Lipids
Background
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Lipid abnormalities are are common in type 2 diabetes and are associated with increased risk of cardiovascular events
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The commonest pattern of dyslipidaemia in type 2 patients is elevated triglycerides and reduced HDL cholesterol levels
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In the Heart Protection Study, patients with diabetes assigned to simvastatin 40mg daily, including those with"normal" pre-treatment lipid levels, had a significant reduction in major cardiovascular events,
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Statin treatment is therefore indicated in all diabetic patients whose 10 year cardiovascular risk exceeds 15%
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The aims of treatment are to lower total cholesterol to <4.0 mmol/l , LDL cholesterol to <2.6 mmol/l and triglycerides to <2.3mmol/l
Management
CHOLESTEROL |
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Lipid Levels (mmol/l) |
Measures to take |
Further measures |
Total cholesterol <4.0 and LDL <2.6
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Offer lifestyle advice
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Reassess level annually |
Total cholesterol >4.0 or LDL >2.6 |
Correct underlying causes * and address other risk factors
Thorough trial of lipid lowering diet, check effect after 3 months
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If diet insufficient add drugs: 1 st choice ~ statin Alternatively use fibrates or ezetimibe if statins contraindicated or not tolerated.
Re-assess level at 6 weeks, and titrate medication dose to achieve desired levels. Reassess levels six weeks after every change of dose. Once target level achieved, reassess annually.
If target levels are not achieved, add ezetimibe to statins. Re-assess levels at 6 weeks, and if still not controlled, refer to specialist lipid clinic
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Familial dyslipidaemia |
Refer to specialist lipid clinic for treatment |
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* Underlying causes |
Pregnancy, hypothyroidism, obesity, anorexia nervosa, alcohol abuse, nephrotic syndrome, chronic renal failure, biliary cirrhosis, biliary obstruction, thiazides, B-blockers, oestrogens, corticosteroids, retinoids. |
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TRIGLYCERIDE |
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Total triglyceride (mmol/l)
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Measures to take |
Further measures |
<2.3 |
None |
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2.3 - 4.5 If total cholesterol normal |
Correct underlying causes Thorough trial of lipid lowering diet to include increase of fish oils, for at least 3 months |
Re-assess If levels not sufficiently reduced initiate statin therapy |
2.3 - 4.5 Plus elevated total cholesterol |
Correct underlying causes Thorough trial of lipid lowering diet to include increase of fish oils, for at least 3 months. |
If levels not sufficiently reduced treat with nicotinic acid or fibrate. Monitor every 3 months until stable Reassess annually If not controlled refer to specialist lipid clinic
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>4.5 |
Refer to specialist lipid clinic. Risk of acute pancreatitis
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Which agents to use
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Lowering of LDL cholesterol is the first priority. Both simvastatin (40 mg daily) and pravastatin (40 mg daily) have been shown to reduce cardiovascular risk in diabetic subjects. There is evidence that atorvastatin is a more potent agent.
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The fibrate drugs such as bezafibrate are effective at increasing HDL levels as well as reducing triglyceride levels. They are therefore sometimes useful in combination with statins to help achieve lipid targets
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Ezetimibe is a new cholesterol lowering agent which works by reducing cholesterol absorption from the gut. It can be used alone or in combination with a statin if maximal doses of the latter fail to achieve target lipid levels
Dosing and monitoring
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Measurement of lipid levels should be taken six weeks after starting and six weeks after each dosage adjustment until desired level achieved. They should be taken annually thereafter
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Advise patient to report any muscular pains immediately. CPK level should then be checked. If strong suspicion of myopathy caused by statins or if CPK level greater than 5 x upper limit of normal then discontinue the drug
Referral
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If cholesterol level above target or triglyceride >10mmol/l despite maximal lipid lowering drugs, refer to the hospital diabetic clinic