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: FEV(1) (forced expiratory volume in 1 second) ≥ 70% predicted normal, PC(30) ≤ 8 mg/McH, ß(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 FEV(1) 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 PC(30), 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 PC(30), 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 PC(30) 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 PC(30). AFAM and whites required a comparable dose of Mch at PC(30). 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.

Prevalence of wheeze, bronchial hyper-responsiveness and asthma in the elderly Chinese.

BACKGROUND: Asthma is a common health problem affecting patients of all ages. Because of the ease of sampling, epidemiological studies have concentrated mainly on the paediatric and general population. OBJECTIVE: This study aimed to determine the prevalence of wheeze, bronchial hyper-responsiveness and asthma amongst our elderly population and deduce any clinical and laboratory risk factors that might identify elderly asthmatics at an earlier stage. METHODS: Two thousand and thirty-two elderly Chinese aged > or = 70 years, randomly selected from a registered list of all recipients of Old Age and Disability Allowances in Hong Kong, were administered a questionnaire on lung health. Two hundred and fifty subjects were invited to attend our laboratory for skin tests and pulmonary function tests and 179 agreed. Of these, 173 (96.6%) and 176 (98.3%) had eosinophil count and serum IgE levels measured, respectively. Two definitions of asthma were used: (1) bronchial hyper-responsiveness (BHR) plus current wheeze, and (2) history of wheezing without previous diagnostic labels of emphysema or chronic bronchitis. RESULTS: Fifteen patients (out of 179: 8.4%) reported wheezing over the past 1 year. Fifty-one patients (28.5%) demonstrated BHR on spirometry or histamine challenge tests. Seven patients had both symptoms of wheezing and evidence of BHR. The prevalence of asthma using this definition is therefore 3.9% (95% CI 1.6-7.9%). Nine patients had symptoms of wheezing without previous diagnostic labels of chronic bronchitis or emphysema and, using this definition, the prevalence is 5.0% (95% CI 2.3-9.3%). Using multiple logistic regression studies, sex, social class, age, smoking habits, serum IgE levels and eosinophil counts did not predict a diagnosis of asthma using either definition. We found no association between a positive skin test and any respiratory symptoms or illnesses including asthma. CONCLUSION: Wheeze, bronchial hyper-responsiveness and asthma are prevalent amongst our elderly population. However, there were no identifiable demographic and laboratory risk factors in this study that may help us predict a diagnosis of asthma.

Validation of the ISAAC video questionnaire (AVQ3.0) in adolescents from a mixed ethnic background.

BACKGROUND: The International Study of Asthma and Allergies in Childhood (ISAAC) has developed an international version of the asthma video questionnaire (AVQ3.0) to measure asthma prevalence. This questionnaire has not been validated in adolescents from a mixed ethnic background. OBJECTIVE: The aims of this study were to compare the video questionnaire with a written questionnaire in the detection of airway hyperresponsiveness to hypertonic saline in a population of adolescents from a mixed ethnic background, and to establish the repeatability and psychometric properties of the asthma video questionnaire. METHODS: The study was conducted in four secondary schools in Sydney, an area with a high proportion of people from a non-English speaking background. Four hundred and seventy-five students from schools 1 and 2 completed the video questionnaire and a subgroup of these students (n = 170) completed the written questionnaire and a hypertonic saline inhalation challenge. Reproducibility of the questionnaire was evaluated by administering the questionnaire to a subsample of students 2 weeks later. The psychometric properties of the video questionnaire were examined in 852 students at two other schools (schools 3 and 4). RESULTS: One hundred and sixty-nine students aged 13.5 (sd 1.3) years completed both written and video questionnaires, and the hypertonic saline challenge. The students had widely different cultural backgrounds including Asian, South Pacific, Middle Eastern, European and African countries. There was good agreement between the questionnaires for wheeze (kappa 0.42). Questions on the video questionnaire concerning wheezing had good sensitivity (90%) and specificity (68%) for airway hyperresponsiveness to hypertonic saline. The video questionnaire was reproducible (kappa 0.82), had good internal consistency (Cronbach's alpha 0.81) and each question pertained to a single construct explaining 58% of the variance in total score. CONCLUSION: This study has validated the international version of the ISAAC video questionnaire against airway hyperresponsiveness to hypertonic saline in adolescents from a mixed ethnic background, and identified that the questionnaire has good psychometric properties. The ISAAC video has proved to be a valuable tool for the assessment of asthma prevalence in populations of ethnic diversity.

Racial differences in physiologic parameters related to asthma among middle-class children.

BACKGROUND: Asthma morbidity and mortality are higher in the United States for African-American (AA) children when compared to European-American (EA) children. STUDY OBJECTIVES: To explore racial differences in physiologic factors associated with pediatric asthma severity. DESIGN: Cross-sectional. METHODS: We analyzed data from two groups of children in suburban Detroit, one of which contains non-urban, middle-class AA children, a group not usually included in childhood asthma studies. All children were 6 to 8 years of age. Clinical evaluations included medical history, physical examination, skin testing, spirometry, and methacholine challenge. RESULTS: The study population (n = 569) was 14% African American, 51% of the participants were male, and the mean age was 6.8 +/- 0.4 years. Socioeconomic status (parental education) was similar overall by race, although some strata-specific differences were observed. The prevalence of physician-diagnosed asthma was 10% for both AA and EA groups. AA children were more reactive to methacholine than EA children (42% vs 22%, respectively; p = 0.001), and had significantly higher total IgE than EA children (geometric mean, 60. 6 vs 27.5 IU/mL; p = 0.001). Serum IgE was related to methacholine reactivity in EA children (p = 0.001), but not AA children (p = 0. 73). These differences remained after adjustment for gender, age, parental education, parental smoking, and maternal smoking during pregnancy. CONCLUSIONS: Our data support previous reports of racial differences in lung volume, airway responsiveness, and serum IgE concentrations. We found a racial difference in the relationship between total serum IgE and airway responsiveness that is unreported elsewhere. Overall, our results suggest that AA children may be predisposed to asthma.

Airway function among Inuit primary school children in far northern Quebec.

The study of the prevalence and determinants of asthma and allergy in different populations may provide clues to their etiology. We describe airway function and its determinants among Inuit schoolchildren living in far Northern Quebec. We assessed the presence of airways hyperresponsiveness (AHR), defined as a 15% drop in FEV1 with exercise, airflow obstruction, as judged by a reduced FEV1/FVC, and atopy, as evidenced by skin test positivity to inhaled aeroallergens, among 509 Inuit aged mostly from 6 to 13 yr. Smoking by the children (31.9%) and their parents was common, including maternal smoking during pregnancy (79.5%). Atopy was found in only 5.3% of children. Apart from age, there were no significant associations between AHR and any of the determinants examined. Airflow obstruction was present among 7.7% of children and occurred most commonly among children with higher levels of salivary cotinine and in those with four or more lower respiratory illnesses in the first 2 yr of life. Asthma and atopy were uncommon in this population whereas evidence of chronic airflow obstruction was frequently found. Measures to reduce the spread of respiratory infection and prevention of smoking are likely to be of most benefit in improving respiratory health in these isolated communities.

The effect of lifestyle on wheeze, atopy, and bronchial hyperreactivity in Asian and white children.

There is increasing evidence linking Western culture to increasing prevalence of asthma. We have measured the prevalence of symptoms of asthma, bronchial hyperreactivity, and atopy in a sample of white and Asian inner city schoolchildren aged 8-11 yr in the U.K. and assessed the influence of certain aspects of western culture on these variables. Bronchial reactivity was measured by methacholine challenge, atopy by allergen skin prick tests, and symptoms of asthma and aspects of lifestyle by questionnaire. Degree of Westernization was assessed from dietary habit categorized as exclusively Asian, mostly Asian, mixed, or exclusively English. The questionnaire was completed by 92% of children. The 308 white and 539 Asian children were of similar age (mean 9.3 yr versus 9.4 yr) with slightly more girls in the Asian group (52.6% versus 47.4%). The white children reported more wheeze within the past year (14.2% versus 8.8%, p = 0.01) but less were atopic (29.5% versus 38.4%, p = 0.01) with no significant difference in the prevalence of hyperreactivity (31.5% versus 29.6%, p = 0.57). Most Asians (97%) included Asian food in their diet; 35% ate a mostly Asian diet, 45% ate a mixed English and Asian diet, and 17% ate an exclusively Asian diet. After controlling for confounding factors whites were at higher risk of hyperreactivity and lower risk of atopy, and the risk of hyperreactivity and to a lesser extent atopy among Asian children was related to diet in a dose response fashion. The relative odds for hyperreactivity with an exclusively Asian, mostly Asian, or a mixed diet relative to an English diet were 0.31 (95% CI 0.15 to 0.62), 0.88 (0.56 to 1.37), and 0.99 (0.65 to 1.49), and for atopy were 1.22 (0.72 to 2.06), 1.47 (0.99 to 2.19), and 1.78 (1.23 to 2.58). These results suggest that diet or other closely related factors associated with Westernization are involved in the etiology of atopy and hyperreactivity.

Respiratory symptoms, bronchial responsiveness, and atopy in Fijian and Indian children.

Hospital admission rates for asthma in the 5 to 14 yr age group are three times higher in Fiji Indians than in Melanesian Fijians. Conversely, admission rates for pneumonia are three times higher for Fijians than Indians. To determine the prevalence of respiratory symptoms, bronchial hyperresponsiveness, and atopy, a questionnaire in three languages was distributed to 2,173 Suva City school children (mean age 9.6 yr), half of whom were sampled for histamine inhalation and skin-prick allergen tests. Prevalence of wheeze in the previous 12 mo was identical in both ethnic groups (20.6%). Productive cough was more common in Fijians (29%) than Indians (17%, p < 0.0001). Bronchial hyperresponsiveness was twice as common in Indians (30%) as Fijians (15%), relative risk 2.1 (95% confidence interval [CI]: 1.5 to 2.8), p < 0.0001. The combination of current wheeze and bronchial hyperresponsiveness was found in nearly three times as many Indian children (11.3%) as Fijians (4.0%), and the mean bronchial dose-response slope to histamine was steeper in Indians than Fijians. Prevalence of atopy was similar in Fijians (36%) and Indians (38%). Wheeze was significantly associated with atopy and a steeper dose-response slope to histamine, but productive cough was not. Indians may have more severe asthma than Fijians due to genetic or environmental factors acting independently of atopy. The higher prevalence of productive cough in Fijians is consistent with a greater burden of respiratory infection, and is associated with domestic crowding.