Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

The results of a study presented today at the Annual European Congress of Rheumatology (EULAR 2018) suggest childhood and adult obesity increase the risk of developing hip osteoarthritis (OA) and knee OA but not hand OA.

Obesity and OA are two interconnected health care problems affecting a large proportion of the adult population worldwide, however studying causality in this association is difficult due to confounding factors. To test the hypothesis that the association between obesity and OA is causal, investigators used a method know as 'mendelian randomisation', which uses genetic variants to investigate whether a biomarker has an effect on the risk of developing disease.

"Our results suggest the effect of adult BMI seems to be stronger on knees, whilst childhood BMI might impact both knee and hip osteoarthritis risk similarly," said Professor Daniel Prieto-Alhambra (senior study author). "Interestingly our findings contradict previous studies that found an association between obesity and hand osteoarthritis."

Results of the study indicated that adult body mass index (BMI) significantly increased the prevalence of self-reported OA, knee OA or hip OA by 2.7%, 1.3%, and 0.4%per unit (1 kg/m2) increase in BMI respectively. Childhood BMI significantly increased the prevalence of self-reported OA, knee OA or hip OA by 1.7%, 0.6%, and 0.6% per BMI unit respectively. No associations were found between either adult or child BMI and hand OA, which contradicts previous cohorts. Investigators suggest that this could be explained by the impact of various confounding factors such as manual work or related socio-economic factors. Finally, no relationship was found with traumatic eye injury which was used in the study as a negative control.1

Investigators used data from two genome wide association studies (GWAS) which identified 15 and 97 specific gene changes, known as SNPs (single nucleotide polymorphism), associated with childhood and adulthood BMI respectively. They then used a separate GWAS of 337,000 unrelated individuals in the UK BioBank. Within this data they identified 13/15 childhood obesity SNPs and 68/97 adulthood obesity SNPs and then analysed the association between these SNPs and self-reported osteoarthritis, as well as hospital data for knee, hip and hand osteoarthritis. Associations with negative controls (myopia, left-handedness, and traumatic eye injury) were all inexistent as expected.

"Obesity in both childhood and adulthood is an important public health issue," said Professor Johannes W. Bijlsma, EULAR President. "These data showing a causal relationship with osteoarthritis should add further impetus to tackle the issue of obesity and reduce related disability."

Similar stories

NDORMS joins research partnership to understand links between overlapping long-term conditions

The links between different long-term health conditions will be explored in new research funded with a £2.5million grant from the Medical Research Council.

New therapeutic targets identified in the treatment of psoriatic arthritis

Researchers identify two inflammatory-driving proteins, osteopontin and CCL2, highly expressed in psoriatic arthritis joints.

Researchers show the role of cilia in cartilage health

New research shows that disrupting primary cilia in juvenile, adolescent and early adulthood in cartilage stops it maturing correctly, making it more prone to thinning and the potential for osteoarthritis (OA) in later life.

New research could improve quality of life for Psoriatic Arthritis patients

Professors Laura Coates and Dani Prieto-Alhambra will take major roles in a new European Commission project to develop innovative personalised treatment options for people affected by psoriatic arthritis.

Exploring the link between joint injury and osteoarthritis

A new study published in The Lancet Rheumatology shows potential ways to predict how likely someone is to develop osteoarthritis after a knee injury.