CHICAGO (Reuters) - People with diabetes are twice as likely to have arthritis, putting them in a double bind as the pain in their joints keeps them from getting the exercise they need to keep both diseases at bay, the U.S. Centers for Disease Control and Prevention said on Thursday.
They found that more than half of U.S. adults diagnosed with diabetes also have arthritis, a condition that makes them far less likely to exercise.
The association was independent of age, gender or body mass index (BMI), a measure of obesity.
"The prevalence of arthritis in a diabetic population is astoundingly high," said Dr. John Klippel, president of the Arthritis Foundation in a telephone interview.
"Over half the people with diabetes have arthritis. If in fact you have both conditions, you are quite unlikely to be physically active," he said.
According to the report, nearly 30 percent of diabetics with arthritis are likely to be physically inactive, compared with 21 percent of diabetics who do not have arthritis.
That compares with 17.3 percent of adults with arthritis alone who are inactive, and 10.9 percent of adults with neither condition who are inactive.
Nationwide, the CDC found 46.4 million adults have arthritis and 20.6 million have diabetes.
The CDC said the study suggests the pain of arthritis presents a barrier to physical activity -- the very thing that might offer people some relief.
"For people with diabetes, physical activity helps control blood glucose and risk factors for complications. For people with arthritis, physical activity reduces pain and improves function," said Janet Collins, director of the CDC's National Center for Chronic Disease Prevention and Health Promotion.
Klippel thinks two things stand in the way.
"Because arthritis affects the joints and is associated with pain, people with arthritis, when they begin to exercise, experience more pain," he said.
"The other thing is there is a common misconception that exercise is bad for arthritis and it will damage joints."
He said many forms of exercise are in fact "joint-safe," including walking, swimming and biking.
"If people walked 30 minutes a day it would have a profound effect on reducing their pain and improving their symptoms," he said.
Given the scope of the problem, Klippel said the finding will likely affect the way doctors and policymakers go about encouraging their patients to exercise.
"Public health programs that are directed at controlling diabetes are going to need to pay a lot more attention to arthritis if they hope to get people to be physically active," he said.
The report is based on data gathered from a random telephone survey in 2005 and 2007. People were asked if they had ever been diagnosed with arthritis or diabetes.
It does not say what type of arthritis people had -- osteoarthritis, rheumatoid arthritis or another form. Nor does it say if people had type 2 diabetes, the most common kind that is associated with obesity and lack of exercise.
Type 1 diabetes is an autoimmune disease often diagnosed at an early age.
Editing by Maggie Fox and Xavier Briand