Ethnic differences in methacholine responsiveness and word descriptors in African Americans, Hispanic-Mexican Americans, Asian-Pacific Islanders, and Whites with mild asthma.

Objective: There is little asthma research that compares ethnic differences in airway responsiveness and word descriptors among African Americans, Hispanic-Mexican Americans, Asian-Pacific Islanders, and Whites. Thus, identifying ethnic differences in symptom descriptors and airway responsiveness may improve health outcomes by educating health professionals about treatment decisions that are culturally and ethnically sensitive.

Methods: Specific Inclusion criteria-forced expiratory volume in one second (FEV(1)) >or= 70% predicted normal; provocative concentration causing a 30% fall in FEV(1) (PC(30))
Results: One hundred eighteen consented, 106 completed procedures, and 90 had a positive PC(30) and were enrolled. Asian-Pacific Islanders had significantly greater airway responsiveness (p <.02). Baseline FEV(1), MCh dose, and PC(30) correlated with race (p <.001); baseline FEV(1) and ethnicity predicted airway responsiveness (p <.001). EWDs differed significantly by ethnicity. Upper airway EWDs for Asian-Pacific Islanders: itchy throat (p < .04), itchy (p <.02), itchy back throat (p <.04), voice tight, tight throat (p <.001), and cough (p <.04). Upper airway EWDs for African Americans: add itchy throat (p <.002), itchy neck (p <.001), tight throat (p <.003), voice tight (p <.02), and cough (p <.04). Hispanic-Mexican Americans used both upper and lower airway EWDs; Whites used only lower airway EWDs.

Conclusion: This study provides new insights about ethnic differences in airway responsiveness and EWDs. Asian-Pacific Islanders required a significantly smaller dose of MCh to achieve a PC(30) compared to the other three ethnic groups. The upper airway EWDs used by African Americans, Asian-Pacific Islanders, and Hispanic-Mexican Americans indicate a shared language of symptoms. A new language of breathlessness that incorporates both cultural and ethnic differences is needed to address the present disparity in the management of asthma symptoms.