Circulating metabolites and general cognitive ability and dementia: Evidence from 11 cohort studies.

INTRODUCTION: Identifying circulating metabolites that are associated with cognition and dementia may improve our understanding of the pathogenesis of dementia and provide crucial readouts for preventive and therapeutic interventions. METHODS: We studied 299 metabolites in relation to cognition (general cognitive ability) in two discovery cohorts (N total = 5658). Metabolites significantly associated with cognition after adjusting for multiple testing were replicated in four independent cohorts (N total = 6652), and the associations with dementia and Alzheimer's disease (N = 25,872) and lifestyle factors (N = 5168) were examined. RESULTS: We discovered and replicated 15 metabolites associated with cognition including subfractions of high-density lipoprotein, docosahexaenoic acid, ornithine, glutamine, and glycoprotein acetyls. These associations were independent of classical risk factors including high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, glucose, and apolipoprotein E (APOE) genotypes. Six of the cognition-associated metabolites were related to the risk of dementia and lifestyle factors. DISCUSSION: Circulating metabolites were consistently associated with cognition, dementia, and lifestyle factors, opening new avenues for prevention of cognitive decline and dementia.

Domains of physical activity and brain volumes: A population-based study.

Observational studies and intervention trials suggest that physical activity (PA) is beneficial for human brain morphology, especially in older individuals. Few population-based studies examined whether domain-specific PA is associated with brain volumes. Accordingly, we studied putative associations of PA during leisure time, sports and work with volumes of the hippocampus, the prefrontal cortex, the temporal lobe, gray matter (GM), white matter (WM) and total brain (TBV) after 5.9 years by applying volumetric analysis and voxel-based morphometry (VBM) with SPM 8/VBM 8 to brain magnetic resonance imaging data of 834 participants (447 women) aged 25 to 83 years from the population-based Study of Health in Pomerania. The Baecke questionnaire was used to assess domain-specific PA (Leisure time, Sport, and Work Index) at baseline. After correcting for multiple testing, volumetric analyses did not show any significant association of domain-specific PA and volumes of the hippocampus, the prefrontal cortex, the temporal lobe, GM, WM and TBV. Multivariable-adjusted VBM analyses of the associations between PA domains with GM and WM volumes did not reveal any statistically significant results. Region of interest analyses revealed a statistically significant cluster of increased GM volume in the bilateral anterior cingulate cortex in association with PA during sports. In conclusion, the overall results contrast with the findings from previous studies that found significant associations between PA and brain volumes. In addition, it remains unclear whether a differential association exists between domains of PA and brain volumes. Thus, future studies with larger sample size and prospective design are needed to investigate potential domain-specific associations of PA with brain volumes.

Longitudinal association of Apolipoprotein E polymorphism with lipid profile, type 2 diabetes and metabolic syndrome: Results from a 15 year follow-up study.

AIMS: To examine the association of different APOE alleles with type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS) as well as the influence of high-sensitive C-reactive protein (hs-CRP) on these associations. METHODS: We analyzed data from 3917 participants aged 20-81 years of the population-based Study of Health in Pomerania (SHIP) from Northeast Germany with a median follow-up time of 10.8 years. Linear and logistic mixed models were performed to test the association of APOE alleles with T2DM and MetS. RESULTS: We observed 393 T2DM and 1411 MetS events at baseline, and 576 T2DM and 1342 MetS events over the follow-up. The E4 carriers had a lower odds of developing T2DM (OR: 0.47 [0.24, 0.94]) than E3 homozygotes even after adjustment for potential confounders. The E2 carriers showed no associations. The inverse association between E4 alleles and T2DM moderately attenuated after adjustment for hs-CRP levels. The lower odds of developing T2DM in E4 carriers was more pronounced in participants without obesity, hypertension or MetS. However, both E2 and E4 carriers had higher odds of developing MetS (E2 OR: 1.45 [1.03, 2.03]; E4 OR: 1.56 [1.17, 2.09]) than E3 homozygotes. CONCLUSIONS: While the presence of APOE E4 allele might increase the chance of MetS through its major action on lipids, E4 allele might offer a protection towards T2DM through its influence on inflammation.

Association between serum neuron-specific enolase, age, overweight, and structural MRI patterns in 901 subjects.

Serum neuron-specific enolase (sNSE) is considered a marker for neuronal damage, related to gray matter structures. Previous studies indicated its potential as marker for structural and functional damage in conditions with adverse effects to the brain like obesity and dementia. In the present study, we investigated the putative association between sNSE levels, body mass index (BMI), total gray matter volume (GMV), and magnetic resonance imaging-based indices of aging as well as Alzheimer's disease (AD)-like patterns. SUBJECTS/METHODS: sNSE was determined in 901 subjects (499 women, 22-81 years, BMI 18-48 kg/m2), participating in a population-based study (SHIP-TREND). We report age-specific patterns of sNSE levels between males and females. Females showed augmenting, males decreasing sNSE levels associated with age (males: p = 0.1052, females: p = 0.0363). sNSE levels and BMI were non-linearly associated, showing a parabolic association and decreasing sNSE levels at BMI values >25 (p = 0.0056). In contrast to our hypotheses, sNSE levels were not associated with total GMV, aging, or AD-like patterns. Pathomechanisms discussed are: sex-specific hormonal differences, neuronal damage/differentiation, or impaired cerebral glucose metabolism. We assume a sex-dependence of age-related effects to the brain. Further, we propose in accordance to previous studies an actual neuronal damage in the early stages of obesity. However, with progression of overweight, we assume more profound effects of excess body fat to the brain.