Osteoarthritis is the most common form of joint disease, and it is often associated with significant disability and an impaired quality of life. A number of trials have suggested a relationship between weight loss and clinical benefit in patients diagnosed particularly with knee osteoarthritis, prompting a Danish study team to assess and quantify whether clinical benefits are evident when overweight patients achieve a weight loss.
A total of 23 clinical trials were identified by the study team. Among these, 4 trials met pre-determined inclusion criteria and provided data suitable for further analysis. Three randomized controlled trials (4 intervention/control groups, n=417) reported changes in pain and disability, with 2 trials reporting changes in the Lequesne index, assessing pain, walking and function (n=117).
The association between improvement in physical disability and weight reduction was convincing, and showed that disability reduction could be predicted with great certainty from weight loss.
Whilst the team were not able to predict the clinical efficacy of pain reduction (owing to contradictory results from published trials), meta-regression evidence shows that osteoarthritis patients will experience at least a moderate clinical effect in their physical disability (ES>0.5) with a moderate dietary regime following more than 7.6% weight reduction. In addition, statistical models predicted that even a modest weight loss of more than 5.02% and an intensity of at least 0.25% per week, respectively - would result in a significant disability reduction.
"Based on the pooled analysis from 3 randomised controlled trials, we can provide category 1a evidence that weight reduction does reduce the pain and physical disability in knee OA patients. As such, weight reduction therapy in overweight osteoarthritic patients is a very appealing goal, both with regards to disease specific pain and disability reduction as well as for overall health benefits such as cardiovascular risk reduction" explained study author Robin Christensen, The Parker Institute, HS Frederiksberg Hospital, Copenhagen. "Weight loss is quite possible in these patients in spite of the lack of mobility and physical exercise, often associated with progression of osteoarthritis. A 10% reduction in body weight results in a moderate to large improvement in self reported physical disability; attention from the health care providers is necessary in support of patients learning to cope with a 'double chronic disease' - i.e. both knee osteoarthritis and obesity" he concluded.