AMSTERDAM — Obese patients with knee osteoarthritis can be told with confidence that a sustained weight loss of at least 5% of their body weight will typically lead to a moderate reduction in physical disability, while a greater weight loss will result in even more marked improvement, Robin Christensen reported at the annual European Congress of Rheumatology.
His metaanalysis of three randomized controlled trials totaling 417 obese osteoarthritis (OA) patients also concluded that the intensity of weight loss required to achieve this benefit corresponded to a loss rate of at least 1% of baseline body weight per month, said Mr. Christensen of HS Frederiksberg Hospital, Copenhagen.
The reduction in physical disability was greater with a sustained weight loss of at least 7.6% than it was with a 5% weight loss.
The impact of weight loss upon pain scores was considerably less consistent than for physical disability, he noted at the congress, sponsored by the European League Against Rheumatism.
Mr. Christensen was principal investigator in one of the randomized trials included in the metaanalysis (Osteoarthritis Cartilage 2005;13:20–7). In that study, patients randomized to a low-energy 3.4 MJ/day diet lost a mean 11.1% of their body weight, and 55% of them sustained at least a 10% weight loss at 1 year. They experienced a mean 20% reduction in symptoms from a baseline Western Ontario and McMaster Universities Osteoarthritis Index of 936 mm.
Under the EULAR system of grading evidence-based medicine, the new metaanalysis ranks as level 1A evidence supporting the benefit of weight loss in obese knee OA patients.
Mr. Christensen added that it has been his impression that knee OA patients have a significantly better than average success rate in losing weight and keeping it off.
Still, sustained weight loss remains a major challenge. In his 1-year randomized trial, Mr. Christensen tried to give patients an edge by having them use a powdered nutritional formula as the core of a low-energy diet during the first 8 weeks before shifting to a more moderate dietary regimen.
“The powdered supplement acts as a catalyst so they can feel that this is really working,” he explained.
'The powdered supplement acts as a catalyst so they can feel that this is really working.' MR. CHRISTENSEN