Clinical impact of hypermagnesemia in acute kidney injury patients undergoing continuous kidney replacement therapy: A propensity score analysis utilizing real-world data

Purpose: While hypomagnesemia is known to be a risk factor for acute kidney injury (AKI), the impact of hypermagnesemia on prognosis in AKI patients undergoing continuous kidney replacement therapy (CKRT) remains unclear. This study investigates the relationship between hypermagnesemia and clinical outcomes in this patient population. Methods: A retrospective analysis was conducted using data from a multicenter medical repository spanning from 2001 to 2019, involving patients who underwent CKRT. Patients were categorized into normomagnesemia (<2 mEq/L) and hypermagnesemia groups based (>= 2 mEq/L) on their levels at CKRT initiation. Results: Among the 2625 patients, 1194 (45.5 %) had elevated serum magnesium levels. The hypermagnesemia group exhibited a similar rate of non-recovery of renal function at 90-days compared to the normomagnesemia group (63.1 % vs. 62.8 %, odds ratio [OR] = 1.01, 95 % confidence interval [CI] 0.90-1.14). Furthermore, the high magnesium group demonstrated higher one-year all-cause mortality (hazard ratio [HR] 1.14, 95 % CI 1.07-1.21) and an elevated risk of one-year arrhythmia (HR 4.77, 95 % CI 1.59-14.29). There was no difference of incidence of seizure between hypermagnesemia and normomagnesemia group. Conclusions: Our study suggests that hypermagnesemia in AKI patients undergoing CKRT is not associated with improved renal recovery but is linked to worse clinical outcomes, including all-cause mortality and arrhythmia. Close monitoring of serum magnesium levels is recommended in this population for optimizing clinical outcomes.