Airway responsiveness in young black and white women

A Walking Intervention Supplemented With Mobile Health Technology in Low-Active Urban African American Women With Asthma: Proof-of-Concept Study

Background

Physical inactivity is associated with worse asthma outcomes. African American women experience disparities in both physical inactivity and asthma relative to their white counterparts. We conducted a modified evidence-based walking intervention supplemented with mobile health (mHealth) technologies to increase physical activity (PA).

Objective

This study aimed to assess the preliminary feasibility of a 7-week walking intervention modified for African American women with asthma.

Methods

African American women with suboptimally controlled asthma were identified from a health system serving low-income minorities. At a baseline data collection visit, participants performed spirometry and incremental shuttle walk test, completed questionnaires, and were given an accelerometer to wear for 1 week. The intervention comprised an informational study manual and 3 in-person group sessions over 7 weeks, led by a nurse interventionist, in a community setting. The supplemental mHealth tools included a wearable activity tracker device (Fitbit Charge HR) and one-way text messages related to PA and asthma 3 times per week. A secure Web-based research platform, iCardia, was used to obtain Fitbit data in real time (wear time, moderate-to-vigorous physical activity [MVPA] and sedentary time) and send text messages. The feasibility of the intervention was assessed in the domains of recruitment capability, acceptability (adherence, retention, engagement, text messaging, acceptability, complaints, and concerns), and preliminary outcome effects on PA behavior (change in steps, duration, and intensity).

Results

We approached 22 women, of whom 10 were eligible; 7 consented, enrolled and completed the study. Group session attendance was 71% (5/7), 86% (6/7), and 86% (6/7), respectively, across the 3 sessions. All participants completed evaluations at each group session. The women reported being satisfied or very satisfied with the program (eg, location, time, and materials). None of them had concerns about using, charging, or syncing the Fitbit device and app. Participants wore their Fitbit device for at least 10 hours per day in 44 out of the 49 intervention days. There was an increase in Fitbit-measured MVPA from week 1 (19 min/week, SD 14 min/week) to the last week of intervention (22 min/week, SD 12 min/week; Cohen d=0.24, 95% CI 0.1 to 6.4). A slight decrease in step count was observed from week 1 (8926 steps/day, SD 2156 steps/day) to the last week of intervention (8517 steps/day, SD 1612 steps/day; Cohen d=−0.21, 95% CI −876.9 to 58.9).

Conclusions

The initial feasibility results of a 7-week community-based walking intervention tailored for African American women with asthma and supplemented with mHealth tools are promising. Modifications to recruitment, retention, and the intervention itself are needed. These findings support the need to conduct a further modified pilot trial to collect additional data on feasibility and estimate the efficacy of the intervention on asthma and PA outcomes.

What Ancestry Can Tell Us About the Genetic Origins of Inter-Ethnic Differences in Asthma Expression

Differences in asthma prevalence have been described across different populations, suggesting that genetic ancestry can play an important role in this disease. In fact, several studies have demonstrated an association between African ancestry with increased asthma susceptibility and severity, higher immunoglobulin E levels, and lower lung function. In contrast, Native American ancestry has been shown to have a protective role for this disease. Genome-wide association studies have allowed the identification of population-specific genetic variants with varying allele frequency among populations. Additionally, the correlation of genetic ancestry at the chromosomal level with asthma and related traits by means of admixture mapping has revealed regions of the genome where ancestry is correlated with the disease. In this review, we discuss the evidence supporting the association of genetic ancestry with asthma susceptibility and asthma-related traits, and highlight the regions of the genome harboring ancestry-specific genetic risk factors.

Methacholine challenge test: diagnostic characteristics in asthmatic patients receiving controller medications

BACKGROUND

The methacholine challenge test (MCT) is commonly used to assess airway hyperresponsiveness, but the diagnostic characteristics have not been well studied in asthmatic patients receiving controller medications after the use of high-potency inhaled corticosteroids became common.

OBJECTIVES

We investigated the ability of the MCT to differentiate participants with a physician's diagnosis of asthma from nonasthmatic participants.

METHODS

We conducted a cohort-control study in asthmatic participants (n= 126) who were receiving regular controller medications and nonasthmatic control participants (n= 93) to evaluate the sensitivity and specificity of the MCT.

RESULTS

The overall sensitivity was 77% and the specificity was 96% with a threshold PC(20) (the provocative concentration of methacholine that results in a 20% drop in FEV(1)) of 8 mg/mL. The sensitivity was significantly lower in white than in African American participants (69% vs 95%, P= .015) and higher in atopic compared with nonatopic (82% vs 52%, P= .005). Increasing the PC(20) threshold from 8 to 16 mg/mL did not noticeably improve the performance characteristics of the test. African American race, presence of atopy, and lower percent predicted FEV(1) were associated with a positive test result.

CONCLUSIONS

The utility of the MCT to rule out a diagnosis of asthma depends on racial and atopic characteristics. Clinicians should take into account the reduced sensitivity of the MCT in white and nonatopic asthmatic patients when using this test for the diagnosis of asthma.

Racial differences in biologic predictors of severe asthma: Data from the Severe Asthma Research Program

BACKGROUND

Biologic factors are known to contribute to asthma severity. It is unknown whether these factors differentially contribute to asthma severity in black compared with white subjects.

OBJECTIVE

We sought to assess the extent to which racial disparities between black and white subjects with severe asthma are attributable to physiologic, immunoinflammatory, and sociodemographic variables.

METHODS

Black and white asthmatic adults enrolled in a cross-sectional study focused on severe asthma were evaluated. Severe asthma was identified by using the American Thoracic Society definition. After initial univariable analyses, unconditional logistic regression models were used to estimate the probability of having severe asthma for black and white subjects.

RESULTS

Differences in severe asthma in black compared with white subjects were observed. In univariable analysis IgE level was not associated with severe asthma in black or white subjects, whereas in multivariable analysis IgE level was significantly associated with severe asthma for black subjects (P = .014) but not for white subjects. The odds of having severe asthma more than doubled for black subjects with 2 or more family members with asthma (P = .026), whereas the odds of severe asthma for white participants with a strong family history of asthma decreased by almost half (P = .05). Atopy was negatively associated with severe asthma in both races in univariable analysis but remained significant only in black subjects, whereas comorbidities were associated with severe asthma in white subjects.

CONCLUSION

Biologic factors were distinctly associated with severe asthma only in black subjects. Studies that incorporate comprehensive evaluation of biologic factors associated with asthma might lead to the development of therapies that target biologic abnormalities in black subjects.

Serum level of immunoglobulin E during pregnancy - does offspring sex matter?

We assessed maternal serum levels of total immunoglobulin E (IgE) in the first, second and third trimester and changes in total IgE levels from first to third trimester in relation to offspring sex. Within a cohort of 29 948 pregnant women, 392 women without a history of pre-eclampsia and with a liveborn child were randomly selected. Information on offspring sex was obtained through linkage to the Medical Birth Registry of Norway. Blood samples from each trimester were analysed for total IgE concentration. Differences in mean levels according to offspring sex were estimated and changes in total IgE levels from first to third trimester were assessed. In all three trimesters there was a tendency of women carrying a male fetus to have a higher mean total IgE level, but significant statistical differences were not reached. The total IgE concentration decreased during pregnancy, but the decrement was less in women carrying a male fetus compared with those who carried a female fetus.

Racial disparities in asthma-related health outcomes in severe or difficult-to-treat asthma

BACKGROUND

The underlying reasons for racial disparities in asthma morbidity are not well understood. Multivariate epidemiologic studies evaluating the presence and extent of racial differences in a large cohort of adults with severe or difficult-to-treat asthma are lacking.

OBJECTIVE

To analyze an extensive array of clinical and patient-reported outcomes, using multivariate analysis with a sequential approach, to explain racial differences in asthma-related outcomes in one of the largest cohorts of difficult-to-treat asthmatic patients.

METHODS

Black and white patients (> or = 18-years-old at baseline) were included (n = 2,128). Differences between the 2 racial groups were assessed using several outcome measures at month 12. Assessments were adjusted for confounding variables using a sequence of statistical models.

RESULTS

Most patients were white (88.6%). Blacks were slightly younger, less educated, and more likely to live in urban areas than whites. Blacks were more likely to have severe asthma and to be treated with 3 or more long-term controllers. Poorer quality of life, more asthma control problems, and higher risk of emergency department visits were observed in blacks compared with whites; differences were not explained by adjustment for broad sets of confounding variables. Differences in asthma-related health outcomes remained statistically significant after adjusting for asthma severity.

CONCLUSIONS

Asthma is a serious health problem in blacks and is not explained by differences in demographics, severity, or other health conditions.

Sensitization to aeroallergens and airway hyperresponsiveness at 7 years of age

STUDY OBJECTIVES

To investigate the relationship between current and early life factors and airway responsiveness to inhaled methacholine in children with a median age of 7.0 years.

PARTICIPANTS

Study subjects were a subset of a prospective birth cohort of children in the Boston area at high risk for atopy.

METHODS

One hundred thirty-one children underwent both skin-prick testing to a panel of aeroallergens and a methacholine challenge test between 6.5 years and 8.8 years of age. Telephone questionnaires were performed at set intervals, and home dust samples were collected in the first year of life.

RESULTS

Of the 131 participating children, 51% (67 patients) had at least one positive skin-prick test response and 28% (37 patients) had airway hyperresponsiveness (AHR) [provocative concentration of methacholine causing a 20% fall in FEV(1) of < 4 mg/mL]. After adjusting for relevant covariates, AHR was strongly associated with sensitization to at least four aeroallergens (odds ratio [OR], 13.41; 95% confidence interval [CI], 3.03 to 59.42). In separate adjusted models, sensitization to cat (OR, 14.73; 95% CI, 3.64 to 59.55), dust mite (OR, 5.13; 95% CI, 1.94 to 13.56), cockroach (OR, 4.00; 95% CI, 1.19 to 13.50), and ragweed (OR, 10.08; 95% CI, 2.31 to 44.10) were significant predictors of AHR. However, no relationship was found with early life exposure to perennial aeroallergens or other perinatal and first-year-of-life factors.

CONCLUSIONS

Among young children at risk for atopy, sensitization to specific aeroallergens, but not early life exposures, is associated with increased airway responsiveness.

Health disparities and differences in asthma: concepts and controversies

Asthma is one of the most common respiratory diseases, with immense social impact. Despite best efforts, asthma prevalence, morbidity, and mortality are increasing in the United States. This is especially the case in select communities which suffer an excess burden of asthma. Studying these groups and attempting to ameliorate the disease burden they suffer has an important moral and social imperative. It also may lend important insight into the complex factors that contribute to asthma outcomes. The factors that affect asthma interact in a complicated manner and require a comprehensive approach that addresses each of them. However, pursuing health disparities research is controversial, and important ethical and operative considerations need to be made by those to engage in health disparities research.

Variation in total and specific IgE: effects of ethnicity and socioeconomic status

BACKGROUND

Asthma is common in minority and disadvantaged populations, whereas atopic disorders other than asthma appear to be less prevalent. It is unclear whether the same holds true for objective markers of sensitization.

OBJECTIVE

To determine the association of asthma, atopic disorders, and specific sensitization with race and socioeconomic factors.

METHODS

We analyzed total and specific IgE among 882 women (577 white, 169 black, and 136 Hispanic) who delivered a child at a large tertiary hospital in Boston, Mass, and who were screened for participation in a family and birth cohort study. Race/ethnicity and other characteristics were obtained from screening questionnaires. Addresses were geocoded, and 3 census-based geographic area socioeconomic variables were derived from block group information from the 1990 US Census.

RESULTS

Black and Hispanic women were more likely to come from areas with low socioeconomic indicators and were more likely to have asthma than white women. However, these women were less likely to have hay fever and eczema than their white counterparts. Compared with white women, black women had higher mean total IgE levels; had greater proportions of sensitization to indoor, outdoor, and fungal allergens; and were more than twice as likely to be sensitized to > or =3 aeroallergens.

CONCLUSION

The racial/ethnic disparities in atopic disorders may represent either underdiagnosis or underreporting and suggest that allergy testing may be underused in some populations. Differences in total IgE levels and specific allergen sensitization are likely a result of the complex interplay between exposures associated with socioeconomic disadvantage.

Ethnic differences in asthma and associated phenotypes: collaborative study on the genetics of asthma

BACKGROUND

In the Collaborative Study on the Genetics of Asthma, 314 families with 2584 subjects were characterized for asthma and allergy.

OBJECTIVE

The purpose of this investigation was to examine clinical heterogeneity observed in asthma and allergic characteristics among 3 ethnic groups (African American, white, and Hispanic family members).

METHODS

Pulmonary function parameters and asthma associated phenotypes were compared among the ethnic groups.

RESULTS

In comparison with the other groups, African American sibling pairs had a significantly lower baseline FEV(1) percent of predicted (P =.0001) and a higher rate of skin test reactivity to cockroach allergen (P =.0001); Hispanic sibling pairs had significantly more skin reactivity overall (P =.001); and white sibling pairs had significantly lower total serum IgE (P <.05). In addition, there were significantly more relatives with asthma among the African American families than among the white and the Hispanic families (P =.001).

CONCLUSION

Although different environmental backgrounds should be considered, these clinical differences could be due to differences in genetic susceptibility among the ethnic groups, such as those suggested by our previous genome screen.

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.

Race, socioeconomic factors, and area of residence are associated with asthma prevalence

Asthma prevalence in the United States has been reported to be higher in minority groups such as Blacks and Hispanics. Because a disproportionate number of individuals from such minority groups are of low socioeconomic status (SES), it is unclear how much of the racial/ethnic differences in asthma prevalence is related to low SES. We investigated the effect of SES on the relationship between race/ethnicity and asthma prevalence in a cohort of families with a history of asthma or allergies from the Boston, Massachusetts area. From 499 families, a cohort of 998 parents and 307 children was identified. We used total yearly family income (<$50,000 vs. > or = $50, 000), highest level of education (< or = high school vs. > or = college), and residence in high-poverty areas vs. low-poverty areas as measures of SES. Yearly family income <$50,000, < or = high school education, and residence in high poverty areas were all associated with increased risks for asthma in both cohorts. In the parental cohort, Blacks and Hispanics (OR = 2.1, 95% CI = 1.5, 2.8; and OR = 2.2, 95% CI = 1.5, 3.2, respectively) were at greater risk for asthma than Whites. In the cohort of children, Black and Hispanic children (OR = 2.9, 95% CI = 1.0, 8.0; and OR = 5.3, 95% CI = 1.6, 17.5, respectively) were also at increased risk for asthma. When the three measures of SES were included in the multivariable models, the risks associated with Blacks and Hispanics decreased in both cohorts: OR = 1.4, 95% CI = 0.9, 2.0; and OR = 1.6, 95% CI = 1.0, 2. 6, respectively, for the parents; and OR = 0.8, 95% CI = 0.2, 3.0; and 2.5, 95% CI = 0.5, 11.7, respectively, for the children. We conclude that a large proportion of the racial/ethnic differences in asthma prevalence in our study is explained by factors related to income, area of residence, and level of education.

The relationship between age and bronchial responsiveness: evidence from a population survey

OBJECTIVES

Increased bronchial responsiveness is a feature of symptomatic asthma, and it predicts the onset of wheezing. We have investigated the relationship between bronchial responsiveness and age in a population sample with an age range of 45 to 86 years.

DESIGN

Cross-sectional population survey.

SETTING

Population of Central Manchester, UK.

PARTICIPANTS

An age-stratified random sample of white adults aged > or = 45 years old and living in Central Manchester. They were recruited from their primary care physician (general practitioner) lists. Patients with confusion and patients who were housebound were excluded.

MEASUREMENTS

Respondents to a mail questionnaire were invited to attend a methacholine bronchial challenge performed using the Newcastle dosimeter method. Respondents with ischemic heart disease or respondents taking oral steroids, beta-blockers, or anticholinergic medication were excluded.

RESULTS

Of the 783 subjects contacted, 92.3% of the subjects responded, and 508 subjects returned enough information for us to deduce their suitability for the bronchial challenge. Of the 395 suitable subjects, 247 subjects participated (62.5% of those invited; 31.5% of the study population), and 208 participants completed the bronchial challenge. Participants were slightly younger than nonparticipants, but they were otherwise representative of the population. Increased bronchial responsiveness (provocative dose of methacholine causing a 20% fall in FEV1 < or = 200 microg) was present in 71 (34.1%) participants. Stepwise multiple regression analysis showed weak, independent, positive associations between bronchial responsiveness and age, and between bronchial responsiveness and the total immunoglobulin E level. There was an independent negative relationship between bronchial responsiveness and the airways caliber (expressed as standardized residuals; R2 = 0.29).

CONCLUSIONS

We have found a high prevalence of increased bronchial responsiveness in this inner-city population of older adults. Bronchial responsiveness showed a weak independent positive association with age.

Racial differences in emergency department use persist despite allergist visits and prescriptions filled for antiinflammatory medications

BACKGROUND

African-American children use the emergency department (ED) for asthma care more than their Caucasian counterparts.

OBJECTIVE

We sought to compare ED utilization for asthma care by race, adjusting for prescriptions filled for antiinflammatory medications, type of index visit (specialist vs nonspecialist), and demographic variables.

METHODS

An index asthma visit was identified for a cohort of managed care enrollees aged 4 to 11 years. Information on asthma encounters and drug claims data was evaluated during a prospective observation period of 12 months.

RESULTS

African-American race was associated with one or more ED visits during the observation period (relative risk [RR] = 1.8, 95% CI = 1.3 to 2.5, p < 0.01). After adjusting for index visit type, prescriptions filled, and selected demographic variables, African-American race remained associated with post-index ED utilization (adjusted RR = 1.6, 95% CI = 1.0 to 2.4, p = 0.05). Additional findings included an inverse relationship between African-American race and antiinflammatory medications among children with nonspecialist index visits (RR = 0.5, 95% CI = 0.3 to 0.9, p = 0.02) and a positive relationship between African-American race and hospitalization after an ED visit for asthma care (RR = 10.2, 95% CI = 1.4 to 74.8, p < 0.01).

CONCLUSION

African-American children were more likely to use ED asthma care even after adjusting for the type of index visit, prescriptions filled for antiinflammatory medications, and selected demographic variables. Racial differences in ED utilization for asthma care could be caused by a higher prevalence of uncontrolled or undertreated disease among African-American children not receiving specialty care.

Respiratory symptoms and bronchial responsiveness in lifeguards exposed to nitrogen trichloride in indoor swimming pools

OBJECTIVES

To measure the levels of exposure to nitrogen trichloride (NCl3) in the atmosphere of indoor swimming pools and to examine how they relate to irritant and chronic respiratory symptoms, indices of pulmonary function, and bronchial hyperresponsiveness to methacholine in lifeguards working in the pools.

METHOD

334 lifeguards (256 men; 78 women) recruited from 46 public swimming pools (n = 228) and 17 leisure centre swimming pools (n = 106) were examined. Concentrations of NCl3 were measured with area samplers. Symptoms were assessed by questionnaire and methacholine bronchial challenge (MBC) test by an abbreviated method. Subjects were labelled MBC+ if forced expiratory volume in one second (FEV1) fell by > or = 20%. The linear dose-response slope was calculated as the percentage fall in FEV1 at the last dose divided by the total dose given.

RESULTS

1262 samples were taken in the 63 pools. Mean NCl3 concentrations were greater in leisure than in public pools. A significant concentration-response relation was found between irritant eye, nasal, and throat symptoms-but not chronic respiratory symptoms-and exposure concentrations. Among women, the prevalence of MBC+ was twice as great as in men. Overall, no relation was found between bronchial hyperresponsiveness and exposure.

CONCLUSIONS

The data show that lifeguards exposed to NCl3 in indoor swimming pools are at risk of developing irritant eye, nasal, and throat symptoms. Exposure to NCl3 does not seem to carry the risk of developing permanent bronchial hyperresponsiveness, but this association might have been influenced by self selection. The possibility that subjects exposed to NCl3 are at risk of developing transient bronchial hyperresponsiveness cannot be confidently ruled out.

Factors affecting oxygen saturation during methacholine challenge in a mixed population

Bronchial challenge with methacholine or histamine is associated with a reduction in arterial oxygen tension, which can be appreciable. In this study, oxygen saturation was monitored during methacholine challenge in subjects with and without respiratory disease, over a wide age range, in order to identify factors predicting a large fall in saturation during the challenge. Two hundred and twenty subjects aged 24-86 years were included, comprising 15 healthy adult volunteers, and 205 adults from a random sample of the local adult population taking part in a survey of bronchial responsiveness. Subjects with ischaemic heart disease or baseline FEV1 < 60% predicted were excluded. Methacholine challenge was performed by the Newcastle Dosimeter technique; oxygen saturation (SaO2) was monitored using a pulse oximeter and finger probe. Of the 220 subjects, 27% were current smokers and 39.5% were ex-smokers; 26% reported asthma or bronchitis. Mean baseline FEV1 was 100% predicted; mean baseline saturation was 97%. Mean fall in saturation was 3.2% (range 0-17.5%). Multiple regression analysis revealed that fall in saturation during methacholine challenge is related to baseline FEV1, baseline SaO2, log of total methacholine dose inhaled, and fall in FEV1 during challenge. Change in saturation was not related to subject age, smoking history, reported asthma or bronchitis, or the presence of respiratory symptoms. Methacholine challenge produces a significant fall in oxygen saturation, but this is not greater in subjects who are old or have low baseline saturation.

Impact of obstructive airways disease on quality of life in older adults

BACKGROUND

Obstructive airways disease adversely affects quality of life, although relationships between quality of life and lung function have been shown to be weak. The relationships between the results of a quality of life questionnaire, spirometric tests, and methacholine bronchial challenge were investigated in a population sample of middle aged and elderly people.

METHODS

A random population sample of the white population of Central Manchester, UK were contacted by post. Respondents were invited to undergo bronchial challenge with methacholine (Newcastle dosimeter method) and to complete the St George's Respiratory Questionnaire. This self-completed questionnaire quantifies quality of life as three component scores, with higher scores indicating greater impairment of quality of life.

RESULTS

Two hundred and twenty seven subjects aged 45-86 years completed the St George's Questionnaire and performed spirometric tests; 190 completed the methacholine challenge. All quality of life scores were higher in subjects with a forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) of < 65%, indicating impaired quality of life in subjects with airways obstruction. There was no relationship between quality of life and age. Multiple regression analysis showed independent relationships between quality of life scores and both baseline FEV1 and bronchial responsiveness. However, the amount of variation in quality of life attributable to variation in FEV1 or bronchial responsiveness was less than 10%. Subgroup analysis indicated that the quality of life score was independently associated with bronchial responsiveness and not FEV1 in subjects aged < 65 years, but with baseline FEV1 and not bronchial responsiveness in older subjects.

CONCLUSIONS

Obstructive airways disease significantly impairs quality of life in adults. The reduction in quality of life in these patients is related to both baseline pulmonary function and non-specific bronchial responsiveness. The impact of airways obstruction on quality of life does not decrease with advancing age.

Prevalence and treatment of chronic airways obstruction in adults over the age of 45

BACKGROUND

Chronic airways obstruction is common in adults and the elderly. To investigate the possibility that older adults with obstructive airways disease frequently do not receive appropriate treatment, the respiratory symptoms, medication use, and pulmonary function were studied in a random sample of white adults aged over 45 living in central Manchester, UK.

METHODS

A postal questionnaire survey was performed on 783 men and women aged 45 years and over selected from GP lists by random number tables. Subjects completing the questionnaire were invited to attend for pulmonary function testing and methacholine challenge (Newcastle dosimeter method).

RESULTS

The questionnaire response rate was 92.3% (723 subjects). The mean age of the population was 66.1 years and 57.2% were women; 29.2% were current smokers and 37.3% were ex-smokers. Asthma or bronchitis was reported by 30.0%. Two hundred and forty seven representative subjects attended for pulmonary function testing and spirometric evidence of chronic airways obstruction was found in 26.4%. Respiratory symptoms were reported by 76.6% of subjects with chronic airways obstruction; 55.0% had features which may predict potential improvement on treatment (increased non-specific bronchial responsiveness or significant bronchodilator reversibility). However, only 55.4% of subjects with airways obstruction had received a diagnosis of asthma or chronic bronchitis and only 36.9% were using inhaled bronchodilators or steroids.

CONCLUSIONS

Chronic airways obstruction is very common in adults in this inner city population, but is frequently overlooked. Most subjects with chronic airways obstruction are not receiving appropriate treatment.

Passive smoking in children. Racial differences in systemic exposure to cotinine by hair and urine analysis

Passive smoking has been shown to adversely affect the health of infants and children. Black children and adults appear to be more susceptible to a variety of tobacco smoke health hazards for unknown reason. The objectives of this study were as follows: (1) to correlate the number of cigarettes reported to have been smoked by parents with urine and hair concentrations of cotinine in children; and (2) to identify race differences in systemic exposure to cotinine in children. This was an observational study in a consulting pediatric office on 169 nonsmoking children between 2 and 18 years of age, not actively smoking. The outcome measures of interest were urinary cotinine concentrations corrected for milligram of creatinine and hair concentration of cotinine (per milligram of hair). There were significant correlations between the number of cigarettes the child was exposed to and urinary cotinine (r = 0.68, p = 0.0001) or hair cotinine concentrations (r = 0.19, p = 0.02), and between urinary and hair cotinine (r = 0.3, p = 0.0005). In this cohort, parents of black children (n = 21) tended to smoke less (6.6 +/- 3/d, mean +/- SEM) than white parents (n = 97) (12 +/- 1.8, mean +/- SEM) (p = 0.2). Despite being exposed to less cigarettes, black children had higher hair concentrations of cotinine than white children (0.89 +/- 0.25 ng/mg vs 0.48 +/- 0.05 ng/mg; p = 0.05). The ratio hair/urine concentrations of cotinine was twofold higher in black children (0.035 +/- 0.01 vs 0.019 +/- 0.002; p = 0.004). White children with dark hair did not differ significantly from white children with fair hair in any of these indexes. The amount of urinary cotinine per milligram of creatinine caused by 1 cigarette per day was twofold higher in black children (14.7 +/- 5.2 ng/mg of creatinine) than in white children (6.3 +/- 1.2 ng/mg of creatinine) (p = 0.02). These data suggest that black children handle cigarette smoke differently from white children and that black children have higher systemic exposure to this constituent of cigarette smoke.