The impact of osteoporosis on quality-of-life: the OFELY cohort.

Although the long-term outcomes of osteoporosis (Op) such as fracture, kyphosis, and pain are well known, the physical, psychological, and social consequences, beyond fracture and pain, are less clear. The Osteoporosis-targeted Quality-of-life (OPTQoL) questionnaire aimed at assessing the physical difficulty, fears, and adaptations to one's daily life was developed as a cross-sectional instrument to characterize the burden of Op within a community. The purpose of this study was to assess the impact of Op and related factors on community women participating in the OFELY study in France. Femoral neck bone mineral density (BMD) and OPTQoL questionnaire data were collected from women randomly selected from a large insurance company. Data were obtained for 756 women (mean age 59 years, range 36-92), most of whom were white. Women were classified into five groups based on the extent of physical manifestations and family history of Op. Women who had prior fractures, height loss, and/or kyphosis or both reported greater physical difficulty, more adaptations to their lives, and greater fears than women reporting no such changes. Scores on the Physical Difficulty domain, however, did not differ significantly based on BMD alone (BMD T score

Spinal-flexibility-plus-aerobic versus aerobic-only training: effect of a randomized clinical trial on function in at-risk older adults.

BACKGROUND: As exercise is associated with favorable health outcomes, impaired older adults may benefit from specialized exercise interventions to achieve gains in function. The purpose of this study was to determine the added benefit of a spinal flexibility-plus-aerobic exercise intervention versus aerobic-only exercise on function among community-dwelling elders. METHODS: We employed a randomized clinical trial consisting of 3 months of supervised exercise followed by 6 months of home-based exercise with telephone follow-up. A total of 210 impaired males and females over age 64 enrolled in this study. Of these, 134 were randomly assigned to either spinal flexibility-plus-aerobic exercise or aerobic-only exercise, with 116 individuals completing the study. Primary outcomes obtained at baseline, after 3 months of supervised exercise, and after 6 months of home-based exercise included: axial rotation, maximal oxygen uptake (VO2max); functional reach, timed-bed-mobility; and the Physical Function Scale (PhysFunction) of the Medical Outcomes Study SF-36. RESULTS: Differences between the two interventions were minimal. Overall change scores for both groups combined indicated significant improvement for: axial rotation (p=.001), VO2max (p=.0001), and PhysFunction (p=.0016). Secondary improvements were noted for overall health (p=.0025) and reduced symptoms (p=.0008). Differences between groups were significant only for VO2max (p=.0014) at 3 months with the aerobic-only group improving twice as much in aerobic capacity as the spinal flexibility-plus-aerobic group. Repeated measures indicated both groups improved during the supervised portion of the intervention but tended to return toward baseline following the home-based portion of the trial. CONCLUSIONS: Gains in physical functioning and perceived overall health are obtained with moderate aerobic exercise. No differential improvements were noted for the spinal flexibility-plus-aerobic intervention.

Measurement of distal forearm bone mineral density: can different forearm segments be used interchangeably ?

Many different forearm sites have been used for the measurement of bone mineral density (BMD) and prediction of risk of future fracture among community dwelling populations. In populations where bone densitometry of peripheral sites may be the most cost effective and practical means of measuring BMD, such as the nursing home population, knowing the characteristics of forearm BMD measures would be beneficial. The purpose of this study was to assess the relationship of four common commercially available measures to each other and to estimate the inter- and intrarater reliability of the measures in a sample of nursing home residents as a first step toward identifying appropriate forearm measurement sites. These sites were the distal radius, the distal ulna, a composite of the distal radius and distal ulna, and the ultra distal radius. BMD measurements on 48 nursing home patients were obtained using single X-ray absorptiometry. Inter- and intrarater reliability was excellent at all four sites (interclass correlation coefficients > 0. 85). Moderate to high correlations (0.84-0.91) between the distal radius and ultra distal radius sites of the forearm suggest that these measures may be interchangeable. Although not directly assessed here, differences in bone composition among forearm sites may partially explain moderate rather than high correlations between sites and may affect the ability of each site to predict future fractures. Thus, different forearm sites may be used interchangeably for diagnostic purposes; however, the prognostic value of each site remains unknown.

Balance performance on the postural stress test: comparison of young adults, healthy elderly, and fallers.

The purpose of this study was to compare the postural responses of three groups of individuals--healthy young adults (n = 42; age, 20-40 years); healthy, community-dwelling, elderly individuals (n = 66; age, 60-102 years), and elderly individuals with a history of frequent falls (n = 10; age, 66-95 years)--using the postural stress test (PST). The PST is a simple, clinically applicable, quantitative measure of an individual's ability to withstand a series of graded destabilizing forces applied at the level of the subject's waist. Elderly fallers tend to score lower on the PST than elderly nonfallers, but age-related differences in postural responses during the PST have not been established. Each subject underwent the PST using a method and scoring procedure described previously. Results of this study confirm previous findings that elderly fallers score significantly lower on the PST than either young adult or nonfalling elderly individuals. This study also showed that there was no difference in balance strategy scores between the young adults and the healthy elderly subjects. Therefore, it appears that poor performance on the PST cannot be attributed to age alone, but may be predictive of pathological processes that predispose an individual to frequent falls.

Exercise to improve physiologic and functional performance in old age.

The purpose of this article is to evaluate the impact of exercise in elderly men and women. The type and intensity of exercise, the health status of the participants, and the outcomes measured vary widely across studies. In general, studies of exercise interventions in older adults show positive physiologic effects in persons of all ages. Musculoskeletal and cardiovascular systems, regardless of age, can respond to both resistance and aerobic training as measured by impairments such as strength and maximum oxygen uptake. The magnitude of physiologic effect may be dampened in frailer individuals in response to lower intensity exercise stimuli. In the most impaired elders, exercise may help to forestall further decline in physiologic reserve rather than produce significant gains. The extent to which exercise programs impact performance and disability is less clear. Exercise programs in frailer individuals appear to have greater effect on gait speed and chair rise time than similar programs in healthier individuals. The impact of exercise on measures of disability has not been widely reported. Studies reviewed in this article suggest that exercise training in elders is a potential means of reducing the burden of impairments and ultimately improving function.

Percent Decline in Peak Torque Production during Repeated Concentric and Eccentric Contractions of the Quadriceps Femoris Muscle.

The purpose of this study was to document the difference between eccentric and concentric fatigue of the quadriceps femoris muscle during a maximal effort 40 repetition bout at 180 degrees /sec. Sixteen female volunteers aged 22 to 32 years were tested twice, at least 7 days apart. The left lower extremity of each subject was used during testing on the Kin-Com(R) dynamometer. Subjects were tested through a range of motion of 0 to 90 degrees of knee flexion while seated. Percent decline in peak torque production was then calculated. The results demonstrated that peak torque production during the 40 repetition bout decreased an average of 0.3% for the eccentric trial and an average of 47.7% for the concentric trial. A significant difference in percent decline in peak torque production between concentric and eccentric trials was found to exist (p < 0.0001). The findings of this study indicate that eccentric training may require the performance of many more repetitions than concentric training in order to obtain muscle fatigue. J Orthop Sports Phys Ther 1989;10(8):309-314.

Eccentric and concentric force-velocity relationships of the quadriceps feimoris muscle.

Most functional activities utilize all three types of muscle contraction. The purpose of this study was to examine concentric and eccentric force-velocity relationships of the knee extensors of 30 young, healthy females at seven velocities between 30 and 210 degrees /sec using the Kinetic Communicator. The average force produced by the quadriceps during three concentric and three eccentric contractions was calculated at each velocity. The force-velocity relationships were graphed and analyzed using linear regression techniques. Results showed that the mean slope of the combined linear regression lines of concentric data was -0.55, which is significantly different from a zero slope. This indicates that concentric force of the knee extensors decreases as velocity increases. The mean slope of the combined linear regression lines of the eccentric data was -0.04, indicating no significant change in eccentric force with an increase in velocity. It appears, therefore, that in the knee extensors of healthy, young females, concentric force decreases as velocity increases to 210 degrees /sec, while eccentric force remains the same. Both concentric and eccentric work are often emphasized in strength training programs. It is, therefore, important for professionals involved in the rehabilitation or training of patients and athletes to be aware of differences between eccentric and concentric force-velocity relationships. J Orthop Sports Phys Ther 1992;16(2):82-86.

Effect of Contraction Type, Angular Velocity, and Arc of Motion on VMO:VL EMG Ratio.

This research was supported by a grant from the Walter P. Inman Fund through the Duke University Medical Research Council. Selected quadriceps muscle action may influence the movement path of the patella in the malaligned patellofemoral joint. The purpose of this study was to investigate the effects of arc of motion, angular velocity, and contraction type on the vastus medialis obliques:vastus lateralis (VMO:VL) absolute averaged electromyographic (AAEMG) ratio. Thirty healthy subjects performed maximum concentric and eccentric isokinetic quadriceps muscle contractions on the Kin-Com(R) dynamometer at velocities of 60 and 120 degrees /sec. Electromyography data from the VMO and the VL were acquired, and a VMO:VL AAEMG ratio was calculated for all combinations of the three independent variables. The results indicate that the VMO:VL AAEMG ratio for the 60 degrees -85 degrees arc was significantly greater than the ratio for the 35 degrees -60 degrees arc (p < 0.05), the ratio for the 60 degrees -85 degrees arc was significantly greater than the ratio for the 10 degrees -35 degrees arc (p < 0.05), and the ratio for the 35 degrees -60 degrees arc was significantly greater than the ratio for the 10 degrees -35 degrees arc (p < 0.05). The VMO:VL AAEMG ratio for concentric contraction at 120 degrees /sec was significantly greater than the ratio for concentric contraction at 60 degrees /sec (p < 0.05) and was significantly greater than the ratio for eccentric contraction at 120 degrees /sec (p < 0.05). The results indicate that the VMO:VL AAEMG ratio is affected by isokinetic exercise parameters. The use of isokinetic exercise parameters that produce a greater VMO:VL AAEMG ratio may be effective in altering muscular imbalance between the VMO and VL. J Orthop Sports Phys Ther 1991;14(6):256-262.

Mode and speed specificity of eccentric and concentric exercise training.

This research was supported by a Duke University Research Council Grant. The purpose of this study was to examine mode and speed specificity of strength training by comparing concentric and eccentric isokinetic exercise of the quadriceps. Forty-eight healthy men (mean age = 23.9 years) were randomly assigned to one of three groups: concentric training (C), eccentric training (E), or control (K). Average force (in Newtons) of 3 concentric and of 3 eccentric quadriceps contractions on the KIN-COM(R) dynamometer at 60, 120, and 180 degrees /sec was evaluated prior to and following a 6 week period during which only the C and E groups trained. Training sessions (3/week) included 4 submaximal and 1 maximal warm-up followed by 10 maximal effort isokinetic contractions of the quadriceps at 120 degrees /sec for each leg. Group C subjects trained concentrically only while Group E subjects trained eccentrically only. A t-test for independent means showed no significant right/left differences. ANOVA and Scheffe's F-tests were then used to assess the differences in training effects among the 3 groups for the left leg only. Results showed that although Group C increased slightly in both concentric and eccentric force at all speeds, the gains were significant only for concentric force at 180 degrees /sec. Group E showed significant gains (p < 0.05) in eccentric force at all speeds but not in concentric force. The K group had no significant change in concentric or eccentric force at any speed. We conclude that the eccentric mode of isokinetic exercise has highly specific strength training effects while the concentric mode has less specific training effects. In addition, speed of exercise does not appear to have specific training effects. J Orthop Sports Phys Ther 1989;11(2):70-75.

Crop-to-weed introgression has impacted allelic composition of johnsongrass populations with and without recent exposure to cultivated sorghum.

Sorghum halepense L. (johnsongrass) is one of the world's most noxious weeds, and a paradigm for the potential dangers of crop-weed hybridization. Introduced into the southeastern United States about 200 years ago, S. halepense is a close relative of cultivated sorghum (Sorghum bicolor). Both artificial crossing and experimental field studies have demonstrated the potential for S. halepensex S. bicolor hybrid formation, but no prior study has addressed the long-term persistence of sorghum genes in johnsongrass populations. We surveyed 283 loci (on all 10 sorghum linkage groups) to identify 77 alleles at 69 loci that are found in US sorghum cultivars but are absent from a worldwide sampling of johnsongrass genotypes. These putatively cultivar-specific alleles were present in up to 32.3% of individuals in johnsongrass populations adjacent to long-term sorghum production fields in Texas and Nebraska. Lower frequencies of cultivar-specific alleles at smaller numbers of loci are found in johnsongrass populations from New Jersey and Georgia with no recent exposure to cultivated sorghum, suggesting that introgressed sorghum alleles may be dispersed across long distances. The number of cultivar-specific alleles and extensive multilocus patterns of cultivar-specific allelic composition observed at both linked and unlinked loci in the johnsongrass populations, are inconsistent with alternatives to introgression such as convergence, or joint retention of ancestral polymorphisms. Naturalized johnsongrass populations appear to provide a conduit by which transgenes from sorghum could become widely disseminated.

Different subcellular distribution of caspase-3 and caspase-7 following Fas-induced apoptosis in mouse liver.

Caspases plays a key role in the execution phase of apoptosis. "Initiator" caspases, such as caspase-8, activate "effector" caspases, such as caspase-3 and -7, which subsequently cleave cellular substrates thereby precipitating the dramatic morphological changes of apoptosis. Following treatment of mice with an agonistic anti-Fas antibody to induce massive hepatocyte apoptosis, we now demonstrate a distinct subcellular localization of the effector caspases-3 and -7. Active caspase-3 is confined primarily to the cytosol, whereas active caspase-7 is associated almost exclusively with the mitochondrial and microsomal fractions. These data suggest that caspases-3 and -7 exert their primary functions in different cellular compartments and offer a possible explanation of the presence of caspase homologs with overlapping substrate specificities. Translocation and activation of caspase-7 to the endoplasmic reticulum correlates with the proteolytic cleavage of the endoplasmic reticular-specific substrate, sterol regulatory element-binding protein 1. Liver damage, induction of apoptosis, activation and translocation of caspase-7, and proteolysis of sterol regulatory element-binding protein 1 are all blocked by the caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp fluoromethyl ketone (Z-VAD. fmk). Our data demonstrate for the first time the differential subcellular compartmentalization of specific effector caspases following the induction of apoptosis in vivo.

Postural responses to platform perturbation: kinematics and electromyography.

Dynamic postural control may be studied using feedback paradigms which disturb standing balance. In this study the kinematics and electromyography of the reaction to an unexpected slip were examined simultaneously in 16 young, healthy volunteers to characterize the response to postural perturbation in the context of the perturbation characteristics. Kinematically, results showed ankle plantarflexion, knee flexion, hip extension, and shoulder flexion. Electromyographically, sequences of activation of the postural muscles of the leg were primarily anterior distal. Data is presented that supports a new model of the reaction to perturbation which incorporates the timing and type of muscular activity, the type of motion (active or passive), and the perturbation characteristics. RELEVANCE--:Understanding the interplay of the neurophysiological and biomechanical aspects of dynamic postural control gives insight into balance reactions. Simultaneous consideration of the kinematics, muscle activation, and perturbation characteristics allows a more comprehensive view of recovery of balance.

The effects of methadone on maternal-fetal interactions in the rat.

Female Sprague-Dawley rats received methadone (25 mg/kg/day) by gavage throughout gestation. Water-gavaged rats served as controls. Fetuses were delivered by cesarean section when parturition was imminent. Our results indicate that methadone may interfere with fetal development and maternal-fetal interactions to some degree. The observed alterations were as follows: fetal growth retardation, an interference with the triggering of parturition once normal delivery size is attained and possible positional malformations.

Activation of CPP32 and Mch3 alpha in wild-type p53-induced apoptosis.

DNA-damaging agents induce apoptosis primarily by a p53-dependent pathway. LTR6 cells containing a temperature-sensitive p53 were used to dissect further the mechanisms of p53-induced apoptosis. Apoptosis was accompanied by the processing and activation of CPP32 and Mch3 alpha, together with the cleavage of poly(ADP-ribose) polymerase and lamin B1. These results demonstrate a critical role for the activation of interleukin-1 beta-converting enzyme-like proteases in p53-induced apoptosis.

Is lower extremity strength gain associated with improvement in physical performance and disability in frail, community-dwelling elders?

BACKGROUND: Strength loss is strongly associated with functional decline and is reversible with exercise. The effect of increased strength on function has not been clearly established. The purpose of this study was to determine whether strength gain is associated with improvement in physical performance and disability. METHODS: One hundred functionally impaired community-dwelling men and women (77.6 +/- 7.6 yrs) were tested at baseline and outcome for lower extremity strength, physical performance, and disability. After random group assignment, exercise participants received strengthening exercises in their homes three times a week for 10 weeks while control subjects continued their normal activities. Using multiple regression techniques, the relationship between strength gain and improvement in physical performance and disability was assessed, controlling for age, depression, and baseline strength. RESULTS: A significant impact of strength gain on mobility skills (p = .0009) was found. The impact of strength gain on chair rise performance was significant in participants who were more impaired (p = .04). Strength gain was associated with gain in gait speed (p = .02) and in falls efficacy (p = .05), but not with other balance, endurance, or disability measures. CONCLUSIONS: Lower extremity strength gain is associated with gains in chair rise performance, gait speed, and in mobility tasks such as gait, transfers, stooping, and stair climbing, but not with improved endurance, balance, or disability. Strength gain is also associated with improvement in confidence in mobility. Factors that may influence the ability of strength gain to affect function are initial level of frailty and specificity of exercise. These results support the idea that strength training is an intervention that can potentially improve physical health status in many frail elders.

The relationship of postural sway to sensorimotor function, functional performance, and disability in the elderly.

OBJECTIVE: To examine the relationship of postural sway to sensorimotor impairment, functional performance, and self-reported disability. DESIGN: Cross-sectional cohort. SETTING: Department of Veterans' Affairs Medical Center. PATIENTS: One hundred community-dwelling elderly unable to climb stairs step over step. MAIN OUTCOME MEASURES: Postural sway (area of ellipse and path length, eyes open and closed), sensorimotor (strength, sensation, range of motion, central processing time), functional performance (functional reach, timed gait, mobility skills, endurance), and disability (MOS-SF36, Falls Efficacy Scale [FES]). RESULTS: Postural sway area measures correlated with sensorimotor measures: (1) During eyes-closed conditions, increased sway occurs in individuals with sensory deficits (p < .05); (2) Sway was positively correlated with tibialis anterior latency (p < .05); (3) Sway area measures increased with increased strength (p < .05). The sway/strength relationship may be explained by week subjects improving their stability by limiting rather than increasing sway. Sway was not significantly correlated with any measures of physical performance. Sway was correlated with some measures of disability: (1) Eyes-closed measures of postural sway were correlated with FES scores (p < .05); (2) Sway was not correlated with the MOS-36 physical functioning question. When controlling for functional measures, eyes-closed measures of sway significantly predicted FES scores (p < .03). CONCLUSIONS: Measures of postural sway are more likely capturing sensorimotor deficits rather than differentiating functional performance abilities, and the relationship between postural sway and self-reported disability is inconsistent.

Low bone mineral density and risk of fracture in white female nursing home residents.

CONTEXT: Low bone mineral density (BMD) is a strong risk factor for fracture in community-dwelling white women, but the relationship in white female nursing home residents, for whom fracture rates are highest, is less clear. OBJECTIVE: To assess the relative contribution of low BMD to fracture risk in nursing home residents. DESIGN: Prospective cohort study with baseline data collected April 1995 to June 1997, with 18 months of follow-up. SETTING: Forty-seven randomly selected nursing homes in Maryland. PATIENTS: A total of 1427 white female nursing home residents aged 65 years or older. MAIN OUTCOME MEASURE: Documented osteoporotic fracture occurring during follow-up as a function of baseline BMD measurements higher vs lower than the median, and after controlling for demographic, functional, cognitive, psychosocial, and medical factors. RESULTS: A total of 223 osteoporotic fractures occurred among 180 women. Low BMD and transfer independence were significant independent risk factors for fracture in this nursing home sample (P<.001) and the 2 factors acted synergistically (P =.06) to further increase fracture risk. Compared with women whose BMD was higher than the median (0. 296 g/cm(2)), those whose BMD was lower than the median had an unadjusted hazard ratio for risk of fracture of 2.1 (95% confidence interval [CI], 1.5-2.8); women who were independent in transfer had a hazard ratio of 1.6 (95% CI, 1.2-2.2) compared with women dependent in transfer. Among residents independent in transfer, those with BMD below the median had a more than 3-fold increase in fracture risk compared with those with higher BMD (unadjusted hazard ratio, 3.1; 95% CI, 2.2-4.4). Among residents dependent in transfer, those with BMD below the median had a 60% increase in fracture risk (unadjusted hazard ratio, 1.6; 95% CI, 1.1-2.3). Adjustment for covariates did not alter the BMD-fracture relationship. CONCLUSIONS: Our data indicate that low BMD and independence in transfer are significant predictors of osteoporotic fracture in white female nursing home residents. JAMA. 2000;284:972-977

Reliability of an Osteoporosis-Targeted Quality of Life Survey Instrument for use in the community: OPTQoL.

A brief Osteoporosis-Targeted Quality of Life (OPTQoL) questionnaire was previously developed as a cross-sectional survey instrument to assess the community impact of osteoporosis on quality of life in women. The initial development process involving item generation through focus groups, item reduction, and content and construct validation yielded a 36-item questionnaire with three domains (physical difficulty, adaptations and fears) and 10 health-related questions. In the present study, test-retest reliability and internal consistency of the questionnaire were assessed in a mail-based study with two clinical sites. Two hundred women (50 with severe osteoporosis, 50 with osteopenia, 50 with normal bone mineral density (BMD) and 50 with osteoarthritis and normal BMD), aged 43-84 years, completed the self-administered questionnaire initially and again about 2 weeks later. Using weighted kappas, agreement between questionnaire administrations ranged from 0.60 to 0.80 for most of the individual items. Intraclass correlation coefficients to assess reliability for the domain scores were 0.93 (physical difficulty), 0.82 (adaptations) and 0.88 (fears). Internal consistency of each of the domains was also high, with Cronbach's alpha coefficients ranging from 0.89 to 0.91. Four items were dropped from the 36-item questionnaire due to high percentage of 'not applicable' responses. Results of the analyses support the validity and reliability of this instrument as a cross-sectional survey tool for assessing the impact of osteoporosis on quality of life in women living in the community. The questionnaire has been translated and culturally adapted into seven languages to allow cross-cultural studies of the community impact of osteoporosis.