Hyponatraemia in acute heart failure is a marker of increased mortality but not when associated with hyperglycaemia.
Previous studies suggest that hyponatraemia is a marker of neurohormonal activation and increased mortality in patients with acute heart failure (AHF). Although diabetes is a common co-morbidity in heart failure, no prior study has considered the impact of serum glucose on this relationship.


METHODS
Over four consecutive months we prospectively registered all patients admitted due to AHF. Sodium and glucose levels were determined immediately upon admission. Patients were followed through admission and for the next 6 months. Of 342 patients enrolled, complete data were available for 331 patients.


RESULTS
Hyponatraemia (sodium <135 mmol/L) was detected in 22% of patients. However, 47% of patients with hyponatraemia had concomitant hyperglycaemia (glucose level >11 mmol/L). Hyponatraemia was associated with increased 6-month mortality (21 vs. 8%, p=0.002). This association was restricted to patients who had hyponatraemia without concomitant hyperglycaemia. The 6-month mortality of patients with and without hyponatraemia was 11% versus 10% (p=0.87) when hyperglycaemia was present versus 29% and 7% (p<0.001) when hyperglycaemia was absent.


CONCLUSIONS
In this preliminary study, hyperglycaemia-associated hyponatraemia was present in a significant proportion of patients admitted with AHF. In patients with hyperglycaemia, hyponatraemia had no prognostic significance, whereas in patients without hyperglycaemia, hyponatraemia remained a powerful predictor of mortality. These results need confirmation in a larger study.
Milo-Cotter
Olga
O
Momentum Research, Inc, Durham, NC 27707, USA. olgacotter@momentum-research.com
Cotter
Gad
G
Weatherley
Beth D
BD
Adams
Kirkwood F
KF
Kaluski
Edo
E
Uriel
Nir
N
O'Connor
Christopher M
CM
Felker
G Michael
GM
D000368:Aged; D000369:Aged, 80 and over; D006333:Heart Failure / Q000453:epidemiology*; D006801:Humans; D006943:Hyperglycemia / Q000453:epidemiology*; D007010:Hyponatremia / Q000401:mortality*; D011379:Prognosis; D011446:Prospective Studies; D016019:Survival Analysis