Edition 5 - the link between obesity & arthritis

The aim of this research roundup is to provide vet professionals with an easy-to-read digest on three items of research in pain management which focus on one common subject area.

These research roundups provide a single point of reference for the reader and are also incorporated into our accredited courses.

Subject

The relationship between obesity and osteoarthritis

Title of the publication

A review of osteoarthritis and obesity: current understanding of the relationship and benefit of obesity treatment and prevention in the dog (Marshall et al 2009). Click here to open the paper.

Aim of the publication

The authors of this review bring us the recognition that obesity is a significant cause of pain in dogs. The papers they review highlight that this is the start of a journey to understand the specific mechanisms in the relationship between obesity and pain in dogs. Despite the apparent early stages of this research, it is clear that obesity must be tackled as part of a multimodal approach to pain.

Review of methodology

This review forms a great summary of the current thinking in human medicine of the link between obesity and OA. The authors review the four studies in the literature pertaining to dogs and succinctly summarise recent studies which makes this paper digestible for the reader.

Summary of information provided

The estimated prevalence of canine obesity is between 25% (UK study 1986) and 41% (Australian study 2005).

In human medicine it is recognised that reducing the prevalence of OA and the associated healthcare resource burden requires obesity to be tackled.

Obesity is thought to alter joint kinematics such that weight bearing is shifted to areas of cartilage which are incapable of sustaining such loads – there may be a role in both initiation and progression of disease.

The increased risk for developing OA in non-weight bearing joints in obese people suggests a metabolic component is at play in addition to alterations in joint loading.

The adipokines play a significant role in OA development in people. Leptin, a peptide hormone, has a detrimental effect of articular cartilage. Adiponectin is an adipocytokine which induces IL-1 and MMP-1 in synovial fibroblasts.

Key points to aid reflection

·      Leptin is a product of the obese (Ob) gene and is secreted mainly by white adipose tissue.

·      Leptin has a detrimental effect on articular cartilage and induces production of IL-1B, MMP-9 and MMP-13.

·      In humans, leptin’s mRNA expression is significantly correlated with a patient’s BMI.

·      A research review of adiponectin states that ‘articular adipose tissue and adipocytokines cannot be regarded as innocent bystanders any more in chronic inflammatory diseases such as arthritis’.

·      Understanding the role of adipokines in OA may yield targets for novel therapeutic compounds.

·      Further understanding in dogs is required – though we must make sensible suggestions to our clients based on current knowledge.

Our assessment of this publication

Obesity is an issue that challenges vet professionals. This publication discusses both the current understanding of the link between obesity and OA, and the difficulties we face with having meaningful discussions with our pet owners. The authors recognise the need to further research into the detail of how exactly obesity affects OA in dogs. Having read this review, it is clear that we cannot avoid the discussion on obesity!

In this section you will find our ‘everyone should read this’ recommendation and a review that we have chosen to support your next steps in integrating this with your clinical practice.

It doesn’t seem fair to mandate that obesity should be managed, without offering useful resources to help vet professionals guide clients on this topic! The following resources are a great update on this subject.

Everyone should read this

Association between canine body condition and lifespan (German 2021)

https://www.vettimes.co.uk/article/association-between-canine-body-condition-and-lifespan-cpdnutrition/

Key points from this work

·      If we are to tackle the link between OA and obesity, we need strategies to manage overweight dogs

·      Most owners see marked improvement in quality of life after successful weight loss – according to this article, this is perhaps the best way to engage owners in weight loss

·      An association between overweight body condition and a shorter lifespan was identified in pet dogs of various breeds (Salt et al, 2017).

·      Losing a modest amount of weight, in the region of 6% to 9%, can improve mobility

·      For puppies and young dogs, a formal growth monitoring programme is recommended, and validated evidence-based growth charts are now available for this purpose (Salt et al, 2017)

For those of you who prefer watching a video on this topic, you can see Alex German in discussion with Hannah Capon from Canine Arthritis Management here

Further resources to link to

This review examines the endocrine functions of white adipose tissue and considers this tissue as an endocrine organ with the ability to influence other body systems.

This paper reviews tissue inflammation and metabolic dysfunction in obesity

References

Ehling A, Schäffler A, Herfarth H, Tarner IH, Anders S, Distler O, Paul G, Distler J, Gay S, Schölmerich J, Neumann E, Müller-Ladner U. The potential of adiponectin in driving arthritis. J Immunol. 2006 Apr 1;176(7):4468-78. doi: 10.4049/jimmunol.176.7.4468. 

Salt C, Morris PJ, German AJ, Wilson D, Lund EM, Cole TJ and Butterwick RF (2017). Growth standard charts for monitoring bodyweight in dogs of different sizes, PLOS One 12(9): e0182064.

Simopoulou T, Malizos KN, Iliopoulos D, Stefanou N, Papatheodorou L, Ioannou M, Tsezou A. Differential expression of leptin and leptin's receptor isoform (Ob-Rb) mRNA between advanced and minimally affected osteoarthritic cartilage; effect on cartilage metabolism. Osteoarthritis Cartilage. 2007 Aug;15(8):872-83. doi: 10.1016/j.joca.2007.01.018.