Role of Nutrition and Hormones in Boys With Disordered Growth

This study will determine whether adding more calories to the diet helps boys with growth problems grow better while being treated with Nutropin, a growth hormone that is used to help children grow taller. The Food and Drug Administration has approved Nutropin for use in children who are very short. This study will examine whether giving nutritional supplements in addition to Nutropin can help children grow better than with Nutropin alone. Boys between 7 and 10 years of age who are very short and below average in weight, but are otherwise healthy may be eligible for this study. Candidates must qualify for Nutropin treatments to boost their growth. Boys will be recruited for the study from the Nemours Children's Clinic in Jacksonville, FL, and from the National Institutes of Health in Bethesda, MD. Participants are randomly assigned to one of two treatment groups. One group is observed for 6 months and then receives a Nutropin injection every day for 12 months. The second group drinks 8 ounces of a high-calorie beverage called Pediasure every day for 6 months and then receives Nutropin plus Pediasure every day for 12 months. In addition to treatment, participants undergo the following tests and procedures at the schedule indicated: Baseline, 3, 6, 9, 12, 15 and 18 months * Clinical examination * Height measurement * Body composition assessment: Skin-fold thickness calipers are used in four places on the body to estimate body fat * Bioelectric impedance: A small amount of electrical current is used to calculate the percentage of body fat. Baseline, 6, 12, and 18 months * Blood tests * Bone age x-ray: x-ray of the left hand to measure growth potential * DEXA (dual energy x-ray absorptiometry) scan: x-ray scan to measure body fat, muscle, and bone mineral content. The subject lies on a flat table during the scan. Baseline, 6, and 12 months * Record of dietary intake: Parents are asked to write down everything the child eats and drinks for 3 days. Using this recor