"We found a significant reduction in the occurrence of AOM and, consequently, in prescriptions of antimicrobials among children at day care centers who regularly received xylitol syrup or chewing gum," said Matti Uhari, MD, from the University of Oulu here. "All forms of xylitol preparations were effective in decreasing the number of days on antimicrobials; however, xylitol given in a lozenge did not appear to be effective enough to prevent the development of AOM."
So, Uhari and his colleagues conducted a randomized, controlled study in which children who were given xylitol syrup, xylitol chewing gum and xylitol lozenges were compared with control subjects who received low doses of xylitol.
The children who participated in the study were recruited from day care centers in the city of Oulu between September and December 1996. Parents provided a history of ear infections and risk factors for AOM. "Before the trial began, tympanometry was performed on all children, and their ear status was recorded. Those with abnormal tympanography findings were examined with pneumatic otoscopy. Middle ear effusions were treated, and effusion had to be cleared before the child was entered into the study," he said.
The children who were too young to chew gum were randomized to receive either 5 mL of control syrup (20g/L of xylitol) or 5 mL of xylitol syrup (400g/L of xylitol) five times per day after a meal. "The control syrup was sweetened with xylitol to avoid possible harmful effect of using sucrose to sweeten the syrup. However, the dose was so low that there were no preventive effect to be expected on otitis media," Uhari said.
A syringe was used to administer the syrups in several small doses to prolong the time xylitol stayed in the mouth.
Children who were able to chew gum were randomized to receive either a control chewing gum sweetened with sucrose and xylitol or xylitol chewing gum sweetened with xylitol only or lozenges sweetened with xylitol and maltitol. Two pieces of gum or three lozenges were given five times a day after a meal.
"The children chewed the gum and the lozenges for at least five minutes or as long as they tasted sweet. In the control chewing gum group, the daily xylitol dose was 0.5 g, and in the xylitol chewing gum group, the daily xylitol dose was 8.4 g. The daily xylitol dose for children receiving lozenges was 10 g," he said. The parents monitored compliance.
"A total of 857 children were screened with tympanometry and were designated to receive chewing gum, lozenge or syrup on the basis of their ability to chew gum. Of the children receiving syrup, 165 were randomized to receive control syrup, and 159 were randomized to receive xylitol syrup. Of those who received syrups, 47 did not complete the trial. Of the children receiving gum, 178 were randomized to receive control chewing gum, 179 to receive xylitol chewing gum and 176 to receive lozenges," he explained. "Altogether, 46 children dropped out, twice as many in the lozenge group as in the chewing gum groups. The number of forgotten doses, approximately 10% of all dosages, was comparable in each treatment group."
Children receiving xylitol syrup had 12.2 episodes of respiratory infection per person years at risk, while children receiving lozenges had 10 episodes. Differences in the treatment groups were not significant.
Sixty-eight of the children receiving control syrup and 46 of the children receiving xylitol syrup had at least one episode of AOM. "The difference was statistically significant and implied a 30% decrease on receiving xylitol. AOM episodes totaled 114 in the control syrup group and 69 in the xylitol syrup group, which was a significant difference," he said.
Forty-nine of the children receiving control chewing gum, 29 of the children receiving xylitol gum and 39 of the children receiving lozenges had at least one episode of AOM. "This difference was statistically significant and implied a 40% decrease. The occurrence of AOM was lower in the lozenge group than in the control chewing gum group, but the difference was not statistically significant," he added.
The total number of AOM episodes in the control chewing gum group was 72. There were 44 total episodes in the xylitol chewing gum group and 52 in the lozenge group. The difference between the chewing gum groups was significant, but the difference between the control chewing gum group and the lozenge group was not.