Search

BackgroundTraditionally, weight loss (WL) trials utilize dual energy X-ray absorptiometry (DXA) to measure lean mass. This method assumes lean mass, as the sum of all non-bone and non-fat tissue, is a reasonable proxy for muscle mass. In contrast, the D3 -creatine (D3 Cr) dilution method directly measures whole body skeletal muscle mass, although this method has yet to be applied in the context of a geriatric WL trial. The purpose of this project was to (1) describe estimates of change and variability in D3 Cr muscle mass in older adults participating in an intentional WL intervention and (2) relate its change to other measures of body composition as well as muscle function and strength.MethodsThe INVEST in Bone Health trial (NCT04076618), used as a scaffold for this ancillary pilot project, is a three-armed, 12-month randomized, controlled trial designed to determine the effects of resistance training or weighted vest use during intentional WL on a battery of musculoskeletal health outcomes among 150 older adults living with obesity. A convenience sample of 24 participants (n = 8/arm) are included in this analysis. At baseline and 6 months, participants were weighed, ingested a 30 mg D3 Cr tracer dose, provided a fasted urine sample 3-6 days post-dosage, underwent DXA (total body fat and lean masses, appendicular lean mass) and computed tomography (mid-thigh and trunk muscle/intermuscular fat areas) scans, and performed 400-m walk, stair climb, knee extensor strength, and grip strength tests.ResultsParticipants were older (68.0 ± 4.4 years), mostly White (75.0%), predominantly female (66.7%), and living with obesity (body mass index: 33.8 ± 2.7 kg/m2 ). Six month total body WL was -10.3 (95% confidence interval, CI: -12.7, -7.9) kg. All DXA and computed tomography-derived body composition measures were significantly decreased from baseline, yet D3 Cr muscle mass did not change [+0.5 (95% CI: -2.0, 3.0) kg]. Of muscle function and strength measures, only grip strength significantly changed [+2.5 (95% CI: 1.0, 4.0) kg] from baseline.ConclusionsAmong 24 older adults, significant WL with or without weighted vest use or resistance training over a 6-month period was associated with significant declines in all bioimaging metrics, while D3 Cr muscle mass and muscle function and strength were preserved. Treatment assignment for the trial remains blinded; therefore, full interpretation of these findings is limited. Future work in this area will assess change in D3 Cr muscle mass by parent trial treatment group assignment in all study participants.

Exposures to fine particulate matter (PM2.5) and nitrogen dioxide (NO2) have been associated with the emergence of depressive symptoms in older adulthood, although most studies used cross-sectional outcome measures. Elucidating the brain structures mediating the adverse effects can strengthen the causal role between air pollution and increasing depressive symptoms. We evaluated whether smaller volumes of brain structures implicated in late-life depression mediate associations between ambient air pollution exposure and changes in depressive symptoms. This prospective study included 764 community-dwelling older women (aged 81.6 ± 3.6 in 2008-2010) from the Women's Health Initiative Memory Study (WHIMS) Magnetic Resonance Imaging study (WHIMS-MRI; 2005-06) and WHIMS-Epidemiology of Cognitive Health Outcomes (WHIMS-ECHO; 2008-16). Three-year average annual mean concentrations (scaled by interquartile range [IQR]) of ambient PM2.5 (in μg/m3; IQR = 3.14 μg/m3) and NO2 (in ppb; IQR = 7.80 ppb) before WHIMS-MRI were estimated at participants' addresses via spatiotemporal models. Mediators included structural brain MRI-derived grey matter volumes of the prefrontal cortex and structures of the limbic-cortical-striatal-pallidal-thalamic circuit. Depressive symptoms were assessed annually by the 15-item Geriatric Depression Scale. Structural equation models were constructed to estimate associations between exposure, structural brain volumes, and depressive symptoms. Increased exposures (by each IQR) were associated with greater annual increases in depressive symptoms (βPM2.5 = 0.022; 95% Confidence Interval (CI) = 0.003, 0.042; βNO2 = 0.019; 95% CI = 0.001, 0.037). The smaller volume of prefrontal cortex associated with exposures partially mediated the associations of increased depressive symptoms with NO2 (8%) and PM2.5 (13%), and smaller insula volume associated with NO2 contributed modestly (13%) to the subsequent increase in depressive symptoms. We demonstrate the first evidence that the smaller volumes of the prefrontal cortex and insula may mediate the subsequent increases in depressive symptoms associated with late-life exposures to NO2 and PM2.5.

The interrelationships among long-term ambient air pollution exposure, emotional distress and cognitive decline in older adulthood remain unclear. Long-term exposure may impact cognitive performance and subsequently impact emotional health. Conversely, exposure may initially be associated with emotional distress followed by declines in cognitive performance. Here we tested the inter-relationship between global cognitive ability, emotional distress, and exposure to PM2.5 (particulate matter with aerodynamic diameter

Background/objectivesExposure to air pollution may contribute to both increasing depressive symptoms and decreasing episodic memory in older adulthood, but few studies have examined this hypothesis in a longitudinal context. Accordingly, we examined the association between air pollution and changes in depressive symptoms (DS) and episodic memory (EM) and their interrelationship in oldest-old (aged 80 and older) women.DesignProspective cohort data from the Women's Health Initiative Memory Study-Epidemiology of Cognitive Health Outcomes.SettingGeographically diverse community-dwelling population.ParticipantsA total of 1,583 dementia-free women aged 80 and older.MeasurementsWomen completed up to six annual memory assessments (latent composite of East Boston Memory Test and Telephone Interview for Cognitive Status) and the 15-item Geriatric Depression Scale (GDS-15). We estimated 3-year average exposures to regional particulate matter with aerodynamic diameter below 2.5 μm (PM2.5 ) (interquartile range [IQR] = 3.35 μg/m3 ) and gaseous nitrogen dioxide (NO2 ) (IQR = 9.55 ppb) at baseline and during a remote period 10 years earlier, using regionalized national universal kriging.ResultsLatent change structural equation models examined whether residing in areas with higher pollutant levels was associated with annual changes in standardized EM and DS while adjusting for potential confounders. Remote NO2 (β = .287 per IQR; P = .002) and PM2.5 (β = .170 per IQR; P = .019) exposure was significantly associated with larger increases in standardized DS, although the magnitude of the difference, less than 1 point on the GDS-15, is of questionable clinical significance. Higher DS were associated with accelerated EM declines (β = -.372; P = .001), with a significant indirect effect of remote NO2 and PM2.5 exposure on EM declines mediated by DS. There were no other significant indirect exposure effects.ConclusionThese findings in oldest-old women point to potential adverse effects of late-life exposure to air pollution on subsequent interplay between DS and EM, highlighting air pollution as an environmental health risk factor for older women.

BackgroundElucidating associations between exposures to ambient air pollutants and profiles of cognitive performance may provide insight into neurotoxic effects on the aging brain.ObjectiveWe examined associations between empirically derived profiles of cognitive performance and residential concentrations of particulate matter of aerodynamic diameter

Evidence suggests exposure to particulate matter with aerodynamic diameter

Objective: The study objective was to determine whether the clinical response of older adults with knee osteoarthritis and overweight or obesity to 18 months of diet and exercise (D + E) or attention control (C) interventions differed between participants from rural versus urban communities. Methods: Participants were 823 older adults (mean age, 64.6 years; 77% women) with knee osteoarthritis and overweight or obesity who resided in rural (n = 410) and urban (n = 413) counties in North Carolina. All were enrolled in the Weight Loss and Exercise for Communities with Arthritis in North Carolina clinical trial that randomly assigned participants to either 18 months of D + E or C interventions. General linear models were used to examine differences in clinical outcomes between rural and urban groups after adjusting for covariates. Results: The rural group had significant differences (P < 0.05) at baseline in clinical outcomes, education, comorbidities, medication use, and income compared with the urban dwellers. After adjusting for baseline differences, the group (rural or urban) by treatment (D + E or C) interactions for Western Ontario McMasters Universities Osteoarthritis Index (WOMAC) pain (rural: D + E – C = −0.63, 95% confidence interval [CI] −1.31 to 0.06; urban: D + E − C= −0.29, 95% CI −0.99 to 0.41; P = 0.50) and WOMAC function (rural: D + E − C = −4.60, 95% CI −6.89 to −2.31; urban: D + E − C = −1.38, 95% CI −3.73 to 0.94; P = 0.054) indicated that the groups responded similarly to the interventions. Conclusion: Among participants with knee osteoarthritis and overweight or obesity, D + E compared to C led to similar pain outcomes in rural and urban dwellers that favored D + E. The possibility that there may be greater differential efficacy in functional outcomes among rural participants needs further study. [ABSTRACT FROM AUTHOR]

BACKGROUND:Data are sparse regarding the value of physical activity (PA) surveillance among older adults-particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study. METHODS AND RESULTS:Cardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home-based activity data were collected by hip-worn accelerometers at baseline and at 6, 12, and 24 months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500 steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84-0.96; P=0.001). At baseline, every 30 minutes spent performing activities ≥500 counts per minute (hazard ratio, 0.75; confidence interval, 0.65-0.89 [P=0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow-up (6, 12, and 24 months), both the number of steps per day (per 500 steps; hazard ratio, 0.90, confidence interval, 0.85-0.96 [P=0.001]) and duration of activity ≥500 counts per minute (per 30 minutes; hazard ratio, 0.76; confidence interval, 0.63-0.90 [P=0.002]) were significantly associated with lower cardiovascular event rates. CONCLUSIONS:Objective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score >10 on the Short Physical Performance Battery) both using baseline and longitudinal data. CLINICAL TRIAL REGISTRATION:URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500.

Survey data are often subject to various types of errors such as misclassification. In this article, we consider a model where interest is simultaneously in two correlated response variables and one is potentially subject to misclassification. A motivating example of a recent study of the impact of a sexual education course for adolescents is considered. A simulation-based sample size determination scheme is applied to illustrate the impact of misclassification on power and bias for the parameters of interest.

Author(s): Diana Younan 1,*, Xinhui Wang 2, Joshua Millstein 1, Andrew J. Petkus 2, Daniel P. Beavers 3, Mark A. Espeland 3, Helena C. Chui 2, Susan M. Resnick 4, [...], Background Late-life exposure to ambient air pollution is a modifiable risk factor for dementia, but epidemiological studies have shown inconsistent evidence for cognitive decline. Air quality (AQ) improvement has been associated with improved cardiopulmonary health and decreased mortality, but to the best of our knowledge, no studies have examined the association with cognitive function. We examined whether AQ improvement was associated with slower rate of cognitive decline in older women aged 74 to 92 years. Methods and findings We studied a cohort of 2,232 women residing in the 48 contiguous US states that were recruited from more than 40 study sites located in 24 states and Washington, DC from the Women&apos;s Health Initiative (WHI) Memory Study (WHIMS)-Epidemiology of Cognitive Health Outcomes (WHIMS-ECHO) study. They were predominantly non-Hispanic White women and were dementia free at baseline in 2008 to 2012. Measures of annual (2008 to 2018) cognitive function included the modified Telephone Interview for Cognitive Status (TICSm) and the telephone-based California Verbal Learning Test (CVLT). We used regionalized universal kriging models to estimate annual concentrations (1996 to 2012) of fine particulate matter (PM.sub.2.5) and nitrogen dioxide (NO.sub.2) at residential locations. Estimates were aggregated to the 3-year average immediately preceding (recent exposure) and 10 years prior to (remote exposure) WHIMS-ECHO enrollment. Individual-level improved AQ was calculated as the reduction from remote to recent exposures. Linear mixed effect models were used to examine the associations between improved AQ and the rates of cognitive declines in TICSm and CVLT trajectories, adjusting for sociodemographic (age; geographic region; race/ethnicity; education; income; and employment), lifestyle (physical activity; smoking; and alcohol), and clinical characteristics (prior hormone use; hormone therapy assignment; depression; cardiovascular disease (CVD); hypercholesterolemia; hypertension; diabetes; and body mass index [BMI]). For both PM.sub.2.5 and NO.sub.2, AQ improved significantly over the 10 years before WHIMS-ECHO enrollment. During a median of 6.2 (interquartile range [IQR] = 5.0) years of follow-up, declines in both general cognitive status ([beta] = -0.42/year, 95% CI: -0.44, -0.40) and episodic memory ([beta] = -0.59/year, 95% CI: -0.64, -0.54) were observed. Greater AQ improvement was associated with slower decline in TICSm ([beta].sub.PM2.5improvement = 0.026 per year for improved PM.sub.2.5 by each IQR = 1.79 [mu]g/m.sup.3 reduction, 95% CI: 0.001, 0.05; [beta].sub.NO2improvement = 0.034 per year for improved NO.sub.2 by each IQR = 3.92 parts per billion [ppb] reduction, 95% CI: 0.01, 0.06) and CVLT ([beta].sub.PM2.5 improvement = 0.070 per year for improved PM.sub.2.5 by each IQR = 1.79 [mu]g/m.sup.3 reduction, 95% CI: 0.02, 0.12; [beta].sub.NO2improvement = 0.060 per year for improved NO.sub.2 by each IQR = 3.97 ppb reduction, 95% CI: 0.005, 0.12) after adjusting for covariates. The respective associations with TICSm and CVLT were equivalent to the slower decline rate found with 0.9 to 1.2 and1.4 to 1.6 years of younger age and did not significantly differ by age, region, education, Apolipoprotein E (ApoE) e4 genotypes, or cardiovascular risk factors. The main limitations of this study include measurement error in exposure estimates, potential unmeasured confounding, and limited generalizability. Conclusions In this study, we found that greater improvement in long-term AQ in late life was associated with slower cognitive declines in older women. This novel observation strengthens the epidemiologic evidence of an association between air pollution and cognitive aging.

Introduction Decline in episodic memory (e.g., the ability to remember details from daily experience, as well as the spatial and temporal context of events) is commonly associated with normal cognitive [...], BACKGROUND: Episodic memory decline varies by age and underlying neuropathology. Whether ambient air pollution contributes to the heterogeneity of episodic memory decline in older populations remains unclear. OBJECTIVES: We estimated associations between air pollution exposures and episodic memory decline according to pollutant, exposure time window, age, and latent class subgroups defined by episodic memory trajectories. METHODS: Participants were from the Women&apos;s Health Initiative Memory Study-Epidemiology of Cognitive Health Outcomes. Older women (n = 2,056; 74-92 years of age) completed annual (2008-2018) episodic memory assessments using the telephone-based California Verbal Learning Test (CVLT). We estimated 3-y average fine particulate matter [PM with an aerodynamic diameter of [less than or equal to]2.5 [micro]m (P[M.sub.2.5])] and nitrogen dioxide (N[O.sub.2]) exposures at baseline and 10 y earlier (recent and remote exposures, respectively), using regionalized national universal kriging. Separate latent class mixed models were used to estimate associations between interquartile range increases in exposures and CVLT trajectories in women [less than or equal to]80 and > 80 years of age, adjusting for covariates. RESULTS: Two latent classes were identified for women 80-y-old cognitively resilient class [-0.10/y (95% CI: -0.24, 0.03)] and steady-decliner class [-0.11/y (95% CI: -0.27, 0.05)]. Associations with recent N[O.sub.2] exposure in women >80years of age were stronger and statistically significant when 267 women with incident probable dementia were excluded [e.g., -0.12/y (95% CI: -0.22, -0.02) for the cognitively resilient class]. In contrast with changes in CVLT over time, there were no associations between exposures and CVLT scores during follow-up in any subgroup. DISCUSSION: In a community-dwelling U.S. population of older women, associations between late-life exposure to ambient air pollution and episodic memory decline varied by age-related cognitive trajectories, exposure time windows, and pollutants. https://doi.org/10.1289/EHP7668