Chair of the Department of Orthopaedic Surgery at the Mayo Clinic in Jacksonville, Fla
Arthritis is the single greatest cause of chronic pain and disability among Americans. Eighty percent of Americans either have or know someone with arthritis, and the numbers continue to escalate. Though there are more than 100 forms of arthritis, 54 percent of arthritis sufferers have osteoarthritis (OA), commonly known as “wear and tear arthritis.” Women, Hispanics and African Americans are the three population segments that suffer most from OA. It’s no coincidence that these same three groups have the highest levels of physical inactivity. Women are almost twice as likely as men to never engage in significant physical activity, and almost 51 percent of African Americans and Hispanics are physically inactive. So, where is all of this “wear and tear” coming from?
Excess body weight directly impacts weight-bearing joints, especially the knees. Just 10 extra pounds of body weight places an additional 30-60 pounds of force on the knee with each step. The constant stress of such a weight load causes the cartilage that cushions the bones on either side of the joint to erode. This is why knee osteoarthritis is four to five times more common in overweight people than in people with a normal body weight. If obese women decreased in weight to be classified as simply overweight, and women in the overweight category lost enough weight to fall into the normal weight category, knee arthritis among women would decrease by up to 33 percent. Alarmingly, because childhood obesity has reached an epidemic level, the road to OA is likely to begin long before the age of 40.
However, osteoarthritis is not always preceded by weight gain or obesity. Sometimes just the opposite occurs. Reports by the Centers for Disease Control and Prevention (CDC) demonstrate that arthritis sufferers are significantly less likely to be physically active . It is a common belief that people with arthritis need to rest their joints. As a result, many arthritis sufferers decrease their physical activity for fear of increasing pain or making symptoms worse when activity and exercise would actually work to relieve their pain and stiffness. In fact, almost 44 percent of adults with doctor-diagnosed arthritis report no leisure time physical activity. Thus, for many uninformed patients, what begins as painful movement can lead to a sedentary lifestyle. This may descend into disability, causing them to gradually go from a normal weight to obesity. In this process, every pound gained represents four pounds of pressure on knees and six times the pressure on hips, creating a vicious cycle of pain, inactivity and weight gain. In the medical community, this is referred to as “co-morbidity.” Co-morbidities are diseases that work together to worsen a patient’s condition. In this case, osteoarthritis and obesity are known to be co-morbid diseases.
As osteoarthritis and obesity worsen, the level of disability and pain may reach the point where joint replacement surgery is the only remedy. But obese patients’ poor health status can lead to medical complications during surgery. The surgery may take longer and be more difficult, and infection, bleeding and blood clots are more likely to occur. Even after a successful surgery, some individuals never achieve the full post-operative mobility improvement experienced by normal weight patients.
No matter how the cycle begins, obesity and OA are inextricably linked and must therefore be addressed together. Physical activity is key to reducing the risk of developing both, as well as countless other related diseases, such as diabetes, heart disease, hypertension and stroke. Change begins with individual choices made based on perceived challenges and benefits. Therefore, it’s vital that we educate and persuade those that are most at risk that the challenges are surmountable, and that the benefits are attainable and worthwhile. A woman of average height can decrease her risk of knee osteoarthritis by 50 percent for every 11 pounds in weight that she loses. This is a perfect illustration of how patients, empowered by information, can take personal responsibility for the prevention and management of co-morbid conditions and avoid the need for medical intervention.
While long-term solutions are needed, short-term action plans are critical to curbing our nation’s epidemic rates of obesity and OA. On Sept. 18-19, Movement is Life will convene in Washington, D.C. for its third annual National Caucus on Arthritis and Musculoskeletal Health Disparities. With a mission of decreasing gender and racial/ethnic musculoskeletal health disparities by raising awareness of the impact of early intervention on chronic disease management, the link between obesity and OA will be at the forefront of discussions. By involving stakeholders from a multitude of disciplines, we will take steps to reduce disability, encourage physical activity and improve the overall health of the nation.