Adiposity and insulin resistance moderate the links between neuroelectrophysiology and working and episodic memory functions in young adult males but not females

INTRODUCTION

Obesity and insulin resistance negatively influence neural activity and cognitive function, but electrophysiological mechanisms underlying these interrelationships remain unclear. This study investigated whether adiposity and insulin resistance moderated neural activity and underlying cognitive functions in young adults.

METHODS

Real-time electroencephalography (EEG) was recorded in 38 lean (n = 12) and obese (n = 26) young adults with (n = 15) and without (n = 23) insulin resistance (18-38 years, 55.3% female) as participants completed three neurocognitive tasks in working memory (Operation Span), inhibitory control (Stroop), and episodic memory (Visual Association Test). Body fat percentage was quantified by a dual-energy X-ray absorptiometry scan (DEXA/DXA). Fasting serum insulin and glucose were quantified to calculate Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) values, for which a higher value indicates more insulin resistance. Hierarchical moderated regression analysis tested these interrelationships.

RESULTS

In males, greater frontal negative slow wave (fNSW) and positive slow wave (PSW) amplitudes were linked to higher working memory accuracy in participants with low, but not high, body fat percentage and HOMA-IR levels. In contrast, body fat percentage and HOMA-IR did not moderate these associations in females. Furthermore, body fat percentage and HOMA-IR values moderated the relationship between greater fNSW amplitudes and better episodic memory accuracy in males, but not females. Finally, body fat percentage and insulin resistance did not moderate the link between neural activity and inhibitory control for either sex.

CONCLUSION

Young adult males, but not females, with higher body adiposity and insulin resistance showed reduced neural activity and worse underlying working and episodic memory functions.

Exploring the secrets of super-aging: a UK Biobank study on brain health and cognitive function

Communities across the globe are faced with a rapidly aging society, where age is the main risk factor for cognitive decline and development of Alzheimer's and related diseases. Despite extensive research, there have been no successful treatments yet. A rare group of individuals called "super-agers" have been noted to thrive with their exceptional ability to maintain a healthy brain and normal cognitive function even in old age. Studying their traits, lifestyles, and environments may provide valuable insight. This study used a data-driven approach to identify potential super-agers among 7121 UK Biobank participants and found that these individuals have the highest total brain volume, best cognitive performance, and lowest functional connectivity. The researchers suggest a novel hypothesis that these super-agers possess enhanced neural processing efficiency that increases with age and introduce a definition of the "neural efficiency index." Furthermore, several other types of aging were identified and significant structural-functional differences were observed between them, highlighting the benefit of research efforts in personalized medicine and precision nutrition.

Alzheimer's Disease Genetic Influences Impact the Associations between Diet and Resting-State Functional Connectivity: A Study from the UK Biobank

BACKGROUND

Red wine and dairy products have been staples in human diets for a long period. However, the impact of red wine and dairy intake on brain network activity remains ambiguous and requires further investigation.

METHODS

This study investigated the associations between dairy and red wine consumption and seven neural networks' connectivity with functional magnetic resonance imaging (fMRI) data from a sub-cohort of the UK Biobank database. Linear mixed models were employed to regress dairy and red wine consumption against the intrinsic functional connectivity for each neural network. Interactions with Alzheimer's disease (AD) risk factors, including apolipoprotein E4 (APOE4) genotype, TOMM40 genotype, and family history of AD, were also assessed.

RESULT

More red wine consumption was associated with enhanced connectivity in the central executive function network and posterior default mode network. Greater milk intake was correlated with more left executive function network connectivity, while higher cheese consumption was linked to reduced posterior default mode network connectivity. For participants without a family history of Alzheimer's disease (AD), increased red wine consumption was positively correlated with enhanced left executive function network connectivity. In contrast, participants with a family history of AD displayed diminished network connectivity in relation to their red wine consumption. The association between cheese consumption and neural network connectivity was influenced by APOE4 status, TOMM40 status, and family history, exhibiting contrasting patterns across different subgroups.

CONCLUSION

The findings of this study indicate that family history modifies the relationship between red wine consumption and network strength. The interaction effects between cheese intake and network connectivity may vary depending on the presence of different genetic factors.

Beer, wine, and spirits differentially influence body composition in older White adults ‐ a UK Biobank study

BACKGROUND

Aging is characterized by body composition alterations, including increased visceral adiposity accumulation and bone loss. Alcohol consumption may partially drive these alterations, but findings are mixed. This study primarily aimed to investigate whether different alcohol types (beer/cider, red wine, white wine/Champagne, spirits) differentially associated with body composition.

METHODS

The longitudinal UK Biobank study leveraged 1869 White participants (40–80 years; 59% male). Participants self‐reported demographic, alcohol/dietary consumption, and lifestyle factors using a touchscreen questionnaire. Anthropometrics and serum for proteomics were collected. Body composition was obtained via dual‐energy X‐ray absorptiometry. Structural equation modeling was used to probe direct/indirect associations between alcohol types, cardiometabolic biomarkers, and body composition.

RESULTS

Greater beer/spirit consumptions were associated with greater visceral adiposity (β = 0.069, p < 0.001 and β = 0.014, p < 0.001, respectively), which was driven by dyslipidemia and insulin resistance. In contrast, drinking more red wine was associated with less visceral adipose mass (β = −0.023, p < 0.001), which was driven by reduced inflammation and elevated high‐density lipoproteins. White wine consumption predicted greater bone density (β = 0.051, p < 0.005).

DISCUSSION

Beer/spirits may partially contribute to the “empty calorie” hypothesis related to adipogenesis, while red wine may help protect against adipogenesis due to anti‐inflammatory/eulipidemic effects. Furthermore, white wine may benefit bone health in older White adults.1

Abstract 289: Variation In 24-hour Physical Activity Patterns By Demographic And Psychological Factors In Women With Myocardial Infarction

Introduction: Despite the importance of physical activity (PA) for cardiovascular health, there is a scarcity of data on objectively measured PA in women with myocardial infarction (MI). We aim to describe 24-hour PA patterns and examine their variation by demographic and psychological factors in women with MI.

Methods: Participants were enrolled in an ongoing multicenter trial of stress management in women with a history of MI. Participants completed self-reported psychological measures and 7-days of wrist-actigraphy monitoring (GT3X, Actigraph) at baseline (≥2 months post-MI). PA volumes were defined as the average vector magnitude (VM) counts per minute (cpm), a metric incorporating movement across all three axes of the accelerometer. This approach minimizes loss of information related to use of cut-points and describes accumulated 24-hour PA volumes. Hourly VM cpm were plotted to visualize 24-hour PA patterns and compared by age groups, race, elevated depressive symptoms (Patient Health Questionnaire-9 ≥5), and high stress levels (top quartile of Perceived Stress Scale-10). Due to the skewness, VM cpm were log-transformed and linear regression analysis was conducted to identify correlates of overall 24-hour PA.

Results: Analyses included 85 participants (age = 59.9 ± 13.0, 20% African American, 16% participating in cardiac rehabilitation, 70% elevated depressive symptoms, 25% high stress). Patterns of PA across 24 hours differed by age, race, stress and depressive symptoms (Figure 1). For example, African American women with MI had peak PA later in the day than non-African American women, and less PA overall. Women with high (vs. low) stress had less PA overall and a less pronounced evening drop in PA, which may affect sleep. Those with elevated (vs. low) depressive symptoms showed lower PA levels, especially during the late afternoon and evening. After adjusting for age, race and cardiac rehabilitation, overall 24-hour PA volumes (log of average VM cpm) were significantly lower with higher stress (b = -0.26, p = 0.02) and elevated depressive symptoms (b = -0.22, p = 0.04).

Conclusion: These findings may be considered to identify women with MI who may benefit from interventions to increase PA, which could reduce risk of recurrent CVD. Our data on timing of PA may be helpful in the tailored design of such programs.

The FIREBIRD-II CubeSat mission: Focused investigations of relativistic electron burst intensity, range, and dynamics

FIREBIRD-II is a National Science Foundation funded CubeSat mission designed to study the scale size and energy spectrum of relativistic electron microbursts. The mission consists of two identical 1.5 U CubeSats in a low earth polar orbit, each with two solid state detectors that differ only in the size of their geometric factors and fields of view. Having two spacecraft in close orbit allows the scale size of microbursts to be investigated through the intra-spacecraft separation when microbursts are observed simultaneously on each unit. Each detector returns high cadence (10 s of ms) measurements of the electron population from 200 keV to >1 MeV across six energy channels. The energy channels were selected to fill a gap in the observations of the Heavy Ion Large Telescope instrument on the Solar, Anomalous, and Magnetospheric Particle Explorer. FIREBIRD-II has been in orbit for 5 years and continues to return high quality data. After the first month in orbit, the spacecraft had separated beyond the expected scale size of microbursts, so the focus has shifted toward conjunctions with other magnetospheric missions. FIREBIRD-II has addressed all of its primary science objectives, and its long lifetime and focus on conjunctions has enabled additional science beyond the scope of the original mission. This paper presents a brief history of the FIREBIRD mission's science goals, followed by a description of the instrument and spacecraft. The data products are then discussed along with some caveats necessary for proper use of the data.

Modeling Associations between Chemosensation, Liking for Fats and Sweets, Dietary Behaviors and Body Mass Index in Chronic Smokers

Chronic smokers have a greater risk for altered chemosensation, unhealthy dietary patterns, and excessive adiposity. In an observational study of chronic smokers, we modeled relationships between chemosensation, fat/carbohydrate liking, smoking-associated dietary behaviors, and body mass index (BMI). Also tested in the model was liking for sweet electronic cigarette juice (e-juice). Smokers (n = 135, 37 ± 11 years) were measured for: Taste genetics (intensity of 6-n-propylthiouracil-PROP); taste (NaCl and quinine intensities) and olfactory (odor identification) function; liking for cherry e-juice; and weight/height to calculate BMI. Smokers survey-reported their food liking and use of smoking for appetite/weight control. Structural equation models tested direct and indirect relationships between chemosensation, fat/carbohydrate liking, dietary behaviors, and BMI. In good-fitting models, taste intensity was linked to BMI variation through fat/carbohydrate liking (greater PROP intensity→greater NaCl intensity→greater food liking→higher BMI). Olfactory function tended to predict sweet e-juice liking, which, in turn, partially mediated the food liking and BMI association. The path between smoking-associated dietary behaviors and BMI was direct and independent of chemosensation or liking. These findings indicate that taste associates with BMI in chronic smokers through liking of fats/carbohydrates. Future research should determine if vaping sweet e-juice could improve diet quality and adiposity for smokers.

Electron acceleration in the heart of the Van Allen radiation belts

The Van Allen radiation belts contain ultrarelativistic electrons trapped in Earth's magnetic field. Since their discovery in 1958, a fundamental unanswered question has been how electrons can be accelerated to such high energies. Two classes of processes have been proposed: transport and acceleration of electrons from a source population located outside the radiation belts (radial acceleration) or acceleration of lower-energy electrons to relativistic energies in situ in the heart of the radiation belts (local acceleration). We report measurements from NASA's Van Allen Radiation Belt Storm Probes that clearly distinguish between the two types of acceleration. The observed radial profiles of phase space density are characteristic of local acceleration in the heart of the radiation belts and are inconsistent with a predominantly radial acceleration process.

Controlled aggregation of superparamagnetic iron oxide nanoparticles for the development of molecular magnetic resonance imaging probes

A method for synthesizing superparamagnetic iron oxide (SPIO) multi-nanoparticle aggregates as molecular magnetic resonance imaging (MRI) contrast agents is described. The approach utilizes organic acid/base interactions in the colloid to induce highly controllable nanoparticle aggregation. Monodisperse aggregates with diameters as large as 100 nm are synthesized by manipulating the interfacial surface chemistry of the SPIO nanoparticles in tetrahydrofuran solvent. Subsequent phospholipid micelle encapsulation yields micellar multi-SPIO (mmSPIO) aggregates with enhanced T(2) relaxivity (368.0 s(-1) mmol(-1) Fe) as compared to micellar single particle SPIO (302.0 s(-1) mmol(-1) Fe). mmSPIO conjugated to anti-CA125 monoclonal antibodies were incubated with ovarian carcinoma cell lines to demonstrate targeted in vitro molecular MRI, resulting in a 66% shortening in T(2) time for CA125 positive NIH:OVCAR-3 cells and a less than 3% change in T(2) time for CA125 negative SK-OV-3 cells. The controllable aggregation of mmSPIO shows potential for the development of molecular MRI contrast agents with optimal sizes for specific diagnostic imaging applications.

[Dogs and health. A review of documented connections]

Companion dogs are widespread in western countries, and scientific studies have proved that dogs have a number of positive effects on human health and well-being. Studies have shown reduced systolic blood pressure in dog owners compared to non-owners, as well as lowered concentrations of plasma triglycerides and cholesterol. Studies have also shown improved survival rates following myocardial infarction in dog owners compared to non-owners. Companion dogs are used systematically in "animal assisted therapy" in various institutions and hospitals, both as specific treatment of a medical condition and to improve well-being in certain groups of patients. The reasons for the positive effects of dogs on human health are not clearly identified. The attachment between people and their pets ("the human-animal bond") seems to have important physiological and psychological effects. Companion dogs have been shown to increase physical activity and social contact, which may also influence human health.

[Physician's role in certification for sick leave]]

The aim of the study was to analyse general practitioners' decisions when certifying patients as sick. The study was conducted among 38 general practitioners in Bergen, Norway, during two weeks in March 1990. The need for certification of sickness was considered for 328 patients. Among these 91% were certified as sick and 9% were not found to be incapable of work. If the patients took the first initiative for certification, 95% received a certificate, while 84% were certified sick when the doctors took the first initiative (p < 0.001). When no objective signs, symptoms or findings were registered by the general practitioners, the patients took the first initiative for sickness certification in 85% and the doctor in 15% (p = 0.001) of the cases. The study indicates that the patients are a stronger controlling element than the general practitioners in the process of certification of sickness.

Effect of testosterone on atherogenesis in cholesterol-fed rabbits with similar plasma cholesterol levels

The aim was to examine the effect of testosterone on atherogenesis in cholesterol-fed, castrated male rabbits not mediated via different plasma cholesterol levels. The rabbits in the testosterone group (n = 19) and in the placebo group (n = 17) were injected intramuscularly twice weekly for 17 weeks with 25 mg testosterone enantate and placebo, respectively, reaching plasma testosterone levels of 50-150 nmol/l in the testosterone group. No effect of testosterone on liver function or body weight was detected, but at week 15 mean blood pressure was 75 +/- 2 mmHg (mean +/- S.E.) in the testosterone group compared with 69 +/- 2 mmHg in the placebo group (P < 0.05). To reduce variation in plasma cholesterol between the two groups, the amount of cholesterol fed to each rabbit was adjusted on the basis of weekly determinations of plasma cholesterol; the mean plasma cholesterol levels during the 17 weeks were 20.9 +/- 1.0 and 20.4 +/- 0.9 mmol/l for the placebo and testosterone groups. In the intima-inner medias of the aortic arch, the thoracic and the abdominal aorta there were no consistent significant differences in aortic cholesterol content, expressed either as nmol/cm2 or nmol/mg protein, between the two groups. However, the aortic cholesterol content tended to be lower in the testosterone group than in the placebo group. These findings suggest that in cholesterol-fed, castrated male rabbits, testosterone does not promote atherogenesis by an effect directly on the arterial wall.

Protective HLA-DR phenotypes in rheumatoid arthritis

In a study of HLA-DR phenotypes in patients with rheumatoid arthritis (RA) and controls from the Saskatoon area and in Newfoundland, we found that certain phenotypes occurred more frequently in the patients than in healthy controls in both populations ("increased risk phenotypes"). The reverse was also true: certain phenotypes were reduced or excluded from patients with RA compared with controls. Three increased risk phenotypes with twice the expected frequencies or more were HLA-DR1,DR4; DR4 and DR4,DR5. Four "protective" phenotypes with half or less the expected frequencies were HLA-DR1, DR5; DR2; DR2,DR3 and DR3,DR7. We speculate that at least for the DR3,DR7 phenotype, the protective effect may be due to a hybrid DQw2 molecule.