Knowing your heart disease risk: How does cholesterol fit in?
It's quite commonly known that high total cholesterol and LDL levels are directly related to an increased risk of heart disease and that the relationship is graded and continuous. This risk even applies to people under the age of 40. Low HDL and high triglycerides also contribute to this risk but apparently to a lesser extent, especially in men. In women, however, low HDL may be as important as high LDL as a risk factor. When talking about heart disease risk, abnormal cholesterol is just one major determinant. The other major risk factors for heart disease include your age (>45yrs for a man and >55yrs for a woman), family history of heart disease (father or brother diagnosed before age 55, mother or sister diagnosed before age 65), smoking, high blood pressure, and diabetes.
Determining your risk of heart disease includes identifying these multiple risk factors. In addition, you can also determine your risk of a heart attack using the Framingham Risk Score. It's called Framingham because the data used to make the risk score calculation comes from a project started in 1948 called the Framingham Heart Study. This project has now studied three generations of people living in Framingham, MA, and has generated a substantial amount of epidemiologic data regarding heart disease risk factors. This risk score takes into account several but not all of the major risk factors and estimates your risk of suffering a heart attack over the next 10yrs. A different risk score schema exists for men and women. Here's what they look like:
Estimate of 10-Year Risk for Men (Framingham Point Scores)
Estimate of 10-Year Risk for Women (Framingham Point Scores)
Notice that 2 of the 5 categories are related to cholesterol and that LDL and diabetes are not listed on this score sheet. That's because this risk score calculation is used to determine what your target LDL should be. In addition, diabetics have such a high risk for heart disease that they are treated as if they already have had a heart attack.
Once you have identified which main risk factors you have and have calculated your 10yr heart attack risk, you can then determine what your target LDL should be using the following chart. Remember that having a high HDL > 60mg/dl actually takes away one of your total risk factors.
Although we know that LDL is not the only cholesterol component to affect heart disease risk, it is the most important and well studied. Treatment of LDL to goal is the primary objective with HDL and triglycerides levels as secondary objectives. My next article will talk about ways in which to achieve your target cholesterol levels without having to take medication.