Childhood infectious diseases and old age cognitive functioning: a nationally representative sample of community-dwelling older adults

Abstract

Background: Cumulative evidence suggests that health-related risk factors during midlife and old-age are associated with cognitive impairment. However, studies are needed to clarify the association between early-life risk factors and impaired cognitive functioning to increment existing knowledge. Objective: To examine the association between childhood infectious diseases and late-life cognitive functioning in a nationally representative sample of older adults. Participants: Eligible respondents were 2994 community-dwelling individuals aged 65–85. Measurements: Cognitive functioning was assessed using the Mini-Mental State Examination (MMSE). Childhood infectious diseases (i.e. chicken pox, measles, and mumps) were self-reported. The study covariates were age, sex, highest educational level achieved, smoking status, body mass index, and depression. The primary statistical analysis examined the association between the number of childhood infectious diseases and total MMSE scores, accounting for all study covariates. Regression models of progressive complexity were examined for parsimony. The robustness of the primary results was tested in 17 sensitivity analyses. Results: The most parsimonious model was a linear adjusted model (Bayesian Information Criterion = 12646.09). Late-life cognitive functioning significantly improved as the number of childhood infectious diseases increased (β = 0.18; 95% CI = 0.11, 0.26; p < 0.001). This effect was not significantly attenuated in all sensitivity analyses. Conclusion: The current study results are consistent with prior ecological findings indicating that some childhood infectious diseases are associated with better cognitive functioning in old-age. This points to an early-life modifiable risk factor associated with older-life cognitive functioning. Our results may reflect selective mortality and/or beneficial effects via hormetic processes.

Baseline Infection Burden and Cognitive Function in Elders with Essential Tremor

“…Ecological studies have found similar results where childhood infectious diseases have been associated with both positive and negative cognitive outcomes in adulthood [ 42 43 ]. A population based study of healthy adults over 65 also determined that late-life MMSE scores improved as the number of reported childhood diseases (chickenpox, measles and mumps) increased [ 44 ]. Nevertheless, the mechanisms for possible positive outcomes in cognition are not clear [ 42 45 ].…”

Infectious diseases and cognition: do we have to worry?

“…According to several epidemiological studies, frequent infections, regardless of etiology, such as pneumoniae (viral or bacterial etiology), urinary tract infections, skin, and soft tissue infections, as well as sepsis from diverse origins, are associated with an increased risk of cognitive decline, vascular dementia, and Alzheimer's disease. Actually, the risk of unspecified dementia would be doubled compared with individuals without a history of severe infectious episodes [4,[26][27][28]. Moreover, a study suggested a risk gradient, with higher infectious burdens associated with higher cognitive risks: an all-cause dementia risk of about 1.4 for a history of one episode of hospital-treated infection, and about 2.5 for two episodes [27].…”