A Population-Based Study of the Association between Trypanosoma cruzi Infection and Cognitive Impairment in Old Age (The Bambui Study)

Background: Limited clinical data suggest that chronic Trypanosoma cruzi infection, which causes Chagas' disease (ChD), is associated with cognitive impairment. This study investigated this association in a large population-based sample of older adults. Methods: Participants in this cross-sectional study comprised 1,449 persons aged 6 60 years from a Brazilian endemic area (Bambu). Cognitive functioning was ascertained by the Mini-Mental State Examination (MMSE), considering its score in percentiles [<= 14 (<5th percentile), 15-22 (5th to <25th) and 6 23]. Hypothesized risk factors were T. cruzi infection, ChD-related electrocardiographic (ECG) abnormalities and use of digoxin medication. Potential confounders included depressive symptoms, smoking, stroke, hemoglobin, HDL cholesterol, blood glucose, systolic blood pressure, and use of psychoactive medication. Results: The prevalence of T. cruzi infection was 37.6%. There was a graded and independent association between infection and the MMSE score (adjusted odds ratios estimated by ordinal logistic regression = 1.99; 95% CI 1.43-2.76). No significant associations between the MMSE score and ECG abnormalities or digoxin medication use were found. Conclusions: This study provides for the first time epidemiological evidence of an association between T. cruzi infection and cognitive impairment which was not mediated by either ChD-related ECG abnormalities or digoxin medication use. Copyright (C) 2008 S. Karger AG, Basel