New research from Australia suggests that, compared with non-asthmatics, people with asthma have a nearly twofold risk for developing any of these chronic conditions. The risk is even higher for heart disease and stroke, they add.

　　"Asthma commonly coexists with other major health problems, particularly in older age groups. This coexistence is associated with significant adverse effects on physical health," conclude the authors of the study, which appears in the February issue of Chest.

　　What's unclear from this study, however, is whether there's any cause-and-effect relationship between asthma and these other diseases, or merely an association. It's also unclear whether maintaining good control over asthma symptoms could lessen the risk for some of these secondary conditions.

　　About 15 million Americans have asthma, according to the U.S. National Heart, Lung, and Blood Institute. Symptoms of the chronic lung disease include wheezing, coughing, tightness in the chest and shortness of breath.

　　The current study included data from phone interviews with more than 7,600 randomly sampled people from three different Australian states. From this sample, 834 had physician-diagnosed asthma.

　　People with asthma were 90 percent more likely to report having another chronic health condition compared to people without asthma, the study authors found.

　　Overall, the risk of stroke was 2.5 times as high for people with asthma vs. people without the illness. For heart disease, asthmatics had 2.2 times the risk compared to those without asthma. People with asthma also had an 80 percent higher chance of having arthritis, and a 70 percent increased chance of developing osteoporosis. Cancer risk was 50 percent higher in people with asthma, according to the study. The risk of diabetes was 20 percent increased in asthmatics.

　　Age may play a role: When the researchers broke the data down by age, they found that people over 55 tended to have the most significant risk of having another chronic illness.

　　"As adults with asthma age, the likelihood of developing other chronic conditions becomes greater," study senior author Dr. Richard Ruffin said in a prepared statement.