What’s the deal with cholesterol?

What’s the deal with cholesterol?This is quite a common question and the most important fact to recognise is that the context for each individual is vital to understand before we can decide on the importance of a cholesterol reading.

Having a high cholesterol reading is not in itself really a disease-there are no symptoms- but with a high cholesterol level deposits of the cholesterol can line the blood vessels and narrow the space through which blood can pass. The less blood that can pass through, the less blood that can reach the vital organs like the brain, heart and kidneys. If the blood vessel clots off completely then this can cause death of the brain tissue: stroke, or heart: heart attack. This is why cholesterol is important.

The other major risk factors for stroke and heart attack are age (no known cure yet), smoking, high blood pressure, kidney disease and diabetes. We need to consider all these factors before we can calculate the importance of any single cholesterol reading. The average cholesterol reading for an Australian adult is about 5.6. This consists of ‘good cholesterol’ and ‘bad cholesterol’. One helps prevent blocking of the blood vessel, one contributes to blocking. When we know all these parameters we can calculate the risk of, say, having a heart attack in the next 5 years. Take two men. One is age 50, a non smoker, with normal blood pressure, no kidney disease and not diabetic. His cholesterol level is 6.2. His risk of a heart attack in the next 5 years would be about 7%.Take a man age 60, smoker, diabetic, high blood pressure, but with a cholesterol of only 4.2. His risk of heart attack in the next 5 years

Maple Street Surgery46 Maple Street(1st Floor of Eden Rehabilitation Centre)

PO Box 2 Cooroy QLD 4563

Phone: (07) 5447 6644 Fax: (07) 5442 6226 After Hours: (07) 5447 6644 info@maplestreetsurgery.com.au

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would be about 28%. So although cholesterol is a risk factor for stroke and heart attack we need to know the whole context before deciding on the importance of a single cholesterol reading. The second man probably needs his cholesterol lowered even more than the first man.

Can diet and exercise lower your cholesterol? Yes. They can also help with blood pressure and diabetes so they are very important. But how much can significant weight loss reduce your cholesterol. It varies but not much more than 15-20% at best. There is a large genetic component to the cholesterol level and so dramatic changes with diet alone are unlikely. What else is there? The main drugs used are called statins. If they lower the cholesterol significantly it can reduce your risk of heart attack by about 30%. Back to the man with a 7% chance of heart attack in the next 5 years. If he took a statin to reduce his cholesterol effectively from say 6.2 down 4 then this would reduce his risk of heart attack from 7% down to

What’s the deal with cholesterol?

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about 5%. The second man might take the statin and reduce his cholesterol from 4.2 down to 3.0. His risk of heart attack would fall from 28% to about 19%. The second man with the greatest absolute risk is getting the greatest benefit, even though his cholesterol might be the lowest to start with.

That’s the benefits, so what are the risks of statins? The most common one is muscle aches and pains in about 5-10% of users. Very rare side effects are transient memory problems and kidney damage. In general in someone with a high risk of heart attack the benefits will outweigh the cons but in those taking it who have a low risk of heart attack the benefits might not be so clear. Best to discuss it with the doctor if uncertain.

Dr Ken Corbett

What’s the deal with cholesterol?

Maple Street Surgery46 Maple Street (1st Floor of Eden Rehabilitation Centre)

PO Box 2 Cooroy QLD 4563

Phone: (07) 5447 6644 Fax: (07) 5442 6226 After Hours: (07) 5447 6644 info@maplestreetsurgery.com.au