Genomic loci influence patterns of structural covariance in the human brain

Normal and pathologic neurobiological processes influence brain morphology in coordinated ways that give rise to patterns of structural covariance (PSC) across brain regions and individuals during brain aging and diseases. The genetic underpinnings of these patterns remain largely unknown. We apply a stochastic multivariate factorization method to a diverse population of 50,699 individuals (12 studies and 130 sites) and derive data-driven, multi-scale PSCs of regional brain size. PSCs were significantly correlated with 915 genomic loci in the discovery set, 617 of which are newly identified, and 72% were independently replicated. Key pathways influencing PSCs involve reelin signaling, apoptosis, neurogenesis, and appendage development, while pathways of breast cancer indicate potential interplays between brain metastasis and PSCs associated with neurodegeneration and dementia. Using support vector machines, multi-scale PSCs effectively derive imaging signatures of several brain diseases. Our results elucidate genetic and biological underpinnings that influence structural covariance patterns in the human brain.

Latin American Initiative for Lifestyle Intervention to Prevent Cognitive Decline (LatAm-FINGERS): Study design and harmonization

INTRODUCTION

Latin American Initiative for Lifestyle Intervention to Prevent Cognitive Decline (LatAm-FINGERS) is the first non-pharmacological multicenter randomized clinical trial (RCT) to prevent cognitive impairment in Latin America (LA). Our aim is to present the study design and discuss the strategies used for multicultural harmonization.

METHODS

This 1-year RCT (working on a 1-year extension) investigates the feasibility of a multi-domain lifestyle intervention in LA and the efficacy of the intervention, primarily on cognitive function. An external harmonization process was carried out to follow the FINGER model, and an internal harmonization was performed to ensure this study was feasible and comparable across the 12 participating LA countries.

RESULTS

Currently, 1549 participants have been screened, and 815 randomized. Participants are ethnically diverse (56% are Nestizo) and have high cardiovascular risk (39% have metabolic syndrome).

DISCUSSION

LatAm-FINGERS overcame a significant challenge to combine the region's diversity into a multi-domain risk reduction intervention feasible across LA while preserving the original FINGER design.

Abstract P103: Associations Between Brain Volumes and Cerebral Blood Flow and Sex Hormones in the Look AHEAD Brain MRI Cohort

Background: Females have greater relative brain volume (BV) and cerebral blood flow (CBF) compared to males. BV decreases after menopause suggesting a possible role of sex hormones. We studied the association of BV, abnormal white matter hyperintensity volumes (WMHV) and cerebral blood flow (CBF) with sex hormones in adults with type 2 diabetes (T2DM), which is associated with risk of brain atrophy.

Methods: The sample was 215 participants with overweight or obesity and T2DM from the Look AHEAD Brain MRI cohort (mean age 68 years [SD: 6.3], 27% male, 73% female [all postmenopausal]; without exogenous hormones), who had brain MRIs to evaluate their total BV, WMHV and CBF. The ratio of brain measurements to intracranial volume was analyzed to account for body size. Estradiol (E2) and testosterone levels (T) were estimated with electrochemoluminescence assays. In females, who have low E2 and T levels, we compared brain measures in those with detectable (vs. undetectable) hormone levels (E2<20 pg/mL, 79%; T<0.02 pg/mL, 37%). In males, we used Spearman correlation to assess the association between brain measures and sex hormone levels. The associations between BV, WMHV and E2 and T were adjusted for age and BMI using linear regression.

Results: Females with detectable (vs. undetectable) T levels had higher BV (p=0.04) (Table), which was attenuated after adjustment for age and BMI. WMHV and CBF were not statistically associated with sex hormone levels in females. In males, no brain measures were significantly associated with sex hormones levels.

Conclusions: In postmenopausal females with T2DM, detectable levels of T were associated greater BV, but not associated any CBF or WMHV. In males, none of the brain measures were associated with sex hormones. Our findings are limited by a small, convenient sample size and low sensitivity of hormone assays with a high proportion of undetectable levels. Our findings suggest that larger samples with high sensitivity hormone assays are needed to assess clinically important differences.

EIGHT-YEAR CHANGES IN DEFICIT ACCUMULATION FRAILTY: RELATION TO GLYCEMIC CONTROL AND DIABETES MEDICATION USE

Type 2 diabetes mellitus (T2DM) has been linked to accelerated biological aging and the accumulation of health deficits. It is unknown whether glycemic control can slow the progression of aging, as expressed by deficit accumulation frailty indices (FIs). We examined the cross-sectional and longitudinal associations that glycemic control, diabetes medication use, and weight change (predictors) had with a FI calculated as the percent of 36 deficits in behavioral, functional, and clinical characteristics (outcome). We drew data from 4177 participants across 8 years of follow-up in the Look AHEAD clinical trial of a multidomain intensive lifestyle intervention in individuals aged 45-76 years with T2DM and overweight or obesity. At baseline, the means(SD) FI(as a percent) for participants grouped as HbA1c< 7%, 7-7.9%, and >8% were: 19.93(6.45), 20.82(6.89), and 21.53(7.27), p< 0.001. Compared with HbA1c>8%, HbA1c< 7% at baseline was associated with 23% less mean 8-year FI progression: 2.42(7.35) vs 3.14(8.02), p< 0.001). Maintaining average HbA1c< 7% vs >8% during follow-up was associated with 47% less 8-year FI progression: 2.05(7.35) vs 3.14(8.02), p< 0.001. With adjustment for HbA1c, sustained weight loss >5% compared with weight gain >5% was associated with an 81% reduction in 8-year FI progression: 1.18(7.25) vs 3.89(8.09), p< 0.001. Use of metformin across >50% of annual visits was associated with a 30% reduction in 8-year progression of FI as compared with less use or no use: 2.25(7.27) vs 3.22(7.90), p=0.002. We conclude that better control of HbA1c, and sustained weight loss (>5%) and metformin use, may slow the accelerated aging associated with T2DM.

AFFECTIVE TRAJECTORIES: RISK OF DEMENTIA AND UNDERLYING STRUCTURAL BRAIN VARIABLES IN OLDER WOMEN

Understanding how trajectories of positive and negative affect relate to dementia risk and underlying structural brain variables is important for dementia prevention. We examined associations between annually assessed Positive and Negative Affect Scale subscales and dementia risk (2000-18) among cognitively-intact community-dwelling women (N=948; aged 72.9±3.7) from the Women’s Health Initiative Study of Cognitive Aging (years 2000-2010) and Magnetic Resonance Imaging Study (2005-2006). Joint latent class mixture models were constructed to identify latent classes of women with similar trajectories of affect and dementia risk over time. Multinomial and logistic regressions examined whether structural MRI measures predicted latent class membership (adjusted for sociodemographic, lifestyle, clinical characteristics, and intracranial volume). Two latent classes of positive affect (high stable:88% and decreasing:12%) and four classes of negative affect (Minimal stable:75%; high stable:4%; emerging:12%; moderate decreasing:9%) were identified. With the high stable trajectory as referent, women with decreasing positive affect were more likely to develop dementia (HR=4.33;p<.001). The odds of being classified as this high-dementia risk group were increased among women with more (per SD) global small vessel ischemic disease (SVID;OR=1.42;p<.001), deep white matter SVID (OR=1.93;p<.001), and smaller parahippocampal volumes (OR=1.41;p=.016). For negative affect, with minimal stable negative affect as referent, women with smaller hippocampal volumes were more likely to be classified as having moderate decreasing negative affect (OR=1.45;p=.024) while emerging negative affect was associated with higher dementia risk (HR=2.00;p=.014). These findings highlight the importance of changes in affect in later-life with dementia risk and potential underlying role of cerebrovascular disease and medial temporal lobe structures.

Effect of renin-angiotensin system antihypertensive medication use on cognitive function in diabetes mellitus with obesity or overweight: An ancillary study to the Action for Health in Diabetes (Look AHEAD) trial

AIM

To determine whether antihypertensive medication (AHM) acting through the renin angiotensin system (RAS-AHM), compared with other AHM, can mitigate effects on cognitive function and risk for impairment in a population with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

This secondary analysis of the randomized controlled Action for Health in Diabetes (Look AHEAD) study included 712 community-dwelling participants who were followed over 15 years. Logistic regression was used to relate RAS-AHM use to cognitive impairment, and linear regression was used to relate RAS-AHM use to domain-specific cognitive function after adjusting for potential confounders.

RESULTS

A total of 563 individuals reported RAS-AHM use and 149 reported other-AHM use during the study. RAS-AHM users have college or higher education (53%), had higher baseline glycated haemoglobin (57 mmol/mol), and reported higher diabetes medication use (86%), while other-AHM users were more likely to be White (72%), obese (25%) and to have cardiovascular history (19%). RAS-AHM use was not associated with a reduced risk of dementia compared with other-AHM use. We did observe better executive function (Trail Making Test, part B, P < 0.04), processing speed (Digit Symbol Substitution Test, P < 0.004), verbal memory (Rey Auditory Verbal Learning Test-delayed recall, P < 0.005), and composite score (P < 0.008) among RAS-AHM users compared with other-AHM users.

CONCLUSION

In this sample of adults with T2DM, free of dementia at baseline, we observed a slower decline in processing speed, executive function, verbal memory, and composite score among RAS-AHM users.

Optimal cardiometabolic health and risk of heart failure in type 2 diabetes: an analysis from the Look AHEAD trial

AIMS

To evaluate the contribution of baseline and longitudinal changes in cardiometabolic health (CMH) towards heart failure (HF) risk among adults with type 2 diabetes (T2D).

METHODS AND RESULTS

Participants of the Look AHEAD trial with T2D and without prevalent HF were included. Adjusted Cox models were used to create a CMH score incorporating target levels of parameters weighted based on relative risk for HF. The associations of baseline and changes in the CMH score with risk of overall HF, HF with preserved (HFpEF) and reduced ejection fraction (HFrEF) were assessed using Cox models. Among the 5080 participants, 257 incident HF events occurred over 12.4 years of follow-up. The CMH score included 2 points each for target levels of waist circumference, glomerular filtration rate, urine albumin-to-creatinine ratio, and 1 point each for blood pressure and glycated haemoglobin at target. High baseline CMH score (6-8) was significantly associated with lower overall HF risk (adjusted hazard ratio [HR], ref = low score (0-3): 0.31, 95% confidence interval [CI] 0.21-0.47) with similar associations observed for HFpEF and HFrEF. Improvement in CMH was significantly associated with lower risk of overall HF (adjusted HR per 1-unit increase in score at 4 years: 0.80, 95% CI 0.70-0.91). In the ACCORD validation cohort, the baseline CMH score performed well for predicting HF risk with adequate discrimination (C-index 0.70), calibration (chi-square 5.53, p = 0.70), and risk stratification (adjusted HR [high (6-8) vs. low score (0-3)]: 0.35, 95% CI 0.26-0.46). In the Look AHEAD subgroup with available biomarker data, incorporating N-terminal pro-B-type natriuretic peptide to the baseline CMH score improved model discrimination (C-index 0.79) and risk stratification (adjusted HR [high (8-10) vs. low score (0-4)]: 0.18, 95% CI 0.09-0.35).

CONCLUSIONS

Achieving target levels of more CMH parameters at baseline and sustained improvements were associated with lower HF risk in T2D.

Higher Arm Versus Lower Arm Systolic Blood Pressure and Cardiovascular Outcomes: a Meta-Analysis of Individual Participant Data From the INTERPRESS-IPD Collaboration

Guidelines recommend measuring blood pressure (BP) in both arms, adopting the higher arm readings for diagnosis and management. Data to support this recommendation are lacking. We evaluated associations of higher and lower arm systolic BPs with diagnostic and treatment thresholds, and prognosis in hypertension, using data from the Inter-arm Blood Pressure Difference—Individual Participant Data Collaboration.

Association of sleep disturbance with Parkinson disease: evidence from the Women's Health Initiative

OBJECTIVE

To examine the association of sleep disturbance with Parkinson disease (PD) during 10+ years of follow-up among postmenopausal women, 50 to 79 years of age at baseline.

METHODS

Longitudinal data on 130,502 study-eligible women (mean ± standard deviation baseline age = 63.16 ± 7.20 y) from the Women's Health Initiative Clinical Trials and Women's Health Initiative Observational Study were analyzed. The cohort was followed for 15.88 ± 6.50 years, yielding 2,829 (2.17%) PD cases. Sleep disturbance (habitual sleep duration, insomnia symptoms, obstructive sleep apnea risk factors, sleep aids among those with WHI Insomnia Rating Scale scores (WHIIRS) > 9) was measured at baseline and one follow-up time by September 12, 2005. Cox proportional hazards models evaluated relationships controlling for sociodemographic, lifestyle, and health characteristics.

RESULTS

PD was significantly associated with long sleep duration (≥9 h) versus a benchmark of 7 to 8 hours (hazard ratio [HR] = 1.296, 95% confidence interval [CI]: 1.153-1.456), WHIIRS (>9 vs ≤9) (HR = 1.114, 95% CI:1.023-1.214), and use of sleep aids (yes vs no) (HR = 1.332, 95% CI:1.153-1.539) among those with WHIIRS > 9. Compared with 7 to 8 hours, short (<7 h) sleep duration was unrelated to PD. Finally, the presence of obstructive sleep apnea risk factors was not associated with PD.

CONCLUSIONS

Among postmenopausal women, sleep disturbance was associated with approximately 10% to 30% increased PD risk after ∼16 years follow-up. Prospective cohort studies with objective exposures and adjudicated outcomes that include men and women of diverse backgrounds are required to confirm and extend these findings.

Comparison of Head Impact Exposure Across Common Activities in Youth Soccer

OBJECTIVE

The objective of this study was to compare head impact exposure across common training activities in soccer.

BACKGROUND

Soccer is a popular youth sport in the United States, but repetitive head impacts during training may result in neurocognitive deficits. Current research has identified factors associated with increased head impact exposure in soccer, but research has yet to contextualize head impact exposure across soccer activities. Modifying practice structure may be an avenue for reducing head impact exposure and concussion risk in soccer.

DESIGN/METHODS

Eight U15 soccer players participated in this study for 2 soccer seasons. Players wore a custom instrumented mouthpiece sensor during all practices and games. On-field activities were recorded with a time-synchronized camera. Research personnel recorded the duration of all practice (e.g., technical training, team interaction) and game activities performed by each player, and film review was performed to identify all head contact events during each session. Head impact exposure was quantified in terms of peak kinematics and impacts per player per hour. The amount of time an athlete was exposed to an activity was also evaluated. Mixed effects models were used to compare peak kinematics and generalized linear models were used to compare impact rates across activity types.

RESULTS

Activity types were associated with peak kinematics and impact rate. Technical training activities were associated with higher impact rates and lower mean kinematics compared to other activity types. Team interaction activities and game play were associated with the highest rotational kinematics, but the lowest impact rates. A similar number of player-to-player contact events occurred within technical training, team interaction, and game play activities.

CONCLUSIONS

Interventions designed to reduce head impact frequency in soccer may benefit from targeting technical training activities; whereas, interventions designed to reduce head impact magnitude may benefit from targeting team interaction and game activities.

Associations Between Endogenous Estrogen, Postmenopausal Hormone Therapy, and Cognitive Changes in Older Women

How markers of brain health are associated with endogenous estrogen and use of postmenopausal hormone therapy (HT) varies depending on women’s years from menopause and metabolic health status, ranging from potential benefit to harm. The Women’s Health Initiative (WHI) included 7,233 women age 65-80 who underwent a randomized clinical trial of various HT preparations for an average of 5.9 years. Over up to 18 years of post-trial follow-up, diabetes (DM2) increased the risk of dementia (hazard ratio [HR] 1.54 [95% CI 1.16–2.06]). Having DM2 and also treatment with unopposed conjugated equine estrogens increased the risk to HR=2.12 [1.47-3.06]. We hypothesize that the metabolic effects of estrogen in the brain drives this interaction. In support of this, the metabolic transition following menopause may alter the impact of other treatments on cognition, for example behavioral weight loss therapy to treat obesity in women with type 2 diabetes (interaction p=0.02 for executive function).

Resilience among older adults with Type 2 Diabetes from the Look AHEAD trial

There is growing interest in identifying factors protecting against aging-related decline. This cross-sectional study evaluated associations of self-reported resilience (ability to bounce back) with factors linked to aging-related decline among older adults with Type 2 diabetes (T2DM). Participants were 3,199 adults (72.2±6.2 years, 61% female, 61% white, BMI 34.2±8.2 kg/m2) enrolled in Look AHEAD (a multi-site RCT comparing weight loss to diabetes education among individuals with T2DM), who were followed observationally after the 10-year intervention was discontinued. The following items were assessed approximately 14.4yrs post-randomization: Brief Resilience Scale; overnight hospitalizations in past year; physical functioning measured objectively (gait speed, grip strength) and via self-report (Pepper Assessment Tool for Disability; Physical quality of life (QOL; SF-36)); a composite measure of phenotypic frailty based on having ≥3 of unintentional weight loss, low energy, slow gait, reduced grip strength, physical activity. Depressive symptoms (PHQ-9) and mental QOL (SF-36) were also measured. Logistic/linear regression was used to evaluate the association of these variables with resilience adjusted for age, race, and gender. Greater resilience was associated with lower BMI (p=.01), fewer hospitalizations (p=.02), better physical functioning (i.e., lower self-reported disability, better self-reported physical QOL, faster gait speed, greater grip strength and lower likelihood of meeting criteria for frailty; all p<.001), fewer depressive symptoms and greater mental QOL. Resilience is associated with better performance on indicators of overall functioning and risk for decline among older adults. Findings correspond with efforts to shift narrative on aging beyond ‘loss and decline’ to highlight opportunities to facilitate healthy aging.

The First Evaluation of a Geroscience Biomarker Index (TAME-BI) in a Trial of Caloric Restriction and Exercise

We leveraged the WF OAIC biorepository to measure a consensus-derived panel of blood-based biomarkers of aging and constructed a geroscience-guided biomarker index (TAME-BI), testing it for the first time in a clinical trial. We measured IL-6, TNF-α-receptor-I, growth differentiating factor-15, cystatin C, and N-terminal pro-B-type natriuretic peptide in a 20-week randomized trial of caloric restriction (CR), aerobic exercise (EX), CR+EX, or attention-control in 88 patients (67±5years) with heart failure with preserved ejection fraction (HFpEF). We calculated TAME-BI (analyte levels ranked, binned by quintile, and summed) and found a time×treatment interaction for improved TAME-BI with intervention (p≤0.05) and detected associations between change in TAME-BI and change in six-minute walk distance (r= -0.24), usual walk speed (r= -0.23), and left ventricular relative wall thickness (r= 0.31). In sum, CR+EX intervention improved TAME-BI and changes in TAME-BI were associated with changes in key functional measures in older HFpEF patients.

8-Year Changes in Frailty in Adults: Links to Cognitive and Physical Function and Mortality

Deficit accumulation frailty indices are being evaluated as clinical markers of biological aging. In this context, it is to be expected that changes over time in such indices should be predictive of downstream changes in cognition, physical function, and mortality. We derived a frailty index (FI) based on deficit accumulation in 38 functional, behavioral, and clinical characteristics and examined associations between 8-year changes in FI and subsequent standardized measures of cognitive and physical function and mortality collected over years 8-18. We drew data from the Look AHEAD clinical trial of a multidomain intensive lifestyle intervention (ILI) in 3841 adults, aged 45-76 years at baseline with overweight/obesity and type 2 diabetes mellitus. Greater FI increases tended to occur among individuals who were older, non-Hispanic White, heavier, and who had greater baseline multimorbidity. Greater increases in FI were associated with subsequently worse levels of composite cognitive function and 400m walk speed (all p<0.001). Additionally, compared with the lowest tertile of FI change, hazard ratios [95% confidence intervals] for 10-year mortality for the middle and highest tertiles of FI change were 1.28 [1.03.1.58] and 1.56 [1.24,1.96], respectively. While assignment to ILI was associated with smaller 8-year increases in FI, this did not translate overall to better cognitive functioning compared to the Diabetes Support and Education control condition across years 8-18. Increase in FI over 8 years predicts subsequent reduced function and greater mortality. However, whether interventions generally targeting FI reduce risks for downstream outcomes remains to be seen.

Air Quality Improvement Is Associated With Decreasing Depressive Symptoms in Older Women

Air pollution exposure is an environmental risk factor in brain aging and may also be associated with late-life depressive symptoms (DS). It is unknown if air quality (AQ) improvement is associated with reductions in DS in later life. Longitudinal data from 917 cognitively intact women with no prior history of depression (baseline age 66.4 ± 1.6 years old) participating in the Women’s Health Initiative Memory Study of Younger Women (WHIMSY; 2008-2016) were analyzed to examine whether AQ improvement over the 5-years prior to WHIMSY baseline was associated with trajectories of DS (measured by 15-item Geriatric Depression Scale). Annual PM2.5 (fine particulate matter of aerodynamic diameter <2.5) and NO2 were estimated at the participants’ residence using regionalized universal kriging models. Estimates were aggregated to the 3-year average at 5 years (remote) and immediately (recent) before WHIMSY baseline. Associations between AQ improvement (difference between remote to recent exposure) and trajectories of DS were estimated using linear mixed effect models, adjusting for sociodemographic, lifestyle, and clinical covariates. AQ improved prior to baseline (PM2.5: 1.62 ± 1.45 μg/m3 and NO2: 3.70 ± 2.81 ppb). Women residing in locations with greater improvement in NO2 (per IQR = 4.34 ppb) or PM2.5 (per IQR = 2.30 μg/m3) reported significant annual reductions in DS (βNO2=3.1%, p=.046; βPM25=1.6%, p=.046), similar to the effect of engaging in moderate to vigorous physical activity four times or more a week. These findings suggest that improving air quality may reduce depressive symptoms in older women.

Ambient Air Pollution and Increasing Depressive Symptoms in Older Women: The Mediating Role of The Prefrontal Cortex

Exposure to air pollution may accelerate brain aging and increase risk of late-life depressive symptoms (DS). Brain structures underlying these associations are unknown. Longitudinal data from 829 community-dwelling women without dementia (baseline age 81.6 ± 3.6 years old) who participated in both the Women’s Health Initiative Memory Study Magnetic Resonance Imaging study (WHIMS-MRI; 2005-06) and the WHIMS-Epidemiology of Cognitive Health Outcomes (2008-16) were analyzed to examine whether volumetric measures of brain structures mediated associations between long-term exposure to ambient air pollutants and annual increases in DS (as measured by annually assessed 15-item Geriatric Depression Scale). Annual PM2.5 (fine particulate matter of aerodynamic diameter <2.5) and NO2 were estimated at the participants’ residence using regionalized universal kriging models and aggregated to the 3-year average prior to the WHIMS-MRI. Structural equation models were constructed to estimate associations between exposure, structural brain variables, and trajectories of DS (standardized on baseline mean and SD). Living in locations with higher NO2 (standardized β = 0.023; 95% Confidence Interval (CI) = 0.004, 0.042) or PM2.5 (standardized β = 0.021; 95% CI = 0.004, 0.038) was associated with larger annual increases in DS (~60% larger annual increase in DS). Higher NO2, but not PM2.5, was associated with smaller prefrontal cortical volumes (standardized β = -0.431; 99% CI = -0.518; -0.344). Prefrontal cortical volume explained 30.4% of the total association between annual DS increase and NO2. These findings underscore the importance of the prefrontal cortex in associations between NO2 exposure and increasing DS in later-life.

Modifiable risk factors for homebound progression among those with and without dementia in a longitudinal survey of community-dwelling older adults

BACKGROUND

Being homebound is independently associated with increased mortality but the homebound population is heterogeneous. In order to improve precision medicine, we analyzed potentially modifiable factors that contribute to homebound progression (from independent to needing assistance, to homebound), stratified by dementia status.

METHODS

Using National Aging and Trends Survey (NHATS), a nationally-representative, longitudinal annual survey from 2011 to 2017 (n = 11,528), we categorized homebound progression if one transitioned from independent or needing assistance to homebound, including competing risks of institutionalization or death between 2011 and last year of data available for each unique respondent. Using proportional hazards regression, we calculated hazard ratios of potentially modifiable risk factors on homebound progression.

RESULTS

Depressive symptoms, mobility impairment, and pain increased risk of homebound progression regardless of dementia status. Social isolation increased risk of homebound progression only among those without dementia at baseline.

CONCLUSION

Future clinical care and research should focus on the treatment of depressive symptoms, mobility, and pain to potentially delay progression to homebound status.

Duration of SARS-CoV-2 sero-positivity in a large longitudinal sero-surveillance cohort: the COVID-19 Community Research Partnership

BACKGROUND

Estimating population prevalence and incidence of prior SARS-CoV-2 infection is essential to formulate public health recommendations concerning the COVID-19 pandemic. However, interpreting estimates based on sero-surveillance requires an understanding of the duration of elevated antibodies following SARS-CoV-2 infection, especially in the large number of people with pauci-symptomatic or asymptomatic disease.

METHODS

We examined > 30,000 serology assays for SARS-CoV-2 specific IgG and IgM assays acquired longitudinally in 11,468 adults between April and November 2020 in the COVID-19 Community Research Partnership.

RESULTS

Among participants with serologic evidence for infection but few or no symptoms or clinical disease, roughly 50% sero-reverted in 30 days of their initial positive test. Sero-reversion occurred more quickly for IgM than IgG and for antibodies targeting nucleocapsid protein compared with spike proteins, but was not associated with age, sex, race/ethnicity, or healthcare worker status.

CONCLUSIONS

The short duration of antibody response suggests that the true population prevalence of prior SARS-CoV-2 infection may be significantly higher than presumed based on earlier sero-surveillance studies. The impact of the large number of minimally symptomatic COVID-19 cases with only a brief antibody response on population immunity remains to be determined.

Predictors and Outcomes of Digital Weighing and Activity Tracking Lapses Among Young Adults During Weight Gain Prevention

OBJECTIVES

Self-monitoring is critical for weight management, but little is known about lapses in the use of digital self-monitoring. The objectives of this study were to examine whether lapses in self-weighing and wearing activity trackers are associated with weight and activity outcomes and to identify objective predictors of lapses.

METHODS

Participants (N = 160, BMI = 25.5 ± 3.3 kg/m2 , 33.1 ± 4.6 years old) were drawn from a sample of young adults in the Study of Novel Approaches to Prevention-Extension (SNAP-E) weight gain prevention trial. Analyses evaluated associations between weighing and tracker lapses and changes in weight and steps/day during the first 90 days after receiving a smart scale and activity tracker.

RESULTS

On average, participants self-weighed 49.6% of days and wore activity trackers 75.2% of days. Every 1-day increase in a weighing lapse was associated with a 0.06-lb gain. Lapses in tracker wear were not associated with changes in steps/day or weight between wear days. Weight gain predicted a higher likelihood of starting a lapse in weighing and tracker wear, whereas lower steps predicted a higher likelihood of a tracker lapse.

CONCLUSIONS

Weight gain may discourage adherence to self-monitoring. Future research could examine just-in-time supports to anticipate and reduce the frequency or length of self-monitoring lapses.

Associations Between Systolic Interarm Differences in Blood Pressure and Cardiovascular Disease Outcomes and Mortality: Individual Participant Data Meta-Analysis, Development and Validation of a Prognostic Algorithm: The INTERPRESS-IPD Collaboration

Systolic interarm differences in blood pressure have been associated with all-cause mortality and cardiovascular disease. We undertook individual participant data meta-analyses to (1) quantify independent associations of systolic interarm difference with mortality and cardiovascular events; (2) develop and validate prognostic models incorporating interarm difference, and (3) determine whether interarm difference remains associated with risk after adjustment for common cardiovascular risk scores. We searched for studies recording bilateral blood pressure and outcomes, established agreements with collaborating authors, and created a single international dataset: the Inter-arm Blood Pressure Difference - Individual Participant Data (INTERPRESS-IPD) Collaboration. Data were merged from 24 studies (53 827 participants). Systolic interarm difference was associated with all-cause and cardiovascular mortality: continuous hazard ratios 1.05 (95% CI, 1.02-1.08) and 1.06 (95% CI, 1.02-1.11), respectively, per 5 mm Hg systolic interarm difference. Hazard ratios for all-cause mortality increased with interarm difference magnitude from a ≥5 mm Hg threshold (hazard ratio, 1.07 [95% CI, 1.01-1.14]). Systolic interarm differences per 5 mm Hg were associated with cardiovascular events in people without preexisting disease, after adjustment for Atherosclerotic Cardiovascular Disease (hazard ratio, 1.04 [95% CI, 1.00-1.08]), Framingham (hazard ratio, 1.04 [95% CI, 1.01-1.08]), or QRISK cardiovascular disease risk algorithm version 2 (QRISK2) (hazard ratio, 1.12 [95% CI, 1.06-1.18]) cardiovascular risk scores. Our findings confirm that systolic interarm difference is associated with increased all-cause mortality, cardiovascular mortality, and cardiovascular events. Blood pressure should be measured in both arms during cardiovascular assessment. A systolic interarm difference of 10 mm Hg is proposed as the upper limit of normal. Registration: URL: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42015031227.

Decreasing Social Support Associated With Risk of MCI and Dementia Is Partially Mediated by Hippocampal Volume

Less supportive social relationships are linked to greater risk of cognitive decline in older adulthood. Few studies have examined if declines in social support predict risk of developing Mild Cognitive Impairment (MCI) or dementia and the neurobiological factors that may contribute to these associations. We analyzed data from 926 women in the Women’s Health Initiative Memory Study-MRI (WHIMS-MRI) to examine whether low social support at baseline and declines over an 8-year period predicted subsequent risk of developing MCI/dementia. Social support (Medical Outcomes Study Social Support Scale) was self-reported at the baseline (1994-1998) and closeout (2004-2005) of the parent WHI hormone therapy clinical trial. Annual neuropsychological assessments were conducted in WHIMS (through 2018) to ascertain incident MCI/dementia; structural brain scans were performed in 2005-2006. Structural equation models assessed the association between level and change in social support and risk of incident MCI/dementia and putative mediation of these associations by structural brain variables in women free of MCI/dementia as of the trial closeout, adjusting for demographic, lifestyle, depression, and biomedical covariates. Both low baseline social support (HR=1.24 per 1-SD; p<.05) and declines in support (HR=1.18 per 1-SD; p<.05) predicted incident MCI/dementia risk. Women reporting decreasing social support had significantly lower hippocampal volumes (β=-.070; p<.05) which accounted for ~14% of the total effect of declining support on MCI/dementia risk. We will highlight the implications of these findings for understanding how changes in social support may be linked to risk of MCI/dementia, including potential bidirectional associations of changes in social support and neurobiological health.

Language and Memory Reserve Mediate Protective Effects of Social Support on MCI or Dementia Risk in Older Women

More supportive social relationships are protective of cognitive decline in older adulthood. Although supportive social relationships are hypothesized to promote cognitive reserve (CR; the cognitive adaption to neuropathology), it is unknown whether CR mediates associations between social support and risk of developing mild cognitive impairment or dementia (MCI/dementia). Data from 815 women (aged 73-87 years) participating in the Women’s Health Initiative Memory Study-MRI cohort (WHIMS-MRI) and Women’s Health Initiative Study of Cognitive Aging (WHISCA) were analyzed to examine whether domain-specific estimates of CR mediate associations between social support and incident MCI/dementia risk. Women completed the Medical Outcomes Study Social Support Scale (MOS-SS) in 2004-2005, a structural MRI (sMRI) of the brain in 2005-06, and annual extensive neuropsychological examinations till 2018. CR (6-months after completing the MOS-SS) was estimated across different domains (e.g. verbal memory, figural memory, language, visuospatial, and attention) as the residual variance after regressing out effects of sMRI variables, sociodemographic factors, and measurement error. Structural equation models were constructed to examine whether CR mediate associations between social support and MCI/dementia risk while adjusting for covariates. Higher social support was associated with lower MCI/dementia risk (hazard ratio=0.85 per 1-SD;p=0.037), higher language reserve (standardized β=0.09;p=0.008) and verbal memory reserve (standardized β=0.08;p=0.025). Language and verbal memory reserve each significantly explained approximately 14% of the protective effect of social support. Findings illustrate the heterogeneous effect of social support on CR, highlighting the importance of language and verbal memory reserve as mediators of the association between social support and MCI/dementia risk.

Associations of Intensive Lifestyle Intervention in Type 2 Diabetes With Health Care Use, Spending, and Disability: An Ancillary Study of the Look AHEAD Study

IMPORTANCE

Intensive lifestyle interventions focused on diet and exercise can reduce weight and improve diabetes management. However, the long-term effects on health care use and spending are unclear, especially for public payers.

OBJECTIVE

To estimate the association of effective intensive lifestyle intervention for weight loss with long-term health care use and Medicare spending.

DESIGN, SETTING, AND PARTICIPANTS

This ancillary study used data from the Look AHEAD randomized clinical trial, which randomized participants with type 2 diabetes to an intensive lifestyle intervention or control group (ie, diabetes support and education), provided ongoing intervention from 2001 to 2012, and demonstrated improved diabetes management and reduced health care costs during the intervention. This study compared Medicare data between study arms from 2012 to 2015 to determine whether the intervention was associated with persistent reductions in health care spending.

EXPOSURE

Starting in 2001, Look AHEAD's intervention group participated in sessions with lifestyle counselors, dieticians, exercise specialists, and behavioral therapists with the goal of reducing weight 7% in the first year. Sessions occurred weekly in the first 6 months of the intervention and decreased over the intervention period. The controls participated in periodic group education sessions that occurred 3 times per year in the first year and decreased to 1 time per year later in the trial.

MAIN OUTCOMES AND MEASURES

Outcomes included total Medicare spending, Part D prescription drug costs, Part A and Part B Medicare spending, hospital admissions, emergency department visits, and disability-related Medicare eligibility.

RESULTS

This study matched Medicare administrative records for 2796 Look AHEAD study participants (54% of 5145 participants initially randomized and 86% of 3246 participants consenting to linkages). Linked intervention and control participants were of a similar age (mean [SD] age, 59.6 [5.4] years vs 59.6 [5.5] years at randomization) and sex (818 [58.1%] women vs 822 [59.3%] women). There was no statistically significant difference in total Medicare spending between groups (difference, -$133 [95% CI, -$1946 to $1681]; P = .89). In the intervention group, compared with the control group, there was statistically significantly higher Part B spending (difference, $513 [95% CI, $70 to $955]; P = .02) but lower prescription drug costs (difference, -$803 [95% CI, -$1522 to -$83]; P = .03).

CONCLUSIONS AND RELEVANCE

This ancillary study of a randomized clinical trial found that reductions in health care use and spending associated with an intensive lifestyle intervention for type 2 diabetes diminished as participants aged. Intensive lifestyle interventions may need to be sustained to reduce long-term health care spending.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03952728.

The Brain Chart of Aging: Machine-learning analytics reveals links between brain aging, white matter disease, amyloid burden, and cognition in the iSTAGING consortium of 10,216 harmonized MR scans

INTRODUCTION

Relationships between brain atrophy patterns of typical aging and Alzheimer's disease (AD), white matter disease, cognition, and AD neuropathology were investigated via machine learning in a large harmonized magnetic resonance imaging database (11 studies; 10,216 subjects).

METHODS

Three brain signatures were calculated: Brain-age, AD-like neurodegeneration, and white matter hyperintensities (WMHs). Brain Charts measured and displayed the relationships of these signatures to cognition and molecular biomarkers of AD.

RESULTS

WMHs were associated with advanced brain aging, AD-like atrophy, poorer cognition, and AD neuropathology in mild cognitive impairment (MCI)/AD and cognitively normal (CN) subjects. High WMH volume was associated with brain aging and cognitive decline occurring in an ≈10-year period in CN subjects. WMHs were associated with doubling the likelihood of amyloid beta (Aβ) positivity after age 65. Brain aging, AD-like atrophy, and WMHs were better predictors of cognition than chronological age in MCI/AD.

DISCUSSION

A Brain Chart quantifying brain-aging trajectories was established, enabling the systematic evaluation of individuals' brain-aging patterns relative to this large consortium.

World-Wide FINGERS Network: A global approach to risk reduction and prevention of dementia

Reducing the risk of dementia can halt the worldwide increase of affected people. The multifactorial and heterogeneous nature of late-onset dementia, including Alzheimer’s disease (AD), indicates a potential impact of multidomain lifestyle interventions on risk reduction. The positive results of the landmark multidomain Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) support such an approach. The World-Wide FINGERS (WW-FINGERS), launched in 2017 and including over 25 countries, is the first global network of multidomain lifestyle intervention trials for dementia risk reduction and prevention. WW-FINGERS aims to adapt, test, and optimize the FINGER model to reduce risk across the spectrum of cognitive decline—from at-risk asymptomatic states to early symptomatic stages—in different geographical, cultural, and economic settings. WW-FINGERS aims to harmonize and adapt multidomain interventions across various countries and settings, to facilitate data sharing and analysis across studies, and to promote international joint initiatives to identify globally implementable and effective preventive strategies.

In-season variations in head impact exposure among youth football players

Sport-related head impacts are of increasing concern as early evidence has demonstrated a relationship between subconcussive head impact exposure (HIE) experienced in contact sports, such as football, and changes in pre-to post-season imaging and cognitive measures. Cumulative HIE is often measured with a single number that amounts to the total exposure measured over the season and does not give any indication as to how the exposure was accumulated, nor how it varies during the season. Therefore, the objective of this study was to compare HIE during preseason, the first and second halves of the regular season, and playoffs in a sample of youth football players (n = 119, ages 9–13). Athletes were divided into 1 of 4 exposure groups based on quartiles computed from the distribution of risk-weighted cumulative exposure (RWECP). The mean 95th percentile linear and rotational accelerations and impacts per session in practices and games were compared across 4 exposure groups and time frames using mixed effects models. Within games, the sample mean 95th percentile linear and rotational accelerations ranged from 47.2 g and 2,331.3 rad/s2 during preseason to 52.1 g and 2,533.4 rad/s2 during the second half of regular season. Mean impacts per practice increased from preseason to the second half of regular season and declined into playoffs among all exposure groups; however, the variation between time frames was not greater than 2 impacts per practice. Time of season had a significant effect on mean 95th percentile linear and rotational acceleration in games (both p = 0.01) but not on practice accelerations or impacts/session. Mean 95th percentile accelerations for games showed significant interaction effects between exposure group and season segment (linear p = 0.05 and rotational p = 0.04). The results of this study improve our understanding of in-season variations in youth football HIE and may inform important opportunities for future interventions.

Particulate Air Pollutants, Brain Structure, and Neurocognitive Disorders in Older Women

Introduction

An increasing number of studies have suggested that exposure to particulate matter (PM) may represent a novel - and potentially amendable - environmental determinant of brain aging. The current longitudinal environmental epidemiological study addressed some important knowledge gaps in this emerging field, which combines the study of air pollution and neuroepidemiology. The investigators hypothesized that long-term PM exposure adversely influences global brain volume and brain regions (e.g., frontal lobe or hippocampus) that are critical to memory and complex cognitive processing or that are affected by neuropathological changes in dementia. It was also hypothesized that long-term PM exposure results in neurovascular damage and may increase the risk of mild cognitive impairment (MCI) and -dementia.

Methods

The investigators selected a well-characterized and geographically diverse population of older women (N = 7,479; average age = 71.0 ± 3.8 years at baseline) in the Women's Health Initiative (WHI) Memory Study (WHIMS) cohort (1996-2007), which included a subcohort (n = 1,403) enrolled in the WHIMS-Magnetic Resonance Imaging (WHIMS-MRI) study (2005-2006). Residence-specific yearly exposures to PM ≤ 2.5 µm in aerodynamic diameter (PM₂.₅) were estimated using a Bayesian maximum entropy spatiotemporal model of annual monitoring data (1999-2007) recorded in the U.S. Environmental Protection Agency (U.S. EPA) Air Quality System (AQS). Annual exposures (1996-2005) to diesel PM (DPM) were assigned to each residential census tract in a nationwide spatiotemporal mapping, based on a generalized additive model (GAM), to conduct census tract-specific temporal interpolation of DPM on-road estimates given by the U.S. EPA National-Scale Air Toxics Assessment Program. Multiple linear regression and multicovariate-adjusted Cox models were used to examine the associations, with statistical adjustment for multiple potential confounders.

Results

The investigators found that participants had smaller brain volumes, especially in the normal-appearing white matter (WM), if they lived in locations with higher levels of cumulative exposure (1999-2006) to PM ₂.₅ before the brain MRI scans were performed. The associations were not explained by sociodemographic factors, socioeconomic status, lifestyle factors, or other clinical characteristics. Analyses showed that the adverse effect on brain structure in the participants was driven primarily by the smaller WM volumes associated with cumulative PM₂.₅ exposures, which were present in the WM divisions of the association brain area (frontal, parietal, and temporal lobes) and corpus callosum. Increased DPM exposures were associated with larger ventricular volume, suggesting an overall atrophic effect on the aging brains. The participants tended to have smaller gray matter (GM) volumes if they lived in areas with the highest (i.e., fourth quartile) estimated cumulative DPM exposure in the 10 years before the brain MRI scans, compared with women in the first to third quartiles. This observed association was present in the total brain GM and in the association brain cortices. The associations with normal-appearing WM varied by DPM exposure range. For women with estimated cumulative exposure below that of the fourth quartile, increased DPM estimates were associated with smaller WM volumes. However, for women with increased cumulative DPM exposures estimates in the fourth quartile, WM volumes were larger. This pattern of association was found consistently in the association brain area; no measurable difference was found in the volume of the corpus callosum. These observed adverse effects of cumulative exposure to PM₂.₅ (linking exposure with smaller WM volumes) and to DPM (linking exposure in the highest quartile with smaller GM volumes) were not significantly modified by existing cardiovascular diseases, diabetes mellitus, obesity, or measured white blood cell (WBC) count. MRI measurements of the structural brain showed no differences in small-vessel ischemic diseases (SVID) in participants with varying levels of cumulative exposure to PM₂.₅ (1999-2006) or DPM (1996-2005), and no associations between PM exposures and SVID volumes were noted for total brain, association brain area, GM, or WM. For neurocognitive outcomes followed until 2007, the investigators found no evidence for increased risk of MCI/dementia associated with long-term PM exposures. Although exploratory secondary analyses showed different patterns of associations linking PM exposures separately with MCI and dementia, none of the -results was statistically significant. A similar lack of associations between PM exposures and MCI/dementia was found across the subgroups, with no strong indications for effect modification by cardiovascular diseases, diabetes mellitus, obesity, or WBC count.

Conclusions

The investigators concluded that their study findings support the hypothesized brain-structure neurotoxicity associated with PM exposures, a result that is in line with emerging neurotoxicological data. However, the investigators found no evidence of increased risk of MCI/dementia associated with long-term PM exposures.

To better test the neurovascular effect hypothesis in PM-associated neurotoxic effects on the aging brain, the investigators recommend that future studies pay greater attention to selecting optimal populations with repeated measurements of cerebrovascular damage and address the possibility of selection biases accordingly. To further investigate the long-term consequence of brain-structure neurotoxicity on pathological brain aging, future researchers should take the pathobiologically heterogeneous neurocognitive outcomes into account and design adequately powered prospective cohort studies with improved exposure estimation and valid outcome ascertainment to assess whether PM-associated neurotoxicity increases the risks of pathological brain aging, including MCI and dementia.

Impact of moderate physical activity on the longitudinal trajectory of a cardiac specific biomarker of injury: Results from a randomized pilot study of exercise intervention

BACKGROUND

In animal models, physical activity (PA) prevents cardiac myocyte cell death. Data for PA mitigating myocyte injury in humans are limited to observational studies. Using a randomized controlled trial design, we sought to determine if introducing moderate PA to previously sedentary older adults could reduce the trajectory of myocardial injury as measured by the high-sensitive cardiac troponin T (hs-cTnT) assay.

METHODS

Participants (age ≥70 years) were assigned to a 1-year intervention of moderate PA or health education control. High-sensitive cTnT was measured at baseline and 1 year in the 307 of 424 subjects who had available stored serum. Changes in hs-cTnT within 1 year were compared between PA and control groups, as were differences in the proportion of subjects with a significant rise in hs-cTnT (prospectively defined as a>50% increase at follow-up from baseline). Moderate to vigorous PA in kcal/wk was estimated with the CHAMPS questionnaire.

RESULTS

Baseline hs-cTnT levels and PA kcal/wk were similar for both groups. Activity kcal/wk increased in the PA, but not in the control group at 1 year. The median increase in hs-cTnT level from baseline was >3 times larger in the control (0.73 ng/L, interquartile range -0.64 to 2.59) vs the PA group (0.19ng/L, interquartile range -1.10 to 1.93) (P=.02). The proportion with a>50% increase in hs-cTnT was larger in the control group than in the PA group (9.3% vs 5.1%), but this difference was not statistically significant (P=.16).

CONCLUSIONS

Initiation of moderate PA in sedentary older adults may favorably modify subclinical myocardial injury.

Weight gain prevention in young adults: design of the study of novel approaches to weight gain prevention (SNAP) randomized controlled trial

BACKGROUND

Weight gain during young adulthood is common and is associated with increased cardiovascular risk. Preventing this weight gain from occurring may be critical to improving long-term health. Few studies have focused on weight gain prevention, and these studies have had limited success. SNAP (Study of Novel Approaches to Weight Gain Prevention) is an NIH-funded randomized clinical trial examining the efficacy of two novel self-regulation approaches to weight gain prevention in young adults compared to a minimal treatment control. The interventions focus on either small, consistent changes in eating and exercise behaviors, or larger, periodic changes to buffer against expected weight gains.

METHODS/DESIGN

SNAP targets recruitment of six hundred young adults (18-35 years) with a body mass index between 21.0-30.0 kg/m2, who will be randomly assigned with equal probability to: (1) minimal intervention control; (2) self-regulation with Small Changes; or (3) self-regulation with Large Changes. Both interventions receive 8 weekly face-to-face group sessions, followed by 2 monthly sessions, with two 4-week refresher courses in each of subsequent years. Participants are instructed to report weight via web at least monthly thereafter, and receive monthly email feedback. Participants in Small Changes are taught to make small daily changes (~100 calorie changes) in how much or what they eat and to accumulate 2000 additional steps per day. Participants in Large Changes are taught to create a weight loss buffer of 5-10 pounds once per year to protect against anticipated weight gains. Both groups are encouraged to self-weigh daily and taught a self-regulation color zone system that specifies action depending on weight gain prevention success. Individualized treatment contact is offered to participants who report weight gains. Participants are assessed at baseline, 4 months, and then annually. The primary outcome is weight gain over an average of 3 years of follow-up; secondary outcomes include diet and physical activity behaviors, psychosocial measures, and cardiovascular disease risk factors.

DISCUSSION

SNAP is unique in its focus on weight gain prevention in young adulthood. The trial will provide important information about whether either or both of these novel interventions are effective in preventing weight gain.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01183689.

Changes in cognitive function in a randomized trial of physical activity: results of the lifestyle interventions and independence for elders pilot study

BACKGROUND

Cognitive impairment is an important contributor to disability. Limited clinical trial evidence exists regarding the impact of physical exercise on cognitive function (CF). We report results of a pilot study to provide estimates of the relative impact of physical activity (PA) on 1-year changes in cognitive outcomes and to characterize relationships between changes in mobility disability and changes in cognition in older adults at increased risk for disability.

METHODS

Sedentary persons (102) at increased risk for disability (aged 70-89 years) were randomized to moderate-intensity PA or health education. Participants were administered the Digit Symbol Substitution Test (DSST), Rey Auditory Verbal Learning Test (RAVLT), modified Stroop test, and Modified Mini-Mental State Examination at baseline and 1 year.

RESULTS

Group differences were not significant but improvements in cognitive scores were associated with improvements in physical function. Specifically, the DSST significantly correlated with change in the Short Physical Performance Battery score (r = .38, p = .0002), in chair stand score (r = .26, p = .012), in balance score (r = .21, p = .046), and in 400-m gait speed (r = .15, p = .147). Change recall on the RAVLT and in the Stroop test was also positively correlated with changes in chair stand and balance, respectively.

CONCLUSIONS

These results provide further support for the benefits of exercise on CF in older adults. An adequately powered clinical trial of PA involving older adults at increased risk for cognitive disability is needed to expand the indications for prescribing exercise for prevention of decline in brain function.

The Lifestyle Interventions and Independence for Elders Pilot (LIFE-P): 2-year follow-up

BACKGROUND

It is well recognized that physical activity (PA) is important for older adults; yet, clinicians remain pessimistic about the ability of older adults with compromised function to adhere to long-term treatment and to maintain behavior change once treatment has been terminated.

METHODS

We examined the functional status of older adults at a field center (Wake Forest University) 2 years after completing 12 months of treatment in the Lifestyle Interventions and Independence for Elders Pilot study. At baseline, participants were randomized to either a PA or a successful aging (SA) control group. Outcome measures included an interview assessment of PA, the Short Physical Performance Battery (SPPB), and performance on a 400-m self-paced walking test.

RESULTS

Two years after the formal intervention had ended, participants who were originally in the PA group continued to engage in more minutes of moderate PA and tended to have better SPPB and walking speed than those in the SA group (effect sizes [ES]: SPPB = 0.40, walking speed = 0.37). Seven (12.7%) participants in the PA group failed the 400-m walk at the 36-month follow-up assessment, whereas this number was 11 (21.6%) in the SA group.

CONCLUSION

Older adults who have compromised physical function are able to sustain some of the benefits derived from participating in structured PA 2 years after supervised treatment has been terminated.

Why African-American women are at greater risk for pregnancy-related death

PURPOSE

Our study aim was to identify factors that may contribute to the racial disparity in pregnancy-related mortality.

METHODS

We examined differences in severity of disease, comorbidities, and receipt of care among 608 (304 African-American and 304 white) consecutive patients of non-Hispanic ethnicity with one of three pregnancy-related morbidities (pregnancy-related hypertension, puerperal infection, and hemorrhage) from hospitals selected at random from a statewide region.

RESULTS

African-American women had more severe hypertension, lower hemoglobin concentrations preceding hemorrhage, more antepartum hospital admissions, and a higher rate of obesity. The rate of surgical intervention for hemorrhage was lower among African-Americans, although the severity of hemorrhage did not differ between the two racial groups. More African-American women received eclampsia prophylaxis. After stratifying by severity of hypertension, we found that more African-Americans received antihypertensive therapy. The rate of enrollment for prenatal care was lower in the African-American group. Among women receiving prenatal care, African-American women enrolled significantly later in their pregnancies.

CONCLUSIONS

We have identified racial differences in severity of disease, comorbidities, and care status among women with pregnancy-related complications that would place African-Americans at disadvantage to survive pregnancy. These differences are potentially modifiable.

Effects of a Physical Activity Intervention on Measures of Physical Performance: Results of the Lifestyle Interventions and Independence for Elders Pilot (LIFE-P) Study

BACKGROUND

The Short Physical Performance Battery (SPPB), which includes walking, balance, and chair stands tests, independently predicts mobility disability and activities of daily living disability. To date, however, there is no definitive evidence from randomized controlled trials that SPPB scores can be improved. Our objective was to assess the effect of a comprehensive physical activity (PA) intervention on the SPPB and other physical performance measures.

METHODS

A total of 424 sedentary persons at risk for disability (ages 70-89 years) were randomized to a moderate-intensity PA intervention or a successful aging (SA) health education intervention and were followed for an average of 1.2 years.

RESULTS

The mean baseline SPPB score on a scale of 0-12, with 12 corresponding to highest performance, was 7.5. At 6 and 12 months, the PA versus SA group adjusted SPPB (+/- standard error) scores were 8.7 +/- 0.1 versus 8.0 +/- 0.1, and 8.5 +/- 0.1 versus 7.9 +/- 0.2, respectively (p < .001). The 400-meter walking speed was also significantly improved in the PA group. The PA group had a lower incidence of major mobility disability defined as incapacity to complete a 400-meter walk (hazard ratio = 0.71, 95% confidence interval = 0.44-1.20).

CONCLUSIONS

A structured PA intervention improved the SPPB score and other measures of physical performance. An intervention that improves the SPPB performance may also offer benefit on more distal health outcomes, such as mobility disability.

Bone mass response to discontinuation of long-term hormone replacement therapy: results from the Postmenopausal Estrogen/Progestin Interventions (PEPI) Safety Follow-up Study

BACKGROUND

Accelerated bone loss after stopping hormone therapy (HRT) is postulated to explain the lack of hip-fracture protection conferred by former HRT use. The abbreviation HRT (traditionally standing for "hormone replacement therapy") is used herein because of its wide recognition in the field. However, the pharmacological doses of estrogens and progestins used are not truly "replacement" in nature.

OBJECTIVES

To determine whether women lose bone mineral density (BMD) after stopping HRT; to assess whether their rate of loss is significantly greater than that of women not undergoing HRT; and to determine whether long-term HRT is associated with continued gains in BMD.

METHODS

A total of 495 women who were adherent to assigned treatment in the 3-year Postmenopausal Estrogen/Progestin Interventions randomized controlled trial (PEPI-RCT) and who had an additional BMD measurement during the PEPI Safety Follow-up Study were observed for an average of 3 years during and 4 years after the PEPI-RCT.

RESULTS

Women who stopped HRT after 1 year during the PEPI-RCT had annual rates of BMD change of -0.54% (hip) and -0.81% (spine) during the following 2 years. Those who underwent HRT for 3 years during the PEPI-RCT and then discontinued it had annual changes of -1.01% (hip) and -1.04% (spine). Rates of BMD loss among women who stopped HRT during or after the PEPI-RCT did not differ significantly from those of women who did not undergo HRT, who lost bone at a rate of approximately 1% yearly during the first year of the PEPI-RCT and about half that rate afterward. Women who continued HRT after the PEPI-RCT did not show additional BMD gains.

CONCLUSIONS

Our results do not support the hypothesis that bone is lost at an unusually fast rate after discontinuation of HRT, nor do they suggest that longer-term HRT leads to additional BMD gain beyond that evident after 3 years.

Multidisciplinary Women's health research: the national centers of excellence in women's health

Contemporary research increasingly needs to consider the value of a multidisciplinary approach in answering critical health questions. The current article outlines the need for multidisciplinary investigations specifically in reference to women's health, and addresses issues related to generating and sustaining interest in such an approach. In addition, the importance of resources and environment for facilitating multidisciplinary research and advocacy efforts for obtaining funding for this approach are discussed. Methodological issues pertinent to the operationalization of multidisciplinary research in women's health are also addressed, and lessons learned from the National Centers of Excellence in initiating multidisciplinary research in women's health are reviewed.