Issue 3 / 1 February 2016

IT’S time GPs threw out the old paradigm of osteoarthritis being a degenerative, “wear and tear” disease of old age – the reality is much more complex and nuanced, says expert Flavia Cicuttini.

Professor Cicuttini, head of the Rheumatology Unit at The Alfred Hospital in Melbourne, and head of Monash University’s Musculoskeletal Unit, has coauthored an editorial published in today’s MJA on the dynamics of osteoarthritis (OA), obesity and inflammation.

“For many years we’ve known that obesity was a risk factor for hand osteoarthritis. Given that we don’t walk on our hands then it really begs the question – can it just be simply loading,” Professor Cicuttini told MJA InSight.

“Many medical students are still taught to think of osteoarthritis as wear and tear. It’s much more complex than [that]. That is partly why we are struggling to come up with treatments.

“OA is the end result of a lot of different pathways.”

While this information was “old hat” to OA specialists and researchers, the message had not been getting through to GPs, she said.

Podcast: Professor Flavia Cicuttini, Monash University
Video: Professor Flavia Cicuttini, Monash University

“There are still [some messages] that haven’t seeped down to medical school training and even specialist rheumatology training.

“First of all, OA is not one disease. Even knee OA and hip OA are different diseases driven by different causes – it’s not going to be one size fits all.

“Second, OA is not wear and tear. It’s a heterogeneous group of diseases.

“[Third], obesity does not cause OA simply through loading.

“A person who is 20kg overweight is worse off than someone who you ask to walk around carrying 20kg of concrete for 5 years,” Professor Cicuttini said.

“The concrete just loads [the joints] but the fat is actually metabolically active.”

Better technology, medical resonance imaging for example, has allowed researchers to see that increased weight was associated with early articular cartilage damage, well before symptoms developed.

Body composition was also a vital marker of pre-clinical OA, Professor Cicuttini said.

“Two people can have the same body mass index but one can largely be muscle and one can largely be fat,” she said. “When we started to look at body composition, we found that [the development of OA] was being driven by the amount of fat that person was carrying.

“That raised the question – is it just loading or is it meta-inflammation?”

It was a mistake to think of fat as an inert substance, Professor Cicuttini said.

“It is actually an endocrine organ producing lots of nasty chemicals.

“The whole picture that is emerging is that obesity damages joints, particularly weight-bearing joints, through both loading and metabolically driven inflammation.”

The implications for treatment of OA were profound, Professor Cicuttini said.

“It highlights the importance of targeting obesity early in life. A lot of these changes are occurring very early in people’s lives. In terms of prevention and trying to deal with these diseases, we are going to need to target the prevention of weight gain much earlier.

“Fairly relentlessly as a community, we’re putting on weight – about 0.7kg each a year.”

Related: MJA — Osteoarthritis — the forgotten obesity-related epidemic with worse to come
Related: MJA InSight — Rob Moodie: The fat fight

Professor Cicuttini said the emphasis should be less on massive weight loss – “we’re not very good at that” – and more on the prevention of weight gain.

“It’s certainly more achievable than suddenly trying to lose weight.”

New treatments were also the focus of a lot of research, she said, including different mechanisms for reducing inflammation.

“You could argue that OA is one of the last frontiers of a big disease, with no disease modifications.”

Professor Cicuttini said there were some “very nice” trials being done on treatments for OA, including targeting statins, bisphosphonates and krill oil as disease modifiers.

“Hopefully in the next few years we will do better than we’re doing at the moment.”

6 thoughts on “More to osteoarthritis than overloaded joints

  1. Barbara Faye Baldock. says:

    When I was first diagnosed with arthritis many years ago I was not over weight. After stress fractures in both feet and a knee replacement I have steadily gained weight. As a merchandiser in grocery stores, I was up and down all day on steps and at the time my right knee was in a lot of pain. Obviously I came down heavily on my left foot to protect my right knee.  That was over 7 years ago and I retired from the workforce. I changed Doctors and had a knee replacement soon after.  After so many years of over use my left foot is now badly affected by arthritis. I find it hard to get comfortable shoes and my foot swells from walking.  I have been told I have to lose at least 10kg before I can have the left knee replaced.  At the age of 69years it is harder and harder to lose the weight, especially as i cannot go for long walks or do exercises where I have to stand.  My weight is currently 100kg.

     

  2. Leigh Deeks says:

    I have rheumatoid arthritis as well as osteo arthritis. I had right knee replacement 12 months ago and now it looks like my left knee is just about ready for a replacement too. I am also overweight currently at 100kg. I am trying to do some walking and recumbent bike riding every day but nothing is happening to my weight. I would like to know how can I lose weight when I have difficulty walking and exercising. I have osteo arthritis in my lower spine as well.

  3. Carolyn Cameron says:

    I have had four hip replacements- I am now 73, my first was at 50 after many years of pain. I have never been overweight until now- when my BMI index has risen to 26.5. I am 174 cms tall, and until the last two years have only ever weighed a maximum of 76 kg- average 73. How does this compare?

  4. Malcolm Mackay says:

    It’s difficult to design RCTs for lifestyle interventions. However, clinical experience and patient reports suggest that a whole foods, plant-based diet most often results in considerable symptomatic improvement in pain and mobility. Mechanisms behind this observation may include: reduced meta-inflammation through the exclusion of animal proteins and oils as well as the down regulation of inflammatory metabolic pathways by phytochemicals, improved tissue oxygenation and normalisation of body weight (which invariably occurs when patients adhere to a diet based on whole grains, legumes, starchy and non-starchy vegetables and fruits). We could wait for someone to fund clinical trials or go ahead and support patients who wish to try an intervention that only has good side effects.

  5. Dr Bennett Franjic says:

    Thanks Malcolm Mackay,

    This is an option that is clear and easy to understand for patients.

    It is initially difficult, but within a few months, should become much easier to manage.

    I am not suprised that it would lead to improvement in many conditions, including OA.

  6. lyn allen says:

    I attend aquaaerobics three or four times a week. It is a great way to exercise without working up a sweat and ena bles jonts to move without pain during or after.You also strengthen your core which improves balance and reduces backpain.

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