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’.