The decline of growth hormone with age is directly associated with many of the symptoms of aging, including cardiovascular disease, increased body fat, osteoporosis, wrinkling, gray hair, decreased energy, reduced sexual function, and other symptoms. Many of these symptoms have been found in younger adults who have growth hormone deficiency.
Most importantly, clinical evidence and recent medical research clearly demonstrate that by replacing growth hormone in IGF-1 deficient adults, we can significantly eliminate these symptoms, reverse the biological effects of aging, reduce body fat, increase lean muscle mass, strengthen the immune system, improve sexual performance, lower blood pressure, lower Human Growth Hormone is one of several endocrine hormones, like estrogen, progesterone, testosterone and DHEA, that decline in production as we age.
While many of these hormones can be replaced to deter some of the effects of aging, growth hormone goes far beyond the effect of any one of these hormones to not only retard biological aging, but also to significantly reverse many of the effects of aging. Researchers have proven growth hormone therapy can reverse the biological effects of aging by as much as 20 years with less than one year of treatment.
Human growth hormone is secreted by the pituitary gland. It is produced at a rate that peaks during adolescence when the accelerated growth occurs. Growth hormone secretion decreases with age in every animal species tested thus far. In humans, the amount of growth hormone after age 30 declines about 14% per decade, so that total daily growth hormone production is reduced dramatically with age.
In numerical values, we produce on a daily basis about 500 micrograms of growth hormone at 20,200 micrograms at age 40, and 25 micrograms at age 80. At age 40 our growth hormone production is only 40% of what we produced at age 20. The fall in IGF-1 levels with age is identical to the decline of growth hormone.
Scientists do not know why persons over age 40 incur such significant decreases in growth hormone secretion with resulting growth hormone deficiency. Medical research has revealed that the aging pituitary somatotroph cells can still secrete as much growth hormone as the young somatotrophs cells if they are adequately stimulated.
This has led researchers to the
theory that the reason for the decreases in HGH secretion must lie in the factors that regulate its release.
Some research scientists believe the problem lies with somatostatin, the natural inhibitor of growth hormone.
Somatostatin has been found to increase with age and may act to block the pituitary’s release of growth
hormone. When researchers eliminated
A second theory is that the precursor hormone, growth hormone-releasing hormone (GH-RH), which stimulates growth hormone release by the pituitary gland, becomes less sensitive to the signals from the hypothalamus. Hence, insufficient GH-RH is released resulting in a decrease of growth hormone secretions over time.
A third theory is that, not only does the growth hormone secreted and available to receptors in our cells decrease with aging, but that the cell receptors become more resistant and less responsive to the growth hormone available. Under this theory, aging can be viewed as a disease of growth hormone resistance within our cell receptors similar to the way in which diabetes is a disease of insulin resistance. Human growth hormone is primarily released in pulses that take place during the beginning phases of sleep.
Growth hormone is rapidly converted in the liver to its powerful growth promoting metabolite, Insulin like Growth Factor - Type 1 (IGF-1), also referred to as Somatomedin C. IGF-1 causes most of the effects associated with growth hormone. It is measured in the blood to determine the level of growth hormone secretion. Most of the beneficial effects of human growth hormone are directly attributable to IGF-1. cholesterol, restore hair color and growth, increase bone tissue, strengthen the heart and increase energy. There is no other substance known to medical science that has such extensive ability to deter and reverse the aging process.
In reviewing the benefits of growth hormone therapy listed above, it is difficult to believe that growth hormone could have so many beneficial effects. However, as we examine more closely the evidence accumulated by medical research and the interaction between growth hormone and the various bodily systems that affect the areas benefited, we develop an understanding as to how an increased level of growth hormone results in so many beneficial effects.
In 1985, Keith Kelley, M.D., a research scientist demonstrated that injections of cells that secrete high amounts of growth hormone could cause the shriveled thymus glands in old rats to grow until they became as large and healthy as those of young rats. The thymus gland is the primary organ of the immune system. Immune system enhancement as a result of an increased level of growth hormone include the following: increased malnutrition of neutrophils; higher activity of natural killer cells; stimulation of macrophages;. increased production of red blood cells; the manufacture of new antibodies; increased production of T-cells and interleukin 2; and the greater proliferation and activity of lymphocyte cells.
Growth hormone is a protein molecule consisting of 191
amino acids. Genetic engineering, a new technology that emerged in the 1970’s, enables researchers
to splice human genes. The process of gene
Consequentially, biosynthetic growth hormone began to be available to medical researchers for the first time in the 1980’s. This genetically engineered recombinant human growth hormone is completely identical to the growth hormone made by the human pituitary gland and is therefore referred to as a natural hormone.
Dr. Daniel Rudman, an endocrinologist and medical researcher from Madison, Wisconsin, conducted the original and remarkable research on the effect of growth hormone replacement therapy in humans. By the time Dr. Rudman began his work in the mid-1980’s, the safety of growth hormone had already been well established through its use in children with growth hormone deficiency. Dr. Rudman believed that the changes in body composition which became apparent around age 35 had to do with declining hormone levels.
The only method of testing his hypothesis was to replace growth hormone in deficient elderly adults to ascertain if the growth hormone replacement reversed some of the effects associated with aging. If growth hormone replacement reversed the changes in body composition (ratios of body fat and lean body mass to total body weight) associated with aging, then growth hormone might reverse the loss of bodily structure and function that occurs with aging.
To test his theory, Dr. Rudman began by replacing missing growth hormone in a group of older men to examine its effects on lean body mass and body fat in elderly adults. Dr. Rudman studied 26 men between the ages of 61 and 80 who had experienced significant adverse changes in body composition with age, but who were otherwise healthy. These men were overweight and had significantly low levels of growth hormone.
Dr. Rudman selected growth hormone as the initial hormone to be replaced for two reasons. First, he was aware that the decline in growth hormone after age 35 was generally accompanied by an increase in body fat and a decline in lean muscle mass. Secondly, medical researchers in Sweden and Denmark had already determined that patients who were deficient in growth hormone due to pituitary dysfunction and had received growth hormone replacement therapy became leaner.
Without altering their lifestyles, diets or exercise programs, the men in Rudman’s who received growth hormone replacement gained an average of 9% in lean muscle mass while losing 14% of body fat during their six month test. Bone density increased and their skin became thicker and firmer. According to Rudman, the men who received growth hormone replacement therapy during the six-month study experienced a reversal of the effects of aging by 10 to 20 years. Dr. Rudman concluded, “The overall deterioration of the body that comes with growing old is not inevitable.”
Rudman’s study, published in the The New England Journal of Medicine in 1990, constituted a tremendous scientific breakthrough in the field of rejuvenation medicine. The magnitude and the far-reaching impact of Rudman’s published study have yet to be determined. For the first time, medical science, empowered with the recently developed genetically engineered recombinant human growth hormone had discovered a means for reversing the effects of aging in humans. The course of the future and history for mankind was forever altered.
Dr. Rudman inspired research scientists and physicians worldwide to investigate and research the use of growth hormone replacement therapy to reverse the effects of aging and treat diseases associated with aging. Concurrent with the time of Dr. Rudman’s study, medical researchers in England, Sweden and Denmark were also discovering with consistency the remarkable effects of growth hormone replacement therapy. Providing patients with growth hormone deficiencies arising from pituitary disease with growth hormone replacement had a remarkable impact upon such patients. These patients had been depressed, experiencing low vitality, fatigue, anxiety, loss of sex drive and were dying prematurely at twice the average rate due to cardiovascular disease and other problems prior to the use of HGH. Growth hormone replacement therapy brought the patients out of their depression and fatigue into higher quality, productive lives.
In 1996, the New England Journal of Medicine, reported growth hormone replacement had reversed heart failure. Today the National Institute On Aging is conducting six clinical trials in a multimillion-dollar study of growth hormone replacement therapy to further confirm that growth hormone retards and reverses aging.
In August 1996, the Food and Drug Administration approved the use of growth hormone in adults with growth hormone deficiency due to pituitary or hypothalamic disease, injury, surgery or radiation therapy. Since the studies conducted in England, Sweden and Denmark since 1985 clearly demonstrate that aging is a pituitary disease, the recent FDA approval of adult growth hormone replacement therapy may now allow physicians in the United States to prescribe growth hormone for adults with low levels of IGF-1, without knowing why there is a failure of the pituitary gland to produce adequate amounts of growth hormone.