# Weight Loss May Not Be Effective in Preventing Progression of Knee Osteoarthritis



## saucywench (Mar 12, 2009)

From http://healthorbit.ca/login1.asp?msg=1&neidws=065030309 

Obesity is known to be a strong risk factor for the onset of knee osteoarthritis (OA), but studies on the relationship between obesity and progression of the disease have shown mixed results and have lacked large numbers of patients. 

Its important to clarify the relationship between weight loss and the risk of OA progression, since patients with knee OA might be motivated to lose weight if it could be shown that it would prevent advancement of the disease. A new study examined the relationship between body mass index (BMI) and the risk of new and progressive knee OA and found no overall relationship between obesity and the progression of knee OA. The study was published in the March issue of _Arthritis Care & Research _(http://www3.interscience.wiley.com/journal/77005015/home).

Led by D.T. Felson of Boston University School of Medicine, the study involved more than 2,600 participants who either had OA or were at high risk for developing it due to the fact that they were overweight or obese, had knee pain, aching or stiffness or had a history of knee injury that made walking difficult or had previous knee surgery. Participants underwent an exam, a hip bone mineral density test and X-rays of both legs at the start of the study and knee X-rays after 30 months.
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Abstract from the article:

[SIZE=+1]*Objective*[/SIZE]To examine whether obesity increases the risk of progression of knee osteoarthritis (OA).
[SIZE=+1]*Methods*[/SIZE]We used data from the Multicenter Osteoarthritis Study, a longitudinal study of persons with or at high risk of knee OA. OA was characterized at baseline and 30 months using posteroanterior fixed-flexion radiographs and Kellgren/Lawrence (K/L) grading, with alignment assessed on full-extremity films. In knees with OA at baseline (K/L grade 2 or 3), progression was defined as tibiofemoral joint space narrowing on the 30-month radiograph. In knees without OA at baseline (K/L grade 0 or 1), incident OA was defined as the development of radiographic OA at 30 months. Body mass index (BMI) at baseline was classified as normal (<25 kg/m2), overweight (25-<30 kg/m2), obese (30-<35 kg/m2), and very obese (




35 kg/m2). The risk of progression was tested in all knees and in subgroups categorized according to alignment. Analyses were adjusted for age, sex, knee injury, and bone density.
[SIZE=+1]*Results*[/SIZE]Among the 2,623 subjects (5,159 knees), 60% were women, and the mean ± SD age was 62.4 ± 8.0 years. More than 80% of subjects were overweight or obese. At baseline, 36.4% of knees had tibiofemoral OA, and of those, only one-third were neutrally aligned. Compared with subjects with a normal BMI, those who were obese or very obese were at an increased risk of incident OA (relative risk 2.4 and 3.2, respectively [_P_ for trend < 0.001]); this risk extended to knees from all alignment groups. Among knees with OA at baseline, there was no overall association between a high BMI and the risk of OA progression; however, an increased risk of progression was observed among knees with neutral but not varus alignment. The effect of obesity was intermediate in those with valgus alignment.
[SIZE=+1]*Conclusion*[/SIZE]Although obesity was a risk factor for incident knee OA, we observed no overall relationship between obesity and the progression of knee OA. Obesity was not associated with OA progression in knees with varus alignment; however, it did increase the risk of progression in knees with neutral or valgus alignment. Therefore, weight loss may not be effective in preventing progression of structural damage in OA knees with varus alignment.


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## GrowingBoy (Aug 27, 2009)

I have OA, and also am fat. There is a causal relationship... my OA made it difficult for me to exercise (used to run 30+ miles a week), so I gained weight. 

After I gained, doctors would tell me that I needed to lose weight to address the OA -- but how could that be true if I first got OA when I weighed 140 pounds with 5 percent body fat?? And how could I lose 100+ pounds if I could barely walk??

Finally I found a doctor who really understood OA -- and helped me address it with weight baring exercises and supplements. 

Then, after I was able to alleviate the symptoms, my mobility improved, and I could exercise more -- and lost some weight as a result. 

So yes, the study doesn't surprise me. Sometimes I wonder what doctors are thinking. "I'll tell him/her to lose weight. It may have nothing to do with their condition, but it can't do any harm, can it?"


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