Lack of vigorous activity linked to functional decline in older adults with arthritis

Study supports physical activity programs for preventing disability among elderly patients

Arthritis is the leading cause of disability in the United States. Nearly 60 percent of Americans ages 65 and older suffer with some form of this progressive joint disease. For more than 1 in 10 sufferers, arthritis makes simple, everyday tasks, from walking up a flight of stairs to bathing and dressing, extremely difficult. By 2010, arthritis is projected to affect almost 40 million Americans over age 65, potentially increasing the ranks of senior citizens with disabilities that can limit independent living.

To avert an epidemic of disability in the future and ease the burden on Medicare, researchers are seeking to understand better and manage all the components – demographic, biological, socioeconomic, and behavioral – that contribute to functional decline in arthritis patients. Toward this goal, a team of researchers at Northwestern University conducted a long-term study of various risk factors, based on a large national sample of older adults with arthritis. Their findings, featured in the April 2005 issue of Arthritis & Rheumatism, offer good news for guiding effective prevention efforts. Among the subjects – 5,715 women and men ages 65 and up – the strongest predictor of the loss of ability to perform basic activities of daily living after developing arthritis was the lack of regular vigorous physical activity.

All patients in this study were diagnosed with having arthritis or rheumatism and were drawn from a large national study of health among people of traditional retirement age. 64 percent of the patients were female. The majority was also white, with 8.6 percent African Americans and 4.5 percent Hispanics. At baseline, nearly 20 percent of the subjects reported some functional limitation. The research team evaluated all participants for a wide range of risk factors, including age, education, income level, and the toll of other adverse health conditions. The researchers also took note of potentially unhealthy behaviors, including smoking, alcohol use, extreme weight gain or loss, and a sedentary lifestyle. Then, they traced each subject’s functional decline over the course of two years. Over the two-year period, nearly 14 percent of the patients experienced a measurable decline in their ability to carry out daily activities. Functional ability deteriorated more frequently among women (15 percent) than men (11 percent), and substantially more frequently among minorities (18 percent of Hispanics and close to 19 percent of African Americans) than Caucasians (about 13 percent). The high rates of functional decline among older women and ethnic minorities with arthritis were attributed to the burden of added ailments, particularly diabetes, stroke, vision loss, depression, and cognitive impairment; no alcohol use and, above all, the lack of regular vigorous physical activity.

Lack of regular physical activity was the most prevalent risk factor for functional decline among older arthritis patients, reported by over 64 percent of the subjects. Other than cognitive impairment, which was present in only 3 percent of the participants, lack of regular vigorous physical activity was the strongest predictor across the spectrum of risk factors. What’s more, when researchers adjusted for all other risk factors, lack of regular vigorous physical activity almost doubled a patient’s odds for functional decline and eventual disability in basic daily tasks essential to maintaining independence.

“The strong association between lack of regular vigorous physical activity and subsequent functional deterioration in this national arthritis cohort is particularly important from a public health point of view, since this risk factor is very common among persons with arthritis and can be changed through intervention,” asserts the study’s leading author, Dorothy Dunlop, Ph.D. “More than 60 percent of adults with arthritis do not meet the U.S. Surgeon General’s recommendations for physical activity. The present study showed that function declined less frequently in older adults with arthritis who engaged in regular vigorous physical activity, regardless of their baseline functional ability.”

To provide a clearer picture of the benefits of exercise for even elderly arthritis patients, the researchers estimated the expected two-year rates of functional decline if all the participants had regularly engaged in exercise or physical activity. According to their calculations, the functional deterioration could have been reduced by as much as 32 percent.

“These findings indicate that older persons with chronic conditions need to be encouraged to participate in physical activities, regardless of their current capabilities,” Dr. Dunlop stresses. “Motivating older persons with arthritis who are not engaged in regular physical activity to change behavior could reduce subsequent functional decline among these persons by almost a third.”