Body Mass Index and Diabetes Incidence Across the Adult Lifespan: The Baltimore Longitudinal Study of Aging.

Context: Body composition and glucose metabolism change with aging. Whether different levels of body-mass-index (BMI) are needed to define diabetes risk across the adult lifespan is unknown. Objective: This work aimed to investigate whether BMI similarly reflects relative fat mass (FM) and diabetes risk across age groups. Methods: Participants without diabetes from the Baltimore Longitudinal Study of Aging (973 men, 1073 women), stratified by age (<50, 50-59, 60-69, ≥70 years) and categorized by either World Health Organization (WHO)-defined BMI categories (for normal weight, overweight or obesity) or BMI quartiles. The primary exposure was BMI. The primary outcome was diabetes incidence. The relationship of BMI to dual-energy x-ray absorptiometry-derived FM was also investigated in older vs younger participants. Results: The median (range) follow-up time was 7.1 years (range, 0-29.0 years). Within WHO-defined BMI categories, different age groups demonstrated significantly different FM percentage, FM/lean mass, and waist circumference (P < .05). WHO-defined BMI categories for overweight and obesity were generally related to higher diabetes risk compared to normal weight in all ages except 50 to 59 years. When BMI was categorized by quartiles, diabetes incidence increased dramatically beginning in quartile 2 (23-25 kg/m2) in older groups. BMI cutoffs with equivalent diabetes incidence rate as BMI 25 kg/m2 and 30.0 kg/m2 in individuals younger than 50 years were 22.7 kg/m2 and 25.2 kg/m2 for ages 50 to 59 years; 22.8 kg/m2 and 25.0 kg/m2 for ages 60 to 69 years; and 23.2 kg/m2 and 25.8 kg/m2 for ages 70 years and older, respectively. Conclusion: WHO-defined BMI categories do not reflect similar diabetes risk across the lifespan. Diabetes incidence is greater at lower levels of BMI in older adults and may lead to underestimation of diabetes risk with aging, particularly among those traditionally classified as normal-weight individuals.

A plasma proteomic signature links secretome of senescent monocytes to aging- and obesity-related clinical outcomes in humans.

Cellular senescence increases with age and contributes to age-related declines and pathologies. We identified circulating biomarkers of senescence associated with diverse clinical traits in humans to facilitate future non-invasive assessment of individual senescence burden and efficacy testing of novel senotherapeutics. Using a novel nanoparticle-based proteomic workflow, we profiled the senescence-associated secretory phenotype (SASP) in monocytes and examined these proteins in plasma samples (N = 1060) from the Baltimore Longitudinal Study of Aging (BLSA). Machine learning models trained on monocyte SASP associated with several age-related phenotypes in a test cohort, including body fat composition, blood lipids, inflammation, and mobility-related traits, among others. Notably, a subset of SASP-based predictions, including a 'high impact' SASP panel that predicts age- and obesity-related clinical traits, were validated in InCHIANTI, an independent aging cohort. These results demonstrate the clinical relevance of the circulating SASP and identify relevant biomarkers of senescence that could inform future clinical studies.

The inverse association between cancer history and incident cognitive impairment: Addressing attrition bias.

INTRODUCTION: Cancer is inversely associated with cognitive impairment. Whether this is due to statistical handling of attrition (death and censoring) is unknown. METHODS: We quantified associations between cancer history and incident cognitive impairment among Health, Aging, and Body Composition Study participants without baseline cognitive impairment or stroke (n = 2604) using multiple competing-risks models and their corresponding estimands: cause-specific, subdistribution, and marginal hazards, plus composite-outcome (cognitive impairment or all-cause mortality) hazards. All-cause mortality was also modeled. RESULTS: After covariate adjustment (demographics, apolipoprotein E ε4, lifestyle, health conditions), cause-specific and marginal hazard ratios (HRs) were similar to each other (≈ 0.84; P values < 0.05). The subdistribution HR was 0.764 (95% confidence interval [CI] = 0.645-0.906), and composite-outcome Cox model HR was 1.149 (95% CI = 1.016-1.299). Cancer history was positively associated with all-cause mortality (HR = 1.813; 95% CI = 1.525-2.156). DISCUSSION: Cause-specific, subdistribution, and marginal hazards models produced inverse associations between cancer and cognitive impairment. Competing risk models answer slightly different questions, and estimand choice influenced findings here. HIGHLIGHTS: Cancer history is inversely associated with incident cognitive impairment. Findings were robust to handling of competing risks of death. All models also addressed possible informative censoring bias. Cancer history was associated with 16% lower hazard of cognitive impairment. Cancer history was associated with 81% higher all-cause mortality hazard.

Age and objectively measured sleep: investigating associations and interactions by sex and race in middle-aged and older adults.

Study Objectives: Few studies of middle-aged and older adults have examined the association between age and sleep using objective sleep measures. We examined these associations in adults aged ≥40 years using wrist actigraphy, and investigated whether these associations differed by sex and race. Methods: Participants were 468 cognitively normal adults aged ≥40 years enrolled in the Baltimore Longitudinal Study of Aging who completed wrist actigraphy. We used Generalized Least Squares Models to examine the associations of age with actigraphic sleep parameters, including total sleep time (TST), sleep efficiency, sleep onset latency, and wake after sleep onset (WASO). We conducted interaction and stratification analyses to test whether cross-sectional age-sleep associations were modified by sex and race. Results: In analyses adjusting for sex, body mass index, and individual medical conditions, older age was associated with longer TST from ages 40-70 that plateaued after age 70. Older age also was associated with lower sleep efficiency, longer sleep onset latency, and greater WASO. In men only, after age 70, older age was associated with shorter TST, lower sleep efficiency, longer onset latency, and greater WASO. However, we did not observe any significant interactions of race with age. Conclusions: Older age was associated with longer TST from ages 40 to 70 and with poorer sleep quality after age 40, and these relationships might vary by sex. Future studies with larger sample sizes are needed to investigate mechanisms that may account for sex differences in the observed age-sleep associations.

Associations of social engagement, and loneliness with the progression and reversal of frailty: longitudinal investigations of two prospective cohorts from the UK and the USA.

BACKGROUND: Social connections may impact the dynamic trajectory of frailty. METHODS: Using data from the British Regional Heart Study (BRHS) in the UK (n = 715), and the US Health, Aging and Body Composition (Health ABC) Study (n = 1256), we conducted multinominal regression analyses to examine the association of baseline and change in social engagement and loneliness with progression to pre-frailty and frailty, as well as their association with reversal to pre-frailty and robust status among older adults. RESULTS: A higher level of social engagement at baseline (BRHS: relative risk ratio (RRR) 0.69 [95%CI 0.55-0.85]; Health ABC: 0.56 [0.45-0.70]), as well as increase in social engagement (BRHS: 0.73, [0.59-0.90]; Health ABC: 0.51 [0.41-0.63]), were associated with a lower risk of developing frailty. In BRHS, a higher level of loneliness at baseline (1.42 [1.10-1.83]) and an increase in loneliness (1.50 [1.18-1.90]), increased the risk of developing frailty. For reversal of frailty, higher social engagement at baseline (Health ABC: 1.63 [1.08-2.47]) and an increase in social engagement (BRHS:1.74[1.18-2.50]; Health ABC: 1.79[1.17-.274]) were beneficial. CONCLUSION: Social connections maybe potentially important and modifiable factors in both preventing and reversing progression of frailty in older adults.

Olfactory Impairment and the Risk of Major Adverse Cardiovascular Outcomes in Older Adults.

BACKGROUND: Olfactory impairment is common in older adults and may be associated with adverse cardiovascular health; however, empirical evidence is sparse. We examined olfaction in relation to the risk of coronary heart disease (CHD), stroke, and congestive heart failure (CHF). METHODS AND RESULTS: This study included 2537 older adults (aged 75.6±2.8 years) from the Health ABC (Health, Aging, and Body Composition) study with olfaction assessed by the 12-item Brief Smell Identification Test in 1999 to 2000, defined as poor (score ≤8), moderate (9-10), or good (11-12). The outcomes were incident CHD, stroke, and CHF. During up to a 12-year follow-up, 353 incident CHD, 258 stroke, and 477 CHF events were identified. Olfaction was statistically significantly associated with incident CHF, but not with CHD or stroke. After adjusting for demographics, risk factors, and biomarkers of CHF, the cause-specific hazard ratio (HR) of CHF was 1.32 (95% CI, 1.05-1.66) for moderate and 1.28 (95% CI, 1.01-1.64) for poor olfaction. These associations were robust in preplanned subgroup analyses by age, sex, race, and prevalent CHD/stroke. While the subgroup results were not statistically significantly different, the association of olfaction with CHF appeared to be evident among participants who reported very good to excellent health (HR, 1.47 [95% CI, 1.01-2.14] for moderate; and 1.76 [95% CI, 1.20-2.58] for poor olfaction), but not among those with fair to poor self-reported health (HR, 1.04 [95% CI, 0.64-1.70] for moderate; and 0.92 [95% CI, 0.58-1.47] for poor olfaction). CONCLUSIONS: In community-dwelling older adults, a single olfaction test was associated with a long-term risk for incident CHF, particularly among those reporting very good to excellent health.

Associations of Relative Intensity of Physical Activity With Incident Cardiovascular Events and All-Cause Mortality.

BACKGROUND: The relative intensity of physical activity (PA) can be estimated as the percent of one's maximal effort required. METHODS: We compared associations of relative and absolute intensity PA with incident major cardiovascular disease (CVD) and all-cause mortality in 5 633 women from the Objective Physical Activity and Cardiovascular Health Study (mean age 78.5 ±â€…6.7). Absolute intensity was measured by accelerometry. Relative intensity was estimated by dividing accelerometer-estimated metabolic equivalents (METs) by maximal MET capacity. Both were aggregated into mean daily hours of light intensity PA (LPA) and moderate-to-vigorous PA (MVPA). Cox proportional hazard models estimated hazard ratios (HRs) for 1-hour higher amounts of PA on outcomes. RESULTS: During follow-up (median = 7.4 years), there were 748 incident CVD events and 1 312 deaths. Greater LPA and MVPA, on either scale, were associated with reduced risk of both outcomes. HRs for a 1-hour increment of absolute LPA were 0.88 (95% CI: 0.83-0.93) and 0.88 (95% CI: 0.84-0.92) for incident CVD and mortality, respectively. HRs for a 1-hour increment of absolute MPVA were 0.73 (95% CI: 0.61-0.87) and 0.55 (95% CI: 0.48-0.64) for the same outcomes. HRs for a 1-hour increment of relative LPA were 0.70 (95% CI: 0.59-0.84) and 0.78 (95% CI: 0.68-0.89) for incident CVD and mortality, respectively. HRs for a 1-hour increment of relative MPVA were 0.89 (95% CI: 0.83-0.96) and 0.82 (95% CI: 0.77-0.87) for the same outcomes. On the relative scale, LPA was more strongly, and inversely associated with both outcomes than relative MVPA. Absolute MVPA was more strongly inversely associated with the outcomes than relative MVPA. CONCLUSIONS: Findings support the continued shift in the PA intensity paradigm toward recommendation of more movement, regardless of intensity. Relative LPA--a modifiable, more easily achieved behavioral target, particularly among ambulatory older adults--was associated with reduced risk of incident major CVD and death.

Differences in Daily Physical Activity by Alzheimer's Risk Markers Among Older Adults.

BACKGROUND: Daily physical activity patterns differ by Alzheimer's disease (AD) status and might signal cognitive risk. It is critical to understand whether patterns are disrupted early in the AD pathological process. Yet, whether established AD risk markers (ß-amyloid [Aß] or apolipoprotein E-ε4 [APOE-ε4]) are associated with differences in objectively measured activity patterns among cognitively unimpaired older adults is unclear. METHODS: Wrist accelerometry, brain Aß (+/-), and APOE-ε4 genotype were collected in 106 (Aß) and 472 (APOE-ε4) participants (mean age 76 [standard deviation{SD}: 8.5) or 75 [SD: 9.2] years, 60% or 58% women) in the Baltimore Longitudinal Study of Aging. Adjusted linear and function-on-scalar regression models examined whether Aß or APOE-ε4 status was cross-sectionally associated with activity patterns (amount, variability, or fragmentation) overall and by time of day, respectively. Differences in activity patterns by combinations of Aß and APOE-ε4 status were descriptively examined (n = 105). RESULTS: There were no differences in any activity pattern by Aß or APOE-ε4 status overall. Aß+ was associated with lower total amount and lower within-day variability of physical activity overnight and early evening, and APOE-ε4 carriers had higher total amount of activity in the evening and lower within-day variability of activity in the morning. Diurnal curves of activity were blunted among those with Aß+ regardless of APOE-ε4 status, but only when including older adults with mild cognitive impairment/dementia. CONCLUSIONS: Aß+ in cognitively unimpaired older adults might manifest as lower amount and variability of daily physical activity, particularly during overnight/evening hours. Future research is needed to examine changes in activity patterns in larger samples and by other AD biomarkers.

Relationship between skeletal mitochondrial function and digital markers of free-living physical activity in older adults.

This study examined the association between in vivo skeletal mitochondrial function and digital free-living physical activity patterns-a measure that summarizes biological, phenotypic, functional, and environmental effects on mobility. Among 459 participants (mean age 68 years; 55% women) in the Baltimore Longitudinal Study of Aging, mitochondrial function was quantified as skeletal muscle oxidative capacity via post-exercise phosphocreatine recovery rate (τPCr) in the vastus lateralis muscle of the left thigh, using 31P magnetic resonance spectroscopy. Accelerometry was collected using a 7-day, 24-h wrist-worn protocol and summarized into activity amount, intensity, endurance, and accumulation patterning metrics. Linear regression, two-part linear and logistic (bout analyses), and linear mixed effects models (time-of-day analyses) were used to estimate associations between τPCr and each physical activity metric. Interactions by age, sex, and gait speed were tested. After covariate adjustment, higher τPCr (or poorer mitochondrial function) was associated with lower activity counts/day (ß = - 6593.7, SE = 2406.0; p = 0.006) and activity intensity (- 81.5 counts, SE = 12.9; p < 0.001). For activity intensity, the magnitude of association was greater for men and those with slower gait speed (interaction p < 0.02 for both). Conversely, τPCr was not associated with daily active minutes/day (p = 0.15), activity fragmentation (p = 0.13), or endurance at any bout length (p > 0.05 for all). Time-of-day analyses show participants with high τPCr were less active from 6:00 a.m. to 12:00 a.m. than those with low τPCr. Results indicate that poorer skeletal mitochondrial function is primarily associated with lower engagement in high intensity activities. Our findings help define the connection between laboratory-measured mitochondrial function and real-world physical activity behavior.

Cross-sectional associations between multisensory impairment and brain volumes in older adults: Baltimore Longitudinal Study of Aging.

Sensory impairment and brain atrophy is common among older adults, increasing the risk of dementia. Yet, the degree to which multiple co-occurring sensory impairments (MSI across vision, proprioception, vestibular function, olfactory, and hearing) are associated with brain morphometry remain unexplored. Data were from 208 cognitively unimpaired participants (mean age 72 ± 10 years; 59% women) enrolled in the Baltimore Longitudinal Study of Aging. Multiple linear regression models were used to estimate cross-sectional associations between MSI and regional brain imaging volumes. For each additional sensory impairment, there were associated lower orbitofrontal gyrus and entorhinal cortex volumes but higher caudate and putamen volumes. Participants with MSI had lower mean volumes in the superior frontal gyrus, orbitofrontal gyrus, superior parietal lobe, and precuneus compared to participants with < 2 impairments. While MSI was largely associated with lower brain volumes, our results suggest the possibility that MSI was associated with higher basal ganglia volumes. Longitudinal analyses are needed to evaluate the temporality and directionality of these associations.

Utricular Dysfunction and Hearing Impairment Affect Spatial Navigation in Community-Dwelling Healthy Adults: Analysis from the Baltimore Longitudinal Study of Aging.

INTRODUCTION: Spatial navigation, the ability to move through one's environment, is a complex skill utilized in everyday life. The effects of specific vestibular end-organ deficits and hearing impairments on spatial navigation have received little to no attention. We hypothesized that hearing impairment adversely affects spatial navigation and that bimodal impairments (vestibular and hearing) further impair navigation ability. METHODS: Data from 182 participants in the Baltimore Longitudinal Study of Aging who had interpretable results for the video head impulse test (vHIT), cervical vestibular evoked myogenic potentials (cVEMP) and ocular vestibular evoked myogenic potentials (oVEMP), audiometric testing, and the triangle completion test (TCT) were retrospectively analyzed. Multiple linear regression, controlling for age, sex, and cognition, was employed to identify predictors of TCT performance in terms of end-point error, angle deviation, and distance walked. RESULTS: oVEMP abnormalities were associated with larger end-point error (p = 0.008) and larger angle deviation (p = 0.002) but were not associated with distance walked (p = 0.392). Abnormalities on cVEMP testing and vHIT were not associated with distance walked (p = 0.835, p = 0.300), end-point error (p = 0.256, p = 0.808), or angle deviation (p = 0.192, p = 0.966). Compared with normal-hearing adults, hearing-impaired adults walked a shorter distance during the TCT (p = 0.049) but had a similar end-point error (p = 0.302) and angle deviation (p = 0.466). There was no interaction between vestibular and hearing function for predicting spatial navigation ability. CONCLUSION: In this cohort analysis, utricular dysfunction and hearing impairment were associated with poorer spatial navigation performance. We postulate that hearing impairment negatively affects one's ability to use real-time, intrinsic auditory cues and/or prior experience to guide navigation.

Development, validation, and transportability of several machine-learned, non-exercise-based VO2max prediction models for older adults.

BACKGROUND: There exist few maximal oxygen uptake (VO2max) non-exercise-based prediction equations, fewer using machine learning (ML), and none specifically for older adults. Since direct measurement of VO2max is infeasible in large epidemiologic cohort studies, we sought to develop, validate, compare, and assess the transportability of several ML VO2max prediction algorithms. METHODS: The Baltimore Longitudinal Study of Aging (BLSA) participants with valid VO2max tests were included (n = 1080). Least absolute shrinkage and selection operator, linear- and tree-boosted extreme gradient boosting, random forest, and support vector machine (SVM) algorithms were trained to predict VO2max values. We developed these algorithms for: (a) the overall BLSA, (b) by sex, (c) using all BLSA variables, and (d) variables common in aging cohorts. Finally, we quantified the associations between measured and predicted VO2max and mortality. RESULTS: The age was 69.0 ± 10.4 years (mean ± SD) and the measured VO2max was 21.6 ± 5.9 mL/kg/min. Least absolute shrinkage and selection operator, linear- and tree-boosted extreme gradient boosting, random forest, and support vector machine yielded root mean squared errors of 3.4 mL/kg/min, 3.6 mL/kg/min, 3.4 mL/kg/min, 3.6 mL/kg/min, and 3.5 mL/kg/min, respectively. Incremental quartiles of measured VO2max showed an inverse gradient in mortality risk. Predicted VO2max variables yielded similar effect estimates but were not robust to adjustment. CONCLUSION: Measured VO2max is a strong predictor of mortality. Using ML can improve the accuracy of prediction as compared to simpler approaches but estimates of association with mortality remain sensitive to adjustment. Future studies should seek to reproduce these results so that VO2max, an important vital sign, can be more broadly studied as a modifiable target for promoting functional resiliency and healthy aging.

Investigating balance-related gait patterns and their relationship with maximum torques generated by the hamstrings and quadriceps in older adults - Results from the Baltimore longitudinal study of aging.

BACKGROUND: Balance-related gait patterns in older adults can be objectively discerned through the examination of gait parameters, maximum leg torques, and their interconnections. OBJECTIVE: To investigate the correlation between leg muscle strength and balance during gait concerning functional performance in healthy older adults. METHODS: Participants included 117 adults aged 60-95 years were recruited from the Baltimore Longitudinal Study of Aging (BLSA). They underwent evaluations of gait, balance, and maximum isometric leg torque (for both hamstrings and quadriceps). Analyses examined the association between leg torque and functional performance among those with higher and lower balances. RESULTS: Individuals with lower balance (n = 43) were older, more prone to experiencing a fear of falling, and exhibited lower functional performance (gait speeds and Generalized Gait Stability Scores (GGSS), ps < 0.001) compared to their counterparts with higher balance (n = 74). At a usual walking pace, the GGSS showed a positive association with concentric Quadriceps Maximum Torque (QMT) in participants with lower balance (p = 0.013). Conversely, it displayed a positive association with eccentric QMT in those with higher balance (p = 0.014). At a fast walking pace, only individuals with higher balance demonstrated a positive muscle torque association with both gait speed and GGSS, encompassing concentric and eccentric actions in both the quadriceps and hamstrings (ps < 0.050). CONCLUSION: Evaluating muscle strength capacity in both concentric and eccentric phases during dynamic high-effort events, along with investigating their associations with gait performance, can be beneficial for identifying subtle gait deficits. This comprehensive approach may assist in the early detection of gait deterioration among healthy older adults, given the intricate muscle activations involved in lower body functional performance.

Longitudinal association between muscle and bone loss: Results of US and Japanese cohort studies.

BACKGROUND: Muscle and bone are physiologically interconnected, but joint changes of muscle and bone with aging, and whether the muscle-bone changes are different by sex and by country has been little studied. We examined longitudinal associations of bone mineral density (BMD) and muscle mass or muscle strength in community-dwelling 65 years or older in the United States and Japan. METHODS: The present analytic sample included 1129 women and men from the Baltimore Longitudinal Study of Aging (BLSA) (mean age, 74.5 ± 7.5 years; women, 49.8%) and 1998 women and men from the National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA) (mean age, 70.0 ± 4.5 years; women, 51.4%). Median follow-up was 4.6 (min-max, 0-15.4) years in the BLSA and 4.0 (min-max, 0-13.4) years in the NILS-LSA. We selected visits at which participants had BMD (whole body, pelvic, femoral neck, trochanter, and Ward's triangle BMDs) and muscle mass [appendicular lean mass, (ALM)] measured by DXA scan. In each bone site, we ran cohort-specific bivariate linear mixed-effects models adjusted for baseline age, sex, body height, body weight, fat mass, education year, and smoking status. Race was an additional adjustment in the BLSA. Additionally, we performed sex-specific analyses. RESULTS: In the BLSA, the rate of change in ALM positively correlated with the rate of change in the whole body (rho = 0.30, P < 0.0001) and pelvic BMD (rho = 0.24, P < 0.0001), but not in trochanter, femoral neck, or Ward's triangle BMD (P > 0.05). In the NILS-LSA, ALM positively correlated with the rate of change in all bone sites (rho ranged from 0.20 to 0.71, P < 0.01). In women, ALM positively correlated with the rate of change in all bone sites in both cohorts (in the NILS-LSA, rho ranged from 0.35 to 0.91, P < 0.01; in the BLSA, rho ranged from 0.26 to 0.56, P < 0.05) except for femoral neck BMD in the BLSA. In men, ALM positively correlated with pelvic, trochanter, and Ward's triangle BMD in the NILS-LSA (rho ranged from 0.45 to 0.68, P < 0.0001), and whole body and trochanter BMD in the BLSA (both, rho = 0.20, P < 0.05). CONCLUSIONS: Muscle loss co-occurred with bone loss in both cohorts, but the association in the NILS-LSA tended to be stronger than in the BLSA, and the association was higher in women than in men, implying that the association may differ by sex and country.

Musculoskeletal Pain Characteristics and Objectively Measured Physical Activity in Older Adults.

BACKGROUND: Pain is associated with reports of restricted physical activity (PA), yet the association between musculoskeletal pain characteristics and objectively measured PA quantities and patterns in late life is not well understood. METHODS: A total of 553 adults (mean age 75.8 ±â€…8.4 years, 54.4% women) in the Baltimore Longitudinal Study of Aging (BLSA) completed a health interview and subsequent 7-day wrist-worn ActiGraph assessment in the free-living environment between 2015 and 2020. Pain characteristics, including pain presence in 6x sites (ie, shoulders, hands/wrists, low back, hip, knees, and feet), pain laterality in each site, and pain distribution were assessed. PA metrics were summarized into total daily activity counts (TAC), activity fragmentation, active minutes/day, and diurnal patterns of activity. Linear regression models and mixed-effects models examined the association between pain characteristics and PA outcomes, adjusted for demographics and comorbidities. RESULTS: Unilateral knee pain was associated with 184 070 fewer TAC (p = .039) and 36.2 fewer active minutes/day (p = .032) compared to those without knee pain. Older adults with shoulder pain or hand/wrist pain had more active minutes compared to those without pain (p < .05 for all). For diurnal patterns of activity, participants with knee pain had fewer activity counts during the afternoon (12:00 pm to 5:59 pm). Analyses stratified by sex showed that these associations were only significant among women. CONCLUSIONS: Our study highlights the importance of assessing pain laterality in addition to pain presence and suggests that pain interferes with multiple aspects of daily activity. Longitudinal studies are needed to assess the temporality of these findings.

Evaluating a novel 24-hour rest/activity rhythm marker of preclinical ß-amyloid deposition.

STUDY OBJECTIVES: To compare sleep and 24-hour rest/activity rhythms (RARs) between cognitively normal older adults who are ß-amyloid-positive (Aß+) or Aß- and replicate a novel time-of-day-specific difference between these groups identified in a previous exploratory study. METHODS: We studied 82 cognitively normal participants from the Baltimore Longitudinal Study of Aging (aged 75.7 ±â€…8.5 years, 55% female, 76% white) with wrist actigraphy data and Aß+ versus Aß- status measured by [11C] Pittsburgh compound B positron emission tomography. RARs were calculated using epoch-level activity count data from actigraphy. We used novel, data-driven function-on-scalar regression analyses and standard RAR metrics to cross-sectionally compare RARs between 25 Aß+ and 57 Aß- participants. RESULTS: Compared to Aß- participants, Aß+ participants had higher mean activity from 1:00 p.m. to 3:30 p.m. when using less conservative pointwise confidence intervals (CIs) and from 1:30 p.m. to 2:30 p.m. using more conservative, simultaneous CIs. Furthermore, Aß+ participants had higher day-to-day variability in activity from 9:00 a.m. to 11:30 a.m. and lower variability from 1:30 p.m. to 4:00 p.m. and 7:30 p.m. to 10:30 p.m. according to pointwise CIs, and lower variability from 8:30 p.m. to 10:00 p.m. using simultaneous CIs. There were no Aß-related differences in standard sleep or RAR metrics. CONCLUSIONS: Findings suggest Aß+ older adults have higher, more stable day-to-day afternoon/evening activity than Aß- older adults, potentially reflecting circadian dysfunction. Studies are needed to replicate our findings and determine whether these or other time-of-day-specific RAR features have utility as markers of preclinical Aß deposition and if they predict clinical dementia and agitation in the afternoon/evening (i.e. "sundowning").

Sensory and motor deficits as contributors to early cognitive impairment.

INTRODUCTION: Age-related sensory and motor impairment are associated with risk of dementia. No study has examined the joint associations of multiple sensory and motor measures on prevalence of early cognitive impairment (ECI). METHODS: Six hundred fifty participants in the Baltimore Longitudinal Study of Aging completed sensory and motor function tests. The association between sensory and motor function and ECI was examined using structural equation modeling with three latent factors corresponding to multisensory, fine motor, and gross motor function. RESULTS: The multisensory, fine, and gross motor factors were all correlated (r = 0.74 to 0.81). The odds of ECI were lower for each additional unit improvement in the multisensory (32%), fine motor (30%), and gross motor factors (12%). DISCUSSION: The relationship between sensory and motor impairment and emerging cognitive impairment may guide future intervention studies aimed at preventing and/or treating ECI. HIGHLIGHTS: Sensorimotor function and early cognitive impairment (ECI) prevalence were assessed via structural equation modeling. The degree of fine and gross motor function is associated with indicators of ECI. The degree of multisensory impairment is also associated with indicators of ECI.

Sleep Duration Polygenic Risk and Phenotype: Associations with Biomarkers of Accelerated Aging in the Baltimore Longitudinal Study of Aging.

We sought to explore whether genetic risk for, and self-reported, short sleep are associated with biological aging and whether age and sex moderate these associations. Participants were a subset of individuals from the Baltimore Longitudinal Study of Aging who had complete data on self-reported sleep (n = 567) or genotype (n = 367). Outcomes included: Intrinsic Horvath age, Hannum age, PhenoAge, GrimAge, and DNAm-based estimates of plasminogen activator inhibitor-1 (PAI-1) and granulocyte count. Results demonstrated that polygenic risk for short sleep was positively associated with granulocyte count; compared to those reporting <6 hr sleep, those reporting >7 hr demonstrated faster PhenoAge and GrimAge acceleration and higher estimated PAI-1. Polygenic risk for short sleep and self-reported sleep duration interacted with age and sex in their associations with some of the outcomes. Findings highlight that polygenic risk for short sleep and self-reported long sleep is associated with variation in the epigenetic landscape and subsequently aging.

Associations of Lower Extremity Muscle Strength, Area, and Specific Force With Lower Urinary Tract Symptoms in Older Men: The Baltimore Longitudinal Study of Aging.

BACKGROUND: Lower urinary tract symptoms (LUTS) in older men are associated with an increased risk of mobility limitations. Lower extremity muscle quality may represent a novel shared mechanism of both LUTS and mobility limitations. METHODS: We evaluated associations of thigh skeletal muscle measures (strength, area, and specific force) with total LUTS severity (American Urologic Association Symptom Index; AUASI) and voiding and storage subscores among 352 men aged ≥60 years enrolled in the Baltimore Longitudinal Study of Aging. Thigh muscle strength (Nm) was defined as maximum concentric 30°/s knee extensor torque, area (cm2), and specific force (Nm/cm2) defined as strength/area. Associations with AUASI score were estimated using multivariable linear regression and linear mixed models. RESULTS: Mean thigh muscle strength at baseline was 139.7Nm. In cross-sectional multivariable models, each 39Nm increment in thigh muscle strength and 0.28Nm/cm2 increment in specific force was associated with -1.17 point (95% CI: -1.93 to -.41) and -0.95 point (95% CI: -1.63 to -0.27) lower AUASI score, respectively. Similar associations were observed for voiding and storage subscores, although somewhat attenuated. In longitudinal analyses, baseline muscle measures were not associated with annual change in AUASI, and current changes in muscle measures and AUASI were unrelated. CONCLUSIONS: Cross-sectionally, higher thigh muscle strength and specific force were associated with decreased LUTS severity in older men. However, we did not observe concurrent worsening LUTS severity with declining thigh muscle strength, area, or specific force in longitudinal analyses.