Serum sodium levels and patient outcomes in an ambulatory clinic-based chronic kidney disease cohort.

Abstract

BACKGROUND:

Chronic kidney disease (CKD) patients are prone to both hypo- and hypernatremia. Little has been published on the epidemiology of hypo- and hypernatremia in ambulatory patients with non-dialysis CKD.

METHODS:

Data collected in two contemporaneous CKD cohort studies, the Renal Research Institute (RRI)-CKD study (n = 834) and the Study of Treatment of Renal Insufficiency: Data and Evaluation (STRIDE) (n = 1,348) were combined and analyzed to study the association between serum sodium (Na(+)) and clinical outcomes.

RESULTS:

Baseline estimated glomerular filtration rate (eGFR) and Na(+) were 26 ± 11 ml/min/1.73 m(2) and 140.2 ± 3.4 mEq/l, respectively. The prevalence of Na(+) ≤135 mEq/l and ≥144 mEq/l was 6 and 16%, respectively. Higher baseline Na(+) was significantly associated with male sex, older age, systolic blood pressure, BMI, serum albumin, presence of heart failure, and lower eGFR. The risk of end-stage renal disease (ESRD) was marginally significantly higher among patients with Na(+) ≤135 mEq/l, compared with 140< Na(+) <144 mEq/l (referent), in time-dependent models (adjusted hazard ratio, HR = 1.52, p = 0.06). Mortality risk was significantly greater at 135< Na(+) ≤140 mEq/l (adjusted HR = 1.68, p = 0.02) and Na(+) ≥144 mEq/l (adjusted HR = 2.01, p = 0.01).

CONCLUSION:

CKD patients with Na(+) ≤135 mEq/l were at a higher risk for progression to ESRD, whereas both lower and higher Na(+) levels were associated with a higher risk of mortality. While caring for CKD patients, greater attention to serum sodium levels by clinicians is warranted and could potentially help improve patient outcomes.

• Authors: Sang-Woong Han, Anca Tilea, Brenda W Gillespie, Fredric O Finkelstein, Margaret A Kiser, George Eisele, Peter Kotanko, Nathan Levin, Rajiv Saran
• Journal: American journal of nephrology (Am J Nephrol) Vol. 41 Issue 3 Pg. 200-9 ( 2015) ISSN: 1421-9670 [Electronic] Switzerland
• PMID: 25871915 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2015 S. Karger AG, Basel.

Chemical References

• Sodium
• Creatinine

Topics

• Adult
• Age Factors
• Aged
• Ambulatory Care Facilities
• Blood Pressure
• Cohort Studies
• Creatinine (blood)
• Disease Progression
• Female
• Glomerular Filtration Rate
• Heart Failure (epidemiology)
• Humans
• Hypernatremia (blood, epidemiology, mortality)
• Hyponatremia (blood, epidemiology, mortality)
• Kidney Failure, Chronic (mortality, physiopathology)
• Male
• Middle Aged
• Prevalence
• Renal Insufficiency, Chronic (blood, mortality, physiopathology)
• Risk Factors
• Sex Factors
• Sodium (blood)