Known risks of GH are few and rare. Few reasonable parents or physicians would incur a high risk of harm to a child to add a few inches to height. Most of the complications have been reported in children over 10 years of age or in adults. Though rare, the following harmful side effects have been reported during GH treatment often enough to be assumed noncoincidental.
Slipped capital femoral epiphysis (SCFE) causes hip pain due to separation of the head of the femur from the shaft. Incidence in GH-treated children may be about 1 in 1000. SCFE usually requires casting or surgical pinning to reverse.
Pseudotumor cerebri (also known as benign intracranial hypertension) is manifested by severe headache, papilledema, nausea, and visual changes. Incidence is also perhaps 1 in 1000. All cases have been reversed, usually by temporary discontinuation or reduced dose of the GH.
Fluid retention and edema in early months of treatment is rare in children but more common and occasionally more severe in adults. It typically disappears with temporary interruption of treatment.
Pancreatitis has been reported in a few patients receiving GH, but a causal relationship seemed plausible in only a couple.
Joint pains are occasionally experienced by children or adults being treated with GH.
Carpal tunnel syndrome has also occurred in adults being treated with GH, presumably due to a combination of tissue growth and fluid retention causing pressure on the tightly confined nerves and tendons of the wrists.
A small but controlled study of GH given to severely ill adults in an intensive care unit setting for the purpose of increasing strength and reducing the muscle wasting of critical illness showed a higher mortality rate for the patients who received GH. The reason is unknown, but GH is now rarely used in ICU patients without severe deficiency.
The following effects are common, but of questionable harm.
Altered body composition refers to the tendency of GH to build bone and muscle mass and reduce body fat.
GH treatment usually decreases insulin sensitivity[1]. This effect does not seem to cause problems in most people but it is possible to envision a combination of factors which would make this a more significant effect.
When GH is given to children and adults who are not deficient, IGF1 levels may be raised above normal. Though no effects are obvious, prolonged periods of extremely high IGF1 levels occur in acromegaly, and a small amount of evidence suggests that higher IGF1 levels in older adults (not receiving GH) are associated with a slightly higher risk of certain cancers; a causal relationship has not been established.
When GH is given to a child in high doses for many years, it can subtly affect the facial bone structure. It rarely is recognized as a change by patients and parents and even less often causes problems.
The following serious problems have been linked by one or two small reports but a true risk has not been confirmed by larger surveillance studies.
Type 2 diabetes has been reported in a few adolescents treated with GH. It uncertain whether this is a causal association because the incidence of adolescent type 2 diabetes is rising so rapidly in most countries that we no longer have reliable incidence statistics for diabetes in the untreated adolescent population.
Leukemia is the most common childhood cancer, occurring in about 1 in 40,000 children each year. Because leukocytes have GH receptors, leukemia cases have been carefully counted since synthetic GH was introduced. Although a few children with no risk factors treated with GH have developed leukemia, the numbers have been no more than would be expected in a similarly sized group. For a variety of reasons, it has been harder to achieve the same level of reassurance for children who do have a higher leukemia risk. These are primarily children who are became GH deficient as a result of treatment for leukemia or a brain tumor. Available statistics are reassuring, but numbers are not large enough to exclude any amplification of risk.
Several extra cases of colon cancer were found in a study of lifelong health and mortality of a group of middle-aged British adults with severe GH deficiency from childhood. All had been treated as children with cadaver GH. This association has not been confirmed and even if it were, it would need to be established whether the GH treatment in childhood or the untreated GH deficient state in adult life represented the true association.
Finally, in any discussion of side effects, our experience with Creutzfeldt-Jacob disease 20 years after cadaver GH treatment reminds us that side effects of an apparently safe treatment may be unforeseeable and long-delayed.
Ethical issues
Hormone treatment seems an unlikely source of social controversy, but for four decades, growth hormone has been second only to estrogens and progestins (diethylstilbestrol, contraception, abortifacients, and post-menopausal replacement) in its ability to engender challenging ethical issues. The principal controversies of the last two decades arise from the intersection of two factors: high cost and the difficulty of defining a boundary between disease and variation of normal. In other words, if GH were inexpensive, it would be no more controversial than orthodontics. If there were zero potential benefit to all but the most easily defined, severely deficient persons, GH would be one more expensive treatment for a rare disease. But neither condition is true.
Growth hormone is one of the most expensive treatments in all of medicine. The cost of adult GH replacement for deficiency (or for “aging”) is about US$2000 per year, or about US$20,000 per decade. The cost of treatment for a non-deficient child (e.g., with Turner syndrome or idiopathic short stature) is about US$25,000 per year. A typical treatment course of 5 years yielding about 2 inches (5 cm) of extra adult height would cost approximately US$125,000. The highest cost, for treatment from infancy to age 70 of severe, congenital GH deficiency, could exceed US$300,000.
The high cost has been a subject of criticism of the pharmaceutical companies. A high cost was originally justified by the new technology and unusually extensive clinical trials. Orphan drug status in the United States (which blocks competing products for several years) was granted to the first two recombinant products (Genentech's Protropin and Lilly's Humatrope) introduced in the mid-1980s. Continuing production costs have been much lower than the drug price. When orphan drug status expired in the early 1990s it was hoped that introduction of additional brands into the market would result in a lower price. Instead, the 5 major companies offering synthetic GH have competed on other grounds than price. While the dollar price has not been increased to keep up with inflation over 2 decades, it hasn't been reduced as net manufacturing costs have fallen. Despite a similar manufacturing process, pricing of synthetic GH for use in cattle (see Bovine somatotropin), turkeys, and chickens is inexpensive compared to the human product since the price is constrained by market prices for the meat and milk products enhanced by the animal GH.
Assessing the value of treatment to balance against the cost is made difficult by the range of severity of conditions treated and the difficulty of cleanly distinguishing disease from human variability. The most expensive treatment cost cited above for lifetime replacement of severe deficiency purchases for that person a 12"; (30 cm) height difference, enough to prevent shortness severe enough to be a physical handicap, enhanced marriage and employment prospects (compared with those under 56”). It also enhances bone and muscle strength, and perhaps even psychological resilience. It can prevent obesity, and may even prolong employability and life span. These are substantial benefits in return for the high cost, but less than 1 in 5000 children is born with this type of severe deficiency. At the other extreme is a child whose only diagnosable disease is a height in the lowest 2% of the population, who may gain 1 inch from 2 years of treatment. In between these extremes is a continuum of more or less severe shortness, greater or lesser response to treatment, and greater or smaller abnormalities to testing.
Questions and dilemmas arise from the previous facts.
Is GH a wise use of finite health care resources? Is there anything wrong with an insurer or government health program declining to spend US$ 100 000 or more to make an otherwise healthy child a few inches taller?
A physician usually assumes the responsibility of advocating for a patient to get coverage for a treatment. If the family of a normal but slightly short child thinks GH treatment is worth the cost and trouble, does the physician have a duty to support it? If the physician declines, is she being “paternalistic” rather than “respecting the patient’s autonomy”.
If the cost of GH drops, and is given to short children whose parents can afford it, will shortness become a lifelong mark of lower social origins, like crooked teeth?
If we treat a child to protect him from the disadvantages of social heightism, is that like lightening skin or straightening hair to protect from racism?
If two children of the same height might gain the same benefit from treatment, is the reason for the shortness (diagnosis) an ethically relevant consideration? Does the child who tests more abnormally have a better claim to treatment?
Is “idiopathic short stature” a medical condition worthy of treatment if it is defined simply as the shortest 1% of the population? Would it make a difference if many or most of this lowest 1% could be shown to have a defect of IGF1 production or responsiveness? If ISS were defined as the shortest 3%, 5%...?
What is the difference between enhancement and therapy?
Should mentally handicapped children be as eligible for GH treatment as those with more “normal” social prospects? Are parents the best judges of potential benefits?
Is it fair that those who can afford it can deceive potential partners into believing that they are naturally tall when they continue to be genetically short and will pass this onto their children
2006-07-25 03:09:23
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answer #1
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answered by Jessica H 3
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