A 20-year study has found that patients with osteoarthritis may have a higher risk of developing severe multimorbidity compared with those without osteoarthritis.

"Our findings strongly indicate that the individuals with OA are more prone to experience multimorbidity as they face an almost threefold higher risk of developing severe multimorbidity over 20 years, even after adjusting for common confounders like age, sex and socioeconomic status," noted study investigators.

In the recent cohort study, published in RMD Open, the investigators identified differences in multimorbidity trajectories between 9,846 patients aged 40 years and older with osteoarthritis and 9,846 age-matched controls from 1998 to 2019 in order to elucidate the progression of chronic conditions.

The mean age of the patients in the osteoarthritis group was 65.9 years, and 58% of them were female. Using group-based trajectory modeling, the investigators identified four distinct classes of multimorbidity progression. Among them were:

• Class 1: mild multimorbidity late progression
• Class 2: mild multimorbidity early progression
• Class 3: moderate multimorbidity
• Class 4: severe multimorbidity. 

At baseline, all of the classes exhibited a low average number of chronic conditions at one or less. The investigators found that the patients in Class 1 showed the slowest progression, with an average of 2.9 chronic conditions, whereas those in Class 4 demonstrated the fastest increase in multimorbidity, culminating in an average of 9.6 chronic conditions by the end of the study period.

Additionally, the presence of osteoarthritis was associated with a higher risk of severe multimorbidity. The adjusted relative risk of being categorized as Class 1 was 1.29 (95% confidence interval [CI] = 1.12–1.48), whereas the risk of being categorized as Class 4 was 2.45 (95% CI = 2.12–2.83). 

The investigators noted systemic factors such as low-grade inflammation and metabolic dysregulation may link osteoarthritis to other chronic conditions, and targeted interventions may help manage and potentially mitigate multimorbidity in this patient population.

Full disclosures can be found in the original study.