Based on the current available evidence, we’re smack-dab in the middle of an obesity epidemic. Rates of obesity are skyrocketing in the United States, in particular.
Researchers currently believe that obesity itself is probably the single most important risk factor for developing osteoarthritis of the knee.
As to why obesity increases your risk of arthritis of the knee, it’s not particularly hard to image. To start with, obesity will increase the load on your knee joints. For those who have any type of anatomical abnormalities of their legs, this load effect will have an even greater impact.
Decreasing the mechanical load on your knee joints can be achieved by simply losing weight. Some research also suggests that lateral wedge insoles can also help to decrease load on the medial (inner aspect) of your knee joint to potentially slow progression of joint damage (Bennell et al, 2011)
Other reasons to account for the increased risk obesity places on knee arthritis may include the pro-inflammatory effects of obesity, among others.
Consequently, for those who suffer from knee arthritis, weight loss is generally recommended as part of the treatment. However, on a practical level, patients who have obesity and knee arthritis are often limited in their mobility which generally makes it more difficult to lose weight.
Though losing weight in this population presents some unique challenges, a recent study by Bilddal et al (2011), presents some hope.
Does weight loss improve symptoms of arthritis?
A previous randomized trial concluded that an intensive weight loss intervention program of diet (calorie deficit) and exercise improved physical function in older obese adults with knee osteoarthritis (Miller et al, 2006). In this particular study, those who lost more weight also experienced greater improvements in functional abilities.
As mentioned, obesity is considered a risk factor for osteoarthritis, particularly osteoarthritis of the knee, but also osteoarthritis of the hip. Patients who suffer from both obesity and osteoarthritis of the hip or knee, should talk to their health care provider about diet and exercise options as these types of interventions may improve their osteoarthritis symptoms.
In the recent study by Bliddal et al (20110), the researchers showed that 30% of obese subjects were able to achieve clinically significant weight loss using a rigorous low-energy diet. On average, the participants in those group lost roughly 11 kg over the course of a year. The control group lost just 3.6 kg in comparison.
For this study, the low-energy diet group had a 50% reduction in pain compared to the control group.
[box type="important"]Important! Always talk to your physician before starting an exercise program or making any dietary modifications. As always, the information on this site is for general information only and should not be considered a substitute for medical advice.[/box]
- Miller GD, Niclas BJ, Davis C, Loeser RF, Lenchik L, Messier SP. Intensive weight loss program improves physical function in older obese adults with knee osteoarthritis. Obesity (Silver Spring). 2006 July;14(7):1219-30.
- Bliddal H, Leeds AR, Stigsgaard L, Astrup A, Christensen R. Weight loss as treatment for knee osteoarthritis symptoms in obese patients: 1-year results from a randomised controlled trial. Ann Rheum Dis. 2011 Oct;70(10):1798-803. Epub 2011 Aug 5.
- Bennell KL, Bowles KA, Wang Y, Cicuttini F, Davies-Tuck M, Hinman RS. Higher dynamic medial knee load predicts greater cartilage loss over 12 months in medial knee osteoarthritis. Ann Rheum Dis. 2011 Oct;70(10):1770-4. Epub 2011 Jul 7.