THURSDAY, April 28 (HealthDay News) -- Rising rates of obesity among the 50 million Americans with arthritis are cause for concern because excess weight is associated with increased problems for arthritis patients, a new study says.

In people with arthritis, obesity is associated with disease progression, reduced activity, disability, poorer quality of life, total joint replacement and poor outcomes after joint replacement.

For the study, U.S. Centers for Disease Control and Prevention researchers analyzed Behavioral Risk Factor Surveillance System data from 2003 to 2009 and found that obesity prevalence among adults with arthritis was 54 percent higher than among adults without arthritis.

During that time period, obesity prevalence among U.S. adults with arthritis increased significantly in 14 states and Puerto Rico, decreased in the District of Columbia and remained about the same elsewhere.

The number of states in which more than 30 percent of adults with arthritis were obese increased from 38 (including D.C.) in 2003 to 48 in 2009. The number of states in which more than 40 percent of adults with arthritis were obese increased from zero in 2005 to seven in 2007 and 12 in 2009, the investigators found.

The median state obesity prevalence among adults with arthritis rose from 33.2 percent in 2003 to 35.2 percent in 2009. In 2003, prevalence ranged from 40.1 percent in Ohio to 25.1 percent in Colorado. In 2009, prevalence ranged from 43.5 percent in Louisiana to 26.9 percent in Colorado.

The findings highlight the urgent need to expand programs to prevent obesity among arthritis patients and to promote treatment and management of the disease, the researchers said.

The study appears in the April 29 issue of the Morbidity and Mortality Weekly Report, published by the CDC.

In the United States, about 50 million adults have arthritis and about 72.5 million adults are obese. Estimated annual medical costs are $128 billion for arthritis and $147 billion for obesity.

More information

The U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases has more about arthritis.