Salt Taste Recognition in a Heart Failure Cohort

Abstract

Background: Heart failure (HF) disproportionately affects older adults. Dietary sodium indiscretion is frequently implicated in HF decompensation. The affinity for and ability to taste salt in this process is unexplored. We sought to evaluate differences in salt taste by age and HF diagnosis and to map changes after hospitalization for acute decompensated heart failure (ADHF).

Methods: Seventy-two subjects underwent initial salt-taste testing during hospitalization for ADHF. Follow-up taste testing occurred at discharge and 1, 4, and 12 weeks after hospitalization. Three different groups were included as control subjects and underwent 1-time salt-taste testing: 10 patients with stable HF, 10 healthy older adults, and 10 healthy younger adults. Salt-taste testing was completed with the use of commercially available and validated Salsave test strips with increasing concentrations of NaCl (0.6-1.6 mg/cm²) to identify salt taste recognition threshold. Respectively, 2-sample t tests, multiple regression, and linear mixed-effects modeling were used for intergroup comparisons, to adjust for confounders, and to assess the effect of time after discharge from ADHF hospitalization.

Results: The baseline salt taste recognition threshold was lowest in the young healthy control group (0.62 [SD 0.05] mg/cm² NaCl) compared with the healthy older control subjects (0.92 [SD 0.29] mg/cm² NaCl), stable HF outpatients, (1.06 [SD 0.22] mg/cm² NaCl), and ADHF subjects on admission (1.06 [SD 0.48] mg/cm² NaCl). There was a strong trend toward higher recognition threshold in HF patients (P = .051) that was independent from age and other potential confounders. Serial salt-taste testing in the ADHF group demonstrated a decrease in recognition threshold that persisted over the 12 weeks after discharge (1.04 [SD 0.44] to 0.76 [SD 0.22] mg/cm² NaCl; P = .003).

Discussion: When compared with young healthy control subjects, HF patients have impaired recognition of salt taste. The salt taste recognition threshold decreases after hospitalization for ADHF. This change demonstrates the first evidence of the phenomenon known as the "hedonic shift" in HF, in which the threshold to recognize salt taste decreases after prescribed sodium restriction.

Keywords: Salt taste; aging; heart failure; hedonic shift.