Abstract: FR-PO308
A Serum Magnesium Concentration Lower Than 2 mg/dL Predicts Mortality in CKD Patients: A Propensity Score-Matching Study
Session Information
- CKD: Epidemiology and Risk Factors
November 08, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: CKD (Non-Dialysis)
- 2101 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention
Authors
- Rodelo-Haad, Cristian, University Hospital Reina Sofia, Córdoba, Spain
- Santamaria, Rafael, University Hospital Reina Sofia, Córdoba, Spain
- López-López, Isabel, University Hospital Reina Sofia, Córdoba, Spain
- Pendon-Ruiz de Mier, Victoria, University Hospital Reina Sofia, Córdoba, Spain
- Peregrin, Cayetana Moyano, University Hospital Reina Sofia, Córdoba, Spain
- Ojeda lopez, Raquel, University Hospital Reina Sofia, Córdoba, Spain
- Rodriguez, Mariano, University Hospital Reina Sofia, Córdoba, Spain
- Munoz-Castaneda, Juan R., Maimonides Biomedical Research Institute of Cordoba (IMIBIC), Cordoba, Spain
- Martin-Malo, Alejandro, University Hospital Reina Sofia, Córdoba, Spain
- Soriano, Sagrario, University Hospital Reina Sofia, Córdoba, Spain
Background
Decreased serum mg may be associated with mortality and vascular calcifications. There is limited information on the impact of low mg (mg) in CKD stage 4 patients. We aimed to evaluate whether serum mg levels are associated with mortality in a matched population of CKD patients.
Methods
Patients were stratified into tertiles according to serum mg (T1<2.0 mg/dl, T2 =2.01-2.39 mg/dl and T3>2.4 mg/dl). For survival analysis, we used log-rank tests to compare Kaplan–Meier (KM) probability of death curves and performed uni- and multivariable Cox regression analysis. Given the comparable survival among T2 and T3 patients, serum mg <> 2 mg/dl was used to further perform propensity score matching (PSM) to minimize potential confounding and selection biases within tertiles. We used the derived propensity scores to match the groups in a 1:1 ratio. Further, KM analysis with the matched population was performed.
Results
This study included 1002 patients evaluated in the advanced-CKD outpatient clinic from 2009 to 2018. During the study follow-up, 158 died, 84 from T1, 34 from T2, and 35 from T3. Furthermore, 616 patients started dialysis, whereas 242 remained under follow-up in the outpatient clinic. KM showed that patients from T1 had a worse survival as compared with T2 and T3 (p<0.001; Figure 1A). Multivariate Cox proportional hazard showed that patients with mg <2 mg/dl had a higher mortality risk (HR 1.61, CI 1.05—2.46) as compared to the other groups. After matching, it was obtained an adjusted population of 343 patients with mg <2 mg/dl and 343 with higher concentrations of mg. Survival analysis with PSM-adjusted cohorts showed that patients with mg <2 mg/dl had worse survival compared to T2 and T3 (log-rank p=0.01; HR 1.73, CI 1.02—2.36, p=0.44; Figure 1B)
Conclusion
In appropriately-matched patients, a serum mg <2 mg/dl predicts mortality.
Figure 1. Survival analysis of not matched cohorts (A) and PSM-adjusted cohorts (B).
Funding
- Government Support - Non-U.S.