Association of non-exercise physical activity in mid- and late-life with cognitive trajectories and the impact of APOE ε4 genotype status: the Mayo Clinic Study of Aging

Impact of physical activity on disability-free and disabled life expectancies in middle-aged and older adults: Data from the healthy aging longitudinal study in Taiwan

AIM

Leisure-time physical activity (LTPA) promotes healthy aging; however, data on work-related physical activity (WPA) are inconsistent. This study was conducted to examine the disability-free life expectancy (DFLE) and disabled life expectancy (DLE) across physical activity levels, with a focus on WPA, in middle-aged and older adults.

METHODS

Data from 5663 community-dwelling participants aged ≥55 years and enrolled in the Healthy Aging Longitudinal Study in Taiwan were evaluated. Energy expenditures from LTPA and WPA were calculated from baseline questionnaires and categorized into sex-specific cutoffs. Disability was based on repeat measures of participants' activities of daily living and instrumental activities of daily living. Mortality was confirmed via data linkage with the Death Certificate database. DFLE and DLE were estimated from discrete-time multistate life-table models.

RESULTS

At age 65, women with low WPA had a DLE of 2.88 years (95% confidence interval [CI], 1.67-4.08), which was shorter than that of women without WPA (DLE, 5.24 years; 95% CI, 4.65-5.83) and with high WPA (DLE, 4.01 years; 95% CI, 2.69-5.34). DFLE and DLE were similar across WPA levels in men. DFLE tended to increase as the LTPA increased in men and women.

CONCLUSION

Women with low WPA had shorter DLE than did those with no or high WPA. To reduce the risks of disability associated with physical activity, public policy should advocate for older people to watch the type, amount, and intensity of their activities as these may go ignored during WPA. Geriatr Gerontol Int 2024; 24: 229-239.

Exercise modulates APOE expression in brain cortex of female APOE3 and APOE4 targeted replacement mice

Apolipoprotein E (ApoE) is the main cholesterol carrier of the brain and the ε4 gene variant (APOE4) is the most prevalent genetic risk factor for Alzheimer's disease (AD), increasing risk up to 15-fold. Several studies indicate that APOE4 modulates critical factors for neuronal function, including brain-derived neurotrophic factor (BDNF) and peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α). Both proteins show exercise-induced upregulation, which is presumed to mediate many of the beneficial effects of physical activity including improved cognition; however, there is variability in results between individuals potentially in-part due to genetic variations including APOE isoform. This study aimed to determine if the two most prevalent human APOE isoforms influence adaptive responses to exercise-training. Targeted replacement mice, homozygous for either APOE3 or APOE4 were randomized into exercised and sedentary groups. Baseline locomotor function and voluntary wheel-running behavior was reduced in APOE4 mice. Exercised groups were subjected to daily treadmill running for 8 weeks. ApoE protein in brain cortex was significantly increased by exercise in both genotypes. PGC-1α mRNA levels in brain cortex were significantly lower in APOE4 mice, and only tended to increase with exercise in both genotypes. Hippocampal BDNF protein were similar between genotypes and was not significantly modulated by treadmill running. Behavioral and biochemical variations between APOE3 and APOE4 mice likely contribute to the differential risk for neurological and vascular diseases and the exercise-induced increase in ApoE levels suggests an added feature of the potential efficacy of physical activity as a preventative and therapeutic strategy for neurogenerative processes in both genotypes.

Association between physical activity and longitudinal change in body mass index in middle-aged and older adults

BACKGROUND

In middle-aged and particularly older adults, body mass index (BMI) is associated with various health outcomes. We examined associations between physical activity (PA) and longitudinal BMI change in persons aged ≥ 50 years.

METHODS

The sample included 5159 community-dwelling individuals aged ≥ 50 years (50.5% males, mean (SD) age 73.0 (10.2) years at baseline) who were enrolled in the Mayo Clinic Study of Aging (MCSA). Participants had information on PA within one year of baseline assessment, BMI at baseline, and potential follow-up assessments (mean (SD) follow-up 4.6 (3.7) years). Linear mixed-effect models were used to calculate the association between PA (moderate-vigorous physical activity, MVPA; and all PA composite score) and the longitudinal change in BMI, adjusted for baseline age, sex, education and medical comorbidities. In addition to interactions between years since baseline and PA, we also included 2- and 3-way interactions with baseline age to further assess whether age modifies the trajectory of BMI over time.

RESULTS

We observed a decrease in BMI among participants engaging at a mean amount of PA (i.e.

, MVPA

2.7; all PA: 6.8) and with a mean age (i.e., 73 years) at baseline (MVPA: estimate = -0.047, 95% CI -0.059, -0.034; all PA: estimate = -0.047, 95% CI -0.060, -0.035), and this decline is accelerated with increasing age. Participants with a mean age (i.e., 73 years) that engage at an increased amount of MVPA or all PA at baseline (i.e., one SD above the mean) do not decrease as fast with regard to BMI (MVPA: estimate = -0.006; all PA: estimate = -0.016), and higher levels of MVPA or all PA at baseline (i.e., two SD above the mean) were even associated with an increase in BMI (MVPA: estimate = 0.035; all PA: estimate = 0.015). Finally, MVPA but not all PA is beneficial at slowing BMI decline with increasing age.

CONCLUSION

PA, particularly at moderate-vigorous intensity, is associated with slower decline in longitudinal BMI trajectories. This implies that engaging in PA may be beneficial for healthy body weight regulation in middle and late adulthood.

APOE in the bullseye of neurodegenerative diseases: impact of the APOE genotype in Alzheimer’s disease pathology and brain diseases

ApoE is the major lipid and cholesterol carrier in the CNS. There are three major human polymorphisms, apoE2, apoE3, and apoE4, and the genetic expression of APOE4 is one of the most influential risk factors for the development of late-onset Alzheimer's disease (AD). Neuroinflammation has become the third hallmark of AD, together with Amyloid-β plaques and neurofibrillary tangles of hyperphosphorylated aggregated tau protein. This review aims to broadly and extensively describe the differential aspects concerning apoE. Starting from the evolution of apoE to how APOE's single-nucleotide polymorphisms affect its structure, function, and involvement during health and disease. This review reflects on how APOE's polymorphisms impact critical aspects of AD pathology, such as the neuroinflammatory response, particularly the effect of APOE on astrocytic and microglial function and microglial dynamics, synaptic function, amyloid-β load, tau pathology, autophagy, and cell–cell communication. We discuss influential factors affecting AD pathology combined with the APOE genotype, such as sex, age, diet, physical exercise, current therapies and clinical trials in the AD field. The impact of the APOE genotype in other neurodegenerative diseases characterized by overt inflammation, e.g., alpha- synucleinopathies and Parkinson's disease, traumatic brain injury, stroke, amyotrophic lateral sclerosis, and multiple sclerosis, is also addressed. Therefore, this review gathers the most relevant findings related to the APOE genotype up to date and its implications on AD and CNS pathologies to provide a deeper understanding of the knowledge in the APOE field.

The effects of substance use and physical activity on cognition: The impact of incongruent health behaviors

BACKGROUND

Cognitive functioning refers to storage and manipulation of information and includes executive functioning (EF) and attention (ATT). While physical activity (PA) improves cognitive functioning, decrements are associated with frequent substance use. This study examined PA on cognitive functioning within the context of past-year substance use.

METHODS

Using NESARC-III data (N = 36,309), cross-sectional analysis examined interactions between self-reported past-year PA and substance use in relation to cognitive functioning.

RESULTS

As hypothesized, light-to-moderate, vigorous, and total PA conditional main effects were positively associated with both facets of cognition, while frequent substance use conditional main effects were negatively associated with ATT and EF. The positive association between PA and cognition was diminished by substance use. Frequent binge drinking, marijuana, cocaine, and opioid use weakened the impact of light-to-moderate PA on EF, and only frequent cocaine use lessened the relationship between vigorous PA on EF. When PA intensities were combined, frequent binge drinking and cocaine use weakened the PA and EF association. Infrequent stimulant use reduced the association between all levels of PA and ATT, while infrequent marijuana use unexpectedly enhanced the relation between vigorous PA and ATT.

CONCLUSIONS

Overall, PA enhanced two facets of cognitive functioning across six substances. However, these benefits are reduced in the context of frequency of substance use. The positive association between light-to-moderate PA and EF appears to be more sensitive in the context of frequent substance use than vigorous PA. Implications for public health messaging and PA as cognitive remediation treatment for substance use disorders are discussed.

The association between physical activity intensity, cognition and brain structure in people with type 2 diabetes

BACKGROUND

Physical inactivity is a risk factor for type 2 diabetes (T2D) and dementia. However, it is unknown if physical activity (PA) intensity is associated with brain health in people with T2D. Therefore, this study aimed to determine 1) associations between PA intensity and step count with both cognition and brain structure and 2) if apolipoprotein E-ε4 (APOE-ε4) or insulin-therapy modifies any associations.

METHODS

Participants were people with T2D (n=220; aged 55-86 years). An accelerometer worn over the left hip was used to obtain step count and moderate-to-vigorous PA (MVPA) averaged over 7 days. Cognition in 7 domains was obtained using a battery of neuropsychological tests. Brain structure was measured by Magnetic Resonance Imaging (MRI). Linear regression models were used to examine associations between step count, MVPA and each cognitive and MRI measure. APOE-ε4 x PA and insulin-therapy x PA product terms were added to the models to examine effect modification.

RESULTS

The mean age of participants was 67.9 (SD 6.3). Higher step count was associated with greater hippocampal volume (β=0.028 95%CI 0.005, 0.051). Insulin-therapy modified the association between MVPA and attention-processing speed, such that associations were significant in people receiving insulin-therapy (P for interaction=0.019). There were no other significant associations.

CONCLUSIONS

Higher step count and greater time spent in MVPA may be associated with better hippocampal volume and attention-processing speed respectively in people with T2D. People with greater diabetes severity (receiving insulin-therapy) may get more cognitive benefit from MVPA.