Scientists funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) have uncovered new clues related to bone loss and the risk of fractures (broken bones) in older men. Osteoporosis, a disease in which bones become weak and prone to fracture, has been less clearly understood in men than in women. But two separate analyses from the Osteoporotic Fractures in Men Study (MrOS) - recently published in the Journal of Bone and Mineral Research - have made important contributions to the understanding of the disease and its consequences in men.

In one study, investigators sought to describe patterns of hip bone loss in older men, and to explain whether bone strength in these men was inversely related to aging - a concept well-documented in women. The researchers analyzed bone mineral density measurements of 4,720 community dwelling men, age 65 and older, over a period of four and one-half years. Results demonstrated that although hip bone loss in these men was typically modest, its rate did, in fact, increase with age. Additionally, researchers learned that men with the lowest bone mineral density at the beginning of the study were at greatest risk for subsequent bone loss, a factor that should ultimately help clinicians identify those men who may need treatment the most.

In the other study, investigators applied a sophisticated mathematical technique known as finite element (FE) analysis to existing quantitative computed tomography (QCT) data to determine whether this approach might be an appropriate predictor of bone strength and fracture risk in older men. (FE analysis includes an estimate of a bone's strength combined with the estimated load that would be applied to the bone from a potential fall or other trauma.) In the study, FE analysis was performed on hip QCT data from 250 men age 65 and older. Forty of the men had experienced a hip fracture, while 210 had not. Researchers discovered that FE analysis of the men's QCT scans was a strong predictor of hip fracture, especially when combined with traditional bone mineral density measurements.

The Osteoporotic Fractures in Men Study (MrOS) is a large multi-center observational study designed to identify risk factors for osteoporosis in men. In addition to NIAMS, the study is supported by the National Institute on Aging (NIA), the National Center for Research Resources (NCRR) and the NIH Roadmap for Medical Research.

The mission of the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), a part of the Department of Health and Human Services' National Institutes of Health (NIH), is to support research into the causes, treatment, and prevention of arthritis and musculoskeletal and skin diseases; the training of basic and clinical scientists to carry out this research; and the dissemination of information on research progress in these diseases. For more information about NIAMS, call the information clearinghouse at 301-495-4484 or 877-22-NIAMS (free call) or visit the NIAMS Web site at For more information about osteoporosis, call the NIH Osteoporosis and Related Bone Diseases ~ National Resource Center at 202-223-0344 or 800-624-2663 (free call) or visit


Cawthon PM, Ewing SK, McCulloch CE, Ensrud KE, Cauley JA, Cummings SR, Orwoll ES; for the Osteoporotic Fractures in Men (MrOS) Research Group. Loss of hip bone mineral density in older men: The Osteoporotic Fractures in Men (MrOS) Study. J Bone Miner Res. 2009 May 6. [Epub ahead of print].

Orwoll ES, Marshall LM, Nielson CM, Cummings SR, Lapidus J, Cauley JA, Ensrud K, Lane N, Hoffmann PR, Kopperdahl DL, Keaveny TM; Osteoporotic Fractures in Men (MrOS) Study Group. Finite element analysis of the proximal femur and hip fracture risk in older men. J Bone Miner Res. 2009 Mar;24(3):475-83.

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