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Biomedical subjects

E M Simonsick

Publications and source records attributed to E M Simonsick.

At least 19 recordsLinked to original sources
PubMed2006

Endogenous sex hormone levels and risk of cognitive decline in an older biracial cohort.

BACKGROUND: Older women treated with conjugated estrogens may have an increased risk of dementia, but the effect of naturally occurring sex hormones on cognition is not certain. METHODS: Bioavailable estradiol and free testosterone level were obtained from 792 (55% men, 51% black) participants. We assessed cognition with the Modified Mini-Mental State Examination (3MS), Selective Reminding Test (SRT) and CLOX 1 at baseline and 2 years later. RESULTS: Women in the lowest estradiol tertile were more likely than those in the highest tertile to decline (> or = 1.0 S.D. of change) on 3MS (25% versus 9%, adjusted odds ratio [OR] = 3.9; 95% confidence interval [CI] = 1.6-9.6) and on SRT (28% versus 12%, adjusted OR [95% CI] = 3.3 [1.4-7.9]) but not CLOX 1. There was a borderline association between low estradiol tertile and decline on SRT in men (22% versus 14%, adjusted OR [95% CI] = 1.9 [0.9-3.9]). Testosterone level was not associated with decline in cognition in either men or women. Findings did not differ by race. CONCLUSIONS: Older women with low estradiol levels were more likely to experience decline in global cognitive function and verbal memory, and a similar trend was observed for verbal memory in men. This supports the hypothesis that endogenous sex hormones may play an important role in the maintenance of cognitive function in older adults.

Age Distribution↗
PubMed2005

Inflammatory markers are associated with ventilatory limitation and muscle dysfunction in obstructive lung disease in well functioning elderly subjects.

BACKGROUND: Inflammatory markers are increased in chronic obstructive pulmonary disease (COPD) and are hypothesised to play an important part in muscle dysfunction and exercise intolerance. METHODS: The Health Aging and Body Composition (Health ABC) study is a prospective observational cohort of well functioning individuals aged 70-79 years. A cross sectional analysis of the baseline data was conducted to examine the association between inflammatory markers and ventilatory limitation, muscle strength, and exercise capacity. These associations were compared in participants with and without obstructive lung disease (OLD). RESULTS: Of the 3075 participants enrolled in the Health ABC cohort, OLD was identified by spirometric testing in 268 participants and 2005 participants had normal spirometric results. Of the participants with OLD, 35%, 38%, and 27% participants had mild, moderate, and severe OLD, respectively. Participants with OLD had lower quadriceps strength (102.5 Nm v 108.9 Nm, p = 0.02), lower maximum inspiratory pressure (64.7 cm H(2)O v 74.2 cm H(2)O, p<0.0001), higher systemic interleukin (IL)-6 levels (2.6 pg/ml v 2.2 pg/ml, p<0.0001), and higher C-reactive protein (CRP) levels (3.5 mg/l v 2.5 mg/l, p<0.0001) than those with normal spirometry. In participants with OLD and those with normal spirometry, forced expiratory volume in 1 second (FEV(1)) was associated with IL-6 (adjusted regression coefficients (beta) = -5.3 (95% CI -9.1 to-1.5) and -3.1 (95% CI -4.3 to -1.9), respectively). IL-6 and TNF were also associated with quadriceps strength among participants with OLD and those with normal spirometry (beta = -6.4 (95% CI -12.8 to -0.03) and -3.4 (95% CI -5.4 to -1.3), respectively, for IL-6 and beta = -10.1 (95% CI -18.7 to -1.5) and -3.8 (95% CI -7 to -0.6), respectively, for TNF). IL-6, quadriceps strength, and maximum inspiratory pressures were independent predictors of reduced exercise capacity in both groups. CONCLUSIONS: In well functioning elderly subjects with or without OLD, IL-6 is associated with reduced FEV(1), quadriceps strength, and exercise capacity.

Aged↗
PubMed2004

Urinary incontinence in elderly women: findings from the Health, Aging, and Body Composition Study.

OBJECTIVE: To estimate the prevalence of and risk factors for stress and urge incontinence in a biracial sample of well-functioning older women. METHODS: We performed a cross-sectional analysis of 1,584 white and black women, aged 70-79 years, enrolled in a longitudinal cohort study. Participants were asked about incontinence, medical problems, and demographic and reproductive characteristics and underwent physical measurements. Using multivariable logistic regression, we compared women reporting at least weekly incontinence with those without incontinence. RESULTS: Overall, 21% reported incontinence at least weekly. Of these, 42% reported predominantly urge incontinence, and 40% reported stress. Nearly twice as many white women as black women reported weekly incontinence (27% versus 14%, P <.001). Factors associated with urge incontinence included white race (odds ratio [OR] 3.1, 95% confidence interval [CI] 2.0-4.8), diabetes treated with insulin (OR 3.5, 95% CI 1.6-7.9), depressive symptoms (OR 2.7, 95% CI 1.4-5.3), current oral estrogen use (OR 1.7, 95% CI 1.1-2.6), arthritis (OR 1.7, 95% CI 1.1-2.6), and decreased physical performance (OR 1.6 per point on 0-4 scale, 95% CI 1.1-2.3). Factors associated with stress incontinence were chronic obstructive pulmonary disease (OR 5.6, 95% CI 1.3-23.2), white race (OR 4.1, 95% CI 2.5-6.7), current oral estrogen use (OR 2.0, 95% CI 1.3-3.1), arthritis (OR 1.6, 95% CI 1.0-2.4), and high body mass index (OR 1.3 per 5 kg/m2, 95% CI 1.1-1.6). CONCLUSION: Urinary incontinence is highly prevalent, even in well-functioning older women, whites in particular. Many risk factors differ for stress and urge incontinence, suggesting differing etiologies and prevention strategies.

Age Factors↗
PubMed2003

Inflammatory markers and cognition in well-functioning African-American and white elders.

BACKGROUND: Several lines of evidence suggest that inflammatory mechanisms contribute to AD. OBJECTIVE: To examine whether several markers of inflammation are associated with cognitive decline in African-American and white well-functioning elders. METHODS: The authors studied 3,031 African-American and white men and women (mean age 74 years) enrolled in the Health, Aging, and Body Composition Study. Serum levels of interleukin-6 (IL-6) and C-reactive protein (CRP) and plasma levels of tumor necrosis factor-alpha (TNFalpha) were measured at baseline; cognition was assessed with the Modified Mini-Mental State Examination (3MS) at baseline and at follow-up. Cognitive decline was defined as a decline of >5 points. RESULTS: In age-adjusted analyses, participants in the highest tertile of IL-6 or CRP performed nearly 2 points lower (worse) on baseline and follow-up 3MS (p < 0.001 for all) and declined by almost 1 point over the >2 years (p = 0.01 for IL-6 and p = 0.04 for CRP) compared with those in the lowest tertile. After multivariate adjustment, 3MS scores among participants in the highest tertile of IL-6 and CRP were similar at baseline but remained significantly lower at follow-up (p < or = 0.05 for both). Those in the highest inflammatory marker tertile were also more likely to have cognitive decline compared with the lowest tertile for IL-6 (26 vs 20%; age-adjusted odds ratio [OR] = 1.34; 95% CI 1.06 to 1.69) and for CRP (24 vs 19%; OR = 1.41; 95% CI 1.10 to 1.79) but not for TNFalpha (23 vs 21%; OR = 1.12; 95% CI 0.88 to 1.43). There was no significant interaction between race and inflammatory marker or between nonsteroidal anti-inflammatory drug use and inflammatory marker on cognition. CONCLUSIONS: Serum markers of inflammation, especially IL-6 and CRP, are prospectively associated with cognitive decline in well-functioning elders. These findings support the hypothesis that inflammation contributes to cognitive decline in the elderly.

Black or African American↗
PubMed2001

Measuring fitness in healthy older adults: the Health ABC Long Distance Corridor Walk.

OBJECTIVES: The Health ABC Long Distance Corridor Walk (LDCW) was designed to extend the testing range of self-paced walking tests of fitness for older adults by including a warm-up and timing performance over 400 meters. This study compares performance on the LDCW and 6-minute walk to determine whether the LDCW encourages greater participant effort. DESIGN: Subjects were administered the LDCW and 6-minute walk during a single visit. Test order alternated between subjects, and a 15-minute rest was given between tests. SETTING: The Baltimore Veterans Affairs Medical Center. PARTICIPANTS: Twenty volunteers age 70 to 78. MEASUREMENTS: The LDCW, consisting of a 2-minute warm-up walk followed by a 400-meter walk and a 6-minute walk test were administered using a 20-meter long course in an unobstructed hallway. Heart rate (HR) and blood pressure (BP) were recorded at rest and before and after all walks. RESULTS: All 20 subjects walked a faster pace over 400 meters than for 6 minutes, in which the mean distance covered was 402 meters. From paired t-tests, walking speed was faster (mean difference = 0.23 m/sec; P < .001), and ending HR (mean difference = 7.6 bpm; P < .001) and systolic BP (mean difference = 8.3 mmHg; P = .024) were greater for the 400-meter walk than for the 6-minute walk. Results were independent of test order and subject fitness level. CONCLUSIONS: Providing a warm-up walk and using a target distance instead of time encouraged subjects to work closer to their maximum capacity. This low-cost alternative to treadmill testing can be used in research and clinical settings to assess fitness and help identify early functional decline in older adults.

Aged↗
PubMed2001

The impact of insomnia on cognitive functioning in older adults.

OBJECTIVES: To examine whether self-reported symptoms of insomnia independently increase risk of cognitive decline in older adults. DESIGN: Longitudinal cohort study. SETTING: The four sites of the Established Populations for Epidemiologic Studies of the Elderly. PARTICIPANTS: Six thousand four hundred forty-four community-dwelling men and women age 65 and older who had no more than one error on the Short Portable Mental Status Questionnaire (SPMSQ) at baseline and an in-person interview at the third annual follow-up (FU3). MEASUREMENTS: Insomnia was defined as report of trouble falling asleep or waking up too early most of the time. Cognitive decline was defined as two or more errors on the SPMSQ at FU3. Logistic regression was used to determine risk of cognitive decline associated with insomnia, controlling for demographic, behavioral, and health-related factors. Analyses were stratified by sex and depressed mood. RESULTS: Among nondepressed men, those reporting symptoms of insomnia at both baseline and FU3 had an adjusted odds ratio (OR) of 1.49 (95% CI = 1.03-2.14) for cognitive decline, relative to those with no insomnia at FU3. Men with insomnia at FU3 only were not at increased risk (OR = 1.16, 95% CI = 0.82-1.65). These relationships were not found in women. Men and women with depressive symptoms at FU3 were at increased risk for cognitive decline independent of insomnia. CONCLUSION: Chronic insomnia independently predicts incident cognitive decline in older men. More sensitive measures of cognitive performance may identify more subtle declines and may confirm whether insomnia is associated with cognitive decline in women.

Age Factors↗
PubMed2001

Measuring higher level physical function in well-functioning older adults: expanding familiar approaches in the Health ABC study.

BACKGROUND: To evaluate development and progression of functional limitation and retain comparability with established approaches, we raised the measurement ceiling of commonly used self-report and performance-based measures of function. This study evaluated the utility and concurrent validity of these expanded measures. METHODS: The study population consisted of 3075 black and white men and women aged 70 to 79 years, with no reported mobility limitations or disability, participating in the Health, Aging, and Body Composition, or Health ABC study. Self-report measures were expanded by ascertaining ease of performance and including more demanding levels of some tasks. A single foot stand and narrow walk supplemented an established performance battery. For walking endurance, we developed the Long Distance Corridor Walk (LDCW), which includes distance covered in 2 minutes and the time to walk 400 m. RESULTS: The expanded self-report items identified one half of the men and one third of the women as exceptionally well functioning and 10% to 13% of men and 21% to 36% of women with lower capacity. The supplemented and rescored performance battery discriminated function over the full range. The LDCW further differentiated walking capacity at the high end and also identified a subgroup with limitations. The self-report and performance measures were significantly, but weakly, correlated (0.13-0.35) and were independent predictors of walking endurance. CONCLUSIONS: Well-functioning persons in their 70s exhibit a broad range of functional capacity readily ascertained by expanded self-report and performance tests. Significant associations among these measures support their concurrent validity, but generally weak correlations indicate they tap different, but important, dimensions of physical function.

Aged↗
PubMed2001

Severity of upper and lower extremity functional limitation: scale development and validation with self-report and performance-based measures of physical function. WHAS Research Group. Women's Health and Aging Study.

OBJECTIVES: To better understand disablement and transitions from impairment to disability, discrete valid measures of functional limitation are needed. This study reports the development and criterion-related validity of scales that quantify severity of upper and lower extremity functional limitation. METHODS: Data are from 3,635 cognitively intact community-dwelling women aged 65 years and older and 1,002 moderately to severely disabled participants in the Women's Health and Aging Study. Scales assessing severity of upper and lower extremity functional limitation were constructed from commonly available questions on functional difficulty. Criterion-related validity was evaluated with self-report and performance-based measures. RESULTS: The upper and lower extremity scales range from 0 to 6 and 0 to 9, respectively. Scale scores were well distributed in the disabled group and discriminated limitations in the broader community. For both scales, rates of difficulty for all ADL and IADL increased (p<.001) with increasing severity score, and percent able and mean performance on respective upper and lower extremity tasks decreased (p<.01). DISCUSSION: These scales, constructed from commonly used self-report measures of function, provide discrete measures of upper and lower functional limitation. Because these scales are distinct from measures of disability and impairment, their use should facilitate increased understanding of the disablement process.

Activities of Daily Living↗
PubMed2001

Aortic stiffness is associated with visceral adiposity in older adults enrolled in the study of health, aging, and body composition.

The central arteries stiffen with age, causing hemodynamic alterations that have been associated with cardiovascular events. Changes in body fat with age may be related to aortic stiffening. The association between vascular stiffness and body fat was evaluated in 2488 older adults (mean age, 74 years; 52% female; 40% black) enrolled in the Study of Health, Aging, and Body Composition (Health ABC), a prospective study of changes in weight and body composition. Clinical sites were located in Pittsburgh, Pa, and Memphis, Tenn. Aortic pulse wave velocity was used as an indirect measure of aortic stiffness. A faster pulse wave velocity indicates a stiffer aorta. Body fat measures were evaluated with dual energy x-ray absorptiometry and computed tomography. Independent of age and blood pressure, pulse wave velocity was positively associated with weight, abdominal circumference, abdominal subcutaneous fat, abdominal visceral fat, thigh fat area, and total fat (P<0.001 for all). The strongest association was with abdominal visceral fat. Elevated pulse wave velocity was also positively associated with history of diabetes and higher levels of glucose, insulin, and hemoglobin A1c (P<0.001 for all). In multivariate analysis, independent positive associations with pulse wave velocity were found for age, systolic blood pressure, heart rate, abdominal visceral fat, smoking, hemoglobin A1c, and history of hypertension. The association between pulse wave velocity and abdominal visceral fat was consistent across tertiles of body weight. Among older adults, higher levels of visceral fat are associated with greater aortic stiffness as measured by pulse wave velocity.

Adipose Tissue↗
PubMed2000

Assessment of physical function and exercise tolerance in older adults: reproducibility and comparability of five measures.

This study examined the reproducibility and comparability of five measures of function and exercise tolerance. The test battery and questionnaire on function and physical activity were administered twice, 7-10 days apart to 38 men and 12 women aged 54-80 years at the Baltimore Veterans Affairs Medical Center. Tests included fast pace 4 and 20-meter walks, 6-minute and graded treadmill walks, and a seated step test. All tests demonstrated good reproducibility with Pearson and intraclass correlation coefficients ranging from 0.84 to 0.98, and percent differences on retest ranging from 4 to 11%. Although correlations between different tests were all significant (range 0.34-0.89), comparison of performance ranks and linear regression analyses indicated that the short fast walks and seated step test may not be suitable substitutes for treadmill or long self-paced corridor walks. Only 28% had the same quintile performance ranking on the step test as on the treadmill walk, and 36% had rankings 2 or more points apart. The fast 20m walk shows the most promise as a low-level alternative to the 6-minute walk; performances had a correlation of 0.73, 82% of ranks were within one point, and 20m speed explained 42% of the variance in distance covered. More development is needed for comprehensive assessment of exercise tolerance in older adults; the 6-minute walk did not adequately discriminate fitness level in persons who walk regularly, and the treadmill posed problems for those with walking difficulty.

Aged↗
PubMed2000

The protective effect of emotional vitality on adverse health outcomes in disabled older women.

OBJECTIVE: Although the adverse physical health consequences of negative emotions have been studied extensively, much less is known about the potential impact of positive emotions. This study examines whether emotional vitality protects against progression of disability and mortality in disabled older women. DESIGN: A community-based study, The Women's Health and Aging Study. PARTICIPANTS: A total of 1002 moderately to severely disabled women aged 65 years and older living in the community. MEASUREMENTS: Emotional vitality was defined as having a high sense of personal mastery, being happy, and having low depressive symptomatology and anxiety. The onset of new disability was determined by semiannual assessments of disability in performing activities of daily living (ADLs), walking across a room, walking 1/4 mile, and lifting/carrying 10 pounds. Mortality status was determined by proxy interviews and linkage with death certificates. Survival analyses with time to onset of specific disabilities (among those not disabled at baseline) and time to mortality were performed and adjusted for age, baseline level of difficulty, physical performance, and chronic conditions. RESULTS: Three hundred fifty-one of the 1002 older disabled women studied were emotionally vital. Among women without the specific disability at baseline, emotional vitality was associated with a significantly decreased risk for incident disability performing ADLs (RR = 0.81, 95% CI = 0.66-0.99), for incident disability walking one-quarter mile (RR = 0.73, 95% CI = 0.59-0.92), and for incident disability lifting/carrying 10 pounds (RR = 0.77, 95% CI = 0.63-0.95). Emotional vitality was also associated with a lower risk of dying (RR = 0.56, 95% CI = 0.39-0.80). These results were not simply caused by the absence of depression since protective health effects remained when emotionally vital women were compared with 334 women who were not emotionally vital and not depressed. CONCLUSIONS: Emotional vitality in older disabled women reduces the risk for subsequent new disability and mortality. Our findings suggest that positive emotions can protect older persons against adverse health outcomes.

Activities of Daily Living↗
PubMed2000

Factors that modify the association between knee pain and mobility limitation in older women: the Women's Health and Aging Study.

OBJECTIVE: To investigate the influence of pain severity, knee extensor muscle weakness, obesity, depression, and activity on the association between recent knee pain and limitation of usual and fast paced walking, and ability to rise from a chair. METHODS: A cross sectional analysis of 769 older women (mean age 77.8, range 65-101) with physical disability, but no severe cognitive impairment. Severity of knee pain in the past month was classified as none, moderate, or severe. Mobility was measured using timed performance tests. RESULTS: The prevalence of recent knee pain was 53% (408/769). One third of the women with pain reported it to be severe. In general, knee pain was only significantly associated with limited mobility if severe. Obesity, activity and, to a lesser extent, depression intensified the effects of pain. Knee extensor weakness did not. Obesity was a distinctive risk factor in that it substantially increased the risk of mobility limitation, but only in women with pain. In women who had severe pain, activity (walking more than three city blocks in the past week) increased the risk of walking disability more than inactivity. Depression had a minor, but statistically significant effect on walking ability, but not the ability to rise from a chair. CONCLUSION: In older women with recent knee pain, a high pain severity score, obesity, and activity are important factors that increase the risk of mobility limitation.

Aged↗
PubMed2000

Marked differences in antidepressant use by race in an elderly community sample: 1986-1996.

OBJECTIVE: Prescriptions of antidepressant medications have increased significantly over the past 15 years across the life cycle. One overall correlate of medication use in older adults is race, with African Americans using fewer medications than whites. Given the frequency of depressive symptoms among elderly populations, as well as the increased potential for adverse side effects from antidepressants, the relative contribution of race in the use of antidepressants is critical for determining well-designed studies. The authors analyzed data from a community-based cohort of elders followed for 10 years to determine the association of race to the use of antidepressants between 1986 and 1996, with control for known correlates of depression in late life. METHOD: Information on antidepressant use and demographic and health characteristics were obtained from a stratified, probability-based sample of 4,162 elders (equally distributed between African American and white community-dwelling subjects) in the Piedmont region of North Carolina during four in-person interviews spanning 10 years. Descriptive statistics were calculated. Logistic regression was used for the final models. RESULTS: A total of 4.6% of whites and 2.3% of African Americans used antidepressants in 1986. Approximately 14.3% of whites and 5.0% of African Americans used antidepressants in 1996. In controlled analyses, the prevalence odds ratio for antidepressant use in whites, compared to African Americans, was 1. 76 in 1986 and 3.77 in 1996. CONCLUSIONS: African American elders are much less likely to take antidepressants, and the difference in use increased over the 10 years of the survey.

Adult↗
PubMed1999

Incidence and remission of insomnia among elderly adults: an epidemiologic study of 6,800 persons over three years.

To determine incidence and remission rates of insomnia in older adults and associated risk factors. Three-year longitudinal study, 1982-198--East Boston, MA; New Haven, CT; Iowa and Washington counties, IA. Participants were 6,899 men and women aged 65 years and older. Self-reported difficulty falling asleep or early morning arousal (insomnia), along with physician diagnosis of heart disease, stroke, cancer, diabetes, or hip-fracture, self-report of physical disability, depressive symptomatology, perceived health status, and use of medications ascertained at both baseline and three-year follow-up. Nearly 15% of the 4,956 participants without symptoms of insomnia at baseline reported chronic difficulty falling asleep or early morning arousal at follow-up, suggesting an annual incidence rate of approximately 5%. Incident insomnia was associated with depressed mood, respiratory symptoms, fair to poor perceived health, and physical disability. In multivariate analyses, these risk factors explained the higher incidence of insomnia among those with medical conditions such as heart disease, stroke, and diabetes. Other factors associated with an increased risk of insomnia included use of prescribed sedatives, and widowhood. Only 7% of the incident cases of insomnia occurred in the absence of associated risk factors. Of the nearly 2,000 survivors with chronic insomnia at baseline, almost half no longer reported symptoms upon follow-up and were more likely to report improved self-perceived health compared to those who continued to report symptoms. Chronic disease, depressed mood, physical disability, poor perceived health, widowhood, and use of sedatives are associated with development and remission of insomnia symptoms. Because the vast majority of incident cases of insomnia were among persons with one or more of these risk factors, these data do not support a model of incident insomnia caused by the aging process per se.

Aged↗
PubMed1999

Severity of hand osteoarthritis and its association with upper extremity impairment in a population of disabled older women: the Women's Health and Aging Study.

Most severity indices of osteoarthritis (OA) include measures of physical function which render them unsuitable for assessing the impact of OA on disability. Data from 1002 moderate to severely disabled community-dwelling women > or = 65 years were used to develop hand OA severity indices which are independent of functional status. Baseline exams and strength tests were conducted by trained nurse examiners. Each distal and proximal interphalangeal joint, and first carpometacarpal joint (20 joints in all) was scored for the presence of a) bony enlargement or deformity, and b) pain on motion or tenderness on palpation. Severity indices were then created: Deformity index (DEF) = sum of joints with bony changes (0-20); Pain/Tenderness index (PT) = sum of joints with pain or tenderness (0-20); and Combined Deformity/Pain index = sum of DEF and PT (0-40). These indices were then validated against grip and pinch strength. All three indices showed a significant trend for weaker grip strength as severity index scores increased. When the 25th, 50th and 75th percentiles were used to divide each severity index into levels of involvement, a threshold effect was observed with significantly poorer grip strength performance above the 75th percentile for each index. Similar results were seen for pinch strength. In conclusion, these hand OA severity indices, based on examination findings alone, help distinguish disease status, and may provide a valuable research tool for investigating the role of hand OA in impairment and disability.

Aged↗
PubMed1999

Disability, physical activity, and muscle strength in older women: the Women's Health and Aging Study.

OBJECTIVE: To study associations of motor disability, physical activity, and muscle strength in older women, in particular to investigate whether model of spiraling decrease is expressed in the data. DESIGN: Cross-sectional analysis using data from the baseline measurements of The Women's Health and Aging Study (WHAS). SETTING: Participants' homes. PARTICIPANTS: A total of 1,002 disabled women aged 65 years and older living in the community. OUTCOME MEASURES: Motor disability was measured by the number of self-reported difficulties in grasping, lifting 101b, walking across a small room, walking 1/4 mile, climbing 10 steps, and doing heavy housework. Level of physical activity was determined from response to a series of questions on the frequency and amount of common activities and physical exercise. Hand grip and knee extension forces were measured using portable hand-held dynamometers. RESULTS: Disability and physical activity were inversely associated, with inactivity being most common among the most disabled women. Those with poorer strength reported more difficulties in motor activities. Greater strength was found among the physically more active. In stratified analyses, the positive association of physical activity on knee extension strength was consistent across disability levels. Multiple regression analysis showed that both physical activity and muscle strength were significant predictors for severity of disability. Structural equation model (LISREL) showed that muscle strength had a mediating role between physical activity and disability; disability was associated with physical inactivity, which correlated with lower muscle strength, which was associated with greater degree of disability. CONCLUSION: Even though causality cannot be confirmed in this cross-sectional analysis, our findings suggested a spiraling model of decline in which muscle strength has a significant role.

Activities of Daily Living↗
PubMed1999

Who walks? Factors associated with walking behavior in disabled older women with and without self-reported walking difficulty.

OBJECTIVES: To determine how severity of walking difficulty and sociodemographic, psychosocial, and health-related factors influence walking behavior in disabled older women. DESIGN: Cross-sectional analyses of baseline data from the Women's Health and Aging Study (WHAS). SETTING: An urban community encompassing 12 contiguous zip code areas in the eastern portion of Baltimore City and part of Baltimore County, Maryland. PARTICIPANTS: A total of 920 moderately to severely disabled community-resident women, aged 65 years and older, identified from an age-stratified random sample of Medicare beneficiaries. MEASUREMENTS: Walking behavior was defined as minutes walked for exercise and total blocks walked per week. Independent variables included self-reported walking difficulty, sociodemographic factors, psychological status (depression, mastery, anxiety, and cognition), and health-related factors (falls and fear of falling, fatigue, vision and balance problems, weight, smoking, and cane use). RESULTS: Walking at least 8 blocks per week was strongly negatively related to severity of walking difficulty. Independent of difficulty level, older age, black race, fatigue, obesity, and cane use were also negatively associated with walking; living alone and high mastery had a positive association with walking. CONCLUSIONS: Even among functionally limited women, sociocultural, psychological, and health-related factors were independently associated with walking behavior. Thus, programs aimed at improving walking ability need to address these factors in addition to walking difficulties to maximize participation and compliance.

Accidental Falls↗