GH-IGF-I axis abnormalities

From: 'Growth Hormone/IGF-I Axis' <a href="https://www.rndsystems.com/research-area/growth-hormone-igf--i-axis">https://www.rndsystems.com/research-area/growth-hormone-igf--i-axis</a>

Growth hormone (GH) is secreted by somatotropic cells of the anterior pituitary gland under the stimulation control of hypothalamic factor GH Releasing Hormone (GHRH). GH acts directly and indirectly through Insulin-like Growth Factor-1 (IGF-1). Together GH and IGF promote mammalian growth and influence regulation of metabolism. In addition, the GH/IGF-1 axis has been shown to actively regulate lifespan in worms, flies and mice. However, it remains to be determined if the GH/IGF-1 axis has an equal influence on human longevity. Secretion of human GH progressively declines with age and is paralleled by decreased levels of IGF-1. GH/IGF-1 exert potent effects on the central nervous system, modulating plasticity and function. Age-related depletion of GH/IGF-1 has been associated with increased vulnerability to the development of cognitive and sleep disorders.

From: 'Changes in growth hormone, insulin, insulinlike growth factors (IGFs), and IGF-binding protein-1 in chronic fatigue syndrome.' <a href="https://www.ncbi.nlm.nih.gov/pubmed/9046989">https://www.ncbi.nlm.nih.gov/pubmed/9046989</a>

Chronic fatigue syndrome (CFS) is characterized by severe physical and mental fatigue of central origin. Similar clinical features may occur in disorders of the hypothalamopituitary axis. The aim of the study was to determine whether patients with CFS have abnormalities of the growth hormone/insulinlike growth factor (GH-IGF) axis basally or following hypothalamic stimulation with insulin-induced hypoglycemia. We compared levels of GH, IGF-I, IGF-II, IGF-binding protein-1 (IGFBP-1), insulin, and C-peptide in nondepressed CFS patients and normal controls. We found attenuated basal levels of IGF-I (214 +/- 17 vs. 263.4 +/- 13.4 micrograms/L, p = .036) and IGF-II (420 +/- 19.8 vs. 536 +/- 24.3 micrograms/L, p = .02) in CFS patients and a reduced GH response to hypoglycemia (peak GH; 41.9 +/- 11.5 vs. 106.0 +/- 25.6 mU/L, p = .017). Insulin levels were higher (7.6 +/- 1.0 vs. 4.3 +/- 0.8 mU/L, p = .02) and IGFBP-1 levels were lower (19.7 +/- 4.6 vs. 43.2 +/- 2.7 mg/L, p = .004) in CFS patients compared with controls. This study provides preliminary data abnormalities of the GH-IGF axis in CFS. It is not apparent whether these changes are components of a primary pathological process or are acquired secondary to behavioral aspects of CFS such as reduced physical activity.