#210 Effects of serum magnesium level on kidney disease progression and major cardiovascular outcome in patients with chronic kidney disease

Abstract

Abstract Background and Aims Magnesium is known for its anti-inflammatory, anti-apoptotic, and anti-oxidative effects, potentially inhibiting renal fibrosis. Additionally, it is believed that magnesium can inhibit vascular calcification, potentially improving cardiovascular outcomes. However, this remains a topic of controversy. This study aims to investigate the association between serum magnesium levels and CKD progression as well as cardiovascular outcomes. Method We analyzed 1,893 patients from The KoreaN Cohort Study for Outcomes in Patients With Chronic Kidney Disease (KNOW-CKD), which is a prospective cohort study. These patients were categorized into three groups based on their baseline magnesium levels: Mg1 (hypomagnesemia, <1.8 mg/dL), Mg2 (normomagnesemia, 1.8-2.4 mg/dL), and Mg3 (hypermagnesemia, >2.4 mg/dL). The primary outcome was defined as meeting one or more of the following criteria during the follow-up period: initiation of dialysis or transplantation, a two-fold increase in baseline serum creatinine levels, or a 50% decline in the estimated glomerular filtration rate. The secondary outcome was a composite of major adverse cardiovascular events (MACEs). We used Cox proportional hazard regression model. Results A total of 673 patients (35.6%) experienced the composite renal outcome. The Mg1 group showed significantly increased adverse renal outcomes compared to the Mg2 group (HR, 1.885; 95% CI, 1.137-3.124; p = 0.013), however, Mg3 group did not show a significant difference (HR, 0.927; 95% CI, 0.783-1.097; p = 0.379). The composite cardiovascular outcome occurred in 138 patients (7.3%). The risk of composite cardiovascular outcomes significantly increased in the Mg1 group compared to the Mg2 group (HR 3.472; 95% CI, 1.492-8.076; p = 0.003). However, we observed no statistically significant differences in the Mg3 group (HR 1.021; 95% CI, 0.689; p = 0.913). The cubic spline curves demonstrated a U-shaped association between serum magnesium levels and both renal and cardiovascular outcomes. Conclusion Hypomagnesemia is associated with the progression of renal disease and a significant increase in MACEs. Beyond a certain level, hypermagnesemia may also be associated with worsening renal and cardiovascular outcomes.