Comorbidities in Osteoarthritis


Osteoarthritis (OA) is the most common form of arthritis and a major cause of disability in older people. The prevalence of OA increases in the past 20 years(1). However, little has been done into its burden such as comorbidities. Our recent systematic review has found that people with OA are more likely to have other diseases, especially stroke, peptic ulcer, hypertension and depression(2).  Whether these comorbidities just co-exist with, share common risk factors with or are causes or consequences of OA remains unknown. 

Facts and figures

Project lead
W Zhang
University of Nottingham
FOREUM research grant: €600'000

Meet the team

W Zhang
University of Nottingham
S Bierma-Zeinstra
Erasmus MC Netherlands
M Englund
Lund University
D Prieto-Alhambra
Autonomous University of Barcelona
Carol Copland
Michael Doherty
Jos Runhaar
Anne Kamps
Kenneth Pihl
Helen He


This project aims to examine:

  • prevalence, incidence and associations and time sequence of comorbidities in OA;
  • common clusters and impact of comorbidities on patient health  states;
  • association between commonly used OA drugs such as non-steroidal anti-inflammatory (NSAIDs) and comorbidities;
  • early biomarkers and mechanistic pathways between OA and the comorbidities; 
  • consistency of OA comorbidities and clusters across countries.

Five work packages (WP) will be performed for these  five objectives.  Four national registration databases in the UK, Netherlands, Sweden and Spain will be used for WP1-3.  Two cohort study databases (the UK Biobank and the Rotterdam study) will be used for WP4.  Finally, data from different countries will be meta-analysed (WP5) to examine the consistency between countries and to pool results together as appropriate.  

So far, UK and Sweden have been able to produce some results on the comorbidities associated with OA.

Swedish database studied the association with 18 conditions. UK database examined the association with 49 conditions before and after the diagnosis of OA. Besides, the clusters of comorbidities were explored among OA and matched controls using UK database.

Interim Results

In Sweden, people with physician-diagnosed knee or hip OA were more likely to develop depression, cardiovascular diseases, back pain, and osteoporosis than people without OA (Figure 1).

In the UK, people with physician diagnosed OA were more likely to develop multimorbidity (≥2 other diseases) (Figure 2).  The hazard ratio was 1.34, (95% CI 1.82-1.41) between OA and non-OA after adjusting for age, gender, BMI, smoking status and alcohol consumption.

Leading comorbidities were fibromyalgia, rheumatoid arthritis, liver diseases, sleep problems, ankylosing spondylitis, dementia, heart failure, osteoporosis, anaemia, and peripheral vascular diseases. In the OA group five clusters were identified including relatively healthy (18%), ‘cardiovascular/musculoskeletal ’ (12.3%), metabolic syndrome (28.2%), ‘pain and psychological (9.1%), and ‘musculoskeletal’ (32.4%). The non-OA group had similar patterns except that the ‘pain+ psychological’ cluster was replaced by ‘thyroid and psychological’.

Patient Voice

Three patient research partners (PRPs) are involved in the project since we applied for this project. They have actively participated in the meetings and shared their views on the list of conditions to be studied, possible ways of disseminations and the challenges they face because of the comorbidities.


  • Swain S, Sarmanova A, Mallen C, Kuo CF, Coupland C, Doherty M, Zhang W. Trends in incidence and prevalence of osteoarthritis in the United Kingdom: findings from the Clinical Practice Research Datalink (CPRD). Osteoarthritis and Cartilage. 2020.
  • Swain S, Sarmanova A, Coupland C, Doherty M, Zhang W. Comorbidities in Osteoarthritis: A systematic review and meta-analysis of observational studies. Arthritis Care Res (Hoboken). 2019.