[Wheezing phenotypes from birth to adolescence: a cohort study in Pelotas, Brazil, 1993-2004].
OBJECTIVE
To study the prevalence of wheezing patterns and their associations with independent variables.


METHODS
Cohort study of live births in 1993 in Pelotas, Brazil. A systematic subsample (20%) of the original cohort was evaluated at 6 months, 12 months and 4 years. At 10-12 years, 87.5% of the original cohort was contacted. Wheezing was categorized: transient, wheezing at 4 years but not at 10-12; persistent, wheezing at all evaluations; late-onset, wheezing at 10-12 years. Independent variables were analyzed: gender; skin color; family income; smoking/asthma during pregnancy; breastfeeding; respiratory infection/diarrhea (during the 1st year); family members with asthma/allergy (at 4 years and at 10-12); physician-diagnosed rhinitis/eczema (at 10-12 years).


RESULTS
The subsample comprised 897 adolescents. Wheezing patterns were expressed as prevalence (95% CI): transient, 43.9% (40.7-47.2); persistent, 6.4% (4.8-8.0); and late-onset, 3.3% (2.2-4.5). The transient pattern was more common in children from low-income families, children breastfed for less time, children with a history of respiratory infections (during the 1st year) and children with asthma in the family (at 4 years). The persistent pattern was almost twice as common in males, in children whose mothers had asthma during pregnancy, in children with respiratory infections (during the 1st year) and in children with asthma in the family (at 4 and 10-12 years). The late-onset pattern was more prevalent among those with asthma in the family (at 10-12 years) and those diagnosed with rhinitis (at 10-12 years), being less prevalent among those reporting respiratory infections (during the 1st year) and those diagnosed with eczema (at 10-12 years).


CONCLUSIONS
Knowledge of the associations of wheezing patterns allows us to adopt preventive and therapeutic measures.
Muiño
Adriana
A
Hospital Maciel, Montevideo, Uruguai.
Menezes
Ana Maria Baptista
AM
Reichert
Felipe Fossati
FF
Duquia
Rodrigo Pereira
RP
Chatkin
Moema
M
D000293:Adolescent; D017677:Age Distribution; D001249:Asthma / Q000150:complications / Q000453:epidemiology*; D001938:Brazil / Q000453:epidemiology; D001942:Breast Feeding / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004485:Eczema / Q000150:complications / Q000453:epidemiology; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010641:Phenotype; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D015995:Prevalence; D012135:Respiratory Sounds / Q000145:classification* / Q000209:etiology; D012220:Rhinitis / Q000150:complications / Q000453:epidemiology; D012737:Sex Factors; D012959:Socioeconomic Factors