One-hour blood-xylose in cystic fibrosis.

One-hour blood-xylose concentrations after an oral xylose load were measured in children with cystic fibrosis (CF) and healthy controls. The mean of the 1-hour blood-xylose values was significantly increased in the group with CF. The finding confirms an earlier observation by Rolles et al. (1973). Its significance is not at present understood but it suggests that small intestinal function should be further investigated in CF.