Long-term GH treatment is not associated with disadvantageous changes of inflammatory markers and adipocytokines in children born small for gestational age

Dietary Energy Intake, Body Composition and Resting Energy Expenditure in Prepubertal Children with Prader-Willi Syndrome before and during Growth Hormone Treatment: A Randomized Controlled Trial

BACKGROUND/AIMS

Dietary management is a difficult but key aspect of care in children with Prader-Willi syndrome (PWS). We therefore investigated the effect of growth hormone (GH) treatment on reported energy intake in children with PWS, in relation with body composition, resting energy expenditure (REE) and hormone levels.

METHODS

In a randomized controlled GH trial including 47 children with PWS, we assessed 5-day dietary records and dual-energy X-ray absorptiometry for body composition. REE was calculated by Müller's equation, based on fat mass, fat free mass and gender.

RESULTS

Baseline energy intake of children with PWS was lower than normal daily energy requirements (p < 0.001), and decreased with age to 50% in prepubertal children. Energy intake in infants [m/f: 11/8; median (interquartile range [IQR]) age 2.7 years (1.5-3.2)] increased after 1 year of GH treatment (p = 0.008); this tended to be higher in the GH group than in the untreated group (p = 0.07). In prepubertal children [m/f: 14/14; median (IQR) age 6.8 years (5.1-8.1)], the increase in energy intake was higher in the GH group, but this was not different compared to the untreated group. REE was not different between the GH group and the untreated group. Increase in energy intake during 2 years of GH treatment was correlated with lower fat percentage standard deviation scores (p = 0.037) and higher adiponectin levels (p = 0.007).

CONCLUSION

Our study demonstrates that parents of children with PWS are very well capable of restricting energy intake up to 50% compared to daily energy requirements for age- and sex-matched healthy children. GH treatment was associated with a slight increase in energy intake, but also improved body composition and adiponectin levels, which suggests a protective effect of GH treatment.

Relationship of adiponectin to endogenous GH pulse secretion parameters in response to stimulation with a growth hormone releasing factor

OBJECTIVE

Obesity is associated with both reduced growth hormone (GH) and adiponectin. However, the relationship between adiponectin and parameters of endogenous GH secretion remains unknown. The aim of this study was to determine the relationship between total and high molecular weight (HMW) adiponectin and parameters of endogenous pulsatile GH secretion and the effects of tesamorelin, a synthetic GH releasing hormone (GHRH(1-44)), on total and HMW adiponectin.

DESIGN

A 2-week interventional study with tesamorelin was conducted at an academic medical center in 13 men with BMI 20-35 kg/m(2). Overnight frequent blood sampling and measurement of total and HMW adiponectin at baseline and after treatment were performed to assess the effects of augmenting endogenous pulsatile GH secretion.

RESULTS

Total, but not HMW, adiponectin was positively associated with log(10)Peak GH area (r=+0.73; P=0.005), basal GH secretion (r=+0.67; P=0.01), and total GH production (r=+0.57; P=0.04), but was not associated with the number of secretion events (P=0.85). Two-week treatment with tesamorelin increased endogenous GH release and IGF-1, but neither total (change -0.16±0.64; P=0.40), nor HMW (change +0.03±0.70; P=0.87) adiponectin changed significantly with treatment. Sub-analyses in overweight and obese men yielded similar results.

CONCLUSIONS

Our study demonstrates a strong relationship between specific parameters of endogenous GH pulsatility and adiponectin. However, short-term augmentation of GH pulsatility over 2-weeks does not change adiponectin. Therefore, the relationship between GH and adiponectin is most likely mediated by specific covariates related to adiposity or other factors.