RESEARCH - Exercise slows pain progression, fuctional decline in elderly arthritis patients

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Exercise slows pain progression, functional decline in elderly arthritis

patients

Oct 3, 2005

Janis

Palo Alto, CA and Chicago, IL - The long-term practice of vigorous exercise

regimens such as running can significantly slow aging-related increases in

musculoskeletal pain in older adults, and older arthritis patients who

maintain a regular exercise program might reduce functional decline by as

much as 32%, according to a pair of studies.

Dr Bonnie Bruce (Stanford University, Palo Alto, CA) reports in a paper

published September 19, 2005 in Arthritis Research & Therapy that older

adults who averaged about five hours of vigorous exercise per week reported

about 25% less musculoskeletal pain than more sedentary subjects [1]. Dr

Dorothy D Dunlop (Northwestern University, Chicago, IL) finds even more

striking benefits of exercise in older adults with arthritis. She reports in

Arthritis & Rheumatism that lack of regular vigorous physical activity

almost doubled the odds of functional decline over a two-year period in

arthritis patients over age 65 [2].

" It is well known that physical activity improves health. That evidence led

to the US surgeon general's physical-activity recommendations. However,

whether or not physical activity is able to reduce disability-a major driver

of healthcare costs-is an open question, " Dunlop tells rheumawire. The study

her group conducted " directly addresses this question for persons with

arthritis, " she says. " These findings from a longitudinal survey of a

national sample by the National Institute of Arthritis and Musculoskeletal

and Skin Diseases and conducted by the University of Michigan show that high

vs low levels of physical activity protect against disability progression in

adults reporting arthritis. "

Lack of exercise speeds functional decline in arthritis patients

Dunlop et al looked at the relation between vigorous activity and functional

decline in older adults with arthritis. This study analyzed two-year

longitudinal data from a cohort of 5715 adults ages 65 or older from a

national probability sample (the 1998 Health and Retirement Study). The

analysis included all patients who answered " yes " to the question, " Have you

ever had or has a doctor ever told you that you have arthritis or

rheumatism? "

The definition of function was based on ability to perform basic activities

of daily living (ADL). The investigators used a multiple logistic regression

model to estimate the association between functional decline and a variety

of potential risk factors.

" Lack of regular vigorous physical activity, the most prevalent risk factor

(64%), almost doubled the odds of functional decline (adjusted OR 1.5, 95%

CI 1.5-2.4) after controlling for all risk factors, " the authors write.

" Because some people with arthritis may be less capable of physical

activity, we also looked at this question within subgroups of people defined

by the number of physical limitations reported. Within each group, those

engaged in higher levels of physical activity were less likely to experience

disability progression than their less active peers. The benefit was

greatest for those who should be most capable-the subgroup reporting no

physical limitations. This is important information to promote the

importance of ongoing public-health efforts (eg, by the Centers for Disease

Control and the Arthritis Foundation) to increase physical activity for

persons with arthritis, " Dunlop says.

More training, less pain

In the other study, Bruce and colleagues Dr F Fries (Stanford

University) and Dr Deborah P Lubeck (Genentech, South San Francisco)

conducted a prospective, longitudinal study in members of a running club

(n=492) and in community controls (n=374). Subjects were followed for six

years and were categorized both as runners' association members vs community

controls and as ever runners ( " runners, " n=565) and never runners

( " controls, " n=301), to include those who had been runners but stopped.

Subjects were surveyed with yearly questionnaires and visual-analog-scale

(VAS) pain measures.

As might be expected, at baseline the runners were significantly younger (62

vs 66 years, p<0.05), slimmer (BMI 23.0 vs 24.3, p<0.05), and less likely to

have arthritis (35% vs 43%, p<0.05). Over the course of the study, the

runners averaged more exercise per week (291 minutes vs 120 minutes, p<0.05)

and also had more fractures (52% vs 48%, p>0.05). The runners were also less

likely to be smokers.

Over the study period, the runners' mean VAS pain scores (adjusted for

group, gender, and baseline BMI) were significantly lower than those of the

controls (p<0.01). " Pain scores were consistently about 25% less in the

exercising group throughout the period of observation, " the authors write.

" Our study adds to the abundance of evidence that being physically active

over the long term contributes to better health outcomes, in this case

reduced pain, but it does not provide insight into mechanisms. These might

include endorphin release, increased resistance to musculoskeletal injury,

increased musculoskeletal strength, psychologically based increase in pain

threshold, or other psychological mechanisms, " Bruce tells rheumawire.

The researchers also tested the extent to which exercise and pain were

affected by increasing age. Their data show that, particularly after age 60,

both male and female controls had steady increases in VAS scores, while

runners had slower rates of increased pain. These trends did not reach

statistical significance.

One of the researchers' concerns had been the possibility that years of

running or similar vigorous exercise might actually increase pain. They

note, " If running creates damage through accumulated trauma, then runners

with about 10-fold the amount of exposure to such high trauma should have

increased pain over time, and any initial differences due to self-selection

should narrow as the study progresses. " No such pain increases were

observed.

Sources

1. Bruce B, Fries JF, Lubeck DP. Aerobic exercise and its

impact on musculoskeletal pain in older adults: a 14-year prospective,

longitudinal study. Arthritis Res Ther 2005; 7:R1263-R1270. Available at:

http://arthritis-research.com/content/7/6/R1263

2. Dunlop DD, Semanik P, Song J, et al. Risk factors for

functional decline in older adults with arthritis. Arthritis Rheum 2005;

52:1274-1282.

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