Inflammation, Oxidation, Caloric Expenditure and Cognitive Impairment in Brazilian Elderly Assisted at Primary Care

Cognitive impairment (CI) has a multifactorial etiology. Some studies have suggested that inflammatory, oxidative and antioxidant status and physical activity are associated with CI. However, the evidence on this subject is still controversial. The goal of this study was to verify the association of caloric expenditure by physical activity, oxidative, antioxidant power and inflammatory biomarkers with CI in older adults. We performed a cross-sectional study of 424 elderly (224 with normal cognitive function and 200 with CI) patients from the Family Health Strategy in Porto Alegre, Rio Grande do Sul, Brazil. The variables investigated were sociodemographic, biochemical, inflammatory (hs-CRP, IL-6), oxidative (TBARS, AOPP), antioxidant power (FRAP) biomarkers, energy expenditure, and cognitive function. The instruments used were the Minnesota Leisure Time Physical Activity Questionnaire + Compendium of Physical Activities, classification of energy costs of human physical activities (for physical activity evaluation and measurement of energy expenditure in METs), and a battery of neuropsychiatric instruments (for cognitive ability assessment). We found statistically significant differences only with respect to HDL-c and age (higher averages in the CI group; P<0.05). We observed no differences between the groups with respect to biochemical, inflammatory, oxidative and FRAP biomarkers or caloric expenditure. Logistic regression showed that HDL-c (OR=1.02 [IC=95%; 1.01-1.04]; P=0.011), and age (OR=1.05 [IC=95%; 1.02-1.08]; P=0.004) are independent factors associated with CI. Our results suggest that the biochemical (except HDL-c), inflammatory, oxidative, and FRAP biomarkers investigated and caloric expenditure are not associated with CI in the elderly assisted at primary care.