A Population-Based Study of the Association between <i>Trypanosoma cruzi</i> Infection and Cognitive Impairment in Old Age (The Bambuí Study)

Abstract

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 ≥60 years from a Brazilian endemic area (Bambuí). 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 ≥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.

Predictors of 10-year mortality in a population of community-dwelling Brazilian elderly: the Bambuí cohort study of aging

“…An earlier crosssectional study showed that infected elderly in Bambuí were more likely to report worse self-rated health, to have stayed in bed recently, to use more prescribed medications, and to be hospitalized independently of other relevant factors 23 . Another cross-sectional study showed a strong and graded relationship between T. cruzi infection and cognitive impairment, which is biologically plausible 31 . A recent cohort study showed that T. cruzi infection is a predictor of all-cause mortality among the elderly Bambuí cohort independent of age, sex and conventional cardiovascular risk factors 32 .…”

Insights into the clinical and functional significance of cardiac autonomic dysfunction in Chagas disease

“…Therefore, chagasic subjects may also be susceptible to psycho-functional derangements attendant on functional demands for higher cerebral processes in association with their autonomic cardiovascular adaptive disability, as suggested by some evidences 91,92 . In fact, at least in other clinical conditions as the Alzheimer's disease, cognitive status and cardiac autonomic modulation evaluated by heart rate variability appear to be correlated in the sense that people with lower cardiac parasympathetic modulation and tendency for higher sympathetic modulation show more severe cognitive deficiencies 93 .…”

Stroke in Asymptomatic <i>Trypanosoma cruzi</i>-Infected Patients

“…The Bambuí study found that 5.4% of T. cruzi -infected people in the community suffered an ischemic stroke [18], a stroke rate that may be even higher than in the general population in endemic areas (2.9%) [19]. However, these studies did not study the proportion of asymptomatic chagasic patients that suffered an ischemic stroke.…”