Measures of carotid atherosclerosis and cognitive function in midlife: The Jerusalem LRC longitudinal study

Intima Media Thickness and Cognitive Function Among Adults: Meta-Analysis of Observational and Longitudinal Studies

Background

Carotid structural changes measured by intima media thickness (IMT) have been related to cognitive complaints during aging. Therefore, the aims of this meta‐analysis were (1) to elucidate the relationship between vascular status, measured as IMT, and cognitive domains distinguishing between global cognition, executive functions, memory and attention; and (2) to explore whether demographic (ie, age and sex), clinical (ie, body mass index and IMT baseline values), and procedure characteristics influence this association.

Methods and Results

We performed a systematic review of MEDLINE (via PubMed), Scopus, and Web of Science databases from their inception to June 2021. Studies meeting the following inclusion criteria were included: (1) the participants were adults; (2) the exposure was carotid IMT; (3) the outcome was cognitive function, including global cognition, executive function, memory, and attention measured using standardized tests; and (4) the study design was cross‐sectional or longitudinal including unadjusted and adjusted analyses. A total of 19 cross‐sectional and 15 longitudinal studies were included and demographic (age and sex), clinical (body mass index and baseline IMT values), and procedure characteristics were analyzed as potential mediator or moderators of the association.

Conclusions

Our data support negative associations between IMT and cognitive function in cross‐sectional studies. The association between IMT and cognition lost significance in longitudinal studies and when controlling for covariates in cross‐sectional studies. Finally, the strength of these associations seems not to be modified by age, sex, body mass index, and baseline IMT values. This systematic review and meta‐analysis adds to the evidence supporting the use of IMT as a measure for identifying patients at risk of cognitive decline.

The metabolic changes in the hippocampus of an atherosclerotic rat model and the regulation of aerobic training

Atherosclerosis has been associated with the progression of cognitive impairment and the effect of metabolic changes in the brain on cognitive function may be pronounced. The aim is to reveal the metabolic changes during atherosclerosis and clarify the possible role of exercise in regulating hippocampal metabolism. Hence, A rat model of atherosclerosis was established by high-fat diet feeding in combination with vitamin D3 intraperitoneal injection, then 4 weeks of aerobic exercise was conducted. Metabolomics based on GC-MS was applied to detect small molecules metabolites and western blot was used to detect the concentration of enzymes involved in metabolic changes in rat hippocampus. Compared to the control group, metabolites including xylulose 5-phosphate, threonine, succinate, and nonanoic acid were markedly elevated, whereas methyl arachidonic acid and methyl stearate decreased in the AS group, accompanied by a raised concentration of aldose reductase and glucose 6-phosphate dehydrogenase as well as a declined concentration of acetyl-CoA carboxylase and fatty acid synthase. After 4 weeks' aerobic exercise, the levels of succinic acid, branched chain amino acids, nonanoic acid, desmosterol, and aldose reductase decreased, whereas methyl arachidonic acid, methyl stearate, and glyceraldehyde-3-phosphate elevated in the hippocampus of the TAS group in comparison with the AS group. These results suggest that atherosclerosis could cause a severe metabolic disturbance, and aerobic exercise plays an important role in regulating atherosclerosis-induced disorder of glucose metabolism in the hippocampus.

Altered brain volume and its relationship to characteristics of carotid plaques in asymptomatic patients

Carotid plaque is an aggregate marker of exposure to vascular risk factors, which are linked to structural brain changes. We investigated prestroke global and regional changes in brain volume in a carotid plaque population of cognitively healthy individuals and the association between carotid plaque characteristics and these changes.A total of 76 participants were divided into healthy control (HC, n = 28), vulnerable plaque (n = 27) and stable plaque groups (n = 21). All subjects underwent carotid ultrasound and brain magnetic resonance imaging (MRI). Voxel-based morphometry (VBM) was used to examine differences in regional gray matter volumes (rGMVs) among the different groups.The plaque group had a significantly lower mean total cerebral brain volume (TCBV) than the HC group (P = .03). Carotid intima-media thickness (CIMT) was negatively correlated with TCBV (r = -0.311, P = .006) and rGMV in the right thalamus (r = -0.589, P = .001). The rGMVs of the right middle occipital gyrus and bilateral lingual gyrus were significantly different between the unstable and stable groups. The gray-scale median (GSM) of the plaque and the total plaque risk score (TPRS) were correlated with the volume of the right middle occipital gyrus (r=-0.478, P = .001; r = 0.541, P = .001) and bilateral lingual gyrus (r = -0.419, P = .003; r = 0.288, P = .04).Carotid plaque is related to the volume of the brain parenchyma and right thalamus. The rGMVs of the right middle occipital gyrus and bilateral lingual gyrus differed between the vulnerable plaque and stable plaque groups, and the characteristics of carotid plaques may serve as indexes that reflect these changes.

Body Mass Index, Height and Socioeconomic Position in Adolescence, Their Trajectories into Adulthood, and Cognitive Function in Midlife

BACKGROUND

Whether life course anthropometric indices relate to cognitive function in midlife remains insufficiently explored. Rarely was socioeconomic position (SEP) adequately accounted for.

OBJECTIVE

To examine the association of the cumulative life course burden of high-ranked body mass index (BMI), its trajectory, and stature with cognitive function in midlife.

METHODS

Weight and height were measured from age 17 across a 33-year follow-up. 507 individuals completed a NeuroTrax computerized cognitive assessment at ages 48-52. Life course SEP was assessed by multiple methods. Using mixed models we calculated the area under the curve (AUC), representing both the life-course burden of BMI (total AUC) and trends in BMI (incremental AUC) from age 17 to midlife. The associations of BMI and height with global cognition and its five component domains were assessed by multiple regression.

RESULTS

Higher BMI in late adolescence and total AUC over the life course were associated with poorer global cognition (Standardized beta (Beta) = -0.111, p = 0.005 and Beta = -0.105, p = 0.018, respectively), adjusted for childhood and adulthood SEP, and demographic characteristics. The associations with higher adolescent and midlife BMI were both restricted to those with low childhood SEP (p < 0.05 for interaction). Short adolescent stature was related to poorer cognition (Beta = 0.115, p = 0.040), whereas late final growth in women was associated with better cognition (Beta = 0.213, p = 0.007).

CONCLUSION

An adverse association of higher BMI with cognitive function began in adolescence and was restricted to low childhood SEP. Taller stature in both sexes and late growth in women were associated with better midlife cognitive performance.

Carotid disease at age 73 and cognitive change from age 70 to 76 years: A longitudinal cohort study

Cognitive decline and carotid artery atheroma are common at older ages. In community-dwelling subjects, we assessed cognition at ages 70, 73 and 76 and carotid Doppler ultrasound at age 73, to determine whether carotid stenosis was related to cognitive decline. We used latent growth curve models to examine associations between four carotid measures (internal carotid artery stenosis, velocity, pulsatility and resistivity indices) and four cognitive ability domains (memory, visuospatial function, crystallised intelligence, processing speed) adjusted for cognitive ability at age 11, current age, gender and vascular risk factors. Amongst 866 participants, carotid stenosis (median 12.96%) was not associated with cognitive abilities at age 70 or cognitive decline from age 70 to 76. Increased ICA pulsatility and resistivity indices were associated with slower processing speed (both P < 0.001) and worse visuospatial function ( P = 0.036, 0.031, respectively) at age 70, and declining crystallised intelligence from ages 70 to 76 ( P = 0.008, 0.006, respectively). The findings suggest that vascular stiffening, rather than carotid luminal narrowing, adversely influences cognitive ageing and provides a potential target for ameliorating age-related cognitive decline.