Hyperlipidemia on the CCFP exam

Approach

• Name the framework. PEER (a Canadian primary care guideline group) and the Canadian Cardiovascular Society (CCS) start at different ages.
• PEER: test lipids as part of a risk estimate from 40 in men and 50 in women.
• PEER tests sooner with a compelling risk factor, such as diabetes, smoking or early heart disease in the family.
• CCS screens all adults from age 40, and postmenopausal women at any age. It screens at any age with diabetes, high blood pressure, smoking, kidney disease or obesity.
• CCS also counts early heart disease in the family, HIV, inflammatory disease and erectile dysfunction, among others.
• CCS needs no fasting sample unless triglycerides are known to be over 4.5 mmol/L.

Approach

• Order a full lipid profile: total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), non-HDL cholesterol and triglycerides.
• CCS adds fasting glucose or A1c (average blood sugar), and lipoprotein(a) once in a lifetime.
• Use a validated calculator, and the same one each time. PEER uses the Framingham risk score.
• CCS accepts the Framingham score or the Cardiovascular Life Expectancy Model.
• Known heart disease or stroke: skip the calculator. PEER treats it as secondary prevention, like the highest risk band.
• CCS: if triglycerides are above 1.5 mmol/L, use non-HDL cholesterol or apoB instead of LDL.

Approach

• Before any statin, rule out secondary causes. The statin monograph lists poorly controlled diabetes, low thyroid and alcohol misuse.
• It also lists kidney disease that leaks protein (nephrotic syndrome), liver disease that blocks bile flow, and abnormal blood proteins.
• Check thyroid-stimulating hormone (TSH). Free thyroid hormone levels (T4 or T3) are not a screening test for low thyroid.
• No thyroid ultrasound unless the gland feels abnormal.
• Treat the cause first. Low thyroid also raises the risk of muscle injury on a statin.
• Estimate risk on lipids drawn once the cause is controlled. Untreated low thyroid raises LDL and overstates risk.
• A baseline creatine kinase (CK, a muscle enzyme) finds no cause. PEER advises against it unless symptoms call for it.

Approach

• Recommend the Mediterranean diet. PEER names it, with physical activity, to lower heart risk.
• CCS also lists the Portfolio diet (soy, nuts, fibre and plant sterols), DASH (the blood pressure diet) and plant-based patterns. It favours diets rich in nuts, legumes, olive oil, fibre and whole grains.
• Activity: CCS suggests at least 150 minutes a week of moderate to vigorous aerobic exercise, plus strength work 2 days a week.
• Cover smoking, weight, alcohol and sleep as well.
• PEER suggests against non-statin lipid drugs in primary prevention, even when a statin is not tolerated.
• Book a review. Ask what has changed, and offer the statin again if risk supports it. At low risk, PEER re-estimates risk in 5 to 10 years.

Approach

• Estimate overall risk first. The plan follows the risk and the framework (table below).
• PEER recommends against repeat lipid tests and cholesterol targets once treatment starts.
• CCS repeats lipids on a statin. On the highest tolerated dose, discuss add-on therapy if LDL stays at 2.0 mmol/L or more. Ezetimibe comes first.
• CCS gives a statin without a score for diabetes from 40, kidney disease from 50, aortic aneurysm, or LDL of 5.0 mmol/L or more.
• PEER estimates risk even when diabetes is present.
• Heart disease or stroke already: both favour a high-intensity statin.
• CCS then adds ezetimibe or a PCSK9 inhibitor (an injected LDL-lowering drug) if LDL stays at 1.8 mmol/L or more.

Approach

• Ask at each visit whether the patient still takes the drug, and how often doses are missed.
• Muscle aches are common on placebo too. In year one, about 15% on a statin had them, against 14% on placebo.
• For mild muscle complaints, rechallenge. Try the same or another statin, a lower dose, or every-other-day dosing.
• PEER: only about 1 in 15 reported muscle complaints is due to the statin. If a retrial fails, PEER suggests against a non-statin drug in primary prevention.
• Check CK for weakness, tenderness, or aches with fever or malaise. Stop the statin if CK is markedly high. PEER advises against baseline CK unless symptoms call for it.
• Higher muscle risk: low thyroid, alcohol misuse, age over 65, kidney or liver disease, and drugs such as fibrates or clarithromycin.
• Statins can raise blood sugar, so monitor patients at high risk of diabetes. PEER notes statins do not worsen memory or dementia.