Study of large, ethnically diverse population shows strong association between high levels of hyaluronic acid and severe osteoarthritis of the knees and hips.
A chronic degenerative joint disease, osteoarthritis (OA) is a common cause of pain and disability among older Americans. OA of the knee affects up to 6 percent of the older population, while OA of the hip affects about another 3 percent. While treatments vary, there is hope that early intervention – before joint destruction can be clearly seen and measured on an X-ray image-will improve outcomes.
The need for better ways to assess OA's activity from its onset has led researchers to investigate possible biomarkers, particularly those related to cartilage and bone turnover. A biomarker is substance found in the blood or joint fluid whose levels can be used to assess the presence or activity of a disease. Among likely candidates for a biomarker for OA is hyaluronic acid, also known as hyaluronan or simply HA. HA is a component of connective tissue that is widely distributed throughout the body and plays an important role in joint function. A recent study, published in the January 2005 issue of Arthritis & Rheumatism, strongly supports the relationship between increased production of HA and increased risk for OA, specifically of the knees and hips, among ethnically diverse men and women.
Led by Drs. Alan L. Elliott and Joanne M. Jordan of the Thurston Arthritis Research Center, University of North Carolina at Chapel Hill, and Dr. Virginia B. Kraus of Duke University Medical Center, the study drew its subjects from a large, local population of participants in the Johnston County Osteoarthritis Project. The study group comprised 753 subjects, including 120 African American men, 245 African American women, 199 Caucasian men, and 189 Caucasian women. The average age of the participants was just shy of 62 years and the mean body mass index was on the heavy side, just over 30. Of the total subjects, 455 had mild to severe knee OA, confirmed by radiographs. 152 of the subjects with knee OA also had hip OA. In 52 of these individuals with OA, the disease had progressed to both knees and both hips.