[Tolerance tests in the diagnosis of mono- and disaccharides malabsorption in children]. / Testes de tolerância no diagnóstico da mal-absorção de mono e dissacarídeos em crianças.

The carbohydrate tolerance test is a very common method employed in the diagnosis of carbohydrate malabsorption, despite the possibility of some pitfalls in its interpretation. There are some factors, namely, the omission of the 15 minute blood sample, slow gastric emptying, malnutrition and venous blood sampling, that can condition the characterization of false positive intolerance. We studied 177 curves performed in 110 children during a 4 year period, and we observed that: a) the highest peak level occurred at 15 minutes in 57,3% of the tolerance tests; b) if the 15 minutes sample was not obtained it resulted in 28% of false positive intolerance; c) regarding the nutritional status malnourished children had more frequently a delayed peak level, been 17% at 15 minutes and 67% at 30 minutes. Misinterpretation of the carbohydrate tolerance test can be minimized taking into account these known factors that induced the diagnosis of false positive intolerance.