title: Effects of age on lactose malabsorption in Oklahoma Native Americans as determined by breath H2 analysis.
abstract: Breath H2 excretion was used to determine lactose malabsorption in 30 health females and 30 healthy males between the ages of 3 and 64 yr who were at least 7/8 Native American. The test meal consisted of 5 ml reconstituted nonfat dry milk (0.25 g lactose) per kg of body weight. On the basis of breath H2 tests in 15 control subjects with normal oral lactose tolerance tests, a response factor of 20 ppm was selected as the upper limit for lactose absorbers. Of the 60 subjects in the study group, 36 (60%) were classified as lactose malabsorbers since they had a response factor of 20 ppm or greater of breath H2. Only 3 of 20 children (15%) who were under the age of 12 yr were nondigesters of the small lactose dose used in this study. Approximately 82 percent (82.5%) of subjects who were 13 yr and older were lactose malabsorbers. Adolescence appears to be the period in which malabsorption of lactose becomes evident in Native North Americans.
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging; D001944:Breath Tests; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006859:Hydrogen / Q000032:analysis*; D007198:Indians, North American; D007787:Lactose Intolerance / Q000175:diagnosis / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009825:Oklahoma
chemical_list: D006859:Hydrogen