Influence of metabolic substrates and obesity on growth hormone secretion.

In addition to stimulating body growth, GH plays an important role in metabolism. In turn, various products of intermediary metabolism, such as glucose, free fatty acids, dietary proteins, and amino acids feed back on both the hypothalamus and the anterior pituitary to control the function of the somatotroph cell. Alterations in nutritional status, such as malnutrition and obesity, markedly influence GH secretion and/or GH actions at tissue level. Therefore, the interaction between metabolic substrates and GH secretion can be viewed as part of the overall regulation of feeding and fasting in order to maintain an adequate body weight and body composition.