Comparison of targeted web-based advertising versus traditional methods for recruiting older adults into clinical trials.

Background: Recruiting older adults into clinical trials can be particularly challenging. Our objective was to determine if targeted web-based advertising is an effective recruitment strategy.

Methods: We compared the recruitment rates of traditional and targeted web-based methods for three representative clinical trials involving older adults.

The Physiologic Complexity of Prefrontal Oxygenation Dynamics Is Associated With Age and Executive Function: An Exploratory Study.

Background: The hemodynamics of prefrontal cortex (PFC) oxygenation are regulated by numerous processes operating over multiple temporal scales, producing complex patterns in its output fluctuations. Age may alter this multiscale regulation of PFC oxygenation, leading to diminished physiologic complexity of this important regulatory process. We aimed to characterize the effects of age on such complexity and its relationship to performance of an executive n-back task.

Six month lower-leg mechanical tactile sensory stimulation alters functional network connectivity associated with improved gait in older adults with peripheral neuropathy - A pilot study.

Foot sole somatosensory impairment associated with peripheral neuropathy (PN) is prevalent and a strong independent risk factor for gait disturbance and falls in older adults. Walkasins, a lower-limb sensory prosthesis, has been shown to improve gait and mobility in people with PN by providing afferent input related to foot sole pressure distributions lower-leg mechanical tactile stimulation. Given that gait and mobility are regulated by sensorimotor and cognitive brain networks, it is plausible improvements in gait and mobility from wearing the Walkasins may be associated with elicited neuroplastic changes in the brain.

Extended effects of a wearable sensory prosthesis on gait, balance function and falls after 26 weeks of use in persons with peripheral neuropathy and high fall risk-The walk2Wellness trial.

Background: We recently reported that individuals with impaired plantar sensation and high fall risk due to sensory peripheral neuropathy (PN) improved gait and balance function following 10 weeks of use of Walkasins, a wearable lower limb sensory prosthesis that provides directional specific mechanical tactile stimuli related to plantar pressure measurements during standing and walking (RxFunction Inc., Eden Prairie, MN, United States). Here, we report 26-week outcomes and compare pre- and in-study fall rates.

Multiscale Dynamics of Spontaneous Brain Activity Is Associated With Walking Speed in Older Adults.

Background: In older adults, compromised white matter tract integrity within the brain has been linked to impairments in mobility. We contend that poorer integrity disrupts mobility by altering the processing of sensorimotor and cognitive and attentional resources in neural networks. The richness of information processing in a given network can be quantified by calculating the complexity of resting-state functional MRI time series.

Motor-Cognitive Neural Network Communication Underlies Walking Speed in Community-Dwelling Older Adults.

While walking was once thought to be a highly automated process, it requires higher-level cognition with older age. Like other cognitive tasks, it also becomes further challenged with increased cognitive load (e.g.

Diminished Locomotor Control Is Associated With Reduced Neurovascular Coupling in Older Adults.

Background: Walking, especially while dual-tasking, requires functional activation of cognitive brain regions and their connected neural networks. This study examined the relationship between neurovascular coupling (NVC), as measured by the change in cerebral blood flow in response to performing a cognitive executive task, and dual-task walking performance.

Methods: Seventy community-dwelling older adults aged 84 ± 5 years within the Maintenance of Balance, Independent Living, Intellect and Zest in the Elderly (MOBILIZE) Boston Study were divided into LOW (n = 35) and HIGH (n = 35) NVC.

The pace and prognosis of peripheral sensory loss in advanced age: association with gait speed and falls.

Background: Peripheral sensory loss is considered one of many risk factors for gait impairments and falls in older adults, yet no prospective studies have examined changes in touch sensation in the foot over time and their relationship to mobility and falls. Therefore, we aimed to determine the prevalence and progression of peripheral sensory deficits in the feet of older adults, and whether sensory changes are associated with the slowing of gait and development of falls over 5 years.

Methods: Using baseline, and 18 and 60 month followup data from the Maintenance Of Balance, Independent Living, Intellect, and Zest in the Elderly (MOBILIZE) Study in Boston, MA, we determined changes in the ability to detect stimulation of the great toe with Semmes Weinstein monofilaments in 351 older adults.

Compromised prefrontal structure and function are associated with slower walking in older adults.

Our previous work demonstrates that reduced activation of the executive network is associated with slow walking speed in a cohort of older adults from the MOBILIZE Boston Study. However, the influence of underlying white matter integrity on the activation of this network and walking speed is unknown. Thus, we used diffusion-weighted imaging and fMRI during an n-back task to assess associations between executive network structure, function, and walking speed.

The Complexity of Standing Postural Sway Associates with Future Falls in Community-Dwelling Older Adults: The MOBILIZE Boston Study.

Standing postural control is complex, meaning that it is dependent upon numerous inputs interacting across multiple temporal-spatial scales. Diminished physiologic complexity of postural sway has been linked to reduced ability to adapt to stressors. We hypothesized that older adults with lower postural sway complexity would experience more falls in the future.

Executive Network Activation is Linked to Walking Speed in Older Adults: Functional MRI and TCD Ultrasound Evidence From the MOBILIZE Boston Study.

Background: Changes in cerebral blood flow velocity (CBF) in response to a cognitive task (task-related ΔCBF) have been shown by Transcranial Doppler ultrasonography (TCD) to be reduced in slow walkers. However, it is unknown whether reduced task-related ΔCBF is associated with reduced neural activity in specific brain regions, as measured by blood-oxygen-level dependent (BOLD) functional magnetic resonance imaging (fMRI).

Methods: We assessed the regional changes in neural activity associated with reduced middle cerebral artery (MCA) task-related ΔCBF to an executive task and slow walking speed in 67 community-dwelling older adults from the MOBILIZE Boston Study.

Functional implications of muscle co-contraction during gait in advanced age.

Older adults often exhibit high levels of lower extremity muscle co-contraction, which may be the cause or effect of age-related impairments in gait and associated falls. Normal gait requires intact executive function and thus can be slowed by challenging executive resources available to the neuromuscular system through the performance of a dual task. We therefore investigated associations between lower limb co-contraction and gait characteristics under normal and dual task conditions in healthy older adults (85.

Elevated Soluble Vascular Cell Adhesion Molecule-1 Is Associated With Cerebrovascular Resistance and Cognitive Function.

Background: Elevated plasma soluble vascular cell adhesion molecule-1 (sVCAM-1) is a presumed marker of endothelial dysfunction, both in the brain and systemic circulation. Impairments in memory and cognition have been associated with cardiovascular diseases, but little is known about their relationships to abnormal cerebral endothelial function.

Methods: We studied the cross-sectional association between sVCAM-1 and markers of cerebrovascular hemodynamics and cognitive function in 680 community-dwelling participants in the MOBILIZE Boston Study, aged 65 years and older.

Evaluation of an Automated Falls Detection Device in Nursing Home Residents.

Objectives: To determine the concordance between falls recorded using an investigational fall detection device and falls reported by nursing staff in a nursing home.

Design: Six-month prospective study.

Setting: Hebrew SeniorLife nursing home units in Boston, Massachusetts.

Circulating vascular cell adhesion molecule-1 is associated with cerebral blood flow dysregulation, mobility impairment, and falls in older adults.

Soluble vascular cell adhesion molecule-1 (sVCAM-1) is associated with hypertension, vascular inflammation, and systemic endothelial dysfunction. We evaluated whether elevated plasma sVCAM-1 is associated with impaired cerebrovascular function and mobility impairments in elderly people. We studied the cross-sectional relationships between plasma sVCAM-1 level, gait speed, and cerebrovascular hemodynamics, and its longitudinal relationship with falls in 680 community-dwelling participants aged ≥65 years in the Maintenance of Balance, Independent Living, Intellect, and Zest in the Elderly (MOBILIZE) Boston Study.

Reexamining the Effect of Antihypertensive Medications on Falls in Old Age.

Conflicting data on the relationship between antihypertensive medications and falls in elderly people may lead to inappropriate undertreatment of hypertension in an effort to prevent falls. We aimed to clarify the relationships between the chronic use of different classes of antihypertensive medications and different types of falls, to determine the effect of medication dose, and to assess whether the risk of falls is associated with differences in cerebral blood flow. We assessed demographics, clinical characteristics, and chronic antihypertensive medication use in 598 community-dwelling people with hypertension, aged 70 to 97 years, then followed them prospectively for self-reported falls using monthly calendar postcards and telephone interviews.

Patterns, predictors, and outcomes of falls trajectories in older adults: the MOBILIZE Boston Study with 5 years of follow-up.

Background: Falls may occur as unpredictable events or in patterns indicative of potentially modifiable risks and predictive of adverse outcomes. Knowing the patterns, risks, and outcomes of falls trajectories may help clinicians plan appropriate preventive measures. We hypothesized that clinically distinct trajectories of falls progression, baseline predictors and their coincident clinical outcomes could be identified.

Neurovascular coupling is impaired in slow walkers: the MOBILIZE Boston Study.

Objective: Neurovascular coupling may be involved in compensatory mechanisms responsible for preservation of gait speed in elderly people with cerebrovascular disease. Our study examines the association between neurovascular coupling in the middle cerebral artery and gait speed in elderly individuals with impaired cerebral vasoreactivity.

Methods: Twenty-two fast and 20 slow walkers in the lowest quartile of cerebral vasoreactivity were recruited from the MOBILIZE Boston Study.

Cerebrovascular hemodynamics, gait, and falls in an elderly population: MOBILIZE Boston Study.

Objective: To determine whether alterations in cerebral blood flow regulation are associated with slow gait speed and falls in community-dwelling elderly individuals.

Methods: The study sample consisted of 419 individuals from the MOBILIZE Boston Study (MBS) who had transcranial Doppler ultrasound measures of cerebral blood flow velocity. The MBS is a prospective cohort study of a unique set of risk factors for falls in seniors in the Boston area.

Enhanced vasoreactivity and its response to antihypertensive therapy in hypertensive elderly women.

Several previous studies have demonstrated sex differences in cardiovascular autonomic control in healthy young women, but little is known about the regulation of blood pressure in hypertensive elderly women, who have the greatest risk of adverse cardiovascular events. Therefore, we examined sex differences in physiological responses to upright tilt in 21 healthy (13 men and 8 women), 22 controlled hypertensive (10 men and 12 women), and 18 uncontrolled hypertensive (9 men and 9 women) elderly men and women. Of these, 19 normotensives, 18 controlled hypertensives, and 14 uncontrolled hypertensives completed 6 months of observation or pharmacological therapy for uncontrolled hypertension.

Antihypertensive therapy increases cerebral blood flow and carotid distensibility in hypertensive elderly subjects.

Many physicians are reluctant to lower blood pressure to recommended levels in elderly hypertensive patients because of concern about producing cerebral hypoperfusion. Because hypertension is associated with potentially reversible structural and functional alterations in the cerebral circulation that may improve with treatment, we investigated whether long-term pharmacological reduction of systolic blood pressure will improve, rather than worsen, cerebral blood flow and its regulation. Three groups of elderly subjects 65 years of age or older were studied prospectively: normotensive subjects (N=19), treated hypertensive subjects with systolic pressure <140 mm Hg (N=18), and uncontrolled hypertensive subjects with systolic pressure >160 mm Hg at entry into the study (N=14).

Effect of blood pressure on cognitive functions in elderly persons.

Background: Little is known about what specific cognitive functions are affected by elevated blood pressure (BP) and how orthostatic BP change is related to cognitive impairment. The aim of this study was to determine the effect of BP and its postural change on cognitive functions in otherwise healthy elders.

Methods: In 70 healthy persons (mean age, 72 +/- 4 years), supine systolic BP (SBP) was assessed 3 times using a sphygmomanometer, and the average values were obtained for the analysis.

Cerebral pressure-flow relations in hypertensive elderly humans: transfer gain in different frequency domains.

The dynamics of the cerebral vascular response to blood pressure changes in hypertensive humans is poorly understood. Because cerebral blood flow is dependent on adequate perfusion pressure, it is important to understand the effect of hypertension on the transfer of pressure to flow in the cerebrovascular system of elderly people. Therefore, we examined the effect of spontaneous and induced blood pressure changes on beat-to-beat and within-beat cerebral blood flow in three groups of elderly people: normotensive, controlled hypertensive, and uncontrolled hypertensive subjects.

Evaluation of ability of biochemical markers of bone turnover to predict a response to increased doses of HRT.

Antiresorptive therapy is usually given in a fixed dose, and we hypothesized that some patients receiving standard doses of hormone replacement therapy (HRT) might benefit from a higher dose, particularly if their bone turnover decreases after increasing the dose of HRT. Eighty-eight women who had been receiving standard-dose (0.625 mg/day) conjugated equine estrogens (CEE) for at least one year were randomized to take either standard-dose (0.