title: Adherence to the low-sodium diet plays a role in the interaction between depressive symptoms and prognosis in patients with heart failure.
abstract: BACKGROUND
  Although a low-sodium diet (LSD) is important in self-management of patients with heart failure (HF), the impact of LSD on event-free survival has not been investigated. Depressive symptoms predict worse event-free survival, in part, by affecting adherence to self-management. However, there are few investigations of the relationship among depressive symptoms, adherence to the LSD, and event-free survival.
  
  
  OBJECTIVE
  The purpose of this study was to determine the relationships among adherence to the LSD, depressive symptoms, and event-free survival.
  
  
  METHODS
  A total of 254 patients (57% male, 62 ± 14 years, 52% New York Heart Association class III/IV, ejection fraction of 36% ± 14%) were recruited from outpatient HF clinics in Korea. Twenty-four-hour urinary sodium excretion was collected as an indicator of patient adherence to the LSD. Patients were grouped based on the cut point of 3 g of urinary sodium excretion. Depressive symptoms were assessed by the Korean version of Beck Depression Inventory, and patients were split into 2 groups at the cutoff of the Korean version of Beck Depression Inventory. Event-free survival for 12 months was determined by medical records. Hierarchical Cox proportional hazards regression was used to determine the association of depressive symptoms and adherence to 3-g sodium intake on event-free survival.
  
  
  RESULTS
  After controlling for age, sex, etiology of HF, body mass index, New York Heart Association class, ejection fraction, N-terminal B-type natriuretic peptide, and total comorbidity score, nonadherence to 3-g sodium intake (hazard ratio = 1.56, 95% confidence interval = 1.05-2.32) and depressive symptoms (hazard ratio = 2.21, 95% confidence interval = 1.47-3.33) independently predicted event-free survival. Patients with sodium intake higher than 3 g and with depressive symptoms demonstrated a 3.7 times higher risk for cardiac events compared with patients with sodium intake lower than 3 g and without depressive symptoms (P < .001).
  
  
  CONCLUSIONS
  Improvement of adherence to the LSD and treatment for depressive symptoms could improve event-free survival.
authors.affiliation: College of Nursing, University of Kentucky, Lexington, KY, USA. gracesong@uky.edu
authors.forename: Eun Kyeung
authors.initials: EK
authors.lastname: Song
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000554:Ambulatory Care Facilities; D003863:Depression / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D004039:Diet, Sodium-Restricted / Q000523:psychology; D018572:Disease-Free Survival; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000178:diet therapy* / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance / Q000523:psychology / Q000706:statistics & numerical data*; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D012648:Self Care / Q000379:methods / Q000523:psychology; D012720:Severity of Illness Index; D015996:Survival Rate