Osteoarthritis (OA), characterized by the breakdown of protective cartilage at bone ends, has been linked to a significant increase in the risk of rapidly progressing to severe long-term conditions, known as multimorbidity, according to findings from a 20-year study published in RMD Open.
The research suggests that there are varying speeds at which multimorbidity can develop, with four distinct patterns identified.
Researchers propose that persistently low physical activity, a high-calorie diet, and chronic low-grade inflammation may underpin the association between OA and increased risk of accumulating other chronic conditions.
\While the exact causes of OA remain unclear, factors such as injury, age, family history, and female sex are believed to contribute to its development, affecting over 500 million people globally.
The study, based on healthcare data from Sweden’s Skåne region covering 1.4 million residents, focused on individuals aged 40 and above who were diagnosed with OA between 2008 and 2009.
This cohort, totaling 9,846 people with an average age of 66 (58% women), was compared with a reference group of 19,692 individuals without OA. The cumulative incidence of 67 common long-term conditions was tracked from 1998 until 2019 or until participants’ deaths or relocation.
The research identified four distinct trajectories of multimorbidity progression over the study period: mild multimorbidity late progression, mild multimorbidity early progression, moderate multimorbidity, and severe multimorbidity.
These trajectories varied in terms of the number and severity of conditions accumulated over time, reflecting different demographic and health profiles.
Participants with OA, particularly those with knee and hip OA, showed a heightened risk of faster progression to severe multimorbidity compared to those without OA.
The severity of multimorbidity, assessed using disability weighting, was highest among those in the severe multimorbidity class, where a majority had died by the end of the tracking period.
The study highlights that while age is a significant factor in the development of chronic conditions, the association between OA and multimorbidity persists independently of age. The findings underscore a complex disease continuum where OA and other chronic conditions interact, potentially exacerbating health outcomes over time.
However, the study’s observational nature precludes definitive causal conclusions. Limitations acknowledged by the researchers include the lack of detailed data on lifestyle factors such as physical activity, diet, and body weight, which could further elucidate the mechanisms linking OA to multimorbidity.
In conclusion, the study underscores the substantial impact of OA on long-term health outcomes, suggesting a need for further research into interventions targeting lifestyle factors and inflammation to mitigate the risk of multimorbidity in OA patients.
