Níveis plasmáticos e eritrocitários de selênio em idosos com Alzheimer: um estudo caso-controle

Abstract

Nutritional disorders are important risk factors capable of enhancing or favoring the appearance of Alzheimer's Disease (AD). Objective: To analyze plasma and erythrocyte levels of selenium among the elderly with and without the diagnosis of Alzheimer's disease. Methodology: This is a case-control study, carried out with one group of elderly people with Alzheimer's disease and another without the diagnosis of the disease. The groups were formed by elderly people accompanied at the Geriatrics outpatient clinic of the University Hospital Prof. Alberto Antunes and outpatient clinic of Nutrition for the Elderly of the Faculty of Nutrition of the Federal University of Alagoas. The diagnosis of Alzheimer's was established by a specialist doctor, respecting the criteria NINCDS - ADRDA. Plasma and erythrocyte concentrations of total selenium (Se) were performed by means of atomic absorption spectrophotometry. Statistical analyzes were performed using SPSS software, version 20.0. Results: The study consisted of 34 elderly people with Alzheimer's disease and 68 elderly patients without the diagnosis of the disease, with the majority of women in both groups. The mean age was 74.41 ± 7.1 years in the case group and 68.46 ± 5.1 years in the control group (p = 0.010). The elderly Alzheimer group had lower concentrations of plasma selenium with a mean of 45.29 ± 14.51μg / dL vs. 55.14 ± 14.01 μg / dL (p = 0.004) and lower concentrations of selerium intraeritrocitaries with median equal to 56.36 μg / L (Min: 40.64μg / L; 76.96μg / L (Min: 26.33μg / L, Max: 141.04μg / L) (p <0.001). In a multivariate linear regression model, a positive correlation was observed between erythrocyte selenium concentrations and the cognitive capacity assessed by MMSE. Logistic regression analysis indicated an association between erythrocyte selenium concentrations and AD. A reduction of approximately 3.5% of the chance of having an AD (OR = 0.975, p = 0.028, 95% CI = 0.953-0.997) was identified at each increase of 1μg / L of intracellular selenium. Conclusion: Under the conditions of the present study, patients with Alzheimer's Disease had lower concentrations of selenium in the compartments evaluated.