Human Growth Hormone's Effects on Normal and hGH Deficient Children

Britt Randall


What is Human Growth Hormone?

Human Growth Hormone (hGH) has many uses with today's medical technology. For instance, hGH has proven to be very useful in treating Chronic Renal Insufficiency and Turner's Syndrome in girls (http://www.novo.dk/backgrou/backgrou/bahghuk.htm). Promising studies have also been performed and completed using hGH to quicken the repair of wounds, torn cartliage, and non-healing fractures, as well as treating juvenile rheumatoid arthritis and osteoarthosis (http://www.novo.dk/backgrou/backgrou/bahghuk.htm). Perhaps Human Growth Hormone's most vital and "popular" function is treating children with a deficiency in their natural hGH levels and children who are shorter than their peers but have no hGH deficiency.

Human Growth Hormone is a hormone produced in the pituitary gland of humans and is secreted throughout a person's life. hGH is important in children during their years of growth and in adult metabloism (http://www.novo.dk/backgrou/backgrou/bahghuk.htm). hGH is a protein consisting of 191 amino acids, with a molecular weight of 21,700 (http://www.eng.rpi.edu/dept/chem-eng/Biotech-Environ/FUNDAMNT/human.htm).

What is Growth Hormone Deficiency?

Growth Hormone Deficiency is defined as disorders of the hypothalamus, pituitary, or of growth hormone (GH) secretion and metabolism which result in short stature (http://www.icondata.com/health/pedbase/files/GROWTHHO.HTM). A Growth Hormone Deficiency may occur at any time during infancy or childhood, with the most obvious sign being a noticeable slowing of growth (http://www.medhelp.org/web/disframe.htm). Incidence of a GH deficiency is 1/4,000-10,000, and males have more occasions of it at a rate of 2.5:1 (http://www.icondata.com/health/pedbase/files/GROWTHHO.HTM).

There are many possible causes for growth hormone failure in children. Some are constitutional, some are genetic, and some are the result of hormonal disorders (http://www.medhelp.org/web/disframe.htm).

Many children are short in stature due to reasons besides a GH deficiency. "Short stature" is not a medical diagnosis; it is a descriptive term for a person whose height is considered significantly below the normal range of measurements for that age, gender, and racial group (http://www.endo-society.org/pubaffai/factshee/shrtstat.htm). Many medical conditions can cause growth impairment in normal children, such as chronic illness affecting the heart, lungs, intestine, or kidneys (http://www.endo-society.org/pubaffai/factshee/shrtstat.htm).

The Use of hGH in Children Without a GH Deficiency

The use of Human Growth Hormone in short children who are normal and have no GH deficiency is quite controversial. hGH seems to work well in children with a GH deficiency, but questions have arisen about whether the same can be said for children without a deficiency.

Growth Hormone therapy appears to improve the height velocity in many short children, at least in the initial stages of therapy, although it also accelerates bone maturation (Kawai et al., 1997). This maturation may counteract the height improvements in some patients and may have an adverse effect on final height (Kawai et al., 1997).

The other side of the controversy is that treatment of non-GH-deficient children is justified. Children are socialized in many ways. Short children are socialized according to their height rather than chronologic age (Sandberg et al., 1994). It is said they are stigmatized by deviant appearance and have low self-esteem, poor academic achievement, and poor social skills (Sandberg et al., 1994).

Studies

The claim that was previously made about short children being stigmatized seems to be true with adults, as well. Studies have demonstrated that in Western society, short adults appear to be at some disadvantage and overall do not attain positions of responsibility and earning potential equal to those of taller individuals (http://php2.silverplatter.com/physicians/digest/abstract/abst73.htm).

Hindmarsh and Brook performed a study in 1987 which involved 16 short normal prepubertal children taking one year worth of synthetic growth hormone treatment. In the end, the children's final heights following treatment were 1.33 Standard Deviation scores below the fiftieth centile. The difference between predicted and actual final heights was statistically significant, although the predicted and actual final heights of the control children was not statistically significant (http://php2.silverplatter.com/physicians/digest/abstract/abst73.htm).

No significant physiological problems arising form the use of GH in these children were detected (http://php2.silverplatter.com/physicians/digest/abstract/abst73.htm).

Kawai et al. conducted a study of the influence of GH therapy on bone maturation and final height in boys with non-growth-hormone-deficient short stature (Kawai et al., 1997). Growth Hormone therapy appeared to contribute to earlier onset of puberty by advancing bone maturation during the prepubertal period. However, GH therapy decreases final height by having a negative effect on pubertal height gain (Kawai et al., 1997). The authors conclude that GH therapy did not improve height and actually reduced height compared to the height that would be attained naturally (Kawai et al., 1997).

Rosenfeld's study agreed with the Kawai et al. study; he also concluded that these normal short children may be negatively affected (Rosenfeld, 1997). Sandberg et al. performed a similar study, as well. However, this particular study assessed the validity of psychosocial justification for growth hormone therapy. Researchers decided that GH therapy should not be administered routinely to all short children for the purpose of improving their psychological health (Sandberg et al., 1994).

Other Treatments Available

There are many treatments available for normal but short children. For instance, recognition and treatment of the underlying condition is the most effective means to restore growth in these children (http://www.endo-society.org/pubaffai/factshee/shrtstat.htm). Inadequate nutrition can also impede the attainment of adequate height, especially during infancy and puberty (http://www.endo-society.org/pubaffai/factshee/shrtstat.htm). Treatments for children with GH deficiency are not as readily available.

Costs

Human Growth Hormone costs about $1000 a week (http://www.immunet.org/immunet/atn.nsf/page/ZQX22601.html), which is also about $800 per gram injected (http://www.eng.rpi.edu/dept/chem-eng/Biotech-Environ/FUNDAMNT/human.htm), or $20,000 a year for a 30 kilogram child (Sandberg et al., 1994). Because of these extremely high prices, hGH is not truly easily available for everyone. The substance itself is produced by the body and cannot be effectively patented; there has been considerable patent litigation (http://www.immunet.org/immunet/atn.nsf/page/ZQX22601.html). However, the price of hGH is still very disproportionate to the cost of production. Hopefully, as methods of production continue to improve, the price of hGH will go down, and availability to all will increase.

Claims

Novo Nordisk marketed its first branded pituitary Human Growth Hormone product, Nanormon, in 1973. In 1982, the company filed its first patent application on the production of genetically engineered hGH. In 1988, Norditropin was approved in several countries (http://www.novo.dk/backgrou/backgrou/bahghuk.htm).

Novo Nordisk points out that until 1988, hGH was used exclusively to treat patients with a GH insufficiency, due to a limited supply. Production has improved, however, and hGH is no longer only supplied from human cadavers. Novo Nordisk was one of the first companies to patent an artificial form of hGH. Now, with a seemingly unlimited supply, Growth Hormone is useful in a wide range of applicaions, according to Novo Nordisk. Such applications include treating females with Turner's Syndrome and children with Chronic Renal Insufficiency (http://www.novo.dk/backgrou/backgrou/bahghuk.htm).

Conclusion

Findings from the research studies on the web concurred with each other. Claims made by companies producing artificial Growth Hormone were all similar. They stressed the many uses of hGH, yet they clarified that Growth Hormone therapy is not for all children, especially short, normal children. hGH has been shown to definitely improve height in GH deficient children. In normal but short children, however, multiple findings suggest that doctors and parents should think twice about beginning treatment.

As for my personal conclusion, I believe that hGH therapy is a wonderful advancement in today's medical technology. I have a couple of cousins (GH deficient) who have completed treatment, and the results have been astounding. However, I believe that more studies should be performed before children who are not GH deficient begin this form of therapy. Positive results are short-lived. Perhaps there are other, better forms of therapy for these children that have yet to be discovered.

References

Kawai, M. et al. (1997). Unfavorable Effects of Growth Hormone Therapy on the Final Height of Boys With Short Stature Caused by Growth Hormone Deficiency. Journal of Pediatrics, 130:205-209.

Rosenfeld, R.G. (1997). Is Growth Hormone Just a Tall Story? Journal of Pediatrics, 130:172- 173.

Sandberg, D.E. et al. (1994). Growth Hormone: Not For All Short Children. Pediatrics, 94:832-840.

Links

http://php2.silverplatter.com/physicians/digest/abstract/abst73.htm

http://www.gene.com/pressrelease/1981/1_12_81.html

http://www.endo-society.org/pubaffai/factshee/shrtstat.htm

http://www.immunet.org/immunet/atn.nsf/page/ZQX22601.html

http://www.eng.rpi.edu/dept/chem-eng/Biotech-Environ/FUNDAMNT/human.htm

http://www.novo.dk/backgrou/backgrou/bahghuk.htm

http://www.medhelp.org/web/growth.htm

http://www.medhelp.org/web/disframe.htm

http://laran.waismen.wisc.edu/fv/www/lib_grow.htm

http://www.icondata.com/health/pedbase/files/GROWTHHO.HTM
 

 

 

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