Homocysteine (Hcy) and cognitive performance in a population sample of elderly Brazilians

Hyperhomocysteinemia (HHcy) has been suggested as a predictive factor of cognitive alterations. Brazil has one of the highest aging dementia rates among the world's emerging countries. The objective of this study was to assess the influence of Hcy levels on the cognitive performance of low-income elderly. This cross-sectional study was developed in an urban center in the Northeast of Brazil and included 205 eligible community-dwelling older adults. A multidimensional questionnaire was used to evaluate sociodemographic aspects, health status and overall clinical aspects. Cognitive performance was assessed by the Portuguese version of Mini Mental State Examination (MMSE). Folic acid, vitamin B12 and Hcy levels were determined by chemical luminescence. The association between sociodemographic variables, Hcy, serum vitamin B12, folic acid levels and total MMSE score was assessed by multiple linear regression. Values indicative of HHcy (>12 μmol/l) were found in 34.8% of the individuals. Age, schooling and HHcy showed a negative correlation with the MMSE score. The R2 values of isolated HHcy explain only 4% of the MMSE score variance, however when associated to schooling and age, this model explained up to 25% of this association.