Longitudinal Lung Function Growth of Mexican Children Compared with International Studies

Abstract

IntroductionOur aim was to compare the longitudinal lung function growth of Mexican children and adolescents with the collated spirometric reference proposed for international use and with that of Mexican-Americans from the National Health State Examination Survey III (NHANES) III study.Materials and MethodsA cohort of Mexican children in third year of primary school was followed with spirometry twice a year through secondary school. Multilevel mixed-effects lineal models separated by gender were fit for the spirometric variables of 2,641 respiratory-healthy Mexican children expressed as Z-scores of tested reference equations. Impact of adjustment by sitting height on differences with Mexican-American children was observed in a subsample of 1,987 children.ResultsAt same gender, age, and height, Mexican children had increasingly higher forced expiratory volume in 1 s (FEV1) and Forced vital capacity (FVC) than the children from the collated reference study (mean Z-score, 0.68 for FEV1 and 0.51 for FVC) and than Mexican-American children (Z-score, 0.23 for FEV1 and 0.21 for FVC) respectively. Differences with Mexican-Americans were not reduced by adjusting by sitting height.ConclusionsFor reasons that remain unclear, the gender-, age-, and height-adjusted lung function of children from Mexico City is higher than that reported by several international studies.

Lung function in woodsmoke-exposed Guatemalan children following a chimney stove intervention

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Inspiratory Capacity and Vital Capacity of Healthy Subjects 9–81 Years of Age at Moderate-High Altitude

“…Second, this was a crosssectional study, which implies that many birth cohorts were included in our study and results often differed from those obtained from longitudinal equations. 42 Third, our population was not obtained by a sampling method representative of the population; however, the participants were more numerous than in previous studies and included a wide age range, which represented a considerable advantage.…”

Lung Function in Rural Guatemalan Women Before and After a Chimney Stove Intervention to Reduce Wood Smoke Exposure

“…Similar overestimations in percent predicted values for lung function have previously been observed in children from Mexico City using the NHANES prediction. 25 Th e use of diff erent spirometers during RESPIRE and the CRECER study complicates study interpretation. Although a correction factor for spirometer type was used, this could contribute to measurement error.…”