TY - JOUR
T1 - Increased Mortality Associated with Higher Pre-Dialysis Serum Sodium Variability
T2 - Results of the International MONitoring Dialysis Outcome Initiative
AU - Ye, Xiaoling
AU - Kooman, Jeroen P.
AU - van der Sande, Frank M.
AU - Canaud, Bernard
AU - Stuard, Stefano
AU - Etter, Michael
AU - Xu, Xiaoqi
AU - Marelli, Cristina
AU - Guinsburg, Adrian
AU - Power, Albert
AU - Usvyat, Len A.
AU - Wang, Yuedong
AU - Kotanko, Peter
AU - Raimann, Jochen G.
AU - MONDO Initiative
N1 - Funding Information:
J.G.R., X.Y., J.P.K., F.M.S., and P.K. contributed to the design, implementation, and discussion of the research. X.Y. analyzed the data. The authors thank Herman Rosen, MD, FASN, Weil Cornell Medical College and Icahn School of Medicine at Mount Sinai, New York, NY for reviewing the manuscript. All authors critically revised the manuscript for intellectual content and approved the final version of the manuscript.
Publisher Copyright:
© 2018 S. Karger AG, Basel.
PY - 2019
Y1 - 2019
N2 - Background: Low serum sodium (SNa) is associated with an increased mortality in chronic hemodialysis (HD) patients. Dialysis patients are thought to have an individual pre-dialysis SNa set-point, yet there is evidence for variability of pre-dialysis SNa in individual patient. In this study, we explored the association of several SNa variability metrics with all-cause mortality in a large patient population from the international MONitoring Dialysis Outcomes (MONDO) Initiative. Methods: All adult incident patients from the MONDO database with more than 5 SNa measurements during the first year on HD were included. All patients were required to survive the first year on HD (defined as the baseline). During the subsequent 2 years of follow-up, all-cause mortality was recorded. The following variability indicators were calculated during baseline: mean SNa and its SD; average real variability (ARV, average the absolute distance of the 2 consecutive SNa measurements), and average directional range (DR, the difference between minimum and maximum values). We used Cox Proportional hazard model with bivariate spline terms to analyze the joint association of SNa and SD, ARV and DR, respectively, with all-cause mortality. While conducting the multivariate Cox regression analyses, patients were stratified into 3 groups of DR (Negative DR: -20 DR -6, Null DR: -6<DR <6 and Positive DR: 6 DR 20) with the Null DR as the reference group. Results: We included 20,216 patients in the study. A SNa 135 mEq/L was observed to be the strongest predictor of evaluated mortality risk. Higher SNa variability (quantified as SD, ARV, and DR) was also associated with an increased mortality irrespective of SNa levels. When compared with higher SD or ARV, greater DR showed a stronger association with an elevated risk of death. Controlling the Cox Proportional hazard models for additional parameters showed consistent results. Conclusion: Higher SNa variability associated with increased all-cause mortality at all levels of SNa. DR of SNa showed the strongest association with mortality and may constitute a Simple and novel prognostic indicator, easily applicable at the bedside.
AB - Background: Low serum sodium (SNa) is associated with an increased mortality in chronic hemodialysis (HD) patients. Dialysis patients are thought to have an individual pre-dialysis SNa set-point, yet there is evidence for variability of pre-dialysis SNa in individual patient. In this study, we explored the association of several SNa variability metrics with all-cause mortality in a large patient population from the international MONitoring Dialysis Outcomes (MONDO) Initiative. Methods: All adult incident patients from the MONDO database with more than 5 SNa measurements during the first year on HD were included. All patients were required to survive the first year on HD (defined as the baseline). During the subsequent 2 years of follow-up, all-cause mortality was recorded. The following variability indicators were calculated during baseline: mean SNa and its SD; average real variability (ARV, average the absolute distance of the 2 consecutive SNa measurements), and average directional range (DR, the difference between minimum and maximum values). We used Cox Proportional hazard model with bivariate spline terms to analyze the joint association of SNa and SD, ARV and DR, respectively, with all-cause mortality. While conducting the multivariate Cox regression analyses, patients were stratified into 3 groups of DR (Negative DR: -20 DR -6, Null DR: -6<DR <6 and Positive DR: 6 DR 20) with the Null DR as the reference group. Results: We included 20,216 patients in the study. A SNa 135 mEq/L was observed to be the strongest predictor of evaluated mortality risk. Higher SNa variability (quantified as SD, ARV, and DR) was also associated with an increased mortality irrespective of SNa levels. When compared with higher SD or ARV, greater DR showed a stronger association with an elevated risk of death. Controlling the Cox Proportional hazard models for additional parameters showed consistent results. Conclusion: Higher SNa variability associated with increased all-cause mortality at all levels of SNa. DR of SNa showed the strongest association with mortality and may constitute a Simple and novel prognostic indicator, easily applicable at the bedside.
KW - Pre-dialysis serum sodium
KW - Hyponatremia
KW - Serum sodium variability
KW - BLOOD-PRESSURE VARIABILITY
KW - INTERDIALYTIC WEIGHT-GAIN
KW - HEART-RATE-VARIABILITY
KW - HEMODIALYSIS-PATIENTS
KW - SEASONAL-VARIATIONS
KW - HYPONATREMIA
KW - PARAMETERS
KW - FAILURE
KW - STABILITY
KW - DISEASE
U2 - 10.1159/000495354
DO - 10.1159/000495354
M3 - Article
C2 - 30544113
SN - 0250-8095
VL - 49
SP - 1
EP - 10
JO - American Journal of Nephrology
JF - American Journal of Nephrology
IS - 1
ER -