Excess Weight Worsens Osteoarthritis
December 6, 2004
(Ivanhoe Newswire)—
Researchers from Boston University found that progression of osteoarthritis of the knee increased significantly with an increase in weight.
However, this effect of weight on the progression was not present in all knees, but was limited to the knees of moderately malaligned legs. In neutrally aligned limbs on one end of the spectrum and severely malaligned limbs on the other, body weight had no effect on progression of knee OA.
Researchers explain that with severe malalignment, the extreme stress already placed on the cartilage may be the only risk factor required for further deterioration. With neutral alignment, the increased body weight would be equally distributed across the knee joint, therefore protecting it against injury from extra weight.
So, why would knees in moderately malaligned limbs be most susceptible to injury from increased body weight? The study authors say malalignment increases stress on the joint, and the additional weight is enough to accentuate the cartilage injury. Researchers say losing weight may relieve stress and slow disease progression for this group.
For the study, 228 individuals with knee OA were examined over 30 months. The body mass index was also computed for each person. Results show for each two-unit increase in BMI, there was an 8-percent increase in the risk of progression in moderately malaligned legs.
The researchers say their findings need to be confirmed in other studies, but they may have broad implications for the effect of body weight and other risk factors on OA.
SOURCE: Arthritis & Rheumatism, 2004;50:3904-3909