pulse of 72 beats per minute and a BMI of 22 kg/m2. She was admitted for a 72 hour fast and at 3 am, 16 hours into the fast she develops typical symptoms.

Her BSL is measured at 2.2 mmol/l, the fast is stopped and bloods taken.

The following are her lab results:

• Plasma Glucose 1.8 mmol/l (3 – 6)
• Plasma 3Beta-HydroxyButyrate 0.5 mmol/l (> 1 mmol/l)
• Plasma Insulin 450 pmol/l (less than 21)
• C-peptide 0.2 nmol/l (less than 0.5)

What is the most likely diagnosis?

An 18 year old girl with oligomenorrhoea since menarche at age 14 presents with a six month history of increasing facial hair and deepening of the voice. There is mild clitoral enlargement on examination. Laboratory results show:

• serum testosterone 5.0 [1.0 – 2.5 nmol/L]
• SHBG 18 [30 – 80 g/dl]
• DHEAS 10 [3 – 12]

What is the NEXT most appropriate investigation to help establish the diagnosis?

Empagliflozin is a novel drug that has been approved for the treatment of Type 2 diabetes in adults.

What is its main mechanism of action?

The SGLT-2 inhibitor used in the treatment of Type 2 diabetes may cause the following adverse effect:

Which of the following best describes the mechanism of action of Sitagliptin?

Liraglutide is an analogue of human glucagon-like peptide 1 (GLP-1) which has a promising role for patients with type 2 diabetes.

Liraglutide causes the following effect, EXCEPT?

A diabetic patient is reported to have a Hemoglobin A1c level of 8.6% (based on the old DCCT format).

What is the new IFCC Hemoglobin A1c equivalent of this and the what is the closest mean glucose level (in mmol/l) that correlates with the above result?

A previously well 53-year-old caucasian lady is found to have a 2 cm right adrenal mass when undergoing a computed tomography (CT) scan for suspected hepatobiliary disease. On examination, she has signs of Cushing’s syndrome with a blood pressure of 150/90 mmHg.

The following laboratory test results are obtained:

• serum sodium 140 mmol/L [133-144]
• serum potassium 3.8 mmol/L [3.5-5.0]
• serum creatinine 0.10 mmol/L [0.05-0.11]
• serum early morning cortisol 200 ug/dl [10 to 20]
• serum adrenocorticotrophic hormone 1 ng/L [9 to 52]
• serum dehydroepiandrosterone 300 ug/dl [35-430]
• urinary catecholamines 0.3 μmol/24 h [<0.6]
• urinary free cortisol 380 nmol/24 h [100-400]
• plasma renin activity 1.5 nmol/L/h [0.4-2.3]

What is the most likely cause of the adrenal mass?

As part of the work up for Cushing’s syndrome, which of the following test may no longer be necessary?

A 65-year-old woman with longstanding rheumatoid arthritis, previous DVT and osteoporosis presents with a mid thoracic crush fracture. She has a history of two previous crush fractures and has been taking alendronate 70mg weekly for three months and is tolerating this medication well. She has a normal serum calcium, phosphate, albumin and 25 hydroxy-vitamin D. She has taken prednisone in the past.

Which of the following treatment is most appropriate for future fracture prevention?

Assessing the anti-thyroglobulin antibodies is most useful in which of the following condition?

In monogenic diabetes, the following statement are all correct about GCK mutation (MODY2) except?

The insulin analogue lispro (Humalog) has a more immediate onset of action than regular human insulin. This is because lispro:

The artificial beta cell or the so called closed-loop insulin-delivery system is increasingly been recognized as a safe and effective treatment for patients with Type 1 diabetes.

Which of the following is likely to occur with its long term use at home (In the adult population)?

An 15-year-old male of Māori descent has type 1 diabetes. He is brought to the Emergency Department at 3 a.m. on Friday morning following a hypoglycaemic convulsion. On questioning, his parents report that he has rugby training on Thursday afternoons before dinner.

His insulin regimen is long acting insulin and a short acting insulin analogue given together at breakfast and dinner.

Which of the following would be the best advice to avoid recurrent nocturnal hypoglycaemia after rugby training?

Where is the main site of Adiponectin production?

Which of the following parameter is most likely to decrease in the first trimester of pregnancy?

In non thyroidal illness syndrome, which of the following is least likely to cause low T3 levels?

A 28 year old man presents to the emergency department with 3 days history of fever, malaise, neck pain and odynophagia. He also described episodes of palpitations and tremors of his hands.

Blood test shows low TSH and High T4.

What is the most likely diagnosis?

Ultraviolet (UV) radiation (sunlight) acts on the skin to catalyse which of the following reaction?

The activity of some hormones are affected by the levels of specific carrier proteins.

Therefore, which of the following hormone is going to have a clinically significant effect as a result of having abnormal levels of carrier proteins?

An asymptomatic patient presents for investigation of hypercalcaemia.

His mother has a similar diagnosis three years ago. She had a parathyroidectomy that was unsuccessful in treating her raised calcium level.

Serum Calcium is 2.8 (2.1 – 2.6 mmol/L), Phosphate is 0.8 (0.75- 1.45 mmol/L), PTH is normal.

What is the most appropriate investigation?

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

What is the most important test to do?

Which of the following patient group is least likely to benefit from oral Risedronate?

A 42-year old woman returned from a holiday in Greece in July. It is now 3 months following her return , but yet her tan has not yet faded. She has also noticed discolouration of her gums.She is on thyroxine for autoimmune thyroiditis and is fatigued despite being optimally replaced.

You suspect she has Addisons’s disease.

What would be the BEST test to perform to confirm the diagnosis?

What is the best marker of tumor recurrence following removal of papillary thyroid cancer?

What is the best investigation for persistent thyroid cancer?

A patient is highly suspected of having recurrent disease of his thyroid cancer following a high serum Thyroglobulin. However his whole body scan was negative.

What should be the next step in management?

Hyperemesis gravidarum is mostly associated with which condition?

Which of the following thyroid medication is associated with scalp defect(aplasia cutis) if used in pregnancy?

In non thyroidal illness syndrome, which of the following factor is least likely to cause low T3 levels?