BOSTON, June 27 /PRNewswire/ -- The administration of growth hormone improves the sensitivity of women with osteoporosis to their own circulating parathyroid hormone, leading to an increase in bone formation and an improvement in bone mineral balance, according to a new study released today at ENDO 2006, the 88th Annual Meeting of The Endocrine Society. The research may lead the way to improved treatment for women who are endangered by thinning bones.
The growth hormone study and another that links heightened levels of a sulfur-containing amino acid to increased risk of hip fracture are among those being discussed at a bone health media roundtable to be held at 2:00 p.m. today at ENDO 2006 at the Boston Convention & Exhibition Center. A third study focused on bone diseases examines the rapid bone loss that occurs when inflammatory diseases are treated with glucocorticoids.
Growth Hormone Administration Improves Treatment of Women with Osteoporosis
Experts have noted that growth hormone has successfully increased bone mineral density in aging women with established osteoporosis, but the mechanism that makes the treatment effective has not been understood. Dr. Franklin Joseph of Royal Liverpool University Hospital in the United Kingdom studied 14 post-menopausal women to determine the impact of growth hormone on a variety of measurements, including parathyroid hormone, calcium, phosphate and other bone markers in blood and urine samples.
Dr. Joseph documented that growth hormone administration was associated with improved parathyroid hormone sensitivity, increased calcium and phosphate concentrations, as well as other biochemical bone markers.
"In addition to improving sensitivity to parathyroid hormones, the growth hormone stimulated greater increases in bone formation," Dr. Joseph said. "Taken together, the changes may explain the increased bone mineral density that follows long-term administration of growth hormone in aging women with osteoporosis."
Plasma Homocysteine and Risk of Hip Fracture among Post-Menopausal Women
Each year, there are 1.5 million osteoporosis-linked fractures in the United States that may be associated with nutritional, lifestyle and genetic factors. The most serious of these broken bones -- hip fractures -- lead to disability and death in 12 to 24 percent of women. A collaborative research team that included doctors from hospitals and universities in Boston, Seattle, Columbus, Ohio, San Francisco and Pittsburgh examined the connection between the risk of hip fracture and high levels of plasma homocysteine, a sulfur-containing amino acid that is already known to contribute to heart disease.
The study used data from the Women's Health Initiative Observational Study, looking at 391 cases of hip fractures and a control group of 391 women matched by age, race and ethnicity. Those with the highest levels had almost double the risk of fracture.
"Our results suggest that high levels of homocysteine are associated with increased risk of hip fractures," said Dr. Meryl LeBoff of Brigham and Women's Hospital. "Further studies are needed to determine why this amino acid has this effect and if the fracture risk can be modified by nutritional factors."
Interplay of Therapeutic Glucocorticoids and Bone Disease
When used to treat inflammatory disease, glucocorticoids cause rapid bone loss. However, clinical studies suggest that in patients without inflammation, glucocorticoids have little impact on bones. A collaborative study lead by Dr. Kirrenjit Kaur at the University of Birmingham in the United Kingdom and a team of doctors from the Erasmus Medical Center in the Netherlands looked for the mechanism by which inflammation magnifies the effect of glucocorticoids.
The doctors determined that the modifying effect of inflammation is due to increased natural glucocorticoid generation in human osteoblasts, cells that normally aid in the growth and development of bone.
Founded in 1916, The Endocrine Society is the world's oldest, largest, and most active organization devoted to research on hormones, and the clinical practice of endocrinology. Today, The Endocrine Society's membership consists of over 13,000 scientists, physicians, educators, nurses and students in more than 80 countries. Together, these members represent all basic, applied, and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society, and the field of endocrinology, visit our web site at http://www.endo-society.org.
Source: The Endocrine Society