Effects of growth hormone and nutritional therapy in boys with constitutional growth delay: a randomized controlled trial

Abstract

Objective: To examine whether supplemental nutrition augments the anabolic actions of growth hormone (GH) in boys with constitutional delay of growth and maturation (CDGM).

Study design: We conducted a randomized, controlled trial at an outpatient clinical research center. Subjects were 20 prepubertal boys (age, 9.3 ± 1.3 years) with CDGM (height standard deviation score, -2.0 ± 0.5; bone age delay, 1.8 ± 0.8 years; body mass index standard deviation score, -1.2 ± 1.0; peak stimulated GH, 15.7 ± 7.7 ng/mL), who were randomized (n = 10/group) to 6 months observation or daily nutritional supplementation, followed by additional daily GH therapy in all for another 12 months. t tests and repeated measures analyses of variance compared energy intake, total energy expenditure (TEE), growth, hormones, and nutrition markers.

Results: Energy intake was increased at 6 months within the nutrition group (P = .04), but not the observation group, and TEE was not statistically different within either group at 6 months. Addition of 6 months GH resulted in higher energy intake and TEE in the GH/nutrition group at 12 months (P < .01), but not in the GH group versus baseline. Height, weight, lean body mass, hormones, and nutrition markers increased comparably in both groups throughout 18 months.

Conclusion: Boys with CDGM use energy at an accelerated rate, an imbalance not overcome with added nutrition. GH therapy increases growth comparably with or without added nutrition in these patients.

Trial registration: ClinicalTrials.gov NCT00102258.

Copyright © 2011 Mosby, Inc. All rights reserved.

Figures

Figure 1

Energy intake and total energy expenditure (TEE) adjusted for lean body mass (LBM). Mean ± SEM shown. P-values are shown for comparisons with baseline within each group. White bars = Observation group. Black bars = Nutrition group. (a) Liquid nutritional supplement was administered to the Nutrition group after the baseline visit and continued throughout the study. GH was added to both groups starting at 6 months. Energy intake adjusted for LBM increased within the Nutrition group in response to liquid nutrition supplementation alone and in combination with growth hormone therapy. P-values between groups NS. (b) TEE was assessed by the doubly-labeled water method and adjusted for lean body mass as assessed by DEXA. TEE adjusted for LBM trended higher in the Nutrition group in response to 6 months of liquid nutritional supplement, and was significantly higher after 6 months of GH combined with liquid nutritional supplement.

Figure 2

Changes in growth parameters. Comparison between Observation and Nutrition groups for height-SDS (a) and weight-SDS (b). Mean ± SEM shown. White bars = Observation group. Black bars = Nutrition group. Symbols next to bars represent p-values for comparisons with baseline within each group (* = p