malabsorption in infants and children.pdf

Archives of Disease in Childhood, 1979, 54, 436-440 Breath hydrogen test for detecting lactose malabsorption in infants and children Prevalence of lactose malabsorption in Japanese children and adults OSAMU NOSE, YOSHIHIKO IIDA, HIROSHI KAI, TOKUZO HARADA, MINORU OGAWA, AND HYAKUJI YABUUCHI Department ofPaediatrics, University of Osaka School of Medicine SUMMARY The breath hydrogen test (BHT) was adapted for use in young infants and children. The diagnostic criterion of sugar malabsorption in the BHT was determined by oral administration of 0 5 g/kg of unabsorbable sugar (lactulose) to 21 healthy infants and children. A maximum increase in breath hydrogen 0 05 ml/min per m2 was observed in all subjects. A good correlation between results by the BHT and by the ordinary lactose tolerance test was obtained after oral administration of 2 g/kg lactose to 21 healthy infants and children, 2 congenital lactase-deficient infants, and 7 adults. Using this test, 80 healthy Japanese infants and children (aged between one month and 15 years) and 18 adults were examined for lactose malabsorption after a dose of 1 g/kg lactose. All infants and children under 2-years old absorbed lactose completely. The incidence of lactose malabsorption was 30 % in 3-year, 36 % in 4-year, 58 % in 5-year, and 86% in 6-year-old children, 85 % in school- children, and 89 % in adults. Thus the incidence of lactase deficiency gradually increases with age from 3 years, and about 90 % of all normal Japanese adults are lactase-deficient. At birth, humans have abundant lactase activity in the small intestine but, in most ethnic groups, there is a pronounced decrease in lactase activity during early childhood (Huang and Gayless, 1967; Johnson et al., 1977). The definitive diagnosis of lactase deficiency requires the collection of biopsy specimens from the small intestine and demon- stration of decreased lactase activity therein. Attempts have therefore been made to develop indirect methods for detecting lac