Human Growth Hormone: HGH Benefits, Uses and Side Effects

This leads to a vicious cycle as the stimulation of lipolysis worsens insulin sensitivity and impairs beta-cell function. Thus, a Mediterranean diet in these patients could be effective in reducing cardiovascular risk 372 and in influencing GH status 369 but further studies are needed. The potential of GH to act as a mitogen has resulted in concern over the possibility of increased de novo tumors or recurrence of pre-existing malignancies in individuals treated with GH.

• Several factors may act to either further stimulate insulin release or inhibit it.
• Human growth hormone treatment has demonstrated positive results in adults who are growth hormone-deficient in treating obesity naturally.
• GH secretion occurs in a pulsatile fashion, and in a circadian rhythm with a maximal release in the second half of the night.
• Thus, the data seem to suggest that GH has a preferential effect on glycogenolysis compared to gluconeogenesis.

Abscisic acid

Identifying the mechanisms by which GH affects β-cell function could help identify potentially new candidates to improve β-cell function in diabetes. Another mechanism by which GH may affect insulin secretion is by modulating Ca2+ fluxes in the β-cell. In insulin secreting cells GH increased intracellular Ca2+ levels by up-regulating the ryanodine receptors (Zhang et al., 2004). Moreover, treatment of BRIN-BD11 β-cells with rhGH also increased intracellular Ca2+ levels in a Jak2 and Src-dependent manner. However, these effects were hypothesized to be acting through the PRLR rather than the GHR as ovine prolactin and not bGH mimicked the effects of the hGH (Zhang et al., 2006). Down-regulation of GHR activation is mediated by the suppressors of cytokine signaling (SOCS) family of proteins, which include SOCS-1, -2, -3, -6, and cytokine-inducible SH2 containing protein (CIS), which are induced by the Jak/STAT pathway.

The alpha subunit binds IGF-I, IGF-II, and insulin; however, the subunit has a higher affinity towards IGF-I compared to IGF-II and insulin. Although insulin and IGF-I share many similarities, during evolution the functionality of the two molecules has become more divergent, where insulin plays a more metabolic role and IGF-I is more involved in cell growth. Because GH and insulin share some common intracellular substrates, a hypothesis arose claiming that competition for intracellular substrates explains the negative effect of GH on insulin signaling (59).

Effects of growth hormone on glucose metabolism and insulin resistance in human

The imbalance of one or more macro- and micronutrients could affect the short- and long-term GH and IGF-I secretion and actions, with repercussions on growth, anabolism, and nutrients sensing 380. All the evidence discussed in this review derives from models aiming to dissect the effect of single nutrients on GH and IGF-I. However, nutritional deficiencies due to peculiar food restrictions could hide multiple deficiencies or excesses, leading to debatable results. Recently, advances in nutritional geometry have helped to study nutrition as a framework to TB 500 (Thymosin Beta-4) 2 mg Deus Medical begin deciphering how nutrients interact and orchestrate mechanisms linked to healthy aging and lifespan 381,382. Expanding this approach to hormonal regulation, like that of the GH/IGF-I axis could add new depth and open perspectives in nutrition management, prevention, and treatment of GH/IGF-I deficiency or excess at different time points of life. Interestingly, vitamin A modulates the GH gene through its interaction with RXR-α, the predominant receptor form in the pituitary 220.

After the third decade of life, there is a progressive decline of GH secretion by approximately 15% for every decade of adult life. Integrated measurements of daily GH secretion demonstrate that secretion peaks at puberty at about 150 µg/kg day, then decreases to approximately 25 µg/kg/day by age 55 (3). The reduction in GH secretion results from a marked reduction in GH pulse amplitude, with only very little change in pulse frequency (4).