There have been numerous studies concerning the etiology of
asthma, but the effect of
asthma on the epidemiologic characteristics of
other chronic diseases has been relatively underinvestigated. There have been studies that assessed the relationship between asthma and chronic conditions (ie, proinflammatory conditions), such as rheumatoid arthritis (RA),7–9 inflammatory bowel disease (IBD),9–12 diabetes mellitus (DM),8,9,13–16 and coronary heart disease (CHD).