Quality of life, sodium intake and cardiorespiratory fitness in heart failure: a longitudinal study.

Background: While adherence to a low-sodium diet and cardiorespiratory fitness (CRF) are important in heart failure (HF) management, their effects on health-related quality of life (HRQoL) remain unclear. This study evaluated the influence of CRF, sodium intake adherence and demographic and clinical variables on HRQoL, cardiovascular mortality and hospitalisation in individuals with HF.

Methods: A longitudinal study assessed outpatients at baseline (T0) and every six months (T1, T2) through telemonitoring. Data were analysed using R. Spearman's correlation examined associations between demographic/clinical variables, CRF, sodium intake, hospitalisation and mortality. Variables with significant correlations were included in stepwise multiple regression. Repeated measures ANOVA was used to assess changes over time in HRQoL.

Results: A total of 81 patients were included at T0, 74 at T1 and 72 at T2. Sodium intake adherence remained below the good adherence cutoff (≥40 points) across all timepoints. Mean CRF was 3 metabolic equivalents (METs). No significant change in sodium intake or CRF was observed over time. Actively working individuals had a 16.5-fold higher risk of mortality, even after adjusting for sex and age, possibly due to limited healthcare access, occupational stress, comorbidities and treatment nonadherence. The HRQoL physical domain was significantly associated with demographic, clinical and functional factors, including gender, obesity, NYHA class, HF severity and CRF (p<0.01).

Conclusion: CRF, gender, obesity, New York Heart Association class and HF severity predicted HRQoL's physical domain. Being actively employed was strongly associated with mortality risk. Despite consistently low adherence to sodium intake recommendations, no association was found with health-related quality of life.