13C-Labeled-Starch Breath Test in Congenital Sucrase-isomaltase Deficiency.

Abstract

BACKGROUND AND HYPOTHESES:

Human starch digestion is a multienzyme process involving 6 different enzymes: salivary and pancreatic α-amylase; sucrase and isomaltase (from sucrose-isomaltase [SI]), and maltase and glucoamylase (from maltase-glucoamylase [MGAM]). Together these enzymes cleave starch to smaller molecules ultimately resulting in the absorbable monosaccharide glucose. Approximately 80% of all mucosal maltase activity is accounted for by SI and the reminder by MGAM. Clinical studies suggest that starch may be poorly digested in those with congenital sucrase-isomaltase deficiency (CSID). Poor starch digestion occurs in individuals with CSID and can be documented using a noninvasive C-breath test (BT).

METHODS:

C-Labled starch was used as a test BT substrate in children with CSID. Sucrase deficiency was previously documented in study subjects by both duodenal biopsy enzyme assays and C-sucrose BT. Breath CO2 was quantitated at intervals before and after serial C-substrate loads (glucose followed 75 minutes later by starch). Variations in metabolism were normalized against C-glucose BT (coefficient of glucose absorption). Control subjects consisted of healthy family members and a group of children with functional abdominal pain with biopsy-proven sucrase sufficiency.

RESULTS:

Children with CSID had a significant reduction of C-starch digestion mirroring that of their duodenal sucrase and maltase activity and C-sucrase BT.

CONCLUSIONS:

In children with CSID, starch digestion may be impaired. In children with CSID, starch digestion correlates well with measures of sucrase activity.

• Authors: Claudia C Robayo-Torres, Marisela Diaz-Sotomayor, Bruce R Hamaker, Susan S Baker, Bruno P Chumpitazi, Antone R Opekun, Buford L Nichols
• Journal: Journal of pediatric gastroenterology and nutrition (J Pediatr Gastroenterol Nutr) Vol. 66 Suppl 3 Pg. S61-S64 (Jun 2018) ISSN: 1536-4801 [Electronic] United States
• PMID: 29762381 (Publication Type: Journal Article)

Chemical References

• Carbon Isotopes
• Starch
• Sucrase-Isomaltase Complex
• Carbon-13

Topics

• Adolescent
• Breath Tests (methods)
• Carbohydrate Metabolism, Inborn Errors (diagnosis)
• Carbon Isotopes (metabolism)
• Case-Control Studies
• Child
• Child, Preschool
• Digestion (physiology)
• Duodenum (enzymology)
• Female
• Humans
• Infant
• Male
• Starch (metabolism)
• Sucrase-Isomaltase Complex (analysis, deficiency)