Showing papers by "Jeff D. Williamson published in 2007"

Cognitive Function, Gait Speed Decline, and Comorbidities: The Health, Aging and Body Composition Study

Abstract: BACKGROUND Emerging evidence indicates an association between cognitive function and physical performance in late life. This study examines the relationship between cognitive function and subsequent gait speed decline among high-functioning older adults. METHODS Measures of global cognitive function (Modified Mini Mental State Examination [3MS]) and executive control function (ECF) (a clock drawing task [CLOX 1] and the 15-item Executive Interview [EXIT 15]) were obtained in the Health, Aging, and Body Composition Study in 1999-2000. Gait-speed (meters/second) was assessed over 20 meters at usual pace. Using a mixed model, we assessed the relationship between baseline cognitive function and gait-speed change over 3 years. RESULTS Two thousand, three hundred forty-nine older adults (mean age 75.6 +/- 2.9 years) completed the assessments. After adjustment for baseline gait speed, a 1-standard-deviation (SD) lower performance on each cognitive test was associated with greater gait-speed decline over 3 years: 0.016 m/s for the 3MS (SD = 8.1), 0.009 m/s for CLOX 1 (SD = 2.4), and 0.012 m/s for EXIT 15 (SD = 4.1) (p <.0005 for all). After adjustment for comorbidities, the effect size was attenuated for 3MS and CLOX 1, and the association for EXIT 15 was no longer significant. Depression score was most strongly associated with the EXIT 15 effect reduction. CONCLUSION Global and executive cognitive functions predict declines in gait speed. The association of ECF with gait speed decline is attenuated by comorbid conditions, particularly depression. Elucidation of the mechanisms underlying these associations may point to new pathways for the treatment of physical decline associated with diminished cognitive function.

Associations of Gait Speed and Other Measures of Physical Function With Cognition in a Healthy Cohort of Elderly Persons

Abstract: BACKGROUND: Recent evidence suggests that physical decline and slower gait may be associated with early signs of dementia, but more information on healthy older adults is needed. METHODS: We determined associations between cognitive function, gait speed, and self-reported measures of physical function in 3035 healthy mobile participants of the Ginkgo Evaluation of Memory Study evaluated in 2000-2001. Gait speed was measured over a 15-foot course with participants walking at both their usual and rapid pace. Self-reported difficulties with Activities of Daily Living (ADLs) and other physical function tasks were also collected. Results of the Modified Mini-Mental State Examination (3MSE) determined cognitive function. RESULTS: The average age of the cohort was 78.6 years (standard deviation [SD] 3.3), and 53.9% of participants were men. Mean gait speed was 0.95 (SD 0.23) m/s at a usual pace and 1.35 (SD 0.58) m/s at a rapid pace. More than three-fourths of participants had 3MSE scores > 90. In multiple logistic models adjusted for demographics and comorbidities, risk of low cognition (defined as 3MSE score of 80-85) was almost twice as great for participants in the slowest quartile of the rapid-paced walking task than for the fastest walkers (odds ratio: 1.96, 95% confidence interval, 1.25-3.08). Associations between cognition and usual-paced walking were borderline, and no relationships were found with self-reported measures of physical function, including ADLs. CONCLUSIONS: In very healthy older adults, performance-based measures better predict early cognitive decline than do subjective measures, and tasks requiring greater functional reserve, such as fast-paced walking, appear to be the most sensitive in assessing these relationships. Language: en

The Action to Control Cardiovascular Risk in Diabetes Memory in Diabetes Study (ACCORD-MIND): rationale, design, and methods.

Abstract: Type 2 diabetes mellitus and cognitive impairment are 2 of the most common chronic conditions found in persons aged ≥60 years. Clinical studies have shown a greater prevalence of global cognitive impairment, incidence of cognitive decline, and incidence of Alzheimer disease in patients with type 2 diabetes. To date, there have been no randomized trials of the effects of long-term glycemic control on cognitive function and structural brain changes in patients with type 2 diabetes. The primary aim of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) Memory in Diabetes Study (ACCORD-MIND) is to test whether there is a difference in the rate of cognitive decline and structural brain change in patients with diabetes treated with standard-care guidelines compared with those treated with intensive-care guidelines. This comparison will be made in a subsample of 2,977 patients with diabetes participating in the ongoing ACCORD trial, a clinical trial sponsored by the National Heart, Lung, and Blood Institute (NHLBI) with support from the National Institute on Aging (NIA). Data from this ACCORD substudy on the possible beneficial or adverse effects of intensive treatment on cognitive function will be obtained from a 30-minute test battery, administered at baseline and 20-month and 40-month visits. In addition, full-brain magnetic resonance imaging will be performed on 630 participants at baseline and at 40 months to assess the relation between the ACCORD treatments and structural brain changes. The general aim of ACCORD-MIND is to determine whether the intensive treatment of diabetes, a major risk factor for Alzheimer disease and vascular dementia, can reduce the early decline in cognitive function that could later evolve into more cognitively disabling conditions. This report presents the design, rationale, and methods of the ACCORD-MIND substudy.

Treatment of minor depression in older adults: A pilot study comparing sertraline and exercise

Abstract: The purpose of this study was to conduct a pilot clinical trial to test the feasibility and efficacy of an exercise program and anti-depressant treatment compared with usual care in improving the emotional and physical functioning of older adults with minor depression. Participants were 37 older adults with minor depression who were randomized to exercise, sertraline, or usual care; 32 participants completed the 16-week study. Outcomes included measures of both emotional (clinician and self-report) and physical (observed and self-report) functioning. There were trends for the superiority of the exercise and sertraline conditions over usual care in improving SF-36 mental health scores and clinician-rated depression scores. Individuals in the exercise condition showed greater improvements in physical functioning than individuals in the usual care condition. Both sertraline and exercise show promise as treatments for late-life minor depression. However, exercise has the added benefit of improving physical functioning as well.

Recruitment Strategies in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) Trial

Abstract: The Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial is a randomized, multicenter clinical trial using a double 2 × 2 factorial design in 10,251 participants with type 2 diabetes mellitus at high risk for cardiovascular disease (CVD) events. ACCORD is testing 3 complementary medical treatment strategies that may reduce high rates of major CVD morbidity and mortality in patients with type 2 diabetes. The ACCORD vanguard phase, conducted at 59 clinics in the United States and Canada, recruited 1,174 participants in 20 weeks from January through June 1, 2001, with a recruitment efficiency (R-factor) of 0.65. The recruitment strategies used in this vanguard phase were almost exclusively chart and database review within clinical practices and institutions. Recruitment for the main trial began in February 2003, involved 77 clinics, and resulted in an additional 9,077 participants by October 29, 2005 (total, 10,251). The R-factor during main trial recruitment was 0.96. Although new and refined recruitment strategies were formulated from the vanguard experience, the most powerful determinant of improved recruitment efficiency was the immediate start of enrollment by most clinics at the beginning of the main trial. Recruitment in the main trial required only a brief extension of 3 months and facilitated the nearly complete capture of the expected number of person-years of observation. Described herein are vanguard and main trial recruitment activities, including strategy implementation, screening procedures, randomization results, problems encountered, and lessons learned.