Second study shows improved immune response linked to exercise
BOSTON -- New research on the effects of exercise on juvenile arthritis indicates it is OK -- advantageous, in fact -- for these kids to be kids.
Children with juvenile arthritis who took part in an eight-week individualized program of resistance exercise at the University at Buffalo significantly improved their ability to function, some by as much as 200 percent, preliminary results of the study have shown. Equally important, their pain, disability and use of medications decreased significantly.
Nadine Fisher, Ed.D., UB assistant professor of occupational therapy and rehabilitation medicine, presented results of the study here today (Nov. 16, 1999) at a joint meeting of the American College of Rheumatology and the Association of Rheumatology Health Professionals.
"We expected to see a change in the disease with exercise," Fisher said, "but we didn't expect to see so much. Everybody showed tremendous physiological improvement -- better strength, endurance and even better aerobic capacity, although these exercises weren't designed for that. Everyone had less pain. Some kids showed 200-percent improvement," she said. "That's pretty exciting."
An accompanying investigation conducted by Jaya Venkatraman, Ph.D., UB associate professor of nutrition, also presented here today, revealed the cellular basis for these changes: Exercise produced a change in immune response. Juvenile arthritis is a form of rheumatoid arthritis, an autoimmune disease in which the body's immune system attacks joints and surrounding tissue.
The children who took part in the exercise program had significantly lower levels of cytokines -- proinflammatory proteins -- and higher levels of anti-inflammatory compounds in their plasma than those who did not exercise, this study showed
Fisher designed the exercise program and had shown its benefits in previous studies of elderly patients with osteoarthritis. An individualized resistance-exercise program had never been tried with children, however. In fact, Fisher said she knows of only one other study of exercise and juvenile arthritis, and that study dealt with aerobic capacity.
Fisher's study, which is half-completed, has involved 11 children with juvenile arthritis to date. Six took part in the exercise program and five served as "disease" controls. Another 13 children without arthritis served as normal controls. All were between the ages of 6 and 13.
To establish a baseline level of disability or deficit, Fisher and colleagues tested the strength and endurance of the children's quadriceps and hamstrings, speed of muscle contraction, oxygen consumption, heart rate and blood pressure, and assessed their pain, disability and general functional performance. Based on this assessment, the researchers designed a resistance program for each child randomly assigned to the exercise program.
All exercises centered on the legs and were based on resistance to avoid injury to joints. They included pressing against a stationary object and lifting and holding weights for strength and endurance. Once the children adapted to the exercises, they were asked to increase the speed of weightlifting to improve coordination and balance.
Venkatraman and colleagues collected blood from all participants at four points: before and after the initial testing, after the eight-week exercise program but before the final test, and after the final test.
Results showed that the exercisers' quadriceps' strength and endurance increased 48 percent and 32 percent, respectively; hamstring strength and endurance increased 99 percent and 59 percent respectively, and muscle-contraction speed increased 51 percent. Maximum systolic blood pressure, oxygen consumption and heart rate also increased.
In addition, functional status of the group, a measure of overall physical capability, increased by 32 percent. Pain dropped nearly by half and disability and number of medications by a quarter.
The children with juvenile arthritis who did not participate in the exercise project experienced significant decreases in hamstring strength and endurance over the eight-week period, results showed. In addition, pain rose nearly 75 percent, disability by 10 percent and use of medications by 54 percent.
Assessment of the blood samples by Venkatraman and colleagues showed higher concentrations of proinflammatory cytokines in children with juvenile arthritis than in normal controls at baseline. The resistance-exercise program produced significant decreases in cytokines and increased production of anti-inflammatory compounds, results showed.
"Showing that exercise actually helps with juvenile arthritis gives parents and children ways to manage the symptoms," Fisher said. "It also allows these kids to behave more like normal kids."
Additional researchers were Kathleen M. O'Neil, M.D., UB associate professor of clinical pediatrics, and Vylma Velazquez, M.D., pediatric fellow.
The study is funded by a grant from the National Institute on Disability and Rehabilitation Research.
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