Endocrinology Module 4

An 82-year-old female with a history of advanced colorectal cancer, now with confirmed metastases to the liver and lungs, presents to the emergency department with episodes of confusion, dizziness, and diaphoresis.

These episodes are particularly noted in the early mornings and are temporarily relieved by the ingestion of sweet beverages. She has experienced significant weight loss over the past few months despite having a reasonable appetite.

Her current medications include palliative chemotherapy and supportive care measures.

On physical examination, she appears cachectic with no focal neurological deficits.

Blood tests taken at the time of her hypoglycemic event showed:

• Glucose 2.5 mmol/L (3.5–7.7)
• Insulin 3 pmol/L (10–80)
• C-peptide 91 pmol/L (350–750)
• Cortisol 1317 nmol/L (170–500)
• Short Synacthen test: pre-stimulation cortisol 582 nmol/L, post-stimulation cortisol 933 nmol/L (>400)
• Serum IGF-2 3000 ng/mL (521–873)

Which of the following is the most likely cause of her recurrent hypoglycemia?

Which of the following is an absolute indication in treating subclinical hypothyroidism?

What is the first-line agent for the treatment of hyperthyroidism in pregnancy after the first trimester?

What is the main reason for the progressive deterioration of glycemic control in patients with type 2 diabetes mellitus?

Which of the following decreases the level of Adiponectin?

Which of the following mutation is the most common monogenetic cause for human obesity?

What is the main function of Leptin?

Which of the following hormone is an appetite stimulant?

Which of the following is the most effective treatment for morbid obesity?

The most important known factor which influences the rate of development of microvascular complications in patients with diabetes is:

After eating a meal containing a large amount of fat, which hormone level changes to cause a feeling of satiety?

A 20-year-old woman presents with hirsutism. The following results are obtained:

• Testosterone 2.0 nmol/L [<2.5]
• Luteinising hormone (LH) 9 IU/L [2-15]
• Follicle stimulating hormone (FSH) 4 IU/L [2-15]
• Oestradiol 500 pmol/L [130-1500]
• Dehydroepiandrosterone (DHEA) 10 umol/L [0.5-12]
• 17OH Progesterone 3 pmol/L [<6]
• 24 hour urinary free cortisol 280 nmol/24hours [100-300]
• Adrenocorticotrophic hormone (ACTH) 3 pmol/L [1-5]

What is the most likely explanation for her hirsutism?

A 40-year-old woman with primary hypothyroidism is admitted to hospital with profound lethargy and marked postural hypotension.

Blood investigations show:

• sodium 125 mmol/L [135-145]
• potassium 6.1 mmol/L [3.5-5.0]
• creatinine 0.15 mmol/L [0.05-0.10]
• glucose 2.8 mmol/L [3.0-6.0]
• calcium 2.8 mmol/L [2.2-2.6]
• albumin 38 g/L [35-44]
• phosphate 1.2 mmol/L [0.9-1.4]
• TSH 30mU/L [0.5- 4.5]
• Free T4 7.6 pmol/L [10 – 23]

Which of the following intervention should be avoided?

A 72-year-old male has been in intensive care for ten days following an episode of urinary tract sepsis. He has a persistent low grade fever. He has a white cell count of 14.1 x 109/L [4.0-10.0], serum sodium is 128 mmol/L [134-145], and potassium is 5.0 mmol/L [3.5-5.0].

He has been weaned from mechanical ventilation, his renal function is normal and his delirium has cleared. His urine is sterile.

His ECG demonstrates a left bundle branch block. A synthetic adrenocorticotrophic hormone (ACTH) stimulation test demonstrates baseline cortisol of 350 nmol/L which rises to 400 nmol/L at 30 minutes. He has been on noradrenaline at doses of 0.08 μg/kg/minute to 0.16 μg/kg/minute. Each attempt to cease the noradrenaline has led to hypotension associated with oliguria and obtundation.

What is the most appropriate treatment?

The most common long-term complication of cranial irradiation is?

A 63-year-old woman presents with weight gain, reduced energy and depression, five years after pituitary surgery and radiotherapy for a non-functioning pituitary adenoma. Current medications are thyroxine 0.15 mg/day, hydrocortisone 20 mg/day (equivalent to cortisone acetate 25 mg/day) in divided doses, conjugated oestrogen 0.625 mg/day, medroxyprogesterone 2.5 mg/day, and fluoxetine 20 mg/day.

Examination is unremarkable except for truncal obesity. Her body mass index (BMI) is 30 kg/m2 [20-25] and her blood pressure is 145/85 mmHg.

Why did she gain weight?

A 78-year-old woman has a history of hypertension on amlodipine, and has been found to have a persistently elevated platelet count for several months. She presents to the emergency department with abdominal pain.

Her full blood examination and serum biochemistry are as follows:

• haemoglobin 104 g/L [128-175]
• white blood cell 70.40 x 109/L [3.90-12.70]
• neutrophils 62.80 x 109/L [1.90-8.00]
• lymphocytes 2.46 x 109/L [0.90-3.30]
• monocytes 0.67 x 109/L [0.30-1.10]
• eosinophils 4.43 x 109/L [0.00-0.50]
• basophils 0.05 x 109/L [0.00-0.20]
• platelets 3524 x 109/L [150-396]
• mean corpuscular volume 74 fL [80-97]
• sodium 142 mmol/L [136-145]
• potassium 7.2 mmol/L [3.5-5.1]
• bicarbonate 16 mmol/L [21-32]
• chloride 112 mmol/L [98-107]
• urea 13.2 mmol/L [2.0-8.5]
• creatinine 0.13 mmol/L [0.04-0.08]

What is most likely cause for her elevated serum potassium?

A 63-year-old man presents with streaky haemoptysis, fatigue and weight loss of 6 kg. He has had no previous serious illness but admits to having been a heavy smoker for over 38 years. Physical examination reveals normal mental status and no evidence of organ failure. He is clinically euvolaemic and is on no medication.

Investigations are as follows.

Serum:

• sodium 113 mmol/L [136-144]
• potassium 3.8 mmol/L [3.4-4.8]
• chloride 83 mmol/L [103-110]
• bicarbonate 23 mmol/L [24-30]
• creatinine 0.06 mmol/L [0.06-0.10]

Urinary:

• specific gravity 1.032 [1.026-1.044]
• sodium 60 mmol/L

The most appropriate initial therapy is:

Which of the following medications induces weight loss when used in patients with type 2 diabetes mellitus?

Which of the following sulphonylurea drug is the most suitable for use in the elderly population?

In a patient with an adrenal incidentaloma, what is the best test to exclude subclinical autonomous cortisol secretion (formerly termed subclinical Cushing’s syndrome)?

The most common cause of ambiguous genitalia is:

Aldosterone is secreted from which site of the adrenal gland?

The most frequent clinical feature due to insulin resistance in obese female children and adolescents with type 2 diabetes is:

In addition to decreased gastrointestinal calcium absorption, in what other mechanism does prednisone cause net bone loss in a 60-year-old man?

In addition to stimulation of gluconeogenesis, in what other mechanism does prednisone cause hyperglycemia in a 40- year-old woman?

A 25-year-old has adrenocorticotrophic hormone -dependent Cushing’s Syndrome. MRI scan of his pituitary shows an 2mm adenoma.

Which of the following is the most appropriate management?

A 30 year old female with background of hypothyroidism becomes pregnant and is currently on Thyroxine 50mcg po od.

She is currently asymptomatic.

Her TSH is 10 [0.5 to 4.5 mU/L] and T4 is normal.

What should you do with her thyroxine dose?

A 45-year-old man is referred with hypercalcaemia which is known to have been present for at least six months, during which time it has been stable. He is asymptomatic and has no past medical history.

Recent investigations are as follows:

• serum calcium 2.7 mmol/L [2.2-2.5]
• serum albumin 41 g/L [38-44]
• serum intact parathyroid hormone 4.5 pmol/L [1.0-5.0]
• 24-hour urine calcium excretion 2.1 mmol/L [3.0-5.0]
• 24-hour urine creatinine excretion 16 mmol/L [8-18]

Which investigation is most likely to be diagnostically useful?

Which of the following mechanism is not consistent with steroid induced osteoporosis?