Zinc in plasma and correlation with metabolic markers of institutionalized elderly in Natal / RN
Zinc in plasma, aging, long-stay institution for the elderly, cytokines, lipid profile, metabolic syndrome.
The objective of this study was to evaluate plasma zinc concentrations and associations with sociodemographic, biochemical, dietary and immunological indicators in institutionalized elderly. A cross - sectional study involving 255 elderly individuals enrolled in 13 Long - Term Institutions for the Elderly (ILPI) in the city of Natal / RN. The associations between zinc plasma concentrations, zinc in the diet, as well as sociodemographic indicators and biomarkers with a glycemic, lipid and inflammatory profile were evaluated. The independent variables were analyzed according to the quartiles of plasma zinc concentration (μg / dL) (Q1: <71.1, Q2: 71.1-83.3, Q3: <83.3-93.7; Q4:> 93.7). The correlation between plasma zinc concentration and predictor variables was also tested. In Q1, higher concentrations of the following variables were observed compared to the other quartiles: total cholesterol and LDL-c (Q1> Q2, Q3, Q4, all p <0.001); triacylglycerols (Q1> Q3, Q4, all p <0.001); IL-6 (Q1> Q3, Q4, p = 0.024, p = 0.010, respectively); and TNF-α (Q1> Q3, p = 0.003). There was a significant reduction in plasma zinc concentration as the time of institutionalization adjusted for age (Δ = -0.10, CI95%: -0.18, -0.01) and total cholesterol concentrations ( Δ = -0.19, CI95%: -0.23, -0.15), LDL-c (Δ = -0.19, CI95%: -0.23, -0.15), triacylglycerols (Δ = -0.11, 95% CI: -0.16, -0.06), IL-6 (Δ = -1.41, 95% CI: -2.64, -0.18) and TNF-α (Δ = -1.04, 95% CI: -1.71, - 0.36). Thus, data from the present study suggest that a decrease in plasma zinc concentration is associated with longer institutionalization time and changes in the lipid and inflammatory profile in institutionalized older adults. In a second study, the prevalence of metabolic syndrome (MS) was evaluated in 202 elderly people, according to the criteria of the National Cholesterol Education Program - Adult Treatment Panel III, as well as the associated factors. The prevalence of MS was 29.2% (95% CI: 23.0-36.0%). The occurrence of MS was higher in women, in the elderly with institutionalization time adjusted for age> 50%, and in the presence of high concentrations of IL-6 and TNF-α (p <0.05). Thus, the results point to a moderate prevalence of MS, which was associated with demographic factors, institutional care and immunological changes.