Young adults' boozing linked to heart danger: CRP levels observed

Milwaukee Journal Sentinel

04-27-07

Apr. 23--College students who drink heavily may be putting themselves at risk for more than just a hangover.

New research suggests that heavy drinking among young adults significantly raises blood levels of a troubling substance linked to heart disease and strokes in older adults.

"If students are drinking heavily, they probably are going to progress to heart disease much more rapidly," said co- author Amy Olson, a professor of nutrition at the College of Saint Benedict in St. Joseph, Minn.

When those heart attacks and strokes might first occur is not known, but Olson and co-author Elizabeth Donovan speculated that it could be 10 or 15 years down the road from college if they continued drinking heavily.

The study extends to younger adults what research already has found with older people, that heavy drinking increases cardiovascular risk and moderate drinking is associated with reduced risk, said David Rutlen, professor and chief of cardiovascular medicine at the Medical College of Wisconsin.

The study also hints at a possible reason -- higher levels of inflammation -- why longtime heavy drinkers have more heart attacks and strokes, said Rutlen, who practices at Froedtert Hospital in Wauwatosa and was not involved in the study.

"This data is consistent with a body of knowledge we already have," Rutlen said. "It extends that because it was done in a much younger population."

The study, which was presented at an American Heart Association meeting Thursday in Chicago, focused on the substance C-reactive protein, or CRP.

Looking at a group of 25 non-smoking college students, the researchers found that those who were heavy drinkers had more than twice the CRP levels of moderate drinkers.

Heavy drinking was defined as three or more drinks of alcohol on at least three days a week or five drinks or more at least two times a week. Moderate drinking was two to five drinks one or two times a week. Low drinking was one drink or less a week.

A drink was 12 ounces of beer, 5 ounces of wine or 1.5 ounces of hard liquor.

The heavy drinkers had an average CRP level of 1.25 milligrams per liter, compared with 0.58 mg/L for the moderate drinkers. Those in the low category had an average CRP of 0.9 ml/L, a finding that bolsters other research suggesting that non-drinkers may be at greater risk for heart disease than moderate drinkers.

A CRP level of 1 to 3 mg/L puts a person at moderate risk for heart disease.

One thing the study did not address is what happens to the CRP levels of college-age people over a period of years, said Robert Bonow, a professor of medicine at Northwestern University in Chicago who was not involved in the study.

"We need to know what happens if you stop drinking," said Bonow, chief of cardiology at Northwestern Memorial Hospital. "Does it come down again? I suspect it will."

Bonow said the study was small but does raise concerns about drinking and cardiovascular disease in young adults. Heavy drinking, he noted, also is known to raise blood pressure.

CRP "is another reason why you shouldn't be drinking heavily," he said.

Unraveling CRP's role

In recent years, CRP has emerged as a key player in coronary inflammation, a process that destabilizes the plaque in the arteries of the heart. It still is unclear whether CRP causes inflammation or is sign of it.

However, research suggests that its role in heart disease may work something like this:

Cholesterol builds up and is oxidized inside the walls of arteries. That, in turn, results in the marshaling of immune cells that, in their effort to eliminate the oxidized cholesterol, inflame the arteries, rupturing the lining. As the body tries to repair the crack, a clot forms, resulting in a heart attack.

Among other things, it is believed that CRP aggravates the immune response.

The protein can be reduced by taking cholesterol-lowering statin drugs, but also by losing weight, exercising and eating healthily. Certain diabetes drugs and some drugs that raise HDL cholesterol (the good kind) also can lower CRP.

Smoking, obesity, gum disease and infections can raise the protein's levels, which can be measured inexpensively by a simple blood measure, known as the high sensitivity C-reactive protein test.