In addition to the already familiar heart disease causes such as smoking, hypertension, high cholesterol, diabetes, obesity, a sedentary lifestyle, family history, and increasing age, there is also a less familiar cause that has been more recently identified and studied: C-Reactive Protein.
C-Reactive Protein (CRP)
CRP was first discovered by Oswald Theodore Avery (1877-1977), a Canadian physician and famous for his work with DNA. He discovered that CRP levels rise quite dramatically when we go through infection or illness, but he didn’t realize there is a connection between CRP and heart disease.
A marker of heart attack risk
When an artery becomes inflamed as a result of cigarette smoke, high blood pressure, diabetes or high cholesterol, the result is the building of plaques –atherosclerosis. CRP levels go up as an indicator of the inflammation. Thus, C-Reactive Protein is considered a good marker of heart attack risk.
There is very good evidence that as CRP levels go up, the risk of heart attack increases. Studies have concluded that CRP is more accurate in predicting cardiovascular risk than LDL, the “bad” cholesterol.
But because there is no accepted treatment for elevated CRP, it is difficult to justify routine screening. In fact, the American Heart Association does not recommend widespread screening for CRP.
What the numbers mean
The level of C-Reactive protein is measured in milligrams per liter (mg/L.).
- A level of less than 1.0 mg/L is considered low
- A level of 1.0 to 3.0 mg/L is average
- Anything above 3.0 mg/L is elevated
Lp(a), another marker of heart attack risk
Lp(a) is a lipoprotein (a molecule that contains cholesterol) that is very similar to LDL, the “bad” cholesterol, only smaller.it carries a substance that may trigger the formation of blood clots, which increases the chances of a heart attack. High levels of Lp(a) have been associated with a higher risk of a heart attack.
There is no indication that testing people for LP(a) is useful. Because Lp(a) levels are so connected to LDL levels, doctors don’t think it is a separate risk.
Homocysteine is also a new kid in the block in the area of predicting heart disease risk. It is one of the 20 amino acids that form proteins. We all have homocysteine in our blood vessels but what makes it a risk factor for heart disease is when we have very high levels.
High levels of homocysteine are most often found in men and are more common in:
- People with kidney disease
- People who follow a high protein diet
- People who use too much caffeine
- People who smoke
- People with certain rare diseases
Thus, men who drink a lot of coffee, eat a lot of meat, smoke, and have kidney disease, have the greatest risk.
The B vitamin complex
B vitamins and folic acid (folate) lower homocysteine levels in the blood. Natural sources of these vitamins are found in:
- Citrus fruits
Testing for homocysteine
Screening everyone for elevated levels of homocysteine would be expensive. Ask your doctor to perform a homocysteine test if:
- You are 50 or 40 years old
- Have coronary artery disease
- Do not have traditional risk factors
- Your family has a history of premature heart disease
If the test shows elevated levels of homocysteine, take a vitamin B supplement or a multivitamin that includes the B vitamin complex.
Knowledge about traditional risk factors for heart disease is making easier to understand and treat this condition. Less traditional markers of risk factors such as C-Reactive Protein, Lp(a), and homocysteine are increasing the tools physicians have at their disposal to predict and treat cardiovascular disease.