Adrenergic responsiveness: FEV1 and symptom differences in Whites and African Americans with mild asthma

Decision-making about inhaler use is, in part, determined by the ability of asthmatic patients to compare their symptoms over time and to recall the previous response to the bronchodilator during an episode of asthma. The perception of airway symptoms across varied ethnic and cultural groups are poorly understood. Study purpose was (1) to determine if African Americans and Whites with mild asthma could accurately perceive bronchodilation and (2) to identify the word descriptors they used to describe their breathing. Sixteen African American and 16 White patients (34.5 +/- 9.7 years old, mean+/-SD) with mild atopic asthma (FEV1 > or =70% predicted normal) were given increasing doses of an inhaled bronchodilator (Albuterol) after a methacholine challenge. Albuterol (180 microg) was given, by spacer, at 15 min intervals until the FEV1 increased < 5%. Borg, VAS, and Word Descriptors were collected at baseline and after each dose of Albuterol. Baseline FEV1 after Methacholine provocation was 1.94 +/- .39 L for African Americans and 2.13 +/- .70 L for Whites. After 180 microg and again after 360 microg Albuterol, FEV1 increased to 2.88 +/- 0.48 L for African Americans and 3.37 +/- 0.91 L for Whites. But after 540 microg Albuterol, FEV1 decreased significantly (16%) to 2.42 +/- 1.19 L for African Americans while increasing only slightly to 3.47 +/- 0.95 L for Whites. After this dose, 10/16 African Americans felt "tight at the base of throat" (p < 0.01); 7/16 felt "speech-voice-tight" (p < 0.03) suggesting persistent airway discomfort despite marked improvement in FEV1, Borg and VAS scores compared with baseline values. Word descriptors by African Americans' are a more reliable measure of airway symptoms compared to FEV1, Borg or VAS.