A population-based study of the association between Trypanosoma cruzi infection and cognitive impairment in old age (the Bambuí 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 > or = 60 years from a Brazilian endemic area (Bambuí). Cognitive functioning was ascertained by the Mini-Mental State Examination (MMSE), considering its score in percentiles [< or =14 (<5th percentile), 15-22 (5th to <25th) and > or =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.
Lima-Costa
M Fernanda
MF
Public Health and Ageing Research Group, Oswaldo Cruz Foundation René Rachou Institute, Belo Horizonte. lima-costa@cpqrr.fiocruz.br
Castro-Costa
Erico
E
Uchôa
Elizabeth
E
Firmo
Joselia
J
Ribeiro
Antonio Luiz P
AL
Ferri
Cleusa P
CP
Prince
Martin
M
D000367:Age Factors; D000368:Aged; D000818:Animals; D001938:Brazil / Q000453:epidemiology; D014355:Chagas Disease / Q000150:complications / Q000453:epidemiology* / Q000523:psychology*; D003072:Cognition Disorders / Q000453:epidemiology* / Q000209:etiology / Q000523:psychology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014349:Trypanosoma cruzi