(RxWiki News) For patients who have osteoarthritis, aching knees don't always seem compatible with physical activity. But a new study shows that exercising may actually add healthy years to a patient's life.
Researchers measured the activity levels of people with osteoarthritis in their knees. Then they followed up two years later to gather information about the participants' health status and quality of life.
They found that people who engaged in 2.5 hours of moderate to vigorous exercise per week added 20 additional days of perfect health to their lives per year.
The authors of the study suggested that physical activity could be a cost-effective way to treat osteoarthritis and improve a patient's quality of life.
"If you have knee OA, talk to your doctor about an exercise plan."
Kai Sun of Northwestern University led the study to see if there was a relationship between physical activity and quality of life for people with osteoarthritis.
Osteoarthritis, or OA, is a joint disease in which the patient's cartilage wears away, leading to pain, swelling, and muscle weakness. OA is normally found in middle-aged and older people — especially those who are overweight.
Knee OA, in which the cartilage in the knees breaks down, is one of the most common forms of OA.
Because joints become tender, OA can sometimes lead to a decrease in mobility and activity, and a sedentary lifestyle can in turn contribute to other health problems. US federal guidelines recommend physical activity to improve the health and symptoms of people with OA.
In the recent study, researchers looked at data from more than 4,700 adults with or at risk for knee OA.
The researchers administered questionnaires, took images of the knee OA, and used laboratory tests to evaluate the progression of the disease.
They also monitored the participants' exercise habits for one week and categorized each of the patients as sufficiently active, insufficiently active and inactive. People who engaged in moderate to vigorous physical activity for 150 minutes or more per week were active, while those who engaged in no moderate to vigorous physical activity were inactive.
At the beginning of the study and two years later, the researchers also used various scores to calculate Quality-Adjusted Life Years, or QALYs — a measure of health outcomes based on both quality and length of a patient's expected lifespan.
The researchers found that people who engaged in physical activity had significantly higher QALYs than those who were inactive.
Patients who met the physical activity guideline of 150 minutes of moderate to vigorous exercise per week had QALYs that were .11 higher than those who were inactive.
In other words, people with knee OA who were sufficiently active had an estimated 20 additional days of perfect health per year. Even people who were only partially active had more healthy days than those who were inactive.
The researchers concluded that there is a strong relationship between increased moderate to vigorous physical activity and quality of life years.
They suggested that encouraging people to become more active would help to increase knee OA patients' quality and length of life.
The study will be presented on October 26 at the annual meeting of American College of Rheumatology.
The researchers reported no conflicts of interest or funding sources for the study.