Effects of Growth Hormone Supplementation to Adults With Growth Hormone Deficient on Metabolism and Adipose Tissue Molecular Phenotype

This study is designed as a follow up study to that performed in 2005.

In the Baseline study (2005) extensive clinical whole body metabolic phenotyping was combined with in depth molecular and cellular biology analyses aimed at investigating the adipose tissue morphology as well as metabolic and inflammatory phenotypes in the adult GHD patients. Results published in (Ukropec et al., 2008)

In this study identical endpoints will be investigated with the same methodology and within the same population; in order to seek relevant answers to questions on how the 6-yrs of rhGH therapy affects the

* whole body insulin sensitivity * energy expenditure * body fat distribution * hepatic and skeletal muscle lipid content;

as well as how it influences the adipose tissue

* endocrine, * metabolic & * inflammatory phenotypes.

The strength of the planned study lies in the extensive whole body and adipose tissue phenotyping before and after the 6-year rhGH replacement therapy, that allows to determine the long-term effects of rhGH replacement therapy in GHD adults.

Envisaged weakness is the limited size of the population; GHD adults (n=20); controls [age BMI and gender matched] (n=20). This, however, reflects [is limited by] the complexity of the study protocol as well as the stringency of the inclusion criteria.

The clinical data obtained by methods of - integrated physiology would provide an excellent interpretation background for molecular-genetic studies at the tissue (adipose tissue) and cellular (adipocytes) level. Integration of the two could bring a new quality in the investigators understanding of metabolic derangements present in GHD, and will allow extending the investigators knowledge on the mechanisms of the long-term rhGH-therapy-induced improvement on body composition, metabolic health and the cardiovascular risk.