title: Evaluation of 2 methods for sodium intake assessment in cardiac patients with and without heart failure: the confounding effect of loop diuretics.
abstract: BACKGROUND
  Twenty-four-hour urine collections are considered the optimal method for sodium intake assessment. Whether a diagnosis of heart failure (HF) or the use of loop diuretic (LD) therapy for HF compromises the validity of 24-h urine collections as a surrogate marker for sodium intake is unknown.
  
  
  OBJECTIVE
  The objective was to determine the strength of association between 24-h urine collections and food records for sodium intake assessment in non-HF cardiac patients and in HF patients stratified by LD usage.
  
  
  METHODS
  Food records and 24-h urine collections were simultaneously completed for 2 consecutive days. Correlation coefficients and the Bland-Altman method of agreement described the relation between the techniques.
  
  
  RESULTS
  Non-HF cardiac patients (n = 96; mean ± SD age: 65 ± 11 y), HF patients who were not taking an LD (n = 47; 62 ± 11 y), and HF patients who were taking an LD (n = 62; age: 60 ± 12 y) were included. Correlation coefficients for sodium intake between food records and urine collections were r = 0.624 (P < 0.001) for non-HF cardiac patients and r = 0.678 (P < 0.001) for HF patients who were not taking an LD. However, no significant association (r = 0.132, P = 0.312) was observed for HF patients who were taking LDs. The 95% limits of agreement between the non-HF cardiac patients and the HF patients who were not taking LDs were similar but were ≈50% wider for HF patients who were taking LDs.
  
  
  CONCLUSIONS
  For the assessment of sodium intake, food records agree well with 24-h urine collections in non-HF patients with cardiovascular disease and in HF patients who are not receiving LD but not for HF patients who are taking LDs. Therefore, food records may provide a better estimate of sodium intake in HF patients who are receiving LD therapy.
authors.affiliation: Department of Nutritional Sciences, University of Toronto, Toronto, Canada.
authors.forename: JoAnne
authors.initials: J
authors.lastname: Arcand
authors.forename: John S
authors.initials: JS
authors.lastname: Floras
authors.forename: Eduardo
authors.initials: E
authors.lastname: Azevedo
authors.forename: Susanna
authors.initials: S
authors.lastname: Mak
authors.forename: Gary E
authors.initials: GE
authors.lastname: Newton
authors.forename: Johane P
authors.initials: JP
authors.lastname: Allard
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000652:urine; D002318:Cardiovascular Diseases / Q000178:diet therapy* / Q000652:urine; D003430:Cross-Sectional Studies; D015930:Diet Records; D004039:Diet, Sodium-Restricted; D005260:Female; D006333:Heart Failure / Q000178:diet therapy / Q000188:drug therapy* / Q000652:urine; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D012964:Sodium / Q000652:urine*; D049994:Sodium Potassium Chloride Symporter Inhibitors / Q000627:therapeutic use*; D012982:Sodium, Dietary / Q000008:administration & dosage*; D013223:Statistics as Topic; D055815:Young Adult
chemical_list: D015415:Biomarkers; D049994:Sodium Potassium Chloride Symporter Inhibitors; D012982:Sodium, Dietary; D012964:Sodium