ZINC AND COPPER STATUS AND ASSOCIATIONS WITH BIODEMOGRAPHIC, CLINICAL, BIOCHEMICAL AND NUTRITIONAL PARAMETERS IN INDIVIDUALS WITH HEART FAILURE
Heart failure; zinc; copper; nutritional status; biomarkers.
Heart failure (HF) is a complex syndrome with two predominant etiologies, ischemic HF and non-ischemic HF. There are gaps on the exact impact of the etiology and other factors associated with HF on zinc and copper status. The aim was to investigate the zinc and copper status in individuals with ischemic and non-ischemic HF, and the associations with biodemographic, clinical, biochemical and nutritional parameters. This is a cross-sectional study that included 80 patients with HF who were treated in an outpatient setting, grouped with ischemic (n=36) and non-ischemic HF (n=44). Biodemographic, clinical, biochemical and nutritional data were evaluated. Zinc biomarkers (plasma zinc, urine zinc and dietary zinc), copper biomarkers (plasma copper, ceruloplasmin and dietary copper) and copper/zinc ratio were investigated. Student's t-tests, Mann-Whitney, Chi-square or Fisher's exact test were used to compare the groups. Multiple linear regression using the stepwise method was used to evaluate associations. We observed lower zinc intake and higher copper intake in the group with ischemic HF (both p=0.02), with higher prevalence of inadequate of zinc intake and lower prevalence of inadequate copper intake. No differences were detected in plasma zinc and copper, copper/zinc ratio, ceruloplasmin and urine zinc between the groups (all p≥0.05). The median values of these biomarkers were within reference range in both groups. Inverse associations were observed between plasma zinc and age (β=-0.001, p=0.005) and use of diuretic (β=-0.047, p=0.013). Transferrin saturation (β=-0.002, p=0.014), plasma copper (β=0.001, p<0.001), albumin (β=0.090, p<0.001) and ischemic etiology (β=0.038; p=0.012) were directly associated with plasma zinc. It was identified a direct association between ceruloplasmin (β=0.011, p<0.001), GGT (β=0.001, p <0.001), albumin (β=0.077, p=0.001), hs-CRP (β=0.001, p=0.024), dietary calcium (β=0,000, p=0,015) and plasma copper. On the other hand, the independent variables previous alcoholism (β=-0.070, p<0.001) and dietary fiber (β=-0.016, p=0.008) were inversely associated with plasma copper. The results suggest that there are no significant changes in zinc and copper status, regardless of the etiology of HF. It is important to monitore the predictive variables of plasma zinc and copper related to the context of HF, especially those associated with oxidative stress and inflammation.