Bronchial Hyperresponsiveness, Word Descriptors, and Ethnicity: Women with Mild Asthma

Background. Few studies have examined the ethnic differences in symptom reporting and airway hyperresponsiveness (AHR) for women with mild asthma during a methacholine (McH) challenge. Objective. The purpose of this sub-analysis was to determine: (1) whether AHR to McH varied by the ethnicity of women with mild asthma and (2) whether ethnic word descriptors (EWDs) varied by the ethnicity during induced bronchoconstriction. Methods. Specific inclusion criteria included the following: FEV1 (forced expiratory volume in 1 second) >= 70% predicted normal, PC30 <= 8 mg/McH, beta(2) inhaler only, and self-reported ethnicity of African American (AFAM), Mexican American-Hispanic-Latino (MexAMLat), Asian-Pacific Islander (Asian PI), or white. Serial pulmonary function testing (PFT) and Borg, visual analogue scale (VAS), and EWDs were collected. Results. A total of 44 women, mean age of 31.3 years old, with a mean baseline FEV1 of 2.85 L comprised this sub-analysis. Ethnic-racial diversity included: 12 AFAMs, 5 MexAMLat, 13 Asian-PIs, and 14 whites. All had atopy >= 2 pinprick responses of 3 mm. At PC30, Asian-PI women required a significantly (p<.05) smaller mean dose of McH 1.9 mg/mL. MexAMLat women required an McH dose of 1.6 mg/mL. At PC30, McH dose was 2.9 mg/mL for AFAMs and 3.0 mg/mL for whites, respectively. Asian-PIs who used only upper airway EWDs at PC30 vere itchy throat, itchy chin, and constricted throat (p<.001). AFAMs significant EWDs were itchy throat, itchy chin/face, and tight throat (p<.01). Lower airway EWD was used by both MexAMLat and whites. Significant EWD for Whites were tight chest (p<.01) and hard to inhale/lungs tight (p<.001). Conclusion. Asian-PI women required a significantly smaller dose (p<.05) of McH to induce a PC30. AFAM and whites required a comparable dose of Mch at PC30. Asian-PI and AFAM women used only upper airway EWD. Asian-PI women may be at a greater risk for acute asthma episodes that are not recognized or treated due to their upper airway symptom reporting.