C-Reactive Protein and Blood Lipids

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By Kenneth H. Neldner, MD

Inquires have been submitted to NAPE regarding C-reactive protein (CRP), what it is and why it is important. Explaining CRP is actually rather difficult but this article provides a brief explanation and a summary of what we need to know about it.

Briefly, CRP is a measure of inflammation anywhere in the body. If it involves blood vessel walls, chronic inflammation seems to have the ability to bind cholesterol to arteries and increase the risk for cardiovascular problems. Hence, an elevated CRP level could be a predictor of heart disease. This is why CRP testing has been added to the list of the so-called lipid profile group of tests.

A recent article in the New England Journal of Medicine reported on a large group of patients with coronary artery occlusion due to cholesterol deposits. They were treated with the statin drugs which reduced their cholesterol and CRP levels, both of which had been elevated.

These observations lead to why CRP and its inclusion in the lipid profile series of blood tests is important. Cholesterol blood levels were the first to be included, followed by triglycerides. Then came the high-density lipoproteins (HDLs) and the low-density lipoproteins (LDLs). But it was soon learned that the HDLs prevent accumulation of cholesterol in blood vessels, so high blood levels are good, whereas the LDLs promote the deposits of cholesterol. Ideally, HDLs should be 50 or above and LDLs should be 100 or below. Since high CRP levels have been associated with high cholesterol levels, CRP has been added to the lipid profile group of tests. It was next learned that homocysteine-a normal substance in the blood was important in determining LDL levels, so a high homocysteine blood level could increase LDL levels further.

In summary, a complete lipid profile must include all six items listed below. If any are abnormal, appropriate measures should be taken to get them back to a normal range.
1. Cholesterol
2. Triglycerides
3. High-density lipoproteins (HDL)
4. Low-density lipoproteins (LDL)
5. Homocysteine
6. C-reactive protein (CRP)

Note that CRP levels could be artificially inflated in the case of an existing injury or infection. The American Heart Association set standards for CRP levels as follows:
* low risk of developing cardiovascular disease: less than 1.0 mg/L
* average risk: between 1.0 and 3.0 mg/L
* high risk: greater than 3.0 mg/L

The last item to consider is blood pressure. Clearly, high blood pressure is undesirable for everyone but perhaps more so for PXE patients more prone to retinal and gastric hemorrhages. Blood pressure of 140/90 was always considered the upper limit of normal, but recently cardiologists have reduced the upper limit to 120/80. Ask that your blood pressure be taken two or three times when in your doctor's office. You will be surprised at how it varies. It is actually best to have your own digital device at home where you can measure your pressure under different conditions. They can be purchased for as little as $50. They are battery operated, so all you have to do is wrap the cuff around your arm and press a button.