Smoking linked with rheumatoid arthritis in women
Long-term smoking increases the risk of rheumatoid arthritis in women, Harvard researchers report.
Although the increase in the risk is modest, researchers are convinced that environmental factors, and not just genetics, play a role in the disease. "We know that there are genetic factors associated with rheumatoid arthritis,'' added Karlson, an assistant professor at Harvard Medical School and Brigham and Women's Hospital in Boston, Massachusetts. The study findings not only reconfirm that people should not smoke in general, they also suggest that individuals with a family risk of rheumatoid arthritis can modify their behavior to reduce the risk, she added. The study findings, published in the May issue of Arthritis and Rheumatism, support previous reports that suggested estrogen may provide protection against the disease. Women had an increased risk of developing rheumatoid arthritis during menopause, when estrogen levels dropped. This risk declined for women who used hormone replacement therapy. Since smoking reduces estrogen levels, Karlson and colleagues hypothesize that it may interfere with these protective effects. However, because they did not measure estrogen levels in this study, this could not be confirmed.