title: Variance in fasting breath hydrogen concentrations in Guatemalan preschool children.
abstract: The concentration of hydrogen (H2) in expired air after an overnight fast is receiving interest as a diagnostic indicator in itself. We analyzed 319 fasting samples collected from 90 healthy, well-nourished preschool children aged 29-72 months in two institutional settings in Guatemala City. The overall range of fasting H2 concentration was 0-40 ppm, with an arithmetic mean of 4.4 +/- 5.4 ppm (+/- SD) and a geometric mean of 3.2 ppm. No differences between boys and girls was found, but there was a progressive increase in the mean levels and an increase in the number of samples with H2 concentrations greater than 10 ppm with decreasing chronological age. One child with three of six samples having H2 concentrations greater than 40 ppm was found to have intestinal multiple parasitism and hence was excluded from the sample. As compared with a previous report from the United States of fasting breath H2 concentrations in older children, the mean and distribution of values for Guatemalan preschoolers is identical. Intraindividual coefficients of variation in 48 children studied on four occasions had a mean of 62 +/- 31% (range 0-143%).
mesh_terms: D001944:Breath Tests; D002648:Child; D002675:Child, Preschool; D005215:Fasting; D005260:Female; D006166:Guatemala; D006801:Humans; D006859:Hydrogen / Q000032:analysis*; D008297:Male
chemical_list: D006859:Hydrogen