Cholesterol
Lipid problems
Overview
17% of all deaths are due to atherosclerosis (blockage of arteries leading to heart attacks and strokes).
High blood cholesterol is responsible for about 50% of heart attacks and about 12% of strokes.
Overall it is responsible for about 4 to 6% of the total burden of all diseases.
Cholesterol and triglyceride are the two major forms of lipids found in the body.
Both are carried in lipoproteins in the blood (Low-Density Lipoprotein + Cholesterol = LDL-C and High-Density Lipoprotein + Cholesterol = HDL-C)
Cholesterol is needed to create cell membranes, bile acids, and steroid hormones like Oestrogen and Testosterone.
Types
The interplay between different lipoproteins and lipids is complicated. The simply version is:
High LDL-C = BAD. Deposits cholesterol into arteries. Causes disease.
High HDL-C = GOOD. Carries cholesterol out of arteries. Protects from disease.
High Triglycerides = BAD.
Generally, we want to try and lower LDL-C and Triglycerides and increase HDL-C.
Risk
Cholesterol levels are just one part of your overall risk of cardiovascular disease which includes smoking, high blood pressure, age, family history, diabetes, and chronic kidney disease.
Cholesterol Targets
Total cholesterol (TC) < 4.0 mmol/L
LDL cholesterol (LDL-C) < 1.8 mmol/L
HDL cholesterol (HDL-C) > 1.0 mmol/L
TC:HDL ratio < 4.0
Non-HDL-C < 2.5 mmol/L
Triglycerides < 1.7 mmol/L
These targets change if you have other high-risk conditions like a previous heart attack or stroke.
Treatment
There is often a strong genetic component to cholesterol metabolism and diet may only make up 20% of the total effect on cholesterol. Medication should be strongly considered in anyone who is at high risk of cardiovascular disease.
Lifestyle Changes
Modifiable changes include
A low-cholesterol diet alone doesn’t seem to help
The focus should be on the quality of cholesterol eaten and the ratio of good to bad
More good cholesterols (monounsaturated and polyunsaturated fats in avocado, olive oil, and fatty fish)
Less bad cholesterol (trans-fatty acid in processed foods like pizza, cakes, biscuits, and saturated meat in red meat)
A high-fibre diet can lower LDL by 10%
Exercise can help to raise HDL by 10% and lower LDL by 10%
Eating more plants helps as they contain sterols with compete with the absorption of other cholesterol in the gut. They lower total cholesterol and LDL
Eating 30g of soy products a day reduced total cholesterol by 7 to 10%
Margarine should be cut out of your diet, but if not possible then replace it with olive oil or plant sterol-enriched spread like Olive Grove.
Medications
Statins are the first-line therapy for high total cholesterol.
Prescribe oral daily dose, preferably taken at night‑time. Options include:
Rosuvastatin 5 to 40 mg
Atorvastatin 10 to 80 mg
Simvastatin 10 to 80 mg
Fluvastatin 20 to 80 mg
Pravastatin 20 to 80 mg
The dose should be titrated up to a maximum tolerated dose.
Statins decrease LDL-C by 30 to 63%
Rosuvastatin and Atorvastatin are the most potent (check info on choice and dose of statin here)
Rosuvastatin 40mg has the highest reduction at 63%
Statins are generally well tolerated. The main possible side effects are muscle and liver problems - more info here)
Ezetimibe is second-line therapy.
Third-line options include tailored therapy with a PSCK-9 inhibitor.
For high triglycerides only options include
Fenofibrate 145mg oral, daily
Gemfibrozil 600 mg oral, twice a day, and/or
Omega‑3 fish oil (1.2 to 3.6 g oral, daily)
For mixed high total cholesterol and high triglycerides consider:
Statin plus fish oil
Fibrate plus ezetimibe
Fenofibrate plus statin
References
https://www.sciencedirect.com/science/article/pii/S0939475321000028
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1312230/
https://www1.racgp.org.au/ajgp/2021/may/lipid-management-and-implications-for-australian-g