Impact of air pollution on pulmonary function and respiratory symptoms in children. Longitudinal repeated-measures study.

BACKGROUND: Salamanca, Mexico occupied fourth place nationally in contaminating emissions. The aim of the study was to determine the impact of air pollution on the frequency of pulmonary function alterations and respiratory symptoms in school-age children in a longitudinal repeated-measures study. METHODS: We recruited a cohort of 464 children from 6 to 14 years of age, from two schools differing in distance from the major stationary air pollution sources. Spirometry, respiratory symptoms and air pollutants (O3, SO2, NO, NO2, NOx, PM10,) were obtained for each season. Mixed models for continuous variables and multilevel logistic regression for respiratory symptoms were fitted taking into account seasonal variations in health effects according to air pollution levels. RESULTS: Abnormalities in lung function and frequency of respiratory symptoms were higher in the school closer to major stationary air pollution sources than in the distant school. However, in winter differences on health disappeared. The principal alteration in lung function was the obstructive type, which frequency was greater in those students with greater exposure (10.4% vs. 5.3%; OR = 1.95, 95% CI 1.0-3.7), followed by the mixed pattern also more frequent in the same students (4.1% vs. 0.9%; OR = 4.69, 95% CI, 1.0-21.1). PM10 levels were the most consistent factor with a negative relationship with FVC, FEV1 and PEF but with a positive relationship with FEV1/FVC coefficient according to its change per 3-month period. CONCLUSIONS: Students from the school closer to major stationary air pollution sources had in general more respiratory symptoms than those from the distant school. However, in winter air pollution was generalized in this city and differences in health disappeared. PM10 levels were the most consistent factor related to pulmonary function according, to its change per 3-month period.

Quality of life in obese pregnant women: a longitudinal study.

OBJECTIVE: The purpose of this study was to assess the contribution of obesity on quality of a woman's life during pregnancy. STUDY DESIGN: At the Hospital of Gynecology and Obstetrics in León, Mexico, we followed-up 220 pregnant women (110 obese and 110 nonobese) who completed the 12-item short-form health survey at the beginning and during the third trimester of pregnancy. RESULTS: The mental component score was lower in obese than in nonobese women at the beginning of gestation and at the third trimester but increased in the entire group during pregnancy. The physical component score (PCS) decreased during pregnancy and was lower in obese than in nonobese pregnant women (43.5 vs 47.2; P = .01) at the third trimester. Baseline body mass index, weight gain, and complications during pregnancy were associated negatively with PCS (R2=0.11; P < .001 for the model). CONCLUSION: Baseline body mass index, weight gain, and complications during gestation are associated negatively with PCS of quality of life.

Prediabetes in rural and urban children in 3 states in Mexico.

The authors studied the frequency, distribution, and factors associated with prediabetes (fasting glucose, 100-125 mg/dL) in rural and urban children from San Luis Potosí, León, and Querétaro in central Mexico. Family history, somatometry, and levels of fasting insulin, glucose, and lipids were collected in 1238 children 6 to 13 years of age. The authors found no cases of type 2 diabetes and a 5.7% frequency of prediabetes. The group with prediabetes had higher homeostasis model assessment of insulin resistance scores and total cholesterol and high-density lipoprotein cholesterol levels. Prediabetes was more frequent in León, with similar distribution in rural and urban children. The frequency of insulin resistance was 24.1%, with higher figures in urban groups and in San Luis Potosí. In multivariate analysis, prediabetes was associated with insulin resistance and residence in León. The authors concluded that in central Mexico the frequency of prediabetes is significant, and it is associated with insulin resistance and a geographic location, but not with obesity or urban vs rural dwelling.