Publications by authors named "Jan A St John"

Background: The combined effects of increased life expectancy and the considerable number of persons reaching old age will magnify the dementia epidemic in the USA. Demonstration that subclinical atherosclerosis precedes and is associated with cognitive impairment suggests a modifiable risk factor for age-associated cognitive impairment and dementia. The purpose of this study is to determine whether subclinical atherosclerosis as measured by carotid artery intima-media thickness (CIMT) is associated with changes in cognitive function over time in older adults.

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Background: Described to be antithrombotic and antihypertensive, nattokinase is consumed for putative cardiovascular benefit. However, no large-scale, long-term cardiovascular study has been conducted with nattokinase supplementation.

Objective: To determine the effect of nattokinase on subclinical atherosclerosis progression and atherothrombotic biomarkers.

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Objective: We hypothesized the association of metabolic profile on cognition in postmenopausal women will be greater among ApoE4 carriers compared with noncarriers.

Methods: Metabolic biomarkers and measures of global cognition, executive functions, and verbal memory, collected among postmenopausal females, were used in this analysis. Clustering analyses of metabolic biomarkers revealed three phenotypes: healthy, predominantly hypertensive, and poor metabolic with (borderline normal laboratory values).

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Objective: To test the hypothesis that effects of estrogen-containing hormone therapy on cognitive abilities differ between postmenopausal women near to, and further from, menopause.

Methods: In this randomized, double-blind, placebo-controlled trial, healthy women within 6 years of menopause or 10+ years after menopause were randomly assigned to oral 17β-estradiol 1 mg/d or placebo. Women with a uterus received cyclic micronized progesterone vaginal gel or placebo.

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Detecting at-risk individuals within a healthy population is critical for preventing or delaying Alzheimer's disease. Systems biology integration of brain and body metabolism enables peripheral metabolic biomarkers to serve as reporters of brain bioenergetic status. Using clinical metabolic data derived from healthy postmenopausal women in the Early versus Late Intervention Trial with Estradiol (ELITE), we conducted principal components and k-means clustering analyses of 9 biomarkers to define metabolic phenotypes.

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Article Synopsis
  • The study aimed to investigate how changes in urine excretion of isoflavonoids affect cognitive changes in healthy postmenopausal women.
  • It involved 350 participants who were given either isoflavonoid-rich soy protein or a placebo over an average of 2.7 years, with urine, plasma isoflavonoid levels, and cognitive function being measured.
  • Results showed no significant link between isoflavonoid changes and overall cognition, but higher isoflavonoid levels correlated with a decrease in general intelligence, suggesting further research is needed to confirm these findings.
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Variations in the hormonal milieu after menopause may influence neural processes concerned with cognition, cognitive aging, and mood, but findings are inconsistent. In particular, cognitive effects of estradiol may vary with time since menopause, but this prediction has not been assessed directly using serum hormone concentrations. We studied 643 healthy postmenopausal women not using hormone therapy who were recruited into early (<6 y after menopause) and late (10+ y after menopause) groups.

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While experiments in animals demonstrate neurotoxic effects of particulate matter (PM) and ozone (O3), epidemiologic evidence is sparse regarding the relationship between different constituencies of air pollution mixtures and cognitive function in adults. We examined cross-sectional associations between various ambient air pollutants [O3, PM2.5 and nitrogen dioxide (NO2)] and six measures of cognitive function and global cognition among healthy, cognitively intact individuals (n=1496, mean age 60.

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Background: It is accepted that markedly elevated thyroid-stimulating hormone (TSH) levels are associated with impaired cognitive function. However, the findings regarding the association between mildly elevated TSH levels and cognition are equivocal. The objective of this study was to assess the relation between TSH levels in the normal to mildly elevated range (0.

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Article Synopsis
  • Subclinical atherosclerosis, particularly measured through carotid artery intima-media thickness (CIMT), may be linked to lower verbal learning abilities in healthy adults with elevated homocysteine levels, despite the absence of clinically evident cardiovascular disease (CVD).
  • The study involved 504 participants, averaging 61 years old, using neuropsychological tests to assess cognitive function and analyzing associations through multivariable linear regression.
  • Results showed that as CIMT increased, verbal learning scores decreased significantly, while other measures of atherosclerosis (CAC and AAC) did not demonstrate a notable impact on cognitive function.
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  • This study investigates the relationship between metabolic syndrome (MetS) and cognitive function in middle-aged and older adults, specifically looking at six areas of cognition.
  • Results show that while there is a weak overall association between MetS and cognitive performance, an increase in MetS criteria correlates with declines in global cognition, verbal learning, and semantic memory.
  • Hypertension was identified as the key MetS component negatively impacting cognitive functions, marking it as an important risk factor for cognitive decline.
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The objective of this study was to determine whether high-sensitivity C-reactive protein (hs-CRP) and serum soluble intercellular adhesion molecule-1 (sICAM-1) correlate with progression of subclinical atherosclerosis. Secondarily, the long-term effect of oral estradiol on hs-CRP and sICAM-1 were determined. Data were analyzed from 180 healthy postmenopausal women aged 45 to 80 years randomly assigned to either unopposed micronized 17beta-estradiol 1 mg/day or placebo in the Estrogen in the Prevention of Atherosclerosis Trial (EPAT).

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