Urban residence is associated with bronchial hyperresponsiveness in Italian general population samples.
BACKGROUND
The role of different risk factors for bronchial hyperresponsiveness (BHR), such as gender, atopy, IgE, and environmental factors (smoking, occupational exposure, infections), has been described. Indoor and outdoor pollution play an important role too, but few studies have analyzed the association with BHR. The aim of this study was to assess the effect of urban residence on BHR.


METHODS
We studied two general population samples enrolled in two cross-sectional epidemiological studies performed in Northern Italy (Po Delta, rural area) and Central Italy (Pisa, urban area). We analyzed 2,760 subjects (age range, 8 to 74 years). We performed analysis of variance and logistic regression analysis using ln slope of the dose-response curve of the methacholine challenge test as dependent variable, and sex, age, smoking habits, respiratory symptoms, skin-prick test results, IgE value, residence, and airway caliber as independent variables.


RESULTS
The mean value of ln slope of the dose-response curve adjusted for initial airways caliber (by baseline FEV(1) percentage of predicted value) was significantly higher in female subjects, in smokers, in subjects with respiratory symptoms, in younger and older ages, in subjects with high values of IgE, and in subjects with positive skin-prick test results. After controlling for the independent effects of all these variables, living in urban area was an independent risk factor for having BHR (odds ratio, 1.41; 95% confidence interval, 1.13 to 1.76).


CONCLUSIONS
Living in urban area is a risk factor for increased bronchial responsiveness.
Maio
Sara
S
Pulmonary Environmental Epidemiology Unit, Institute of Clinical Physiology, National Research Council, Pisa, Italy.
Baldacci
Sandra
S
Pulmonary Environmental Epidemiology Unit, Institute of Clinical Physiology, National Research Council, Pisa, Italy.
Carrozzi
Laura
L
Cardiopulmonary Department, University and Hospital, Pisa, Italy.
Polverino
Eva
E
Pulmonary Environmental Epidemiology Unit, Institute of Clinical Physiology, National Research Council, Pisa, Italy.
Angino
Anna
A
Pulmonary Environmental Epidemiology Unit, Institute of Clinical Physiology, National Research Council, Pisa, Italy.
Pistelli
Francesco
F
Cardiopulmonary Department, University and Hospital, Pisa, Italy.
Di Pede
Francesco
F
Pulmonary Environmental Epidemiology Unit, Institute of Clinical Physiology, National Research Council, Pisa, Italy.
Simoni
Marzia
M
Pulmonary Environmental Epidemiology Unit, Institute of Clinical Physiology, National Research Council, Pisa, Italy.
Sherrill
Duane
D
College of Public Health, University of Tucson, Tucson, AZ.
Viegi
Giovanni
G
Institute of Biomedicine and Molecular Immunology, National Research Council, Palermo, Italy. Electronic address: viegig@ifc.cnr.it.
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000704:Analysis of Variance; D016535:Bronchial Hyperreactivity / Q000175:diagnosis* / Q000453:epidemiology* / Q000209:etiology; D001985:Bronchial Provocation Tests; D002648:Child; D003430:Cross-Sectional Studies; D004787:Environmental Pollution / Q000009:adverse effects*; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000150:complications; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged; D016017:Odds Ratio; D011336:Probability; D012129:Respiratory Function Tests; D012307:Risk Factors; D012494:Sampling Studies; D012720:Severity of Illness Index; D017678:Sex Distribution; D012882:Skin Tests; D012907:Smoking / Q000009:adverse effects; D014505:Urban Population / Q000706:statistics & numerical data*; D055815:Young Adult
D016210:Methacholine Chloride