Cognitive function, gait speed decline, and comorbidities: The health, aging and body composition study
ABSTRACT 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.
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.
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.
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.
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- "The reliability and validity of the gait protocol used herein has been reported in separate study (Verghese, Wang, Lipton, Holtzer, & Xue, 2007) and examined in relation to outcomes of interest such as falls (Verghese et al., 2002). The second class of studies correlated gait performance with standardized measures of attention and executive function that were assessed independently of gait (Atkinson et al., 2007; Ble et al., 2005; Holtzer et al., 2006; Inzitari et al., 2007). Establishing causality is more difficult using this method because attention demands are not experimentally manipulated. "
ABSTRACT: The current study critically assessed the relationship between cognitive functions and gait in nondemented older adults. Quantitative measures of gait (velocity, cadence, and a coefficient of variance in stride length) were assessed in single and dual-task conditions. Three cognitive factors captured the domains of Executive Attention, Verbal IQ, and Memory. Linear regressions showed that Executive Attention was related to velocity in both walking conditions. However, Memory and Verbal IQ were also related to velocity. Memory was related to Cadence in both walking conditions. Executive Attention was related to the coefficient of variance in stride length in both walking conditions. Linear mixed effects models showed that dual-task costs were largest in velocity followed by cadence and the coefficient of variance in stride length. The relationship between cognitive functions and gait depends, in part, on the analytic approach used, gait parameters assessed, and walking condition.Motor control 01/2012; 16(1):64-80. · 1.45 Impact Factor
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- "Briefly, the test battery is an extension of the lower-extremity performance tests used in the Epidemiologic Studies of the Elderly (EPESE) (Brach et al. 2004) and includes five repeated chair stands and gait speed assessment. Gait speed was assessed over a 20-m straight course (Atkinson et al. 2007). "
ABSTRACT: Previous studies have reported associations of polymorphisms in the IGF1 gene with phenotypes of body composition (BC). The purpose of this study was to identify phenotypes of BC and physical function that were associated with the IGF1 promoter polymorphism (rs35767, −C1245T). Subjects from the Health, Aging, and Body Composition Study, white males and females (n = 925/836) and black males and females (533/705) aged 70–79 years were genotyped for the polymorphism. Phenotypes of muscle size and function, bone mineral density, and BC were analyzed for associations with this polymorphism. To validate and compare these findings, a cohort of young (mean age = 24.6, SD = 5.9) white men and women (n = 173/296) with similar phenotypic measurements were genotyped. An association with BC was identified in elderly females when significant covariates (physical activity, age, smoking status, body mass index) were included. White women with C/C genotype had 3% more trunk fat and 2% more total fat than those with C/T (P < 0.05). Black women with C/C genotype had 3% less total lean mass and 3% less muscle mass than their T/T counterparts (P < 0.05). Associations were identified with muscle strength in white women (P < 0.01) that were in agreement with the C/C genotype having lower muscle function. Thus, in an elderly population but not a young population, a polymorphism in the IGF1 gene may be predictive of differences in body composition, primarily in black females. Electronic supplementary material The online version of this article (doi:10.1007/s00421-010-1500-0) contains supplementary material, which is available to authorized users.Arbeitsphysiologie 09/2010; 110(2):315-24. DOI:10.1007/s00421-010-1500-0 · 2.30 Impact Factor
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- "Alternatively, diminishing cognitive functioning may interfere with an individual's ability to accurately perceive and report his/her functional status . A number of studies have shown a relationship between cognitive and physical functioning        with both cross-sectional     and longitudinal    study designs, but the studies have been limited to various elderly populations. A recent review noted that in cross-sectional studies of the elderly that executive control function and general measures of cognition are particularly strong correlates of physical functioning . "
ABSTRACT: Studies have reported declines with age in cognitive or physical functioning, but rarely identify whether these are parallel or linked events in the same study. Furthermore, most research in this area has focused on persons in late life rather than midlife. The objective of the study was to determine (1) if cognitive functioning was related to physical functioning and whether this relationship persisted after adjustment for age, menopause status, metabolic status, depression and socioeconomic resources, and (2) if changes in physical functioning were associated with changes in cognitive functioning over a 4-year follow-up period. Data were from the Study of Women's Health Across the Nation (SWAN), a multi-site, longitudinal study of women aged 46-56 years at follow-up examination 4. Three follow-up examinations (study years 04, 06 and 08) included measures of physical functioning perception (MOS SF-36) and cognitive functioning [Symbol Digit Modality Test (SDMT), Digit Span Backward Test (DSBT), and East Boston Memory Test (EBMT)] (n = 2,405). Women with lower cognitive functioning scores also had lower perceived physical functioning scores. While adjustment for covariates attenuated the association between perceived physical functioning and both the SDMT and EBMT cognitive measures, these associations remained statistically significant. Additionally, the 4-year change in perceived physical functioning was significantly associated with the 4-year change in the EBMT. At midlife, there were associated declines in cognitive and perceived physical functioning scores, commencing at midlife in women.Gerontology 10/2009; 56(3):250-8. DOI:10.1159/000247132 · 2.68 Impact Factor