Ethnic differences in intestinal disaccharidase values in children in Finland

Background: Intestinal disaccharidase activities tend to be low in villous atrophy, but there are only a few reports of enzyme activities in children with normal villous architecture. Methods: in the current study the data were reviewed on disaccharidase acti vities in duodenal biopsy specimens of normal villous structure in 223 chil dren undergoing upper gastrointestinal endoscopy in 1997 and 1998. The ance stry was Finnish in 188 children (median age 8.0 years; range, 0.2-18 years ), African in 27 children (median age 5.0 years; range, 1-13 years), and ot her in eight children. Results: The mean activities of lactase, sucrase, and maltase were signific antly higher in Finnish children than in children of African origin (P < 0. 0001, P < 0.002, and P < 0.02, respectively). Lactase activity decreased wi th increasing age (P < 0.001), but age had no significant effect on maltase and sucrase activities. Among Finnish children, 31% (59/188) had lactase a ctivity below the established reference range of 20 units (units are microm oles of substrate hydrolyzed per minute at 37 degrees C per gram of protein ) and one child had a probable sucrase-isomaltase deficiency. When these 60 children with low enzyme activities were excluded, the geometric means wer e lactase, 35.7 units (95% confidence interval [CI], 32.8-38.6 units); malt ase, 241 units (95% CI, 225-258 units); and sucrase, 57.5 units (95% CI, 53 .5-61.6 units). Among the children of African origin, lactase activity was decreased in 67% (18/27), All three enzyme activities were decreased in par allel more often among the African children (8/27) than among the Finnish c hildren (9/188; P < 0.002). Conclusions: Ethnicity has a strong effect on disaccharidase values in chil dren with normal villous structure. African children have lower activities of lactase, sucrase, and maltase in duodenal specimens than do children of Finnish origin. (C) 2000 Lippincott Williams & Wilkins, Inc.