Researchers believe that arthritis and arthritis-attributable activity limitations (AAL) may be connected to obesity and physical inactivity. The findings, published in the journal Arthritis Care & Research, also indicate that the relationship is more prominent in Americans than Canadians, particularly American women, and represent the first time that arthritis rates between the two countries have been compared.

By studying the results of a joint study conducted by Statistics Canada and the U.S. National Center for Health Statistics, researchers analyzed data on over 3500 Canadians and 5100 Americans. What they found was that the prevalence of both arthritis and AAL were higher in the U.S. (18.7% and 9.6% respectively) than in Canada (16.8% and 7.7%). The comparison was even more striking when it focused on women (13.0% in the U.S. vs. 9.2% in Canada), while in men, the numbers were similar for both countries.

The authors of the study went on to suggest that higher rates of arthritis and AAL may be due to the higher rates of obesity and physical inactivity that are seen in the United States, especially in women. Therefore, any policies that are geared toward alleviating obesity and encouraging physical activity might very well, by extension, help stem the incidence of this painful affliction.

Arthritis is a chronic condition and one of the primary causes of physical disability in the U.S. and Canada. While the true definition refers to inflammation of the joints, arthritis has come to include over 100 rheumatic disorders that affect the joints, as well as the surrounding tissue. The condition is characterized by pain and stiffness in the joints, and the symptoms can develop quickly or over time. In certain instances, the immune system is involved.

Certain risk factors increase a person’s chance of developing arthritis, some of which are within a person’s control, others which are not. Modifiable risk factors include body weight or obesity, occupation, injury, and infection. Non-modifiable risk factors include heredity, gender (affecting women more than men), and age.

In fact, our risk increases as we get older, and because of this, experts predict that rates of arthritis will increase as the baby-boomer population ages. According to the National Health Interview Survey, 46 million adults have “self-reported doctor diagnose arthritis,” and 19 million have arthritis and AAL. The costs attributed to the condition is estimated to be nearly $128 billion, and experts predict that by 2030, the number of adults affected will increase to 67 million.

The link between obesity and arthritis has been supported with research. Studies have found that overweight and obese people, as indicated by their body mass index (BMI) report more doctor diagnosed arthritis than people with a lower BMIs, with 66% of arthritis sufferers being overweight or obese. Doctors have also reported that a loss of weight by as little as 11 pounds can cut the risk of developing knee arthritis by as much as 50% in women.

For more information about arthritis and obesity, speak with your doctor and visit the websites for the Center for Disease Control and Prevention (CDC) and the Arthritis Foundation.