SAN ANTONIO Asthma sufferers appear to be unusually prone to heart disease, a study found, offering new clues about the hazards of lingering inflammation.
Other research has linked asthma with heart trouble, but those studies did not clearly distinguish the effect of smoking, which contributes to both asthma and cardiovascular disease.
In the new study, doctors from the Kaiser Permanente health plan found that even nonsmokers have a clearly elevated risk of heart disease. It appears to be at least one-third higher than the risk in people without asthma.
The reason for this is unclear. The researchers speculate that asthmatics' chronic lung inflammation might damage their arteries over time. However, they said it is also possible that medicines used to treat asthma have ill effects on the heart.
"This is a beginning," said Dr. Carlos Iribarren, the lead author. "It's a provocative finding that we need to understand."
Iribarren presented the findings Friday at a meeting in San Antonio of the American Heart Assn.
The re-searchers re-viewed questionnaires filled out by 22,036 nonsmoking Kai-ser patients between 1979 and 1985 and followed their health through 1998. Among them were 1,062 men and women who said they had been diagnosed with asthma at some time in their lives.
Those who ever had asthma were 32 percent more likely than those without to be hospitalized with heart disease or die from it during the follow-up. People actually being treated for asthma at the study's start had an even higher risk. Twelve percent of them developed heart disease by the end of the study, compared with 7 percent of those without asthma an increased risk of more than 70 percent.
About 6 percent of Americans are thought to have asthma. Iribarren said these people should be especially careful to eat a healthy diet, keep their weight under control and watch their blood pressure and cholesterol levels.
"The universal recommendations for heart disease prevention apply to these people, because they may be at increased risk," he said.
Some experts believe that chronic inflammation may increase the risk of heart disease. Much of the attention in this research has focused on bacterial causes, such as lingering gum disease or sinus infections. Earlier this week in the journal Circulation, European doctors reported that people with a variety of chronic bacterial infections have triple the usual risk of developing hardening of the arteries.