Unexpected comorbidity in patients with knee and hip osteoarthritis

A study revealed that osteoarthritis is associated with a wide variety of diseases previously thought to be unrelated, such as anaemia and thromboembolic disease.

Findings were obtained from a Dutch primary care database of 2.5 million patients

Osteoarthritis (OA) is the most prevalent form of arthritis with burdensome symptoms that often lead to disability. As Dr Anne Kamps (Erasmus University Medical Center, the Netherlands) pointed out, 1 in 4 adults with OA has ≥2 chronic conditions, which is a considerable burden for the healthcare system and the quality of life. Yet, only a few comorbidities have been studied until now. “Therefore, we wanted to determine the risk of comorbidity after incident diagnosis of hip or knee OA compared with individuals with no prior diagnosis of OA,” said Dr Kamps. Together with her team, she used an integrated primary care information database from general practices with >2.5 million patients from the Dutch population.

The study population consisted of over 1.8 million patients and examined 58 comorbidities. Overall, patients previously diagnosed with OA had an increased risk of a subsequent diagnosis in about 50% of comorbidities studied. Moreover, the wide variety of comorbidities included not only known cardiovascular factors, like obesity or other musculoskeletal diseases, or complaints such as gout, back and neck pain, but also anaemia, cataracts, chronic kidney disease, coronary heart disease, hearing loss, sleep disorders, and thromboembolic disease. In OA patients, the largest associations were found for obesity (HR 2.55), fibromyalgia (HR 2.06) polymyalgia (HR 1.72), drug abuse (HR 1.40), and rheumatoid arthritis (HR 1.52).  In patients with hip OA, the largest positive associations were noticed with polymyalgia rheumatica (HR 1.81), fibromyalgia (HR 1.70), spinal disc herniation (HR 1.64), thromboembolic disease (HR 1.47), and alcohol abuse (HR 1.44).

“Whereas associations with obesity and other musculoskeletal conditions were known previously, we found remarkable and less known associations that should be starting points for future research,” Dr Kamp said. Further studies should evaluate whether these comorbidities are prevalent due to shared risk factors or a result of the OA.

1. Kamps A, et al. Risk of comorbidity following osteoarthritis diagnosis: a cohort study in the Netherlands from the FOREUM* Initiative. Abstract OP0225, EULAR 2022, 1-4 June, Copenhagen, Denmark.