52 Risk Factors Associated to Wheezing in Mexican Children. A Multicentric Isaac-based Survey Study

BACKGROUND: Asthma affects around 300 million people around the world, and is expected to increase 100 million more in the next 15 years. Multiple risk factors had been associated with its prevalence, though little is known about the regional variations of these risk factors. OBJECTIVE: Identify the main risk factors associated to the presence of wheezing in the last 12 months in Mexican children aged 6 to 7 years old. METHODS: Multicentric, cross-sectional survey. The standardized Spanish-version ISAAC questionnaire was applied to tutors of children aged 6 to 7 years old in 8 cities of the Mexican Republic. Sample was randomly selected through public and private schools of each city, and a sample of 3000 children per center was advisable. Risk analysis was made through multivariate logistical regression, central tendency and dispersion measures were obtained with respective 95% confidence intervals. RESULTS: Nine centers of 8 cities participated, data of 24,504 questionnaires were analyzed with an answer rate of 90.7%. Grouping the 9 participating centers, a prevalence of 8.4% (95% CI, 8.1-8.8%) for wheezing in the last 12 months was found, with the next distribution: Monterrey 8.6% (95% CI, 7.6-9.6%), Mexicali 9.6% (95% CI, 8.4-10.7%), Ciudad Victoria 8.6% (95% CI, 7.5-9.7%), Villahermosa 10.2% (95% CI, 9.1-11.4%), Northern Distrito Federal 7.3% (95% CI, 6.5-8.2%), Southeast Distrito Federal 9.9% (95% CI, 8.5-11.3%), Toluca 5.9% (95% CI, 5.1-6.7%), Tijuana 8.2% (95% CI, 7.2-9.2%), Veracruz 9.7% (95% CI, 8.4-10.9%). Identified risk factors for the presence of wheezing in the last 12 months were: nasal symptoms accompanied with ocular symptoms (itching and tearing) in the last 12 months, OR 2.31 (95% CI, 2.01-2.66; P ≤ 0.0001). Nasal symptoms (blocked nose, runny nose, and/or itching) in the last 12 months, OR 2.2 (95% CI, 1.66-2.92; P ≤ 0.0001). Hay fever diagnosis by medical staff OR 2.02 (95% CI, 1.72-2.37; P ≤ 0.0001). Atopic dermatitis symptoms (classic morphology and distribution) in the last 12 months, OR 1.65 (95% CI, 1.39-1.96; P ≤ 0.0001). Use of antibiotics in the first 12 months of life, OR 1.68 (95% CI, 1.48-1.90; P ≤ 0.0001). Use of acetaminophen in the last 12 months, OR 1.49 (95% CI, 1.35-1.65; P ≤ 0.0001). CONCLUSIONS: The presence of allergic rhinoconjuntivitis symptoms in the last 12 months doubles the risk for the presence of wheezing in Mexican children.