New Series Little Gems
How hot are you on... Lipid lowering?
Test your knowledge for the nMRCGP with this little GEM from GPnotebook
Clinical scenario: 46-year-old man with a history of type 2 diabetes. Glycaemic control revealed an HbA1c of 7.2 per cent. Lipid profile revealed a total cholesterol of 6.5mmol/l, LDL of 3.4mmol/l, HDL 1.1mmol/l and fasting triglycerides of 3.4mmol/l.
Q. Should a cardiovascular risk equation be used in this situation?
A. There are no separate cardiovascular risk charts for patients with diabetes. This is because diabetic patients are at high risk of cardiovascular disease (CVD) and the aim of management should be prevention of CVD – through lifestyle and risk factor interventions and appropriate drug therapies to lower blood pressure, modify lipids and reduce glycaemia. Other pharmacological interventions such as aspirin and an ACE inhibitor/ angiotensin receptor blocker (ARB) may also be indicated in patients with diabetes.
Q. If lipid-lowering treatment was to be used, then what base-line investigations would be considered before starting statin therapy?
A. Exclude secondary causes of hyperlipidaemia – these include diabetes, hypothyroidism, cholestatic liver disease and renal failure. Check baseline lipids, liver and renal function, creatine phosphokinase (CK) – the Joint British Guidelines (JBS2) suggest it is common practice to measure baseline CK and alanine/aspartate transaminases (ALT or AST) before starting treatment with a statin as some people may have high values that are physiological, not pathological.
Q. This gentleman had his lipids monitored four weeks after initiating a statin. Is this period of time too soon?
A. A four-week period of treatment will be sufficient for maximal statin response. About 70 per cent and 90 per cent of the full response is seen at one and two weeks of treatment, respectively.
Q. In diabetes patients aged 18 to 39 years old, the JBS2 guidelines have stipulated circumstances when statin treatment would be indicated. What are these circumstances?
A. Statin treatment is indicated for people aged 18 to 39 years with either type 1 or 2 diabetes with at least one of the following:
•retinopathy (pre-proliferative, proliferative, maculopathy)
•nephropathy, including persistent microalbuminuria
•poor glycaemic control (HbA1c >9 per cent)
•elevated blood pressure requiring antihypertensive therapy
•raised total blood cholesterol (>6.0mmol/l)
•features of metabolic syndrome (central obesity and fasting triglyceride >1.7 mmol/l and/or HDL cholesterol <1.0mmol/l in men or <1.2mmol/l in women)
•family history of premature CVD in a first degree relative.
Q. Which two important statin trials are concerned with the use of statins in patients with diabetes?
A. The most significant trials in this area are the Heart Protection Study and the Collaborative Atorvastatin Diabetes Study.
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