Serum oxalate concentration is associated with coronary artery calcification and cardiovascular events in Japanese dialysis patients

Abstract Coronary artery calcification (CAC) is associated with cardiovascular disease (CVD). CAC might contain calcium oxalate, and a high serum oxalate (SOx) concentration is associated with cardiovascular mortality in dialysis patients. We assessed the associations between SOx and CAC or CVD events in Japanese hemodialysis patients. This cross-sectional and retrospective cohort study was done in 2011. Seventy-seven hemodialysis patients’ Agatston CAC score was measured, and serum samples were collected. SOx concentrations were measured in 2021 by using frozen samples. Also, new-onset CVD events in 2011–2021 were retrospectively recorded. The association between SOx concentration and CAC score ≥ 1000, and new-onset CVD events were examined. Median SOx concentration and CAC score were 266.9 (229.5–318.5) µmol/L and 912.5 (123.7–2944), respectively. CAC score ≥ 1000 was associated with SOx [adjusted odds ratio (OR) 1.01, 95% confidence interval (CI), 1.00–1.02]. The number of new-onset CVD events was significantly higher in patients with SOx ≥ median value [hazard ratio (HR) 2.71, 95% CI 1.26–6.16]. By Cox proportional hazard models, new-onset CVD events was associated with SOx ≥ median value (adjusted HR 2.10, 95% CI 0.90–4.91). SOx was associated with CAC score ≥ 1000 and new-onset CVD events in Japanese hemodialysis patients