Growth Hormone – The Controversial and Misunderstood Hormone
Growth hormone (GH) is an endogenous substance that is synthesized, stored, and secreted by the pituitary gland. Like most hormones, growth hormone has multiple varied functions in the body. It is typically secreted at night to stimulate growth, repair, and cell regeneration. It also has a profound effect on bone health as it stimulates osteoblasts and bone growth via retention of calcium. It is, in fact, the most potent substance that may be used to fight bone loss. It is also released in stressful or fight or flight reactions and raises the levels of glucose, free fatty acids, and IGF-1.
Deficiency of growth hormone has been shown to overlap with aging. The reasons are many and varied but primarily focus on the loss of vital function. These include bone health issues, reduced exercise tolerance, and sarcopenia (loss of muscle mass). These conditions increase the risk for fall, fracture, impairment, and disability. Loss of GH also increases fat deposition and insulin resistance. Dyslipidemia occurs which raises LDL which may be problematic in patients with prior heart attacks and strokes. Overall, there is an increased morbidity and mortality from all cardiovascular causes with diminishing levels. Cognitive decline and the risk of Alzheimer’s disease increases with decreasing GH levels. All of these deleterious effects have a negative impact on quality of life.
Growth hormone has many beneficial effects and therefore may be of benefit to improving healthspan and longevity. It maximizes bone health and reduces the risk of osteopenia/osteoporosis. It increases muscle mass via hypertrophy of existing cells and potentially via creating new ones. It increases protein synthesis which helps with repair and recovery from exercise and/or injury. It plays a role in homeostasis thus maintaining an equilibrium in our bodies limiting entropy and chaos. It stimulates the immune system and helps to fight acute and chronic inflammation. It helps with the conversion of T4 (inactive precursor) to T3 (active thyroid hormone). It increases lipolysis and thus reduces visceral fat and its negative health consequences such as diabetes mellitus and metabolic syndrome. It also serves to maintain the size of all organs including the heart. This has the benefit of maintaining and increasing cardiac output thus reducing the risk and negative effects of congestive heart failure.
Growth hormone levels are measured indirectly by looking at IGF-1 levels in the blood. IGF-1 (insulin-like growth factor 1) is produced via the effect of GH on the liver. IGF-1 has growth-stimulating effects on multiple tissues in the body as outlined in the above discussion. Growth hormone is typically administered via daily injection. Levels are typically checked every six weeks until optimization has occurred. GH may typically take upwards of six months to start showing benefit. Side effects of the medication may include edema, arthralgias, myalgias, and carpal tunnel syndrome. These effects are primarily due to the antinatriuretic effect of GH on the kidney and thus fluid is retained. The main drawback of using growth hormone on a long-term basis is the cost of the medication. For this reason, alternatives including sermorelin (growth hormone releasing hormone-GHRH analog) may be used which provide similar results and are more cost-effective for the patient.
Growth hormone (and to a lesser degree testosterone) have become common negative targets in the media due to their use by celebrities and patients for their anti-aging effects; and sports-talk radio due to abuse and potential performance enhancement in athletes. While these substances are banned for use by all professional, college, and Olympic athletes, the information put forth in the discussion of these substances is oftentimes erroneous and just plain wrong. This only serves to further cloud the picture and pollute the message for potential use of these hormones by the patient who is looking for the health benefits. In the right setting and with the proper prescription via a trained physician or health professional, these hormones have a place in the treatment of multiple health issues. I would also bet that in our lifetimes that the professional sports leagues will come around to the idea of physician-assisted hormone replacement for their constituents. Treatment will likely have the effect of limiting injury and the number of lost games due to health problems. Bio-identical hormone replacement would also likely have the effect of extending the careers of many of the stars of sport further maintaining interest in the game by the fan. Money talks, and ultimately I think that these restrictions will be relaxed and a scientific program of treatment and replacement will be a mainstay of every team. This will significantly reduce cheating due to the constant monitoring of levels and drug amounts, thus creating a level playing field for all players involved and reducing any laboratory advantage. I also believe that this will happen for cannabis (marijuana) as the medical benefits for this “sacred plant” far outweigh the negatives.