In The News: 11/07
Family History of Knee OA? Stop Smoking to Save Cartilage
Here’s another reason to kick the habit: If you have at least one parent with knee osteoarthritis (OA), if you continue to smoke you’re likely to lose knee cartilage as well. According to a recent Australian study reported in the May issue of Arthritis & Rheumatism, there is strong evidence of a gene-environment interaction in the development of knee OA. Subjects, average age 45, included 325 patients with cartilage defects, 163 of whom had at least one parent with knee OA and 162 of whom had no family history of OA. Of the total sample, current smokers were found to have a higher prevalence of pain and cartilage loss than former smokers or nonsmokers, regardless of an OA family history. Somewhat unexpectedly, however, researchers also found that the effect of smoking in the development of knee OA was much stronger and more consistent in those with a family history of OA.
Zoledronic Acid Reduces Spine Fracture Risk in Women
A single 5mg injection of zoledronic acid (Reclast), given once a year, can reduce the risk of vertebral fractures in women with osteoporosis by 77 percent. According to results of a three-year trial involving 7,736 postmenopausal women that appeared in the May 2007 issue of the New England Journal of Medicine, zoledronic acid, a bisphosphonate that is believed to stabilize bone against resorption, also improved bone mineral density. In addition to significant reduction in vertebral fractures, hip fractures were reduced by 41 percent and non-vertebral fractures were reduced by 25 percent. The reduction in fractures was also greater than what had been observed with oral bisphosphonates.
Bowlegged and Overweight? Your Risk for Knee OA May Double
Varus alignment of the knee (bowleggedness) doubles the risk of knee osteoarthritis (OA) in overweight patients and increases the risk five-fold for those who are obese. According to a study conducted in The Netherlands and reported in the April 2007 issue of Arthritis & Rheumatism, increased varus alignment was not only associated with the development and progression of knee OA, but it was especially notable in overweight and obese subjects. Authors of the study, which comprised 1,501 participants, explained that varus alignment shifts the knee’s load-bearing axis medially (toward the inside of the knee), and since the medial compartment carries most of the knee’s load, the increased force associated with obesity and varus alignment is particularly destructive.
OA Pain Found to Trigger "Emotional" Areas of the Brain
Patients with knee osteoarthritis (OA) process arthritic pain and experimental pain in somewhat different ways, according to research conducted in England and reported in the April 2007 issue of Arthritis & Rheumatism. After examining 12 patients with knee OA, researchers found arthritic pain to be associated with more activation of areas of the brain—the cingulate cortex, thalamus, and amygdala—that are involved in the processing of emotions, while non-arthritic pain was processed by other parts of the brain’s "pain matrix," which processes more sensory-specific aspects of pain, such as intensity, location, and duration. The study’s authors hope that their findings may lead to the development of a new class of analgesics aimed at relieving arthritis pain.
Biologics for RA Linked to Skin Cancer Risk
Biologic therapy for rheumatoid arthritis (RA), using TNF inhibitors such as infliximab, etanercept, adalimumab, and anakinra, is associated with an increased risk for skin cancer but not for other types of cancers, according to a study in the August 2007 issue of Arthritis & Rheumatism. From 1998 to 2005, researchers studied incidences of cancer in 13,001 RA patients, 49 percent of whom had been exposed to biologic therapy for approximately three years. Although biologics were associated with increased rates of melanoma and basal cell skin cancers, they were not associated with other types of cancer, including breast, lung, colon and lymph node cancer.