Literacy, but not memory, is associated with hippocampal connectivity in illiterate adults.

Background: The influence of hippocampal connectivity on memory performance is well established in individuals with high educational attainment. However, the role of hippocampal connectivity in illiterate populations remains poorly understood. Methods: Thirty-five illiterate adults were administered a literacy assessment (Test of Functional Health Literacy in Adults - TOFHLA), structural and resting state functional MRI and an episodic memory test (Free and Cued Selective Reminding Test). Illiteracy was defined as a TOFHLA score below 53. We evaluated the correlation between hippocampal connectivity at rest and both free recall and literacy scores. Results: Participants were mostly female (57.1%) and Black (84.8%), with a median age of 50 years. The median TOFHLA literacy score was 28.0 [21.0;42.5] out of 100 points and the median free recall score was 30.0 [26.2;35] out of 48 points. The median gray matter volume of both the left and right hippocampi was 2.3 [2.1; 2.4] cm3. We observed a significant connectivity between both hippocampi and the precuneus and the ventral medial prefrontal cortex. Interestingly, the right hippocampal connectivity positively correlated with the literacy scores (ß = 0.58, p = 0.008). There was no significant association between episodic memory and hippocampal connectivity. Neither memory nor literacy scores correlated with hippocampal gray matter volume. Conclusions: Low literacy levels correlate with hippocampal connectivity in illiterate adults. The lack of association with memory scores might be associated with low brain reserve in illiterate adults.

Cortisol, HDL-c, VLDL-c, and APOE Polymorphisms as Laboratorial Parameters Associated to Cognitive Impairment No Dementia (CIND) and Dementia.

BACKGROUND: Population aging is a global phenomenon whose main consequence is the increase of chronic degenerative diseases, including dementia. The aim of this case-control study was to evaluate the laboratorial parameters lipid profile, cortisol, and apolipoprotein E (APOE) gene genotype, comparing cognitively healthy controls and subjects with cognitive impairment no dementia (CIND) and dementia in a group of elderly people. METHODS: Three hundred and nine individuals enrolled in the Pietà Study (Brazil) were divided into three groups: control (n = 158), CIND (n = 92), and dementia (n = 59). Participants were interviewed, went through examination, and had blood samples taken. RESULTS: Age and APOE showed significant differences among the groups, while sex and lipid profile did not. According to multivariate regression logistic analyses, higher cortisol levels, lower high-density lipoprotein (HDL-c) and very low-density lipoprotein (VLDL-c), presence of ε4 allele of APOE, and aging were associated with CIND and dementia. CONCLUSION: These laboratorial parameters are risk factors associated to CIND and dementia in the elderly people and should be investigated in order to develop strategies to prevent or delay the onset of dementia in the oldest-old populations.

TGF-ß1 Codon 10 T>C Polymorphism Influences Short-Term Functional and Cognitive Decline in Healthy Oldest-Old Individuals: The Pietà Study.

BACKGROUND: Inflammation and cytokine production are a common finding in aging, which probably exert influence on cognitive and functional abilities in elderly people. Transforming-growth-factor beta 1 (TGF-ß1) is an important multifunctional anti-inflammatory cytokine that displays immunomodulatory activities. OBJECTIVE: This prospective investigation aimed to evaluate the TGF-ß1 codon 10 T>C on functional and cognitive decline in subjects aged 75+ years. METHODS: The Functional Activities Questionnaire evaluated the functional performance and the cognitive assessment was evaluated through brief cognitive tests, consisting of: the Mini-Mental State Examination, animal category fluency test, and picture drawings memory test. All tests were administered twice, with a one-year interval. RESULTS: Carriers of Tlower allele showed significant short-term decline in cognitive and functional performance, while individuals with CChigher genotype of TGF-ß1 codon 10 T>C remained stable or showed improvement. CONCLUSION: Our findings indicate that the lower production of TGF-ß1 could predict a longitudinal functional and cognitive decline in oldest-old individuals.

High cortisol levels are associated with cognitive impairment no-dementia (CIND) and dementia.

BACKGROUND: This study aimed to compare serum cortisol concentrations in cognitively healthy elderly and in subjects with cognitive impairment no dementia (CIND) and dementia, besides to evaluate these concentrations according to apolipoprotein E genotype (APOE). METHODS: Three-hundred and nine elderly enrolled in the Pietà Study (Brazil) were divided in 3 groups: control (n=158), CIND (n=92) and dementia (n=59) and had concentrations of morning serum cortisol measured. Hormone concentrations were measured by chemiluminescence and APOE genotypes were determined by PCR followed by restriction fragment length polymorphism (RFLP). RESULTS: Medians of cortisol concentrations (µg/dl) for the groups were 12.14 (interquartile range - IQR 6.34) for control, 13.65 (IQR 5.88) for CIND and 14.47 (IQR 7.35) for dementia. Significant differences were observed for control vs. CIND (P=0.003), control vs. dementia (P=0.001), but not for CIND vs. dementia (P=0.269). No association was observed between cortisol concentrations and APOE genotype among the groups (P=0.348). CONCLUSIONS: The elevation in cortisol concentrations is associated with dementia, independently of APOE genotypes. Further studies are required to understand if elevation of cortisol is an initial event and how hippocampal damage and the loss of hypothalamus-pituitary-adrenal (HPA) axis inhibition may affect its concentrations.