To test the hypothesis that respiratory muscle strength is associated with the rate of change in mobility even after controlling for leg strength and physical activity.
Prospective study of 890 ...ambulatory older persons without dementia who underwent annual clinical evaluations to examine change in the rate of mobility over time.
In a linear mixed-effect model adjusted for age, sex, and education, mobility declined about 0.12 unit/year, and higher levels of respiratory muscle strength were associated with a slower rate of mobility decline (estimate 0.043, SE 0.012, p < 0.001). Respiratory muscle strength remained associated with the rate of change in mobility even after controlling for lower extremity strength (estimate 0.036, SE 0.012, p = 0.004). In a model that included terms for respiratory muscle strength, lower extremity strength and physical activity together, all three were independent predictors of mobility decline in older persons. These associations remained significant even after controlling for body composition, global cognition, the development of dementia, parkinsonian signs, possible pulmonary disease, smoking, joint pain and chronic diseases.
Respiratory muscle strength is associated with mobility decline in older persons independent of lower extremity strength and physical activity. Clinical interventions to improve respiratory muscle strength may decrease the burden of mobility impairment in the elderly.
Abstract
Introduction
Daytime napping is common in elderly adults and has been associated with cognitive impairment. Prior studies have assessed napping at one time point, making it difficult to ...examine the longitudinal progression of napping and its association with cognitive aging. We examined objectively measured daytime napping longitudinally across different stages of Alzheimer’s disease (AD): from no cognitive impairment (NCI), to mild cognitive impairment (MCI), and to Alzheimer’s dementia.
Methods
We studied 1,066 participants (female: 810; age: 81.0±7.3 SD) in the Rush Memory and Aging Project who have been followed for up to 13 years. Motor activities of up to 10 days were recorded annually and used to assess napping objectively. We defined daytime napping episodes as segments between 10AM and 7PM with continuous zero-activity for ≥10min but <1h (to avoid off-wrist periods). Segments that were <5min apart were merged. Cognitive and clinical evaluations were administered annually to render a clinical diagnostic classification of NCI, MCI, or Alzheimer’s dementia. To examine how napping duration and frequency change with the progression of AD, we performed linear mixed-effects models with 2 change points anchored at the diagnoses of MCI and AD while adjusted for age, sex, and education.
Results
At baseline, participants had 1.44±0.04 (mean±standard error) naps with an accumulated duration of 35.0±1.1 min per day. Napping duration increased by 5.2±0.3 min and frequency increased by 0.21±0.01 times every year (both p<0.0001). The rate of increase was more than doubled after MCI diagnosis with an annual increase of 11.4±0.7 min in duration and 0.40±0.02 times in frequency (both p<0.0001); these were doubled further after AD diagnosis with an annual change of 26.3±3.1 min in duration and 0.84±0.08 times in frequency (both p<0.0001).
Conclusion
Daytime napping duration and frequency increase with aging, and the increase was accelerated with AD progression.
Support
This work was supported by NIH grants RF1AG064312, RF1AG059867, R01AG017917, and R01AG56352.
Recent findings suggest that lower extremity motor dysfunction may be a feature of mild cognitive impairment (MCI), but little is known about the nature and significance of lower extremity motor ...dysfunction in MCI. The aim of this study was to examine the extent to which MCI is associated with impaired gait, balance, and strength and to examine the relation of lower extremity function to disability among persons with MCI in the Rush Memory and Aging Project, a clinical-pathologic study of common chronic conditions of old age. In a series of analyses adjusted for age, sex, and education, individuals with MCI exhibited more impaired gait and balance than individuals without cognitive impairment. Because vascular factors can contribute to lower extremity motor dysfunction, the authors repeated the initial analyses including terms for vascular risk factors and vascular disease, and the associations between MCI and lower extremity motor dysfunction persisted. Moreover, among those with MCI, impairments in gait and balance were associated with an increased likelihood of disability. These findings suggest that lower extremity motor dysfunction is common and contributes to disability in MCI, but lower extremity motor dysfunction in MCI does not appear to be explained by the vascular factors examined in this study.
Expanding the Toolkit for Studies of Aging Buchman, A S; Boyle, P A; Bennett, D A
The journal of prevention of Alzheimer's disease,
2017, Letnik:
4, Številka:
2
Journal Article
Abstract
Introduction
Human motor activity possesses fractal structures as characterized by similar fluctuation patterns across multiple time scales from seconds to hours. Such fractal regulation ...(FR) is robust in healthy young subjects and is degraded with aging. Evidence indicates a mechanistic link between fractal regulation and sleep/circadian control. Here, we tested whether FR degradation is associated with changes in brain structure and whether the FR brain correlates overlap with those for sleep disturbance in older adults.
Methods
We examined motor activity recordings of 338 older non-demented adults (age: 81.5 ± 7.1 SD) in the Rush Memory and Aging Project. All participants underwent magnetic resonance imaging and actigraphy assessment (continuously recorded motor activity for 10 days) in the same year. Gray matter volumes of 34 cortical and 10 subcortical regions were obtained. To assess FR, temporal correlations in activity fluctuations at time scales ~0.1–1.5h were examined. We explored the associations between FR and gray matter volumes using bivariate Pearson correlation with Bonferroni correction. We confirmed the associations using linear regression models adjusted for age, sex, and years of education.
Results
Fractal activity correlations were positively associated with gray matter volumes in 14 cortical regions and 2 subcortical regions (Bonferroni corrected p<0.05). After adjustment for age, sex, and education, the associations remained in 13 cortical and 1 subcortical regions, including 7 regions that are known to be linked to Alzheimer’s disease pathology: lateral orbitofrontal, supra marginal, isthmus cingulate, superior temporal, fusiform, and accumbens area.
Conclusion
Using the same database, we previously found that lower gray matter volumes in the lateral orbitofrontal cortex and inferior frontal gyrus pars orbitalis are associated with greater sleep fragmentation. Thus, FR degradation and sleep fragmentation involve certain common brain region in older adults (lateral orbitofrontal cortex), while FR degradation involves the decrease of gray matter volumes in more brain regions.
Support (If Any)
This work was supported by NIH grants R01AG048108, R00HL102241, P01AG009975, R01AG017917, and R01NS078009.
Abstract
Introduction
Excessive napping duration has been associated with cognitive decline. The effect of napping frequency is less understood, and little is known about the development of ...Alzheimer’s dementia associated with napping. We tested whether longer or more frequent naps in the elderly are linked to the development of incident Alzheimer’s dementia.
Methods
We studied 1,180 older adults (age: 81.0±7.3 SD) in the Rush Memory and Aging Project who have been followed for up to 14 years. Motor activities of up to 10 days were recorded at baseline to assess napping characteristics objectively. We defined daytime napping episodes as motor activity segments between 10AM and 7PM with continuous zero-activity for ≥10min but <1h (to avoid off-wrist periods). Segments that were <5min apart were merged. Alzheimer’s dementia diagnosis was determined using the criteria of the National Institute of Neurological and Communicative Disorders and Strone and the Alzheimer’s Disease and Related Disorders Association. Cox proportional hazards models were performed to examine the associations of daily napping duration and frequency with incident AD.
Results
Of 1,180 non-demented participants at baseline (including 264 with mild cognitive impairment), 277 developed Alzheimer’s dementia within 5.74±3.36 years. On average, participants napped for 38.3±1.0 (SE) min and1.56±0.04 (SE) times per day at baseline. After adjustment for age, sex, and education, every 30-min increase in daily napping duration was associated with a 20% increase in the risk of incident AD (95% confidence interval CI: 9%-31%; p=0.0002). One more nap per day was associated with a 19% increase in the risk of AD (95% CI: 8%-30%; p=0.0003). These associations remained after further adjustment for total sleep time.
Conclusion
Longer and more frequent daytime naps predict a higher risk of incident Alzheimer’s dementia. Future studies are needed to examine specific underlying mechanisms.
Support
This work was supported by NIH grants RF1AG064312, RF1AG059867, R01AG017917, and R01AG56352.
Abstract
Introduction
Healthy physiological systems exhibit fractal regulation, generating similar fluctuation patterns in physiological outputs across different time scales from seconds to hours. ...Evidence indicates a mechanistic link between fractal regulation and sleep/circadian control, both degraded with aging and in Alzheimer’s disease (AD). Recent studies showed that sleep and circadian disturbances may be early signs of AD. We tested whether degraded fractal regulation predicts AD risk.
Methods
We examined 1,097 older adults (844 females) in the Rush Memory and Aging Project who have undergone annual neuropsychological tests to assess their cognitive status for up to 11 years. These subjects were non-demented and aged between 65–100 years old at baseline. Motor activity was monitored on the wrist continuously for up to 10 days at baseline. Detrended fluctuation analysis was performed to obtain a metric α that quantifies fractal temporal correlations of motor activity at time scales ~0.1–1.5h. Cox proportional hazards models were performed to examine the associations of α with incident AD and incident mild cognitive impairment (MCI). Linear mixed effect models were used to examine the associations of α with cognitive decline.
Results
Of the 1,097 participants, 220 developed AD (4.6 ± 2.8 SD years after baseline). For 1-SD decrease in α (~0.06), the risk of AD increased by 1.31-fold (95% CI: 1.15–1.49, p<0.0001) after adjusting for age, sex, and education. The association remained after further accounting for physical activity, sleep fragmentation, or stability of daily activity rhythms. Consistently, with 1-SD decrease in α, the risk of MCI increased by 1.15-fold (95% CI: 1.02–1.29, p=0.018); and the annual cognitive decline was accelerated by 12.5% that was equivalent to the effect of being 2 years older.
Conclusion
Degraded fractal regulation predicts increased AD risk that is independent of other AD risk factors including age, physical activity, sleep, and stability of daily activity rhythms.
Support (If Any)
This work was supported by NIH grants R01AG048108, R00HL102241, P01AG009975, R01AG017917, and R01NS078009.
Previous work in this laboratory established that an onlay bone graft's survival is determined primarily by its relative cortical and cancellous composition rather than its embryologic origin. A ...volumetric analysis of external bone graft resorption, however, does not explain the internal microarchitectural changes that may be occurring as these grafts become incorporated. To expand the knowledge of bone graft dynamics beyond volumetric parameters, a better understanding of the internal processes of bone graft remodeling is needed. In this comparative study of cortical onlay bone graft microarchitecture, the authors propose to show that cortical onlay bone grafts undergo measurable internal microarchitectural changes as they become incorporated into the surrounding craniofacial skeleton. In addition, the authors propose to further demonstrate similarities between the internal microarchitecture of cortical onlay bone grafts of different embryologic origin over time. Twenty-five adult New Zealand White rabbits were used for this study. They were divided into two groups of eight animals and one group of nine. The groups were killed at 3, 8, and 16 weeks. Cortical membranous and endochondral bone grafts were placed subperiosteally onto each rabbit's cranium. In addition, five ungrafted cortical endochondral and membranous bone specimens were used as controls. Microcomputed tomography (MCT) scanning and histomorphometric analysis were performed on all of the specimens to obtain detailed information regarding the microarchitecture of the cortical bone grafts. The parameters of bone volume fraction, bone surface area to volume, mean trabecular number, and anisotropy were used to give quantitative information about a bone's micro-organization. The results showed that there is no statistically significant difference between the cortical endochondral and the cortical membranous bone grafts for bone volume fraction, bone surface to volume, mean trabecular number, and anisotropy measurements for all time points. There were, however, statistically significant differences when comparing the control and 3-week groups to the 16-week group for all parameters. The advanced MCT technology and histomorphometric techniques proved to be effective in providing a qualitative and quantitative ultrastructural comparison of cortical endochondral and membranous onlay bone grafts over time. In this study, a statistically significant change in the internal microarchitecture of cortical onlay bone grafts of different embryologic origins was seen as they were remodeled and resorbed at all time points. Specifically, the onlay cortical bone grafts developed a less dense, more trabecular, and less organized internal ultrastructure. In addition, no difference in the three-dimensional ultrastructure of cortical endochondral and membranous bone was found. These results challenge some of the currently accepted theories of bone-graft dynamics and may eventually lead to a change in the way clinicians approach bone-graft selection for craniofacial surgery.
We report the results of low back pain treatment using a combination of nucleotides, uridine (UTP), cytidine (CMP) and vitamin B
, vs a combination of vitamins B
, B
, and B
.
Randomized, ...double-blind, controlled trial, of a 60-day oral treatment: Group A (n=317) receiving nucleotides+B
and Group B (n=317) receiving B vitamins. The primary endpoint was the percentage of subjects in each group presenting adverse events (AEs). Secondary endpoints were visual analog scale (VAS) pain scores at Visit 2 (day 30) and Visit 3 (day 60) in relation to pretreatment values, Roland-Morris Questionnaire (RMQ) scores and finger-to-floor distance (FFD) (percentage of subjects per group presenting improvement ≥5 points and ≥3cm, respectively).
Seventy-five (24%) and 105 (33%) subjects (
=0.21) presented 133 and 241 AEs, with 3159% of subjects presenting ≥2 AEs (
=0.0019) in Group A and Group B, respectively. Twenty-four subjects in Group B were discontinued due to AEs, while no AE-related discontinuations occurred in Group A (
<0.0001). VAS score reduction after 30 and 60 days of treatment was statistically significant (
<0.0001) in both groups, with Group A showing greater reduction at Visit 2 (
<0.0001). RMQ score improvement ≥5 points occurred in 99% of subjects from each group, and FFD improvement ≥3 cm occurred in all subjects.
Treatment with nucleotides+B
was associated with a lower number of total AEs, fewer AEs per subject, and no AE-related treatment discontinuation. Pain intensity (VAS) reduction was superior at 30 days of treatment in the nucleotides+B
group and equivalent between groups at 60 days of treatment. Improvements in efficacy measures RMQ and FFD were observed in both groups at treatment days 30 and 60.
The recent development of information technologies has dramatically increased the tools available for facilitating motor rehabilitation. This review focuses on technologies which can be used to ...augment movement-related information both to patients as well as to their therapists. A brief outline of the motor system emphasizes the role of spinal motor neurons in the control of voluntary movement and rehabilitative efforts. Technologies which induce passive motion to stimulate spinal motor output as well as technologies that stimulate active voluntary movements are discussed. Finally, we review technologies and notational methods that can be used to quantify and assess the quality of movement for evaluating the efficacy of motor rehabilitation efforts. We conclude that stronger evidence is necessary to determine the applicability of the wide range of technologies now available to clinical rehabilitation efforts.
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