Which one of the following is most likely to be found in a patient with Hashimoto's thyroiditis?
Correct Answer C: Hashimoto's thyroiditis = hypothyroidism + goitre + anti-TPO.
Hashimoto'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. It is 10 times more common in women.
Features:
Each one of the following is associated with autoimmune poly-endocrinopathy syndrome type 1, except:
Correct Answer C:
Autoimmune poly-endocrinopathy syndrome: Addison's disease (autoimmune hypoadrenalism) is associated with other endocrine deficiencies in approximately 10% of patients. There are two distinct types of autoimmune poly-endocrinopathy syndrome (APS), with type 2 (sometimes referred to as Schmidt's syndrome) being much more common.
APS type 2 has a polygenic inheritance and is linked to HLA DR3/DR4. Patients have Addison's disease plus either:
APS type 1 is occasionally referred to as Multiple Endocrine Deficiency Autoimmune Candidiasis (MEDAC). It is a very rare autosomal recessive disorder caused by mutation of AIRE1 gene on chromosome 21
Features of APS type 1 (2 out of 3 needed):
Vitiligo can occur in both types.
A 49-year-old woman with type 2 diabetes mellitus is being considered for exenatide therapy.
Which one of the following is not part of the NICE criteria for starting or continuing this drug?
Correct Answer C: Patients do not need to have been on insulin prior to using exenatide.
Diabetes mellitus: GLP-1 and the new drugs: A number of new drugs to treat diabetes mellitus have become available in recent years. Much research has focused around the role of glucagon-like peptide-1 (GLP-1), a hormone released by the small intestine in response to an oral glucose load.
Whilst it is well known that insulin resistance and insufficient B-cell compensation occur other effects are also seen in type 2 diabetes mellitus (T2DM). In normal physiology an oral glucose load results in a greater release of insulin than if the same load is given intravenously - this known as the incretin effect. This effect is largely mediated by GLP-1 and is known to be decreased in T2DM. Increasing GLP-1 levels, either by the administration of an analogue or inhibiting its breakdown, is therefore the target of two recent classes of drug.
Glucagon-like peptide-1 (GLP-1) mimetics (e.g. exenatide):
NICE guidelines on the use of exenatide:
The Medicines and Healthcare products Regulatory Agency has issued specific warnings on the use of exenatide:
Dipeptidyl peptidase-4 (DPP-4) inhibitors (e.g. Vildagliptin, sitagliptin):
NICE guidelines on DPP-4 inhibitors:
A 20-year-old man presents with a nine month history of weight gain. Prior to this he was of a normal weight and cannot identify any obvious lifestyle changes that would account for his obesity. On examination he is noted to have abdominal striae and a degree of proximal myopathy. Blood pressure is 130/80 mmHg. Bloods show the following:
What is the most appropriate test to confirm the diagnosis?
Correct Answer D: The overnight dexamethasone suppression test is the best test to diagnosis Cushing's syndrome.
There is some debate as to whether a 24 hour urinary free cortisol or an overnight dexamethasone suppression test should be used to screen patients for Cushing's. The overnight (not high-dose) dexamethasone suppression test has however been shown to be more sensitive and is now much more commonly used in clinical practice. As this is not offered then 24 hour urinary free cortisol is the next best answer.
For a review comparing diagnostic methods see 'Specificity of first-line tests for the diagnosis of Cushing's syndrome: assessment in a large series, J Clin Endocrinol Metab. 2007 Nov;92(11):4123 9'
The high-dose dexamethasone suppression test is used to help differentiate the cause of Cushing's syndrome.
Cushing's syndrome:
investigations Investigations are divided into confirming Cushing's syndrome and then localizing the lesion. A hypokalaemic metabolic alkalosis may be seen, along with impaired glucose tolerance. Ectopic ACTH secretion (e.g. secondary to small cell lung cancer) is characteristically associated with very low potassium levels. An insulin stress test is used to differentiate between true Cushing's and pseudo-Cushing's.
Tests to confirm Cushing's syndrome: The two most commonly used tests are:
Localization tests:
The first-line localization is 9am and midnight plasma ACTH (and cortisol) levels. If ACTH is suppressed then a non-ACTH dependent cause is likely such as an adrenal adenoma.
High-dose dexamethasone suppression test:
CRH stimulation:
Petrosal sinus sampling of ACTH may be needed to differentiate between pituitary and ectopic ACTH secretion.
Which one of the following drugs used in the management of type 2 diabetes mellitus has the Medicines and Healthcare products Regulatory Agency warned is associated with an increased risk of severe pancreatitis and renal impairment?
Correct Answer D:
Diabetes mellitus: GLP-1 and the new drugs:
A number of new drugs to treat diabetes mellitus have become available in recent years. Much research has focused around the role of glucagon-like peptide-1 (GLP-1), a hormone released by the small intestine in response to an oral glucose load .
Click to expand