Half of American Adults Will Get Knee Osteoarthritis
Posted Dec 28 2009 6:00am
Recently released research says that nearly half of all adults will develop osteoarthritis of the knee by age 85. People who had previous knee injuries or are obese have an even higher risk.
Researchers from the University of North Carolina at Chapel Hill and the U.S. Centers for Disease Control (CDC) reviewed data on more that 3,000 people from Johnston County, N.C. All of the participants, who were all over 45 years of age, were interviewed, given physical exams and X-rays. They were then evaluated twice over an average of 6 years. The average age of the group was 61.
At the beginning of the study, approximately 60% of the participants were overweight or obese and 15% already had knee osteoarthritis. In spite of the research group being located within a small geographic area, researchers believe that the results would likely apply to all Americans.
The results of the study showed that the lifetime risk of developing osteoarthritis of the knee was 44.7%. Several factors were ruled out as contributors to that risk, those being race, sex and level of education.
Two factors that did contribute were the existence of a prior knee injury and whether or not the patient was obese or overweight.
Those participants with a previous knee injury have a risk of 56.8%, compared to 42.3% for those without a prior knee injury.
Those people with a normal weight have a risk of 30.2% of developing osteoarthritis of the knee. However, those that were overweight increased their risk to 46.9% and those who were obese have an even higher risk of 60.5%. People that were normal weight at age 18, but were obese or overweight by age 45 had the greatest risk.
“These results show how important weight management is for people throughout their lives,” says Joanne Jordan, M.D., in a news release. Dr. Jordan is principal investigator of the Johnston County Osteoarthritis Project and a senior study researcher. “Simply put, people who keep their weight within the normal range are much less likely to develop symptomatic knee osteoarthritis as they get older and thus much less likely to face the need for major surgical procedures, such as knee replacement surgery.”
The results of the 13 year study were published in the September 15th issue of Arthritis Care and Research.