RESUMO
INTRODUCTION: Heart failure (HF) is a clinical syndrome resulting from the structural and/or functional impairment of blood supply to tissues. Congestion and edema associated with water retention are the main symptoms presented by patients. Fluid (FR) and sodium restriction are non-pharmacological measures indicated in clinical practice to mitigate this symptom, despite their low evidence level. AIM: Assessing the impact of sodium and/or fluid restriction on nutritional parameters of adult patients with HF, based on systematic review with meta-analysis. METHODS: The study was conducted in June 2020, on the following databases: EMBASE, PubMed/MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL) and Web of Science. Citations were also collected in the gray literature such as thesis banks and preprints. Randomized clinical trials conducted with patients in the age group 18 years, or older, who were hospitalized or under outpatient/clinical follow-up, and who were subjected to intervention based on fluid and/or sodium restriction in comparison to the control, were herein selected. RESULTS: Although FR-based diets are effective in reducing liquid intake, they increase individuals' thirst sensation and body weight in comparison to non-FR diets. The association between this intervention and sodium restriction is also effective in reducing liquid intake as sodium intake decreases. However, the association of the most severe (<2000 mg/day) and moderate (2000-2400 mg/day) sodium restrictions with FR has reduced energy intake, although without evidence of weight change - only the most severe sodium restriction was capable of keeping individuals' thirst sensation. In addition, moderate sodium restrictions (2300 to 3000 mg/day) in association with FR were capable of decreasing urinary sodium excretion. On the other hand, prescriptions of severe or moderate sodium restriction (<2,400 mg/d) alone have reduced individuals' body weight and BMI, although they did not change their caloric intake. However, severe sodium restriction (<2,000 mg) has led to higher body weight than the low-sodium diet (2000 to 2,4000 mg/day). CONCLUSION: Sodium restriction may not be an effective strategy because it adversely affects individuals' weight, a fact that suggests increased congestion. Weight-based FR is supported to bethe best way to individualize this non-pharmacological treatment and it does not appear to affect nutritional parameters capable of putting patients with HF at higher malnutrition risk.
