Cognitive Performance following Single- or Multi-Session Exercise Intervention in Middle Age: A Systematic Review

BACKGROUND

Research in modifiable behaviors, like exercise, on risk for dementia is increasing. Although many studies focus on older adults, brain pathology for Alzheimer's Disease can begin in middle age, suggesting an ideal target for intervention.

METHODS

We conducted a systematic review from exercise intervention studies on cognitive function among healthy, middle-aged participants (45-65). We searched multiple databases (PubMed, PsycINFO, MEDLINE, Cochrane Central Register of Controlled Trials, Google Scholar) for studies using standard, validated, neuropsychological measures following either single- or multi-session interventions in cognitively-unimpaired, middle-aged adults.

RESULTS

We identified 13 eligible studies. There was notable heterogeneity across studies, with varying design, measures, interventions, and results. Results from single-session studies showed improvement in response inhibition, while results for cognitive flexibility were mixed. No significant changes were found on measures of attention, working memory, or processing speed. Results from multi-session studies were more varied. Verbal memory was found to improve while performance on tests of attention and working memory, processing speed, and executive function were mixed.

CONCLUSION

Importantly, for both single-session and multi-session studies, there was no standard set of neuropsychological tests administered, making it more difficult to synthesize the findings into a single narrative. We end with a discussion on future directions and implementation.

Role of light walking pace on cognition: Findings from the Maine-Syracuse Longitudinal Study

Moderate- to vigorous intensities of physical activity are recommended for health promotion, including brain health. Regular physical activity is considered a modifiable factor to delay -perhaps prevent- onset of dementias such as Alzheimer's disease. Little is known about the benefits of light physical activity. We analyzed data from a 998 community-dwelling, cognitively unimpaired participants from the Maine-Syracuse Longitudinal Study (MSLS) and investigated the role of light physical activity, defined by walking pace, across two time points. Results revealed light levels of walking pace were associated with higher performance at the first timepoint and less decline by time 2 in the domains of verbal abstract reasoning and visual scanning and tracking, which includes both processing speed and executive function skills. When examining change over time (N = 583), increasing walking pace was associated with less decline at time two for the domains of visual scanning and tracking, working memory, visual spatial ability, and working memory, but not verbal abstract reasoning. These findings highlight the relevance of light physical activity and the need to investigate its contribution to cognitive function. From a public health perspective, this may encourage more adults to adopt a light level of exercise and still reap health benefits.

Sleep movements and respiratory coupling as a biobehavioral metric for early Alzheimer's disease in independently dwelling adults

INTRODUCTION

Sleep disorder is often the first symptom of age-related cognitive decline associated with Alzheimer's disease (AD) observed in primary care. The relationship between sleep and early AD was examined using a patented sleep mattress designed to record respiration and high frequency movement arousals. A machine learning algorithm was developed to classify sleep features associated with early AD.

METHOD

Community-dwelling older adults (N = 95; 62-90 years) were recruited in a 3-h catchment area. Study participants were tested on the mattress device in the home bed for 2 days, wore a wrist actigraph for 7 days, and provided sleep diary and sleep disorder self-reports during the 1-week study period. Neurocognitive testing was completed in the home within 30-days of the sleep study. Participant performance on executive and memory tasks, health history and demographics were reviewed by a geriatric clinical team yielding Normal Cognition (n = 45) and amnestic MCI-Consensus (n = 33) groups. A diagnosed MCI group (n = 17) was recruited from a hospital memory clinic following diagnostic series of neuroimaging biomarker assessment and cognitive criteria for AD.

RESULTS

In cohort analyses, sleep fragmentation and wake after sleep onset duration predicted poorer executive function, particularly memory performance. Group analyses showed increased sleep fragmentation and total sleep time in the diagnosed MCI group compared to the Normal Cognition group. Machine learning algorithm showed that the time latency between movement arousals and coupled respiratory upregulation could be used as a classifier of diagnosed MCI vs. Normal Cognition cases. ROC diagnostics identified MCI with 87% sensitivity; 89% specificity; and 88% positive predictive value.

DISCUSSION

AD sleep phenotype was detected with a novel sleep biometric, time latency, associated with the tight gap between sleep movements and respiratory coupling, which is proposed as a corollary of sleep quality/loss that affects the autonomic regulation of respiration during sleep. Diagnosed MCI was associated with sleep fragmentation and arousal intrusion.

Adherence to a Mediterranean diet associated with lower blood pressure in a US sample: Findings from the Maine-Syracuse Longitudinal Study

Hypertension is a key modifiable risk factor for cardiovascular disease. The Mediterranean diet (MedDiet) may be associated with improvements in blood pressure. However, few studies have examined the association between MedDiet adherence and blood pressure in non-Mediterranean populations, and findings are mixed. We analyzed cross-sectional data (Wave 6) for 851 participants of the Maine-Syracuse Longitudinal Study. MedDiet adherence was calculated using food frequency questionnaire data and a literature-based MedDiet adherence score. Dependent variables included systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), and mean arterial pressure (MAP). Separate linear robust regression analyses revealed significant associations between MedDiet adherence and for SBP (b = -0.69, 95% CI = [-1.25, -0.20]), DBP (b = -0.33, 95% CI = [-0.58, -0.04]), and MAP (b = -0.45, 95% CI = [-0.77, -0.11]), but not for PP. These findings indicate that the MedDiet is associated with some metrics of blood pressure in a large, community-based, non-Mediterranean sample.

Subclinical atherosclerosis, airflow obstruction and emphysema: the MESA Lung Study

Airflow obstruction is an independent risk factor for cardiovascular events in the general population. The affected vascular bed and contribution of emphysema to cardiovascular risk are unclear. We examined whether an obstructive pattern of spirometry and quantitatively defined emphysema were associated with subclinical atherosclerosis in the carotid, peripheral and coronary circulations. The Multi-Ethnic Study of Atherosclerosis recruited participants aged 45-84 yrs without clinical cardiovascular disease. Spirometry, carotid intima-media thickness (IMT), ankle-brachial index (ABI) and coronary artery calcium (CAC) were measured using standard protocols. Percentage of emphysema-like lung was measured in the lung windows of cardiac computed tomography scans among 3,642 participants. Multiple linear regression was used to adjust for cardiac risk factors, including C-reactive protein. Decrements in forced expiratory volume in 1 s (FEV(1)) and FEV(1)/forced vital capacity ratio were associated with greater internal carotid IMT, particularly among smokers (p=0.03 and p<0.001, respectively) whereas percentage emphysema was associated with reduced ABI regardless of smoking history (p=0.004). CAC was associated with neither lung function (prevalence ratio for the presence of CAC in severe airflow obstruction 0.99, 95% CI 0.91-1.07) nor percentage emphysema. An obstructive pattern of spirometry and emphysema were associated distinctly and independently with subclinical atherosclerosis in the carotid arteries and peripheral circulation, respectively, and were not independently related to CAC.

Executive function mechanisms of theory of mind

This study examined the relationship between Executive Function (EF) and Theory of Mind (ToM) using the Delis-Kaplan Executive Function System (D-KEFS) and three tests of ToM (Reading the Mind in the Eyes test (RMET), Strange Stories test, and Faux Pas test). Separate regression analyses were conducted, and EF predictors varied by ToM test. No EF domains accounted for significant variance in RMET scores; only estimated IQ scores were significant predictors of RMET performance. Verbal fluency and deductive reasoning were significant predictors of performance on the Strange Stories test, while verbal fluency, problem solving, and gender accounted for a significant variance in the Faux Pas test. Results suggest that the ToM tests each utilized differing cognitive mechanisms.

A cross-linguistic investigation of locus equations as a phonetic descriptor for place of articulation

A previous study [H. Sussman, H. McCaffrey, and S. Matthews, J. Acoust. Soc. Am. 90, 1309-1325 (1991)] of American English CV coarticulation showed a remarkably linear relationship between onset frequencies of F2 transitions, plotted on the y axis, in relation to the F2 midvowel "target" frequencies, plotted on the x axis, for CVC tokens with initial [b d g] and ten medial vowel contexts. Slope and y-intercept values of regression functions fit to these scatterplots ("locus equations") were shown to serve as statistically powerful phonetic descriptors of place of articulation. The present study extends the locus equation metric to three additional languages--Thai, Cairene Arabic, and Urdu--having both two and four place contrasts for syllable-initial voiced stops. A total of 14 speakers (Thai = 6, Arabic = 3, Urdu = 5) produced 1740 CVC tokens that were acoustically analyzed using MacSpeech Lab II. Strong linear regression relationships were found for every stop category across all speakers. Slopes and y intercepts systemically varied as a function of place of articulation. Cross-language comparisons of stop place categories were performed but variability of slope and y intercept means tempered conclusions concerning the existence of CV "phonetic hot spots."

Synthesis of some 3-hydroxynaphthalene-2-carbonylamino acid and dipeptide derivatives

Synthesis of a series of 3-hydroxynaphthalene-2-carbonylamino acid methyl esters (II-XI) and some of their corresponding hydrazides (XII-XXI), dipeptide methyl esters (XXII-XXXV) and dipeptide hydrazides (XXXVI-XXXIX) is described. 3-Hydroxynaphthalene-2-CO-L-Tyr-N2H3 (XX) and the corresponding L-Val-L-Ala-N2H3 (XXXVI) were found to be active against a number of micro-organisms.

Synthesis and biological activity of some new 2-(aminoacyl- and dipeptidyl-)aminopyrazine derivatives

Synthesis of some new 2-(N-tosyl- or N-phthalylaminoacyl or free aminoacyl or N-tosyldipeptidyl- or N-phthalyldipeptidyl)aminopyrazine derivatives (II-XXX) are described. All 2-(aminoacyl)aminopyrazines (XIV-XVIII) have been found to be biologically active against a number of microorganism.

Synthesis and biological activity of some new substituted aminoacyl-carbazole derivatives. Part II

3-Nitro-9-(N-phthalyl- and N-tosylaminoacyl)carbazoles (II-XI) have been synthesized by the action of 3-nitro-9H-carbazole (I) on N-phthalyl- or N-tosylamino acid in THF-Et3N medium using the DCC method. Treatment of the 3-nitro derivatives (II-XI) with Sn/HCl gave the corresponding 3-amino-9-(N-phthalyl- or N-tosylaminoacyl)carbazoles (XII-XIX). Hydrazinolysis of the N-phthalylcarbazoles derivatives (III-VII) in ethanol gave the corresponding 3-nitro-9-(aminoacyl) carbazoles (XX-XXIII). Compounds (II-XI and XXI, XXII) were found to be active against some microorganisms.

Synthesis of some biologically active substituted thiazole and thiazoline-amino acid derivatives. Part I

Synthesis of a series of N-(2-acetylaminothiazole-5-sulphonyl) amino acids (II-VI) and some of their corresponding methyl esters (VII-XI) is described. Coupling of N-tosyl-or N-phthalylamino acid with 2-amino-2-thiazoline using the DCC method furnishes 2-(N-tosyl- or N-phthalylamino acyl) amino-2-thiazoline (XII-XXI). Hydrazinolysis of 2-(N-Pht-L-Phe or N-Pht-L-Ala) amino-2-thiazoline in ethanol afforded 2-(L-Phe or L-Ala) amino-2-thiazoline (XXII and XXIII) respectively. Synthesis of the dipeptide 2-(N-Tos-L-Val-L-Leu) amino-2-thiazoline (XXIV) has been achieved employing the azide method. Sixteen thiazole- and thiazoline-amino acid derivatives were found to be active against a number of microorganisms.