Exercise reduces heart-attack protein

Men who achieve higher levels of cardiorespiratory fitness have reduced levels of a protein that has been linked to heart attacks, according to a report in the journal Arteriosclerosis, Thrombosis and Vascular Biology.

People with elevated values of this substance, called C-reactive protein, have a greater risk of cardiovascular disease. The reduction in CRP may be a primary reason why exercise is so heart-healthy, says study author Timothy Church, M.D., of Dallas' Cooper Institute. (Blood flow may be involved; see related story, page 48.)

The researchers placed 722 subjects in five groups based on how long they could walk on a treadmill. "We found an inverse association across fitness levels, with the highest CRP in the lowest fitness quintile and the lowest CRP in the highest fitness quintile," notes the report. The likelihood of having elevated CRP dipped from 57 percent in the fourth-fittest group to 83 percent among the most fit.

The presence of CRP, either as cause or result, increases when there has been inflammation of the blood vessels. The inflammatory process, which may have a bacterial or viral origin, is an important factor in the buildup of arterial fat.

An earlier study in the New England Journal of Medicine found that men with the most CRP have a threefold jump in heartattack risk and a twofold boost in stroke risk. Elevated CRP can be a predictor of vascular incidents six to eight years in advance, enough time for patients to undergo a prevention program.

On Jan. 27, the CDC called for CRP tests for people with certain heart risks. But even if you don't have high cholesterol or hypertension, the test may give you some real insight into the state of your health.

10-SECOND TIP

To get out of the fitness basement and cut your level of CRP in half, the Cooper Institute suggests moderate activity--such as walking--for at least 30 minutes a day, five days a week.