TY - JOUR
T1 - Hyponatremia and mortality risk
T2 - a Danish cohort study of 279 508 acutely hospitalized patients
AU - Holland-Bill, Louise
AU - Christiansen, Christian Fynbo
AU - Heide-Jørgensen, Uffe
AU - Ulrichsen, Sinna Pilgaard
AU - Ring, Troels
AU - Jørgensen, Jens Otto L
AU - Sørensen, Henrik Toft
N1 - © 2015 European Society of Endocrinology.
PY - 2015
Y1 - 2015
N2 - OBJECTIVE: We aimed to investigate the impact of hyponatremia severity on mortality risk and assess any evidence of a dose-response relation, utilizing prospectively collected data from population-based registries.DESIGN: Cohort study of 279 508 first-time acute admissions to Departments of Internal Medicine in the North and Central Denmark Regions from 2006 to 2011.METHODS: We used the Kaplan-Meier method (1 - survival function) to compute 30-day and 1-year mortality in patients with normonatremia and categories of increasing hyponatremia severity. Relative risks (RRs) with 95% CIs, adjusted for age, gender and previous morbidities, and stratified by clinical subgroups were estimated by the pseudo-value approach. The probability of death was estimated treating serum sodium as a continuous variable.RESULTS: The prevalence of admission hyponatremia was 15% (41 803 patients). Thirty-day mortality was 3.6% in normonatremic patients compared to 7.3, 10.0, 10.4 and 9.6% in patients with serum sodium levels of 130-134.9, 125-129.9, 120-124.9 and <120 mmol/l, resulting in adjusted RRs of 1.4 (95% CI: 1.3-1.4), 1.7 (95% CI: 1.6-1.8), 1.7 (95% CI: 1.4-1.9) and 1.3 (95% CI: 1.1-1.5) respectively. Mortality risk was increased across virtually all clinical subgroups, and remained increased by 30-40% 1 year after admission. The probability of death increased when serum sodium decreased from 139 to 132 mmol/l. No clear increase in mortality was observed for lower concentrations.CONCLUSIONS: Hyponatremia is highly prevalent among patients admitted to Departments of Internal Medicine and is associated with increased 30-day and 1-year mortality risk, regardless of underlying disease. This risk seems independent of hyponatremia severity.
AB - OBJECTIVE: We aimed to investigate the impact of hyponatremia severity on mortality risk and assess any evidence of a dose-response relation, utilizing prospectively collected data from population-based registries.DESIGN: Cohort study of 279 508 first-time acute admissions to Departments of Internal Medicine in the North and Central Denmark Regions from 2006 to 2011.METHODS: We used the Kaplan-Meier method (1 - survival function) to compute 30-day and 1-year mortality in patients with normonatremia and categories of increasing hyponatremia severity. Relative risks (RRs) with 95% CIs, adjusted for age, gender and previous morbidities, and stratified by clinical subgroups were estimated by the pseudo-value approach. The probability of death was estimated treating serum sodium as a continuous variable.RESULTS: The prevalence of admission hyponatremia was 15% (41 803 patients). Thirty-day mortality was 3.6% in normonatremic patients compared to 7.3, 10.0, 10.4 and 9.6% in patients with serum sodium levels of 130-134.9, 125-129.9, 120-124.9 and <120 mmol/l, resulting in adjusted RRs of 1.4 (95% CI: 1.3-1.4), 1.7 (95% CI: 1.6-1.8), 1.7 (95% CI: 1.4-1.9) and 1.3 (95% CI: 1.1-1.5) respectively. Mortality risk was increased across virtually all clinical subgroups, and remained increased by 30-40% 1 year after admission. The probability of death increased when serum sodium decreased from 139 to 132 mmol/l. No clear increase in mortality was observed for lower concentrations.CONCLUSIONS: Hyponatremia is highly prevalent among patients admitted to Departments of Internal Medicine and is associated with increased 30-day and 1-year mortality risk, regardless of underlying disease. This risk seems independent of hyponatremia severity.
U2 - 10.1530/EJE-15-0111
DO - 10.1530/EJE-15-0111
M3 - Journal article
C2 - 26036812
SN - 0804-4643
VL - 173
SP - 71
EP - 81
JO - European Journal of Endocrinology
JF - European Journal of Endocrinology
IS - 1
ER -