Reviews of pediatric research

November 1, 2007

Prebiotic supplements * Food ads for kids * Viral bronchiolitis * ... and more

• Supplementation affects pubertal body mass index

A recent analysis suggests that avoidance of low-calcium intake and supplementation with a prebiotic may play roles in maintaining appropriate rates of increase in body mass index (BMI) during puberty. (A prebiotic is a food substance that promotes intestinal growth of potentially beneficial bacteria.)

Investigators assigned about 100 adolescents from 9 to 13 years of age to one of two supplement groups: One group received 8 g/day of a prebiotic (a mixture of oligofructose and long-chain inulin) and the control group 8 g/day of maltodextrin. Subjects mixed the carbohydrate supplement with calcium-fortified orange juice, for breakfast.

The benefit of supplementation with a prebiotic for maintaining an appropriate BMI increase during pubertal growth was maximized in those with high calcium intakes. Specifically, in subjects with calcium intakes of 700 mg/d or more, prebiotic supplementation was associated with a relative change in BMI that was 0.82 kg/m2 less than in controls. Those with the higher calcium intake also demonstrated smaller changes in BMI Z-score (a difference of 0.2), fat mass (1.3 kg), and body weight (2.0 kg) compared with subjects who did not receive the prebiotic. These differences tended to be maintained one year after supplementation was stopped. Use of the prebiotic had no significant effect on body composition outcomes in those whose calcium intake was less than 700 mg/d (Abrams SA et al: J Pediatrics 2007;151:293).

Commentary:

It appears that ITF, the combination of oligofructose and long-chain inulin used in the study, may increase calcium absorption and decrease or regulate appetite. The authors caution that this data is preliminary, and requires further study. Imagine the impact if ITF could be included in school lunches of middle-schoolers who are at risk of overweight.

• Nebulized hypertonic saline shortens hospitalization for viral bronchiolitis

Investigators compared the length of stay of two groups of infants up to age 18 months who were admitted to the hospital for treatment of moderately severe viral bronchiolitis. The two groups comprised about 100 babies with a mean age of 4.7 months. One group was treated with 4 mL of nebulized 3% hypertonic saline (treatment group) and the other with 0.9% normal saline (control group), in addition to routine therapy. The two study solutions were administered every two hours for three doses, followed by every four hours for five doses, then every six hours until discharge. The study was conducted at three regional tertiary care hospitals-one in the United Arab Emirates and two Canadian sites-during three winter bronchiolitis seasons. More than half the study infants (69%) tested positive for respiratory syncytial virus (RSV).

Length of stay of infants in the hypertonic saline group was reduced by 26% compared with the control group: 2.6 days vs. 3.5 days. A trend was seen toward greater improvement in infants under age 6 months, but this difference did not attain statistical significance. All study participants tolerated the therapy without apparent adverse effects (Kuzik BA et al: J Pediatr 2007;151:266).

Commentary:

Many study participants also received steroids and nebulized bronchodilators, treatments for which little supporting evidence exists. An accompanying editorial calls for a repeat trial, restricted to children younger than six months, that excludes use of steroids and compares 0.9% vs. 3.0% saline nebs with and without albuterol. I hope this study is done soon and supports these early findings. It would be good to have more to offer as we head into RSV season.