A longitudinal cohort study published in the Arthritis & Rheumatology Journal unveiled a significant association between acute calcium pyrophosphate (CPP) crystal arthritis and an elevated risk of fractures. This discovery enhances the existing understanding of the broader implications of CPPD (calcium pyrophosphate deposition) disease which was previously observed for its connection to osteopenia in two cross-sectional studies.
The study utilized extensive electronic health record data from a large academic health system that covered from 1991 to 2023. The research focused on patients who underwent one or more episodes of acute CPP crystal arthritis which is commonly referred to as pseudogout and is characterized by the presence of synovial fluid CPP crystals. These patients were meticulously matched with comparators based on the index date of their first documented pseudogout episode or a similar health system encounter. The primary outcome of interest was the incidence of first fractures occurring at critical skeletal sites like the humerus, wrist, hip or pelvis.
To ensure the robustness of the findings, the research excluded any individuals with a history of fractures before the index date. They also adjusted for a range of covariates, including demographics, body mass index, smoking status, comorbidities, healthcare utilization and the use of glucocorticoids and osteoporosis treatments.
The study identified a total of 1,148 patients diagnosed with acute CPP crystal arthritis and matched them with 3,730 comparators. The average age of participants was 73 years. Also, the cohort with acute CPP crystal arthritis expressed a higher frequency of glucocorticoid and osteoporosis treatment use when compared to the control group.
The results found the incidence rate of fractures in the acute CPP crystal arthritis cohort to be more than double that of the comparators, at 11.7 versus 5.5 per 1,000 person-years, respectively. After adjusting for multiple variables, the hazard ratio for fracture risk in the acute CPP crystal arthritis group was 1.8 (95% confidence interval 1.3–2.3) that indicated an almost twofold increase in risk. The sensitivity analyses excluded patients on glucocorticoids or osteoporosis treatments and the individuals with rheumatoid arthritis which confirmed the robustness of these findings after additional adjustments for chronic kidney disease.
This study is the first to systematically examine the relationship between fractures and CPPD. The findings highlight a nearly doubled risk of fractures in patients with acute CPP crystal arthritis by illuminating the need for increased awareness and potentially revised management strategies for this patient population.
Reference:
Tedeschi, S. K., Hayashi, K., Rosenthal, A., Gill, M., Marrugo, J., Fukui, S., Gravallese, E., & Solomon, D. H. (2024). Fractures in Patients With Acute Calcium Pyrophosphate Crystal Arthritis Versus Matched Comparators in a Large Cohort Study. In Arthritis & Rheumatology. Wiley. https://doi.org/10.1002/art.42798