Very attainable weight loss goals are sufficient to reduce pain and therefore motivate overweight patients with knee osteoarthritis to keep that weight off, according to research presented this week at the American College of Rheumatology Annual Scientific Meeting in Washington, DC.

Weight gain dramatically multiplies the pounds of pressure and loading forces on the knee structure. Because this pressure leads to more wear and tear over time, body weight is considered one of the significant contributors to the onset and progression of knee osteoarthritis. Conversely, weight loss can relieve those realities. However, for the 35,000,000 people, 65 years of age and older, whose quality of life is already compromised by osteoarthritis, the need to make large scale changes in their eating and lifestyle habits can be as overwhelming as the symptoms of the disease itself.

Now, a long-term weight loss program has demonstrated that even modest weight loss contributed to improved quality of life in 30 mildly obese patients, and the resulting reduction in pain was so dramatic as to motivate their keeping the weight off. While participants were generally in their late 50s/early 60s, female and white, the improvements they realized in losing and keeping weight off were consistent despite age, race, sex, education or magnitude of weight loss. On average, the group lost 6.8 kg (15 pounds) over 4 months of weekly meetings focused on diet, exercise and lifestyle changes. After quarterly meetings over the following year, they had regained an average of only 2.5 kg (5.5 pounds). The initial weight loss was associated with reduced body pain levels and a quality of life comparable to healthy adults in the same age bracket. The reduction in body pain then motivated participants to maintain their weight loss.

"For someone who is very overweight, as little as a 15-pound weight loss over 16 weeks can result in decreased discomfort, increased quality of life, and motivation for staying active and healthy," explains Steffany Haaz, Project Director, Johns Hopkins Arthritis Center, Baltimore, Maryland; doctoral candidate, Department of Health, Behavior and Society, Johns Hopkins School of Public Health; and an investigator in the study. "That means just one pound a week translates into significant improvements in comfort and movement."

The American College of Rheumatology is the professional organization for rheumatologists and health professionals who share a dedication to healing, preventing disability and curing arthritis and related rheumatic and musculoskeletal diseases. For more information on the ACR's annual meeting, see http://www.rheumatology.org/annual.

Presentation Number: 2075

Evidence for Reciprocal Relationships Among Pain, Weight Loss, and Long Term Weight Maintenance for Obese Persons with Knee OA

Steffany Haaz, Kevin R. Fontaine, Joan M. Bathon, Susan J. Bartlett. Johns Hopkins University, Baltimore, MD

Background. Knee OA is a common, chronic disease that causes pain, disability and reduced quality of life (QOL).

Purpose. To determine the long-term effects of a comprehensive behavioral weight loss program for overweight patients with knee OA.

Participants. Participants were 30 adults who met ACR criteria for knee OA, reported knee pain on most days and had difficulty with daily activities. Participants were generally (mean ? SD) older (58.2 ? 6.1 yrs), female (80%), mildly obese (BMI 32.6 ? 3.0 kg/m2) and white (81%).

Methods. Participants completed a 16-week behavioral weight loss program of weekly meetings focused on diet, exercise and lifestyle change. For 1 year after the intervention, participants met quarterly to discuss weight maintenance strategies. The SF-36 was administered at baseline, post-intervention, and after 1 year. Changes in QOL were assessed with paired t-tests and linear regression models were used to identify predictors of weight loss, weight maintenance and QOL.

Results. Over 4 months, participants lost an average of 6.8 ? 4.7 kg (p<.001). They regained an average of 2.5 ? 4.8 kg in the following year, but remained significantly (p = .05) below baseline weight.

At baseline, participants scored in the lowest quartile on SF-36 physical function (PF), role physical (RP) and bodily pain (BP) domains, compared to age-matched norms. Each of these domains improved (p<.001) during the intervention, with scores moving into the normal range. Improvements were maintained at one year (p<.01) and stayed in the normal range, regardless of age, race, sex, education or magnitude of weight change.

Neither weight loss nor weight change during the 1 year follow-up was associated with age, race, sex, education, baseline PF or initial weight. Baseline BP was not associated with weight loss during the intervention. However, weight loss was associated with improved BP (r = .34, p <.05). In turn, low post-intervention BP was the most robust predictor of keeping weight off during follow-up (r = .46, p =.01). Change in BP during the intervention was also associated with weight maintenance during follow-up (r = .36, p<.05). There was a trend for weight change during the follow-up to predict BP at one year (r = .33, p=.07).

Conclusions. These data suggest that weight loss is associated with significant improvements in QOL, and especially pain, in obese persons with knee OA, which persist 1 year later. Initial QOL impairments are resolved, so that QOL becomes comparable to that of healthy age-matched adults. Baseline pain does not appear to be associated with ability to lose weight, but it is predictive of long-term weight maintenance. Thus, it appears that losing weight and keeping weight off are associated with significant reductions in OA-related pain. This suggests a cyclical relationship, whereby weight loss reduces pain, and lower pain levels may facilitate behaviors that promote long-term weight maintenance.

Supported by NIH NIAMS AR02160-01.

Disclosure Block: S. Haaz, None.

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