In The News: August 2010
High-Dose Vitamin D Linked With Increased Fracture Risk
Older women who receive a single annual high dose of vitamin D have a higher rate of falls and fractures compared to women given a placebo. According to a study in the May issue of the Journal of the American Medical Association, 2,256 women age 70 or older, considered to be at high risk of fracture, were recruited from June 2003 to June 2005 and randomly assigned to receive 500,000 International Units (IU) of vitamin D or a placebo once a year for three to five years. An analysis indicated that women in the annual high-dose vitamin D group experienced 15 percent more falls (including a 31 percent higher incidence of falls in the first three months following dosing) and 26 percent more fractures. Earlier studies that used the same annual dose, but administered four times a month rather than annually, showed that subjects experienced no apparent harm, leading researchers to conclude that more frequent dosing of vitamin D is preferable to administering a large annual dose.
Bone Marrow Plasma Injection Improves Healing of Rotator Cuff Tear
An injection of bone marrow plasma after athroscopic repair of a torn rotator cuff can improve a patient’s healing rate. The findings, presented during a recent meeting of the American Academy of Orthopaedic Surgeons, stem from a study of 56 patients who had arthroscopic repair of a torn rotator cuff tendon; 28 of the patients also received injections of bone marrow plasma at the repair site. After evaluating pain and shoulder function before surgery and at six and 12 weeks following surgery, investigators found that bone marrow plasma was associated with significant improvements in function and more rapid tendon healing. Authors of the study considered the results "promising" and plan to embark on another study to determine how plasma injections might benefit patients with rheumatoid arthritis.
Age, Not Decrease in Estrogen, at Root of Osteoporosis
Researchers at the University of Arkansas have identified an age-related mechanism—not, as long believed, a decrease in the hormone estrogen—as the cause of osteoporosis. Aging and the body’s increased inability to defend against bone-damaging molecules produced through a process known as oxidative stress are most directly responsible for the bone-weakening disease, the researchers concluded. The study, which appeared in the journal Cell Metabolism, pointed to research that showed bone loss in both women and men begins as the early part of the third decade, which is long before any change in sex hormone production. In a companion study, scientists identified a specific family of proteins that serves as a defense mechanism against oxidative stress. When the proteins, called forkhead box transcription factors, were removed in young mice, oxidative stress increased and bone weakness developed. When the protein was increased, oxidative stress decreased and the number of bone-forming cells increased and bone mass improved.
RA Biologic Drugs Increase Risk of Skin Cancer
Rhuematoid arthritis (RA) patients treated with potent tumor necrosis inhibitors run an increased risk of developing skin cancer. In one study conducted from 2001 to 2008, doctors reported a trend toward increased risk of basal cell or squamous cell skin cancer among 11,757 people taking anti-TNF drugs such as etanercept (Enbrel), infliximab (Remicade), or adalimumab (Humira), when compared to 3,515 patients who were treated with more traditional, disease-modifying anti-rheumatic drugs (DMARDs), such as methotrexate (Rheumatrex) or leflunomide (Arava)—a 70 percent increase in the number of cases of skin cancer among patients receiving the anti-TNF drugs. However, researchers cautioned that even though the risk is increased, the overall risk remains very low, suggesting that older patients should be watched closely for the development of skin cancer, especially if they are male, have been on anti-TNF treatments for a long time, or have a history of other cancers.