Association between ankle-brachial index and cognitive function in participants in the PREDIMED-Plus study: cross-sectional assessment.

INTRODUCTION AND OBJECTIVES: The ankle-brachial index (ABI) is an indicator of peripheral artery disease (PAD). The aim of this study was to assess the association between PAD, measured with the ABI, and cognitive function in persons with overweight or obesity and metabolic syndrome. METHODS: Cross-sectional study conducted with baseline data from the PREDIMED-Plus study, which included 4898 participants (after exclusion of those without ABI measurements) aged between 55 and 75 years, and with overweight or obesity and metabolic syndrome. At the baseline assessment, we measured the ABI with a standardized protocol and assessed the presence of other cardiovascular risk factors (eg, diabetes, dyslipidemia, hypertension). Cognitive function was evaluated using several tests validated for the Spanish population (mini-mental state examination [MMSE], phonological and semantic verbal fluency test, WAIS-III working memory index [WMI], parts A and B of the trail making test (TMT), and clock drawing test). Generalized linear models were used to assess the association between the ABI and cognitive function. RESULTS: Among the participants, 3.4% had PAD defined as ABI ≤ 0.9, and 3.3% had arterial calcification defined as ABI ≥ 1.4. PAD was associated with age, systolic blood pressure and obesity indicators, while arterial calcification was also associated with obesity and diabetes. No significant associations were observed between cognitive function and ABI or PAD. CONCLUSIONS: In our sample, the presence of PAD increased with age, blood pressure, and obesity. No significant association was observed between ABI, PAD, or cognitive function.

Epigallocatechin-3-gallate, a DYRK1A inhibitor, rescues cognitive deficits in Down syndrome mouse models and in humans.

SCOPE: Trisomy for human chromosome 21 results in Down syndrome (DS), which is among the most complex genetic perturbations leading to intellectual disability. Accumulating data suggest that overexpression of the dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A (DYRK1A), is a critical pathogenic mechanisms in the intellectual deficit. METHODS AND RESULTS: Here we show that the green tea flavonol epigallocatechin-gallate (EGCG), a DYRK1A inhibitor, rescues the cognitive deficits of both segmental trisomy 16 (Ts65Dn) and transgenic mice overexpressing Dyrk1A in a trisomic or disomic genetic background, respectively. It also significantly reverses cognitive deficits in a pilot study in DS individuals with effects on memory recognition, working memory and quality of life. We used the mouse models to ensure that EGCG was able to reduce DYRK1A kinase activity in the hippocampus and found that it also induced significant changes in plasma homocysteine levels, which were correlated with Dyrk1A expression levels. Thus, we could use plasma homocysteine levels as an efficacy biomarker in our human study. CONCLUSION: We conclude that EGCG is a promising therapeutic tool for cognitive enhancement in DS, and its efficacy may depend of Dyrk1A inhibition.

Functional alteration in frontolimbic systems relevant to moral judgment in cocaine-dependent subjects.

Cocaine addiction is characterized by persistent decision-making deficits, which are linked to structural and functional abnormalities in frontolimbic systems. Moral judgment is as a special instance of decision making, in which both cognitive and emotional signals must be adequately integrated to decide how to resolve moral dilemmas. Here, we employed a moral dilemmas functional magnetic resonance imaging (fMRI) task to explore possible alterations of frontolimbic systems in cocaine-dependent subjects. We also explored if these alterations relate to more basic deficits in functional connectivity within these systems during spontaneous resting-state activation. Ten cocaine-dependent subjects and 14 non-drug-using controls participated in the study. Cocaine-dependent subjects were carefully selected to discard potentially confounding co-morbidities, and they underwent a uniform supervised abstinence period of 10 days. Both groups were scanned, and fMRI maps were generated to identify (1) brain response to moral dilemmas; and (2) the strength of functional connectivity within frontolimbic systems during resting-state. During the moral dilemmas task, cocaine-dependent subjects showed reduced activation involving frontolimbic structures as the anterior cingulate cortex (ACC), left insula and brain stem. Connectivity analyses showed that cocaine users had less resting-state functional connectivity between ACC, thalamus, insula and brain stem. These results demonstrate that cocaine-dependent subjects have functional alterations in the frontolimbic systems that support moral judgment and social decision making.

COMT val158met and 5-HTTLPR genetic polymorphisms moderate executive control in cannabis users.

The adverse effects of cannabis use on executive functions are still controversial, fostering the need for novel biomarkers able to unveil individual differences in the cognitive impact of cannabis consumption. Two common genetic polymorphisms have been linked to the neuroadaptive impact of Δ9-tetrahydrocannabinol (THC) exposure and to executive functions in animals: the catechol-O-methyltransferase (COMT) gene val158met polymorphism and the SLC6A4 gene 5-HTTLPR polymorphism. We aimed to test if these polymorphisms moderate the harmful effects of cannabis use on executive function in young cannabis users. We recruited 144 participants: 86 cannabis users and 58 non-drug user controls. Both groups were genotyped and matched for genetic makeup, sex, age, education, and IQ. We used a computerized neuropsychological battery to assess different aspects of executive functions: sustained attention (CANTAB Rapid Visual Information Processing Test, RVIP), working memory (N-back), monitoring/shifting (CANTAB ID/ED set shifting), planning (CANTAB Stockings of Cambridge, SOC), and decision-making (Iowa Gambling Task, IGT). We used general linear model-based analyses to test performance differences between cannabis users and controls as a function of genotypes. We found that: (i) daily cannabis use is not associated with executive function deficits; and (ii) COMT val158met and 5-HTTLPR polymorphisms moderate the link between cannabis use and executive performance. Cannabis users carrying the COMT val/val genotype exhibited lower accuracy of sustained attention, associated with a more strict response bias, than val/val non-users. Cannabis users carrying the COMT val allele also committed more monitoring/shifting errors than cannabis users carrying the met/met genotype. Finally, cannabis users carrying the 5-HTTLPR s/s genotype had worse IGT performance than s/s non-users. COMT and SLC6A4 genes moderate the impact of cannabis use on executive functions.

The influence of genetic and environmental factors among MDMA users in cognitive performance.

This study is aimed to clarify the association between MDMA cumulative use and cognitive dysfunction, and the potential role of candidate genetic polymorphisms in explaining individual differences in the cognitive effects of MDMA. Gene polymorphisms related to reduced serotonin function, poor competency of executive control and memory consolidation systems, and high enzymatic activity linked to bioactivation of MDMA to neurotoxic metabolites may contribute to explain variations in the cognitive impact of MDMA across regular users of this drug. Sixty ecstasy polydrug users, 110 cannabis users and 93 non-drug users were assessed using cognitive measures of Verbal Memory (California Verbal Learning Test, CVLT), Visual Memory (Rey-Osterrieth Complex Figure Test, ROCFT), Semantic Fluency, and Perceptual Attention (Symbol Digit Modalities Test, SDMT). Participants were also genotyped for polymorphisms within the 5HTT, 5HTR2A, COMT, CYP2D6, BDNF, and GRIN2B genes using polymerase chain reaction and TaqMan polymerase assays. Lifetime cumulative MDMA use was significantly associated with poorer performance on visuospatial memory and perceptual attention. Heavy MDMA users (>100 tablets lifetime use) interacted with candidate gene polymorphisms in explaining individual differences in cognitive performance between MDMA users and controls. MDMA users carrying COMT val/val and SERT s/s had poorer performance than paired controls on visuospatial attention and memory, and MDMA users with CYP2D6 ultra-rapid metabolizers performed worse than controls on semantic fluency. Both MDMA lifetime use and gene-related individual differences influence cognitive dysfunction in ecstasy users.