Poor Lower Extremity Performance Research Articles

Circulating Blood Markers and Functional Impairment in Peripheral Arterial Disease

To determine whether higher levels of inflammatory blood markers, D-dimer, and homocysteine were associated with greater impairment in lower extremity functioning in persons with peripheral arterial disease (PAD). Cross-sectional. Three Chicago-area medical centers. Four hundred twenty-three persons with PAD (ankle-brachial index (ABI) <0.90). Lower extremity performance was assessed using the 6-minute walk and with usual- and fast-paced 4-m walking speed. Blood markers were D-dimer, C-reactive protein (CRP), interleukin-6 (IL-6), soluble vascular cellular adhesion molecule-1 (sVCAM-1), soluble intracellular adhesion molecule-1 (sICAM-1), and homocysteine. Calf muscle area was measured using computed tomography. Adjusting for confounders, higher levels of D-dimer (P<.001), IL-6 (P<.001), sVCAM-1 (P=.006), CRP (P=.01), homocysteine (P=.004), and sICAM-1 (P=.046) were associated with poorer 6-minute walk performance. Higher levels of D-dimer (P<.001), IL-6 (P=.003), sVCAM-1 (P=.001), and homocysteine (P=.005) were associated with slower usual-paced 4-m walking speed. Higher levels of D-dimer, sVCAM-1, sICAM-1, IL-6, and homocysteine were associated with slower fast-paced walking speed. Results were attenuated after additional adjustment for calf muscle area. Higher levels of inflammation and D-dimer were associated with poorer lower extremity performance in participants with PAD, independent of confounders including ABI.

Risk factors for falls in older disabled women with diabetes: the women's health and aging study.

The aim of this study was to determine whether older disabled women with diabetes have an increased risk of falls compared to women without diabetes and to identify fall risk factors among this high-risk subgroup of patients. Data are from the Women's Health and Aging Study I (n = 1002, age > or = 65 years), a prospective, population-based cohort study of the one third most disabled women in the Baltimore (MD) urban community-dwelling population. Participants were followed semiannually for 3 years. Falls were ascertained at each interview. Diabetes was ascertained by means of a standardized algorithm using multiple sources of information. Baseline prevalence of diabetes was 15.5%. Of the 878 women who participated in at least one follow-up visit and were able to walk at baseline, 64.9% fell at least once during the study and 29.6% experienced two or more falls during a follow-up interval. After adjustment for traditional risk factors, women with diabetes had a higher probability of any fall (odds ratio [OR] 1.38; 95% confidence interval [CI], 1.04-1.81) and of falling two or more times during a follow-up interval (OR 1.69; CI, 1.18-2.43), compared with women without diabetes. Among diabetic women, presence of widespread musculoskeletal pain (OR 5.58; CI, 1.89-16.5), insulin therapy (OR 2.02; CI, 1.10-3.71), overweight (OR 3.50; CI, 1.21-10.1), and poor lower-extremity performance (OR 7.76; CI, 1.03-58.8) were independently associated with increased likelihood of recurrent falls, after adjusting for major risk factors. There were synergistic effects of diabetes and lower-extremity pain and also diabetes and body mass index levels on the risk of falling (p for interactions <.05). Even among disabled older women diabetes is associated with an increased risk of falling, independent of established fall risk factors. In this specific group of older women, pain, high body mass index, and poor lower-extremity performance are powerful predictors of falling.

Screening for poor performance of lower extremity in primary care: the Camucia Project

Individuals with poor lower extremity performance are prime candidates for disability prevention. The Camucia Project is a collaborative study between geriatricians and primary care physicians (PCPs) testing the hypothesis that PCPs can use a simple performance-based test to identify older persons with poor lower extremity function, without excessive interference with their clinical routine. We also hypothesized that the number needed to screen (NNTS) a positive case would be lower in physicians' clinics than in the general population. 23 PCPs administered the short physical performance battery (SPPB) to 360 consecutive, non-disabled and non-demented, 70- to 79-year-old outpatients. PCPs were asked to: 1) evaluate the feasibility and usefulness of administering the SPPB; 2) ascertain selected diseases according to predefined criteria; 3) identify causes of poor lower extremity function in patients with a SPPB score < or =9. NNTS from this study were compared with those estimated in non-disabled and non-demented, 70- to 79-year-old persons randomly selected from the InCHIANTI study population. The majority of PCPs (20/23) reported that using the SPPB to evaluate older patients was feasible and useful. The NNTS in the outpatient clinics was lower than in the InCHIANTI participants (1.6 vs 4.3). Poor lower extremity performance was attributed to musculo-skeletal diseases in 75%, to more than one cause in 55% (128/234), and to no specific cause in 16.2% (37/234) of the participants with SPPB < or =9. Screening of older persons with poor lower extremity perfomance by PCPs is feasible and efficient.

Leg muscle mass and composition in relation to lower extremity performance in men and women aged 70 to 79: the health, aging and body composition study.

The loss of muscle mass with aging, or sarcopenia, is hypothesized to be associated with the deterioration of physical function. Our aim was to determine whether low leg muscle mass and greater fat infiltration in the muscle were associated with poor lower extremity performance (LEP). A cross-sectional study, using baseline data of the Health, Aging and Body Composition study (1997/98). Medicare beneficiaries residing in ZIP codes from the metropolitan areas surrounding Pittsburgh, Pennsylvania, and Memphis, Tennessee. Three thousand seventy-five well-functioning black and white men and women aged 70 to 79. Two timed tests (6-meter walk and repeated chair stands) were used to measure LEP. Muscle cross-sectional area and muscle tissue attenuation (indicative of fat infiltration) were obtained from computed tomography scans at the midthigh. Body fat was assessed using dual-energy x-ray absorptiometry. Blacks had greater muscle mass and poorer LEP than whites. Black women had greater fat infiltration into the muscle than white women. After adjustment for clinic site, age, height, and total body fat, smaller muscle area was associated with poorer LEP in all four race-gender groups. (Regression coefficients, expressed per standard deviation (+/-55 cm2) of muscle area, were 0.658 and 0.519 in white and black men and 0.547 and 0.435 in white and black women, respectively, P <.01.) In addition, reduced muscle attenuation-indicative of greater fat infiltration into the muscle-was associated with poorer LEP, independent of total body fat and muscle area. (Regression coefficients per standard deviation (= 7 Hounsfield Units) of muscle attenuation were 0.292 and 0.224 in white and black men, and 0.193 and 0.159 in white and black women, respectively, P <.05). The most important body composition components related to LEP were muscle area in men and total body fat in women. Results were similar after additional adjustment for lifestyle factors and health status. No interactions between race and muscle area (P>.7) or between race and muscle attenuation (P>.2) were observed. Smaller midthigh muscle area and greater fat infiltration in the muscle are associated with poorer LEP in well-functioning older men and women.

Lower Extremity Performance in Nondisabled Older Persons as a Predictor of Subsequent Hospitalization

This study examines, in initially nondisabled older persons, the impact of reduced lower extremity performance on subsequent hospitalizations. A 4-year prospective cohort study was conducted among 3381 persons, aged 71 years and older, who initially reported no disability. At baseline, lower extremity performance was measured by an assessment of standing balance, a timed 2.4-m walk, and a timed test of rising from a chair five times. Data on subsequent hospital admissions and discharge diagnoses over 4 years were obtained from the Medicare database. During the follow-up period, nondisabled persons with poor lower extremity performance spent significantly more days in the hospital (17.7 days) than those with intermediate and high performance (11.6 and 9.7 days, respectively). Poor lower extremity performance in nondisabled persons significantly predicted subsequent hospitalization over 4 years (relative risk for hospitalization in those with poor vs high performance: 1.78; 95% confidence interval, 1.45-2.17). This increased hospitalization risk could not be explained by several indicators of baseline health status. Increased hospitalization risks were especially found for geriatric conditions, such as dementia, decubitus ulcer, hip fractures, other fractures, pneumonia, dehydration, and acute infections. Even in persons who are currently nondisabled, a simple measure of lower extremity performance is predictive of subsequent hospitalization, especially for geriatric conditions.

Characteristics of Nondisabled Older Persons Who Perform Poorly in Objective Tests of Lower Extremity Function

It has been suggested that nondisabled older persons with poor performance of lower extremity function are ideal targets for interventions of disability prevention. However, health-related factors associated with poor performance are largely unknown. Using data from a representative sample of nondisabled older persons, this study identifies the diseases and biological markers that characterize this group of the population. A total of 3,381 persons aged 71 or older, interviewed and administered a battery of physical performance tests at the sixth annual follow-up of the Established Populations for Epidemiologic Studies of the Elderly (EPESE), who reported no need for help in walking 1/4 mile or climbing stairs. Lower extremity performance was measured using a short battery of tests including assessment of standing balance, a timed 2.4-m walk, and timed test of rising 5 times from a chair. Chronic conditions were ascertained as self-report of a physician diagnosis. Data on previous hospitalizations were obtained from the Medicare database. Nonfasting blood samples were obtained and processed with standard methods. In a multivariate analysis, older age, female gender, higher BMI, history of hip fracture and diabetes, one or more hospital admissions for acute infection in the last 3 years, lower levels of hemoglobin and albumin, and higher leukocytes and gamma-glutamyl transferase were all associated independently with poor performance. Screening for older patients who are not disabled but have poor lower extremity performance selects a subgroup of the population with a high percentage of women, high prevalence of diabetes and hip fracture, and high levels of biological markers of inflammation. This group represents about 10% of the US population 70 to 90 years old. These findings should be considered in planning specifically tailored interventions for disability prevention in this subgroup.

Skeletal muscle mass and muscle strength in relation to lower-extremity performance in older men and women.

Low muscle strength is associated with poorer physical function, but limited empirical evidence is available to prove the relationship between muscle mass and physical function. We tested the hypothesis that persons with lower muscle mass or muscle strength have poorer lower-extremity performance (LEP). A cross-sectional, population-based study. A cohort of 449 men and women aged 65 years and older living in Amsterdam and its surroundings participating in the second examination (1995-1996) of the Longitudinal Aging Study Amsterdam. Leg skeletal muscle mass was measured using dual-energy X-ray absorptiometry (DXA). Grip strength was used as an indicator of muscle strength. Timed functional performance tests, including walking and repeated chair stands, were used to assess LEP. After adjustment for body height and age, leg muscle mass was positively associated with LEP in men (regression coefficient 0.178 [95% confidence interval 0.013-0.343], P = .035). In women an inverse association was observed, which became positive after additional adjustment for body mass index (BMI) (0.202 [-0.001-0.405], P = .052). Grip strength was positively associated with LEP in men and women. After additional adjustment for behavioral, physiological, and psychological variables, the associations between leg muscle mass and LEP disappeared, whereas grip strength remained to be independently associated with LEP in men (0.079 [0.042-0.116], P = .0001), with a tendency in women (0.046 [-0.009-0.101], P = .11). Results were similar when quartiles of leg muscle mass or grip strength were used. These results suggest that low muscle strength, but not low muscle mass, is associated with poor physical function in older men and women. However, prospective studies are needed to investigate the association between loss of muscle mass and physical function.