Status de selênio e insuficiência cardíaca: associações com parâmetros clínicos, nutricionais e impacto sobre desfechos clínicos

Abstract

Selenium deficiency has been a frequent finding in individuals with heart failure (HF), but there are gaps in the literature regarding factors associated with this condition, as well as the impact of selenium status on mortality and hospitalization outcomes. This study aimed to evaluate selenium status and its associations with clinical, nutritional parameters, and clinical outcomes in outpatients with HF. Eighty individuals with a diagnosis of reduced/slightly reduced HF Ejection Fraction or preserved HF Ejection Fraction, adults and older people of both sexes, attended the Interprofessional Heart Failure Outpatient Clinic of the University Hospital Onofre Lopes, in a follow-up period of up to 36 months, were studied. Plasma selenium levels, dietary selenium intake, sociodemographic, anthropometric, clinical, and biochemical parameters, and clinical outcomes (hospitalization and mortality) were evaluated. Plasma selenium was measured by inductively coupled plasma mass spectrometry (ICP-MS). Independent variables were analyzed according to tertiles of plasma selenium concentrations. Multiple linear regression models were run using the stepwise method to determine associations between plasma selenium and other variables. Analysis of the Receiver Operating Characteristic Curve (ROC) was performed to define a cutoff point for plasma selenium values with greater sensitivity and specificity for the clinical outcomes of mortality and hospitalization. Relationships between selenium status and clinical outcomes were observed using Cox regression. Individuals with HF were predominantly male (61.3%) and overweight (52.5%). The most frequent type of HF was reduced or slightly reduced ejection fraction (HFrEF) (70.0%), non-ischemic etiology (55.0%), and functional class I (71.2%). A significant percentage of participants had plasma selenium levels within the reference range (91.2%) and the prevalence of inadequate selenium intake was 29.12%. Regression analysis indicated associations between albumin (β=0.113, p<0.001; R²=0.291) and triglycerides (β=0.0002, p<0.021, R²=0.376) with plasma selenium. Plasma selenium cutoff ≥ 83.80 µg/L was associated with increased risk of all-cause mortality [HR =17.085(1.488-196.146); p=0.023)] and hospitalizations [HR=7.596 (1.114-51.808); p==0.038)]. In conclusion, it was observed that the majority of individuals with HF treated at the outpatient clinic had plasma selenium levels within the normal range, with albumin and triglycerides as independent predictors of plasma selenium levels. In addition, plasma selenium cutoff ≥ 83.80µg/L was associated with an increased risk of unfavorable clinical outcomes in this population.