Acute CPP Crystal Arthritis Linked to Two-Fold Increase in Fracture Risk – Renal and Urology News

Patients diagnosed with acute calcium pyrophosphate (CPP) crystal arthritis were associated with a nearly a two-fold increased risk for fracture, according to study results published in Arthritis & Rheumatology.

Calcium pyrophosphate deposition (CPPD) disease, a prevalent and incapacitating form of arthritis in older populations, encompasses a spectrum of manifestations, including: acute CPP crystal arthritis, chronic CPP inflammatory arthritis, osteoarthritis with chondrocalcinosis, and crowned dens syndrome.

Investigators conducted a longitudinal cohort study using electronic health record data from Mass General Brigham medical network from 1991 to 2023. They aimed to assess the occurrence of incident fractures and fracture risk in a cohort of individuals with at least 1 episode of acute CPP crystal arthritis, comparing them with matched counterparts. The primary study outcome was incident fracture of the humerus, wrist, hip, or pelvis.

Eligible participants included patients with at least 1 episode of acute CPP crystal arthritis, matched with comparators based on the index date — defined as the first documentation of “pseudogout” or synovial fluid positive for CPP crystals — and the patient’s first encounter in the health system. Comparators were matched in 4:1 ratio, with index dates matched to encounters within 30 days.

A total of 1148 patients with acute CPP crystal arthritis were identified and matched with 3730 comparators, accounting for 35,973 person-years of follow-up. The majority of patients in both cohorts were women and the average patient age was 73 years.

Within the acute CPP crystal arthritis cohort, 65.1% had a positive synovial fluid aspirate. This cohort exhibited higher rates of healthcare utilization, multimorbidity scores, and more frequent prescriptions for glucocorticoids, osteoporosis treatments, and proton pump inhibitors vs comparators.

Overall, 5.1% (n=251) of patients experienced fractures, with the acute CPP crystal arthritis cohort associated with age- and sex-adjusted incidence rates (IRs) for any fracture that were two-fold higher than the comparator group (IR, 11.7 vs. 5.5 per 1000 person-years).

After adjusting for age and sex, the incidence rate ratios (IRRs) for any fracture risk were twice as high among individuals with acute CPP crystal arthritis vs comparators (IRR, 2.1; 95% CI, 1.0-4.5).

When accounting for covariates, it was observed that acute CPP crystal arthritis was significantly associated with an 80% higher risk for any fracture vs comparators (hazard ratio [HR], 1.8; 95% CI, 1.3-2.3), with the wrist exhibiting the highest relative risk (HR, 3.6; 95% CI, 1.8-7.1).

Study limitations included the observational design, potential underestimation of fractures occurring outside the health system, uncertainty about fracture causes, absence of data on falls and frailty measures, and the inability to assess recurrent episodes of acute CPP crystal arthritis.

“Our observation of elevated fracture risk in patients with acute CPP crystal arthritis supports the need for additional prospective studies of bone turnover markers, bone density, and effects of osteoporosis treatments in patients with CPPD, as well as future mediation analysis to understand the potential contribution of CPPD treatment on fracture risk,” the study authors noted.

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

This article originally appeared on Rheumatology Advisor