Research on osteoporosis is currently being conducted by members of the University of Maryland School of Medicine's Division of Endocrinology, Diabetes and Nutrition, including Dr. Streeten, Dr. Braxton Mitchell [professor of medicine and a genetic epidemiologist] and Dr. Dan McBride [a molecular biologist].
Their research focuses on the genetics of osteoporosis (in the Old Order Amish) and on rare hereditary disorders of bone fragility. Examples of these rare disorders under study are osteogenesis imperfecta and osteoporosis pseudoglioma syndrome (this is also associated with blindness from birth).
In addition, their research and that of others have shown that numerous genes contribute to bone health. The goals of this research are to better understand osteoporosis and to identify new genes related to bone health that could lead to the development of new treatments and eventually to a blood test, which could identify those at highest risk.
Dr. Elizabeth Streeten [assistant professor of medicine and pediatrics at the University of Maryland School of Medicine] is also studying genetic factors related to Vitamin D production in the skin and Vitamin D activation by the kidney.
“Our studies have shown genes control about 85 percent of peak bone mass (the best bone mass of your life, achieved in the early 20s in women and mid-20s in men),” said Streeten. Others have had similar results. “After the ages of 40 to 50, bone mass and strength decline. Studies by our group have shown that in women, genes control 30-50 percent of bone loss with aging.”
This means that genetic factors are very important in the risk of developing osteoporosis. “Although you can maximize your peak bone mass and help to prevent bone loss from aging by exercise, getting the recommended amount of calcium and Vitamin D, you may still develop osteoporosis if one of your parents had it,” says Streeten. “Similar to the case of height, where your chance of being tall is remote if both of your parents are short, if you are genetically determined to have low bone mass, you can't prevent it.”
In other departments, Dr. Jay Magaziner [professor of medicine and physiology at the University of Maryland School of Medicine and head of the Division of Gerontology] has been studying recovery from hip fracture for the past 20 years. His group first documented the high rate of death following hip fracture and currently is focusing on the effect of exercise on recovery after hip fracture. Dr. Marc Hochberg [head of the Division of Rheumatology and Clinical Immunology] has had a long interest in osteoporosis research, and is currently studying osteoporosis in men. Drs. Streeten and Hochberg both collaborate with Dr. Magaziner on his studies of hip fracture recovery.