Effects of Intensive Diet and Exercise on Knee Joint Loads, Inflammation, and Clinical Outcomes Among Overweight and Obese Adults With Knee Osteoarthritis The IDEA Randomized Clinical Trial

Department of Health and Exercise Science, Wake Forest University, Winston-Salem, North Carolina 27109, USA.
JAMA The Journal of the American Medical Association (Impact Factor: 30.39). 09/2013; 310(12):1263-73. DOI: 10.1001/jama.2013.277669
Source: PubMed

ABSTRACT IMPORTANCE Knee osteoarthritis (OA), a common cause of chronic pain and disability, has biomechanical and inflammatory origins and is exacerbated by obesity. OBJECTIVE To determine whether a >= 10% reduction in body weight induced by diet, with or without exercise, would improve mechanistic and clinical outcomes more than exercise alone. DESIGN, SETTING, AND PARTICIPANTS Single-blind, 18-month, randomized clinical trial at Wake Forest University between July 2006 and April 2011. The diet and exercise interventions were center-based with options for the exercise groups to transition to a home-based program. Participants were 454 overweight and obese older community-dwelling adults (age >= 55 years with body mass index of 27-41) with pain and radiographic knee OA. INTERVENTIONS Intensive diet-induced weight loss plus exercise, intensive diet-induced weight loss, or exercise. MAIN OUTCOMES AND MEASURES Mechanistic primary outcomes: knee joint compressive force and plasma IL-6 levels; secondary clinical outcomes: self-reported pain (range, 0-20), function (range, 0-68), mobility, and health-related quality of life (range, 0-100). RESULTS At 18 months, 399 participants (88%) completed the study. Compared with exercise participants, knee compressive forces were lower in diet participants and IL-6 levels were lower in diet and diet + exercise participants. [GRAPHICS] CONCLUSIONS AND RELEVANCE Among overweight and obese adults with knee OA, after 18 months, participants in the diet + exercise and diet groups had more weight loss and greater reductions in IL-6 levels than those in the exercise group; those in the diet group had greater reductions in knee compressive force than those in the exercise group.

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    ABSTRACT: In obese persons, general and specific musculoskeletal pain is common. Emerging evidence suggests that obesity modulates pain via several mechanisms such as mechanical loading, inflammation, and psychological status. Pain in obesity contributes to deterioration of physical ability, health-related quality of life, and functional dependence. We present the accumulating evidence showing the interrelationships of mechanical stress, inflammation, and psychological characteristics on pain. While acute exercise may transiently exacerbate pain symptoms, regular participation in exercise can lower pain severity or prevalence. Aerobic exercise, resistance exercise, or multimodal exercise programs (combination of the two types) can reduce joint pain in young and older obese adults in the range of 14%-71.4% depending on the study design and intervention used. While published attrition rates with regular exercise are high (∼50%), adherence to exercise may be enhanced with modification to exercise including the accumulation of several exercise bouts rather than one long session, reducing joint range of motion, and replacing impact with nonimpact activity. This field would benefit from rigorous comparative efficacy studies of exercise intensity, frequency, and mode on specific and general musculoskeletal pain in young and older obese persons.
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    ABSTRACT: Osteoarthritis (OA) is the most common type of arthritis found in the United States' population and is also the most common disease of joints in adults throughout the world with the knee being the most frequently affected of all joints. As the United States' population ages along with the increasing trends in obesity prevalence in other parts of the world, it is expected that the burden of OA on the population, healthcare system, and overall economy will continue to increase in the future without making major improvements in managing knee OA. Numerous therapies aim to reduce symptoms of knee OA and continued research has helped to further understand the complex pathophysiology of its disease mechanism attempting to uncover new potential targets for the treatment of OA. This review article seeks to evaluate the current practices for managing knee OA and discusses emerging therapies on the horizon. These practices include non-pharmacological treatments such as providing patient education and self-management strategies, advising weight loss, strengthening programs, and addressing biomechanical issues with bracing or foot orthoses. Oral analgesics and anti-inflammatories are pharmacologicals that are commonly used and the literature overall supports that some of these medications can be helpful for managing knee OA in the short-term but are less effective for long-term management. Additionally, more prolonged use significantly increases the risk of serious associated side effects that are not too uncommon. Disease-modifying osteoarthritis drugs are being researched as a treatment modality to potentially halt or slow disease progression but data at this time is limited and continued studies are being conducted to further investigate their effectiveness. Intra-articular injectables are also implemented to manage knee OA ranging from corticosteroids to hyaluronans to more recently platelet-rich plasma and even stem cells while several other injection therapies are presently being studied. The goal of developing new treatment strategies for knee OA is to prolong the need for total knee arthroplasty which should be utilized only if other strategies have failed. High tibial osteotomy and unicompartmental knee arthroplasty are potential alternatives if only a single compartment is involved with more data supporting unicompartmental knee arthroplasty as a good treatment option in this scenario. Arthroscopy has been commonly used for many years to treat knee OA to address degenerative articular cartilage and menisci, however, several high-quality studies have shown that it is not a very effective treatment for the majority of cases and should generally not be considered when managing knee OA. Improving the management of knee OA requires a multi-faceted treatment approach along with continuing to broaden our understanding of this complex disease so that therapeutic advancements can continue to be developed with the goal of preventing further disease progression and even potentially reversing the degenerative process.


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May 30, 2014