Insulin-like growth factor 1 - Wikipedia
GH and IGF-1 are associated with higher rates of cancer, both in humans defect in the receptor for GH, which interrupts the connection GH → IGF and development in youth, even though IGF-1 has long-term side effects. If you have low IGF-1 levels, you might want to focus a Vitamin C [R] – there's a correlation between. IGF-1 is a naturally occurring growth factor or hormone that It is the hormone through which human growth hormone (hGH) exerts most of its growth promoting effects. Campaigns · Consultation · Research · Publications · Key Links trials have been discontinued because of significant side effects.
IGF-1's chemical structure is similar to that of insulin, so in very high quantities it can produce the same effects as insulin such as low blood sugar, or 'hypoglycaemia'. IGF-1 is legitimately produced for research purposes and is used by pharmaceutical companies to stimulate cell growth in cell cultures. Some overseas pharmaceutical companies have also been trialing the use of IGF-1 for human therapeutic purposes, however some clinical trials have been discontinued because of significant side effects.
It is illegal to use IGF-1 without a prescription in Australia. What are the perceived benefits? It has been reported that some athletes use IGF-1 in an attempt to increase muscle bulk, reduce muscle cell breakdown and reduce body fat in the belief it will have the same effects as insulin in insulin-dependent diabetics. Abstract The Growth Hormone and Insulin-like Growth Factor-1 axis plays a pivotal role in critical illness, with a derangement leading to profound changes in metabolism.
Protein wasting with skeletal muscle loss, delayed wound healing, and impaired recovery of organ systems are some of the most feared consequences. This article reviews the current knowlegde and clinical practice of the use of rhGh and IGF-1 in critically ill patients, with a special focus on the trauma and burns patient population. Trauma, Burns, Hypermetabolism, protein wasting, IGFBP-3, hepatic acute care response, gut atrophy, nutrition, mortality, anabolic therapy Introduction The elevation of catecholamine, cortisol, and glucagon levels are a hallmark of the critically ill patient.
In the population of critically ill and thermally injured patients, this derangement perpetuates the profound changes in metabolic rates, growth and pathophysiology. The other binding proteins are relatively small, but have various physiologic functions. On the other hand, the binary complexes of IGFBP-1, 2, 4, and 6 bind to IGF-1 to increase its bioavailability, allowing it to cross the endothelial barrier more easily.
This fall is thought to be due to critical illness associated protease activity, which leads to changes in IGF-1 clearance rates. This theory is substantiated by evidence that IGF-1 increases hepatocyte proliferation and liver protein synthesis and, therefore, attenuates the hypermetabolic response and diminishes the negative nitrogen balance. Research with unbound IGF-1 is limited by its side effects, which include hypoglycemia, mental status changes, electrolyte imbalances, edema, fatigue, and headaches.
Recombinant IGF-1 binding protein and gene transfer Gene transfection using viruses as delivery vectors have been used in the treatment of a variety of clinical disorders for decades. Unfortunately, the potential dangers associated with this method have made it relatively undesirable. This has been found to be more successful for the transfer of genes and is associated with several advantages, such as resulting in robust, prompt, and transient localized gene expression, without triggering immunological responses or tachyphylaxis.
IGF-1 and gut atrophy Gut mucosal barrier function has become an area of research interest since it became a potential etiology related to the inflammatory response involved in multiple organ failure syndrome. Ultimately, IGF-1 serum levels are decreased. Strock and Herndon used a burn model to demonstrate that IGF-1 treatment may attenuate the catabolic response, as seen with a reduction in weight loss and basal metabolic expenditure.
Treatment with IGF-1 resulted in a decrease in bacterial translocation to mesenteric lymph nodes, and suggested that the distal small bowel may be less sensitive to IGF-1 than proximal small bowel. The tissue damage induced by thermal injury is due to membrane destabilization and energy depletion at the cellular level.
This ultimately leads to delayed cell death secondary to tissue necrosis, inflammation, ischemia, and reperfusion inadequacies. During recovery from burn injury, cell proliferation, angiogenesis, and re-epithelialization are abundant. As systemic inflammation persists, organ failure commences, and amino acids are mobilized from peripheral tissues, often serving as an energy source for the immune system and wound healing.
Less ill patients have been found to reach peak IGF-1 levels earlier than 10 hours after IGF-1 administration, with a more rapid clearance after administration. On the other hand, those who fail to recover after several days, tend to develop complications such as prolonged immobilization, difficulty weaning from mechanical ventilation, impaired tissue repair, and atrophy of intestinal mucosa.
In addition to advanced age, prior cognitive impairment, a variety of drugs, severe physical illness, and other inflammatory and anti-inflammatory markers, a deficit in IGF-1 has been suggested to play a role in the pathogenesis of delirium in the critically ill. A recent, preliminary investigation performed on critically ill mechanically ventilated patients went further to investigate this theory and found no association between IGF-1 levels and the duration of normal mental state, measured as days without delirium.
Gene transfer also does not appear to increase types I or III collagen, but does increase type IV collagen, which is expressed in the early stages of re-epithelialization. This has led to the suggestion that this growth factor potentially facilitates the reduction of apoptotic outcomes to ultimately promote the reformation of skin epithelium. The production of GH used to be extremely cumbersome, but the advent of a recombinant form recombinant human growth hormone, rhGH in the mids made it widely available.
Growth Hormone is a amino acid, single chain polypeptide hormone, produced in the anterior pituitary gland.
Insulin-like growth factor 1
The production of GH is, moreover, stimulated and inhibited by multiple external and internal regulators. Stimuli for GH release include hypoglycemia, high insulin levels, stress, exercise, and deep sleep. In children, periods of rapid growth and elevation of specific amino acids function as strong stimuli for GH release.
Inhibitors of GH release include hyperglycemia, obesity, and increased glucocorticoid levels. Recombinant human growth hormone given at 0.
IGF-1 for bodybuilders and athletes
Additionally, hormone replacement therapy with rhGH improved the quality of life in these patients when compared to patients without hormone therapy. Growth Hormone in critically ill patients Growth Hormone is a powerful anabolic hormone that can potentially ameliorate or reverse the hypermetabolism and catabolism of critically ill patients.
In these patients, both protein synthesis and breakdown are upregulated, leading to a net negative nitrogen balance associated with muscle wasting, prolonged need for mechanical ventilation, impaired wound healing and immune response.
Many authors argue that in critical illness, this protein catabolism can be, at least partly, explained by acquired resistance to GH. Van den Berghe et al. Benefits of rhGH application to critically ill patients were, untilreported only in a number of smaller controlled clinical studies.
In a prospective, randomized, placebo-controlled trial, Voerman et al. He reported an improved nitrogen balance, but also increased insulin resistance. These patients received rhGH after they failed weaning protocols for a mean time of 38 days.
The authors showed a marked nitrogen retention, but no improvement in muscle strength or shorter duration of ventilatory supports.
InJukkaTakala and EskoRuokonen performed a pair of prospective, randomized, placebo-controlled trials that profoundly changed the use of rhGH in critically ill patients. The therapy was continued during the ICU stay, but for not more than 21 days. The primary outcome of the study was the duration of stay in the ICU. Secondary outcomes included length of mechanical ventilation, length of hospital stay, incidence and clinical course of organ failures, grip strength, exercise tolerance, overall nitrogen balance, and mortality.
IGF-1 for bodybuilders and athletes
The authors reported no differences in general demographics, organ failure patterns respiratory, gastrointestinal and cardiovascular failure. The administration of rhGH led to increased blood levels of IGF-1, decreased blood levels of its binding protein-1 and increased levels of its binding protein An improved nitrogen balance was also found in both arms of the study. Unsurprisingly, the results of this well-designed and controlled clinical trial led to all but a cessation of the use of rhGH in critically ill patients.
A heated debate between the main study groups followed the Takala article, with the main objective of elucidating the cause of the massively increased mortality in the rhGH groups.
The speculations were ranging far, including: Meanwhile, it has been found that Ghrelin, a natural ligand for the GH receptor, has orexigenic effects, stimulates GH secretion, and furthermore plays a role in glucose homeostasis, lipid metabolism and immune function [ 59 ].
Wu et al showed in a rodent sepsis model that Ghrelin ameliorates gut barrier dysfunction in sepsis by vagus nerve activation via central ghrelin receptors. Koch at al found that Ghrelin serum concentrations are significantly elevated in critically ill patients at admission and that high ghrelin levels indicate a favorable prognosis in ICU patients.
Growth Hormone in burns The effect of rhGH administration in severely burned children has been initially examined during the acute phase after burn.
A significant increase in net protein synthesis and an improved wound healing have been observed in children treated with 0. In a summary of clinical application of rhGH in three different doses 0.
- The GH/IGF-1 System in Critical Illness
- Performance and Image Enhancing Drugs - What is Insulin-like Growth Factor (IGF-1)
A subset analysis revealed most lean body mass gain in the 0. Bone mineral content showed an unexpected decrease in the 0. This is interesting because many users of the hormone do note its apparent ability to reduce or maintain body fat levels during periods of high calorie consumption, yet this is likely down to the insulin-like effect of IGF-1 which promotes a state of lower blood sugar.
The GH/IGF-1 System in Critical Illness
This is important to note and is covered later when we discuss side effects. With such an extended half-life the hormone has a far greater timeframe to circulate around the body, bind to receptors and exert its effects.
With IGF-1 LR3 it is neither necessary nor effective to perform site specific injections as the hormone will have ample opportunity to propagate from the injection site given its half-life. Site specific injections using IGF-1 DES can be particularly effective and worthwhile, with bodybuilders typically injecting the muscle group they are about train pre-workout.
The theory behind this is sound; high lactic acid build up causes the IGF-1 receptors to be more accepting, therefore injecting into a muscle group that is about to be trained should provide the best results. Pre-workout site injections are taking advantage of the inbuilt biological response which naturally occurs during a workout — lactic acid builds up in the muscle being work, signalling for the release of HGH and IGF-1 to help repair the micro-traumatised muscle tissue.
Cycles, doses and results The first thing that must be said is that IGF-1 is an advanced hormone and should only be considered by those with several AAS cycles under their belt. IGF-1 does however provide several unique qualities which are highly prized by many advanced bodybuilders and athletes.