Question 111#

Which one of the following conditions may cause hypokalaemia in association with hypertension? 

A. Gitelman syndrome

Correct Answer E: 21-hydroxylase deficiency, which accounts for 90% of congenital adrenal hyperplasia cases, is not associated with hypertension.

Hypokalaemia and hypertension:
For exams it is useful to be able to classify the causes of hypokalaemia in to those associated with hypertension, and those which are not.

Hypokalaemia with hypertension:

• Cushing's syndrome
• Conn's syndrome (primary hyperaldosteronism)
• Liddle's syndrome
• 11-beta hydroxylase deficiency*
• Carbenoxolone, an anti-ulcer drug, and liquorice excess can potentially cause hypokalaemia associated with hypertension 

Hypokalaemia without hypertension:

• Diuretics
• GI loss (e.g. Diarrhoea, vomiting)
• Renal tubular acidosis (type 1 and 2**)
• Bartter's syndrome
• Gitelman syndrome

*21-hydroxylase deficiency, which accounts for 90% of congenital adrenal hyperplasia cases, is not associated with hypertension

**type 4 renal tubular acidosis is associated with hyperkalaemia

Question 112#

Which one of the following statements regarding NICE guidance on the primary prevention of cardiovascular disease is incorrect?

A. Premature coronary heart disease is defined as < 65 years in females

Correct Answer B: Primary prevention CVD: 10-year risk of 20% is cut-off.

Hyperlipidaemia: management:
In 2008 NICE issued guidelines on lipid modification. Key points are summarized below.

Primary prevention:
A systematic strategy should be used to identify people aged 40-74 who are likely to be at high risk of cardiovascular disease (CVD), defined as a 10-year risk of 20% or greater.

NICE updated their lipid guidelines so that the following risk models are valid:

• Framingham
• Joint British Society 2 (JBS2)
• QRISK
• ASSIGN (Scotland only) 

The 1991 Framingham equations may still be used. It is however recommended that adjustments are made in the following situations:

• First-degree relative with a history of premature coronary heart disease (defined as < 55 years in males and < 65 years in females) - increase risk by 1.5 times if one relative affected or up to 2.0 times if more than one relative affected
• Males of South Asian ethnicity - increase risk by 1.4 times

Along with lifestyle changes drug treatment should be considered for patients with a 10-year CVD risk of 20% orgreater:

• Simvastatin 40mg on is the first line treatment
• There is no target level for total or LDL cholesterol for primary prevention
• Liver function tests should be check at baseline, within 3 months and at 12 months but not again unless clinically indicated

Secondary prevention:
All patients with CVD should be taking a statin in the absence of any contraindication NICE recommend increasing simvastatin to 80mg if a total cholesterol of less than 4 mmol/litre or an LDL cholesterol of less than 2 mmol/litre is not attained.

Question 113#

A 41-year-old woman presents with palpitations and heat intolerance. On examination her pulse is 90/min and a small, diffuse goitre is noted which is tender to touch. Thyroid function tests show the following:

• Free T4 24 pmol/l
• TSH < 0.05 mu/l

What is the most likely diagnosis? 

A. Grave's disease

Correct Answer C: Thyrotoxicosis with tender goitre = subacute (De Quervain's) thyroiditis.

Whilst Grave's disease is the most common cause of thyrotoxicosis it would not cause a tender goitre. In the context of thyrotoxicosis this finding is only really seen in De Quervain's thyroiditis. Hashimoto's thyroiditis is an autoimmune disorder of the thyroid gland. It is typically associated with hypothyroidism although there may be a transient thyrotoxicosis in the acute phase. The goitre is non-tender in Hashimoto's.

Subacute (De Quervain's) thyroiditis:
Subacute thyroiditis (also known as De Quervain's thyroiditis) is thought to occur following viral infection and typically presents with hyperthyroidism.

Features:

• Hyperthyroidism
• Painful goitre
• Raised ESR
• Globally reduced uptake on iodine-131 scan

Management:

• Usually self-limiting - most patients do not require treatment
• Thyroid pain may respond to aspirin or other NSAIDs
• In more severe cases steroids are used, particularly if hypothyroidism develops 

Question 114#

A 45-year-old woman presents with weight gain and recurrent 'dizzy' episodes. Over the past four months she has gained 20 kg. The episodes occur on an almost daily basis and are characterized by blurred vision, sweating, headaches and palpitations. Her GP checked a blood sugar during one of these episodes which was record as being 1.4 mmol/l.

What is the single most useful test?

A. Glucagon stimulation test

Correct Answer C: This patient has symptoms typical of an insulinoma. Whilst supervised fasting is normally the investigation of choice if this option is not given then insulin + C-peptide levels during an acute hypoglycaemic episode are useful.

Insulinoma:
An insulinoma is a neuroendocrine tumour deriving mainly from pancreatic Islets of Langerhans cells.

Basics:

• Most common pancreatic endocrine tumour
• 10% malignant, 10% multiple
• Of patients with multiple tumours, 50% have MEN-1

Features:

• Of hypoglycaemia: typically early in morning or just before meal, e.g. diplopia, weakness etc
• Rapid weight gain may be seen
• High insulin, raised proinsulin:insulin ratio
• High C-peptide

Diagnosis:

• Supervised, prolonged fasting (up to 72 hours)
• CT pancreas

Management:

• Surgery
• Diazoxide and somatostatin if patients are not candidates for surgery

Question 115#

You review a 70-year-old who has a long past medical history and is on multiple drugs. He has developed excessive amounts of breast tissue bilaterally.

Which one of the following drugs is most likely to be responsible?

A. Tamoxifen

Correct Answer D: Goserelin is a gonadorelin analogue used in the treatment of advanced prostate cancer. Tamoxifen may be used to treat gynaecomastia.

Gynaecomastia:
Gynaecomastia describes an abnormal amount of breast tissue in males and is usually caused by an increased oestrogen:androgen ratio. It is important to differentiate the causes of galactorrhoea (due to the actions of prolactin on breast tissue) from those of gynaecomastia.

Causes of gynaecomastia:

• Physiological: normal in puberty
• Syndromes with androgen deficiency: Kallman's, Klinefelter's
• Testicular failure: e.g. mumps
• Liver disease
• Testicular cancer e.g. seminoma secreting hCG
• Ectopic tumour secretion
• Hyperthyroidism
• Haemodialysis
• Drugs: see below

Drug causes of gynaecomastia:

• Spironolactone (most common drug cause)
• Cimetidine
• Digoxin
• Cannabis
• Finasteride
• Gonadorelin analogues e.g. Goserelin, buserelin
• Oestrogens, anabolic steroids

Very rare drug causes of gynaecomastia:

• Tricyclics
• Isoniazid
• Calcium channel blockers
• Heroin
• Busulfan
• Methyldopa