In a study published online ahead of print by Arthritis & Rheumatology, a decrease in body mass index (BMI) was associated with a lower incidence of the structural defects of knee osteoarthritis (OA) and a lower likelihood that such defects would progress.
The researchers used radiographic analyses from 3 studies – the Osteoarthritis Initiative, the Multicenter Osteoarthritis Study, and the Cohort Hip and Cohort Knee – to evaluate the association between BMI and incidence and progression of knee OA.
Baseline radiographs and radiographs at 4 to 5 years’ follow-up were available for nearly 10,000 adults with and without the structural defects that are characteristic of knee OA. Patients were divided into an incidence cohort (9683 knees in 5774 study participants) and a progression cohort (6075 knees in 3988 participants).
The researchers found a positive association between changes in BMI and:
- Incidence and progression of the structural defects of knee OA
- Degeneration of the joint space
- Degeneration of the femoral and tibial surfaces on the medial side of the knee
A 1-unit decrease in BMI corresponded to a 4.76% reduction in odds of the incidence and progression of knee OA. The odds of incidence and progression was reduced by 21.65% with a 5-unit decrease in BMI, which is an amount that can lead to a reduction in the BMI category (for example, from overweight to normal).
“These findings could be empowering for people with or at risk of knee osteoarthritis,” said lead author Zubeyir Salis, BEng, and a PhD student for Public Health at the University of New South Wales in Australia.
“The current prevailing view is that knee osteoarthritis is part of ageing and that we have no control over it. However, [our] analyses suggest that some people could potentially prevent, slow, or delay knee osteoarthritis by losing weight.”
Salis Z, Gallego B, Nguyen TV, Sainsburgy A. Decrease in body mass index is associated with reduced incidence and progression of the structural defects of knee osteoarthritis: a prospective multi-cohort study. Arthritis Rheumatol. 2022 Aug 16. doi: 10.1002/art.42307. Online ahead of print.