Unraveling the relationship between mortality, hyponatremia, inflammation and malnutrition in hemodialysis patients: results from the international MONDO initiative.
Hyponatremia is a risk factor for mortality in hemodialysis (HD) patients. It is not well known to which extent the comorbidities, malnutrition, fluid status imbalance and inflammation are related to hyponatremia and affect outcomes.



We studied 8883 patients from the European subset of the international MONitoring Dialysis Outcomes initiative. Nutritional and fluid statuses were assessed by bioimpedance spectroscopy. Fluid depletion was defined as overhydration⩽-1.1 l and fluid overload as overhydration>+1.1 l, respectively. Malnutrition was defined as a lean tissue index below the 10th percentile of age- and gender-matched healthy controls. Hyponatremia and inflammation were defined as serum sodium levels <135 mEq/l and C-reactive protein levels>6.0 mg/l, respectively. We used logistic regression to test for predictors of hyponatremia and Cox proportional hazards analysis to assess the association with all-cause mortality.



Hyponatremia was predicted by the presence of malnutrition (odds ratio (OR)=1.49 (95% confidence interval (CI)=1.30-1.70), inflammation (OR=1.44 (95% CI=1.26-1.64)) and fluid overload ((>+1.1 l to +2.5 l) OR=0.73 (95% CI=0.62-0.85)) but not by fluid depletion (OR=1.34 (95% CI=0.92-1.96)). Malnutrition, inflammation, fluid overload, fluid depletion and hyponatremia (hazard ratio=1.70 (95% CI=1.46-1.99)) were independent predictors for all-cause mortality.



In HD patients, hyponatremia is associated with malnutrition, inflammation and fluid overload. Hyponatremia maintained predictive for all-cause mortality after adjustment for malnutrition, inflammation and fluid status abnormalities. The presence of hyponatremia may assist in identifying HD patients at increased risk of death.
Division of Nephrology, Department of Internal Medicine, Maastricht University Medical Center, Maastricht, The Netherlands.|Catharina Hospital, Eindhoven, The Netherlands.
M J E
MJ
Dekker
Fresenius Medical Care, Bad Homburg, Germany.
D
D
Marcelli
Fresenius Medical Care, Bad Homburg, Germany.
B
B
Canaud
Catharina Hospital, Eindhoven, The Netherlands.
C J A M
CJ
Konings
Division of Nephrology, Department of Internal Medicine, Maastricht University Medical Center, Maastricht, The Netherlands.
K M
KM
Leunissen
Renal Research Institute, New York, NY, USA.|Icahn School of Medicine at Mount Sinai Health System, Waltham, MA, USA.
N W
NW
Levin
Fresenius Medical Care, Bad Homburg, Germany.
P
P
Carioni
Renal Research Institute, New York, NY, USA.
V
V
Maheshwari
Renal Research Institute, New York, NY, USA.
J G
JG
Raimann
Division of Nephrology, Department of Internal Medicine, Maastricht University Medical Center, Maastricht, The Netherlands.
F M
FM
van der Sande
Renal Research Institute, New York, NY, USA.|Fresenius Medical Care North America, Waltham, MA, USA.
L A
LA
Usvyat
Renal Research Institute, New York, NY, USA.|Mount Sinai Hospital, New York, NY, USA.
P
P
Kotanko
Division of Nephrology, Department of Internal Medicine, Maastricht University Medical Center, Maastricht, The Netherlands.
J P
JP
Kooman
D000368:Aged; D002097:C-Reactive Protein / Q000378:metabolism; D002423:Cause of Death; D005060:Europe; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000097:blood / Q000209:etiology* / Q000401:mortality; D007249:Inflammation / Q000097:blood / Q000150:complications* / Q000401:mortality; D016015:Logistic Models; D008297:Male; D044342:Malnutrition / Q000150:complications* / Q000401:mortality; D008875:Middle Aged; D009752:Nutritional Status; D016017:Odds Ratio; D016016:Proportional Hazards Models; D011446:Prospective Studies; D006435:Renal Dialysis / Q000009:adverse effects* / Q000401:mortality; D051437:Renal Insufficiency / Q000628:therapy; D012307:Risk Factors; D012709:Serum Albumin / Q000378:metabolism; D012964:Sodium / Q000097:blood*; D014883:Water-Electrolyte Imbalance
D012709:Serum Albumin; D002097:C-Reactive Protein; D012964:Sodium