Serum sodium and mortality in a national peritoneal dialysis cohort

Abstract

A B S T R A C TBackground: Sodium disarrays are common in peritoneal dialysis (PD) patients, and may be associated with adverse outcomes in this population. However, few studies of limited sample size have examined the association of serum sodium with mortality in PD patients, with inconsistent results. We hypothesized that both hypo-and hypernatremia are associated with higher death risk in a nationally representative cohort of US PD patients. Methods: We sought to examine the association of serum sodium over time and mortality among 4687 adult incident PD patients from a large US dialysis organization who underwent one or more serum sodium measurements within the first 3 months of dialysis over January 2007 to December 2011. We examined the association of time-dependent and baseline sodium with allcause mortality as a proxy of short-and long-term sodium-mortality associations, respectively. Hazard ratios were estimated using Cox models with three adjustment levels: minimally adjusted, case-mix adjusted, and case-mix þ laboratory adjusted. Results: In time-dependent analyses, sodium levels <140 mEq/ L were associated with incrementally higher death risk in casemix models (ref: 140 to <142 mEq/L); following laboratory covariate adjustment, associations between lower sodium and higher mortality remained significant for levels <136 mEq/L. In analyses using baseline values, sodium levels <140 mEq/L were associated with higher mortality risk across all models (ref: 140 to <142 mEq/L). Conclusions: In PD patients, lower time-dependent and baseline sodium levels were independently associated with higher death risk. Further studies are needed to determine whether correction of dysnatremia improves longevity in this population.

Electrolyte and Acid-Base Disorders in Chronic Kidney Disease and End-Stage Kidney Failure

“…Dysnatremia in CKD and ESRD has mortality significance. A U-shaped association between serum Na and mortality was found in both non-dialysis CKD [123,127] and dialysis patients [128,129]. The management of dysnatremia in CKD patients is similar to that for the general patients and should start with identifying and, if possible, correcting the underlying cause.…”

Possible association between dysnatremias and mortality during hospitalization in patients undergoing acute hemodialysis: analysis from a Peruvian retrospective cohort

“…These include changes of urine dilution and concentration in response to antidiuretic hormone, and alteration of water and Na and CI reabsorption and excretion 13,14 . Previous studies have reported that dysnatremias and hypochloremia are associated factors for mortality in patients with chronic kidney disease (CKD), with or without dialysis [15][16][17][18][19][20][21][22] . Thus, dyschloremias and dysnatremias have been proposed as potential useful factors for mortality prediction in this population [15][16][17][18][19][20][21][22] .…”

Mortality rates are lower in SIAD, than in hypervolaemic or hypovolaemic hyponatraemia: Results of a prospective observational study

“…Most mortality studies in hyponatraemia have been retrospective, and as a result, there has been poor ascertainment of the essential diagnostic criteria of SIAD. [2][3][4][5][6][7][8][9][10][11][12][18][19][20] On the basis of existing data; therefore, it is not possible to distinguish between the mortality in SIAD, and that associated with hypovolaemic hyponatraemia (HON) or hypervolaemic hyponatraemia (HEN). [2][3][4][5][6][7][8][9][10][11][12]14,15 The aim of this study was to clearly define the mortality in SIAD, with specific reference to the following questions; (i) whether mortality in a well-defined cohort of SIAD patients was elevated compared to eunatraemic controls, (ii) whether the increased mortality was explainable on the basis of comorbid conditions and (iii) whether the mortality in SIAD was different to that in patients with HON or HEN.…”