Osteoarthritis (OA) is the most common joint disorder in the industrialized world. The joints most commonly affected by OA are the knee, hip, hand, foot, and spine.1 Knee OA is the most common and persistent cause of mobility dependency and disability; its prevalence is estimated at over 250 million, or 3.6% of the world’s population.2
Osteoarthritis is a disease of the whole joint, involving cartilage—soft tissue within the joint—and the underlying bone. Current thinking indicates there are at least 2 pathways of disease development, biomechanical (excessive joint loads), and physiological (excessive inflammation). Osteoarthritis pain comes from the highly innervated soft tissue and underlying bone. Osteoarthritis affects people differently. In some, it may progress quickly, but for most people, joint damage develops gradually over years. In some people, OA is relatively mild and interferes little with day-to-day life; in others, it causes significant pain and disability. Symptoms of knee OA include stiffness, swelling, and pain, which make it hard to walk, climb, and get in and out of chairs and bathtubs.
How do we reduce osteoarthritis pain?
Clinical guidelines strongly encourage exercise and weight management to relieve pain and improve function.3 However, many physicians who treat people with knee OA have no practical means to implement these behavioral interventions as recommended by numerous OA treatment guidelines.
Dr. Messier and a team of researchers at Wake Forest University conducted the Intensive Diet and Exercise for Arthritis (IDEA) trial where they compared diet-induced weight-loss (D) and exercise (E) interventions, separately and in combination (D+E). In that trial, an intensive diet-induced weight loss of 10% combined with exercise was significantly more effective at reducing pain in men and women with symptomatic knee OA than either the diet intervention or exercise intervention alone (Figure 1).4,5
IDEA was an efficacy study implemented in a university setting under rigorously monitored and controlled conditions. Thus, the clinically important question is:
Can this successful solution to a pervasive public health problem be adapted for real-world clinical and community settings?
Our new study aims to develop a systematic, practical, cost-effective diet-induced weight loss and exercise intervention implemented in community settings and to determine its effectiveness in reducing pain and improving other clinical outcomes in persons with knee OA.
Weight-loss and Exercise for Communities with Arthritis in North Carolina (WE-CAN) is the first long-term trial of diet-induced weight loss and exercise in older adults with knee OA implemented under pragmatic conditions in both rural and urban communities. The WE-CAN study is a combined effort from the Wake Forest University Department of Health and Exercise Science and the University of North Carolina Thurston Arthritis Research Center, with collaborators from Wake Forest School of Medicine, Haywood Regional Medical Center, East Carolina University, Harvard Medical School, and the University of Sydney Australia. This 18-month intervention trial builds on the results of IDEA. The intent of the WE-CAN trial is to translate this highly beneficial, long-term intervention for a major chronic health condition to geographically and socioeconomically diverse community settings across the state of North Carolina (Figure 2).
This study will establish the effectiveness of a community program that will serve as a blueprint and exemplar for clinicians and public health officials in urban and rural communities who wish to implement a weight loss and exercise program designed to reduce knee pain and improve other clinical outcomes in overweight and obese adults with knee OA.
Intensive diet-induced weight loss
The dietary plan is characterized by frequency of contacts, methods to induce caloric restriction, and behavioral strategies. Losing 10% of baseline body weight is necessary for a moderate to large clinical effect. IDEA participants who lost more than 10% of baseline body weight had greater reductions in pain and improvement in function than participants who lost between 5 and 10%.3 Based on IDEA, most participants will reach their weight-loss goal after 9 months. Once it is achieved, they may self-select to begin weight maintenance or continue to lose weight using safe, healthy nutrition practices, provided the participant is motivated to continue losing weight and has not reached a level associated with possible health hazards.6,7 The intervention staff members conduct group and individual sessions throughout the 18 months. Content emphasizes nutrition and behavioral strategies to attain the weight-loss goal and will be presented to participants in their preferred contact method.
The exercise component includes 60-minute sessions 3 days per week for 18 months at one of the designated community facilities. The prescribed exercise program consists of four phases: aerobic (15 min), resistance-training (20 min), a second aerobic (15 min), and cool-down (10 min). Walking is the primary mode of aerobic training. Strength training is particularly relevant to offset any loss of muscle and bone mass resulting from weight loss. Depending on the resources available at each community facility, machines, Thera-bands™, free weights, or the participants’ own body weight are used for resistance. In addition to the 3 scheduled days, participants are encouraged to exercise most other days of the week on their own. Monthly exercise logs are used to monitor progress. Our protocol is consistent with the American College of Sports Medicine (ACSM) guidelines for exercise for older adults.8
The challenge of weight management and exercise
Exercise and weight loss have been shown to work well9 for pain relief and the combination is most efficacious4,5, yet health practitioners often do not refer patients to community programs, either because they do not exist or because non-pharmacologic alternatives are not part of the treatment plan.10 Intensive weight loss combined with exercise reduces abnormal stress on knees by decreasing joint loads and reduces abnormal physiology by lowering inflammation; both result in less pain and less disability.4
Losing weight and maintaining weight loss are both difficult and people are often unsuccessful. Biological changes fight attempts to lose weight. In an attempt to defend higher weights, the body behaves in “starvation mode” as it increases feelings of hunger, suppresses satiety, and slows metabolic rate.11 The mean weight loss goal of 10% in IDEA was exceeded, in part, because participants received regular attention. Indeed, a possible consequence of a pragmatic approach with little or no participant contact is low adherence. The use of multiple communication techniques with participants is critical to achieving compliance and high retention rates. The WE-CAN trial has hired interventionists from the communities and is working with participants to make sure communication is strong and conducted in the manner most acceptable to the participant.
To meet the chronic disease burden in our nation the Centers for Disease Control and Prevention has launched several strategic initiatives of which one is to establish community-based programs that support healthy behaviors.12 One of these strategic methods is the development of a Physical Activity Implementation Guide from the Osteoarthritis Action Alliance (OAAA), a coalition of more than 90 organizations committed to elevating OA as a national health priority. OAAA works to increase access to community-based programs through their resource library, newsletters, and mini-grant program that funds community organizations to deliver evidence-based physical activity interventions such as the Arthritis Foundation’s Walk With Ease program.
One dilemma for physicians is the lack of practical means to implement and sustain a diet and exercise program in a community-based environment. WE-CAN is designed to test the effectiveness of a community program that can be implemented in various settings and develop guidelines and protocols for the scalability of a weight loss and exercise program designed to reduce knee pain, as well as improve other clinical outcomes in overweight and obese adults with knee OA. We envision a national implementation of this systematic program that will serve as a model for healthcare professionals on implementing platforms that are accessible to consumers and clinicians, and would be of value to insurers because it can be sustained long-term and at a reasonable cost.
For the latest in Osteoarthritis research subscribe to the Osteoarthritis Action Alliance Research Round-up. The Osteoarthritis Action Alliance serves as an excellent resource that can help physicians, researchers and patients stay up-to-date with OA research, treatment and prevention.
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Messier SP, Loeser RF, Miller GD, Morgan TM, Rejeski WJ, Sevick MA, et al. Exercise and dietary weight loss in overweight and obese older adults with knee osteoarthritis: the Arthritis, Diet, and Activity Promotion Trial. Arthritis Rheum. 2004;50(5):1501-10.
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Chodzko-Zajko WJ, Proctor DN, Fiatarone Singh MA, Minson CT, Nigg CR, Salem GJ, et al. American College of Sports Medicine position stand. Exercise and physical activity for older adults. MedSciSports Exerc. 2009;41(7):1510-30. doi: 10.1249/MSS.0b013e3181a0c95c [doi].
Zhang W, Moskowitz RW, Nuki G, Abramson S, Altman RD, Arden N, et al. OARSI recommendations for the management of hip and knee osteoarthritis, Part II: OARSI evidence-based, expert consensus guidelines. Osteoarthritis Cartilage. 2008;16(2):137-62.
Brand CA, Ackerman IN, Bohensky MA, Bennell KL. Chronic disease management: a review of current performance across quality of care domains and opportunities for improving osteoarthritis care. Rheum Dis Clin North Am. 2013;39(1):123-43. Epub 2013/01/15. doi: 10.1016/j.rdc.2012.10.005. PubMed PMID: 23312413.
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