Weight Management and Osteoarthritis

Why weight management is important for osteoarthritis 

Being overweight or obese is determined by BMI (body mass index), which considers your height and weight. Studies have shown that a high BMI is the single greatest risk factor for knee osteoarthritis; in fact, people who are obese are twice as likely to develop knee osteoarthritis compared to those who are not obese. Research has also shown that reductions in weight have a significant effect on the severity of knee osteoarthritis symptoms. It is for this reason that international guidelines now recommend weight loss as a core treatment for osteoarthritis. 

There are a few reasons for this, and it can be thought of as mechanical and system pathways: 

Mechanical: 

Studies have found that every 1kg of body weight leads to a reduction of up to 4kg of pressure on the knee joint. 

This statistic alone highlights how you can have significant improvements in symptoms without any drastic changes. Does carrying heavy shopping make your joints more painful? Then just imagine the pain reduction of carrying around less weight on your body. 

Systemic: 

It was found that obesity is an increased risk factor for hand osteoarthritis, which was interesting as the hand is not a weight bearing structure. This prompted further research into systemic reasons. It was found that losing weight can decrease inflammation by reducing fat and improving lipids. Both body fat and lipids can generate low-grade inflammation in the body, and we know that inflammation can be a major driver in osteoarthritis flare ups and increased symptoms. 

A study found that every 1% reduction in body fat was more than three times more powerful in improving pain, function and stiffness compared to a 1% body weight reduction. This means that it is not simply about reducing the weight on the scales, it is about reducing body fat specifically to get a more favourable body composition. 

Recommended weight loss for osteoarthritis management 

We know that the improvement in symptoms and function that people experience is proportional to the percentage of weight loss (in other words – the more weight loss, the better). The current guidelines recommend a reasonable target of >5-10% weight reduction. 

The weight loss will transfer directly to functional improvements such as enabling you to walk down to the shops or fulfill important family roles like caring for your grandchildren. Also, it will play a role in preventing replacement surgery, reducing severity of pain and other symptoms, whilst also allowing you to feel better in your body and reduce the risk of other chronic diseases. 

 

To read more, visit https://www.nps.org.au/assets/1d6da3e63dabca4a-a5700398aed6-MedicineWise-News-Osteoarthritis-October-2017-updated.pdf (This article also provides the specific references for the research studies mentioned). 

 

Tamika Hassum

Accredited Exercise Physiologist