A 36-year-old female with a BMI of 34 kg/m^2 is reviewed after managing to lose 3 kg in the past month. She asks about the possibility of starting a drug to help her lose weight.
What is the primary mode of action of orlistat?
Correct Answer B: The primary mode of action of orlistat is to inhibit pancreatic lipases, which in turn will decrease the absorption of lipids from the intestine.
Obesity: therapeutic options: The management of obesity consists of a step-wise approach:
Orlistat is a pancreatic lipase inhibitor used in the management of obesity. Adverse effects include faecal urgency/incontinence and flatulence. A lower dose version is now available without prescription ('Alli'). NICE have defined criteria for the use of orlistat. It should only be prescribed as part of an overall plan for managing obesity in adults who have:
Sibutramine:
Rimonabant:
Which of the following secondary causes of hyperlipidaemia result in predominantly hypercholesterolaemia, as opposed to hypertriglyceridaemia?
Correct Answer C: Hypercholesterolaemia rather than hypertriglyceridaemia: nephrotic syndrome, cholestasis, hypothyroidism.
Hyperlipidaemia: secondary causes:
Causes of predominantly hypertriglyceridaemia:
Causes of predominantly hypercholesterolaemia:
Which one of the following is not part of the diagnostic criteria for the metabolic syndrome?
Correct Answer C: High LDL levels are not part of the World Health Organization or International Diabetes Federation diagnostic criteria.
Metabolic syndrome:
Unfortunately there are a number of competing definitions of the metabolic syndrome around at the present time. It is thought that the key pathophysiological factor is insulin resistance.
SIGN recommend using criteria similar to those from the American Heart Association. The similarity of the International Diabetes Federation criteria should be noted. For a diagnosis of metabolic syndrome at least 3 of the following should be identified:
The International Diabetes Federation produced a consensus set of diagnostic criteria in 2005, which are now widely in use. These require the presence of central obesity (defined as waist circumference > 94cm for Europid men and > 80cm for Europid women, with ethnicity specific values for other groups) plus any two of the following four factors:
In 1999 the World Health Organization produced diagnostic criteria which required the presence of diabetes mellitus, impaired glucose tolerance, impaired fasting glucose or insulin resistance, AND two of the following:
Other associated features include:
A 45-year-old female is reviewed in the medical clinic with a two month history of lethargy. Blood tests reveal the following:
Which one of the following investigations is most likely to reveal the diagnosis?
Correct Answer E: The short synacthen test is the best test to diagnose Addison's disease.
Hyponatraemia and a high potassium in a patient with lethargy is highly suggestive of Addison's disease. The thyroxine level is slightly low and she may indeed have co-existing hypothyroidism but this would not explain the high potassium.
Many labs have an upper reference range for potassium of 5.5 mmol/l, but in the context of the other results hypoadrenalism should be suspected.
Addison's disease: investigations:
In a patient with suspected Addison's disease the definite investigation is a ACTH stimulation test (short Synacthen test). Plasma cortisol is measured before and 30 minutes after giving Synacthen 250ug IM. Adrenal autoantibodies such as anti-21-hydroxylase may also be demonstrated Associated electrolyte abnormalities:
Which one of the following is not an indication for treating a patient with subclinical hypothyroidism?
Correct Answer C:
Subclinical hypothyroidism: Basics:
Significance:
Treat if:
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