High body fatness, but not low fat-free mass, predicts disability in older men and women: the Cardiovascular Health Study

The impact of obesity on the musculoskeletal system

Obesity is associated with a range of disabling musculoskeletal conditions in adults. As the prevalence of obesity increases, the societal burden of these chronic musculoskeletal conditions, in terms of disability, health-related quality of life, and health-care costs, also increases. Research exploring the nature and strength of the associations between obesity and musculoskeletal conditions is accumulating, providing a better understanding of underlying mechanisms. Weight reduction is important in ameliorating some of the manifestations of musculoskeletal disease and improving function.

Is the metabolic syndrome, with or without diabetes, associated with progressive disability in older Mexican Americans?

BACKGROUND

The metabolic syndrome (MetS) is highly prevalent in the growing U.S. Latino population. We hypothesize that MetS, with or without diabetes, is associated with progressive disability in older Mexican Americans.

METHODS

Data from Mexican Americans 60-98 years old participating in the Sacramento Area Latino Study on Aging (SALSA) were analyzed from baseline through 3 years (3 years of follow-up). Disability was assessed by self-reported limitations in activities of daily living (ADLs), instrumental ADLs (IADLs), and mobility/strength tasks. MetS (46% of sample) was defined by National Cholesterol Education Program (NCEP) Adult Treatment Panel III criteria. Diabetes (DM, 33%) was defined by fasting blood sugar>125 mg/dL, physician diagnosis, and/or medication use. Four metabolic groups were defined: MetS with diabetes (MetS+DM+, n=402); MetS without diabetes (MetS+DM-, n=330); diabetes without MetS (MetS-DM+, n=125); and neither (MetS-DM-, n=749). Generalized estimating equation (GEE) regression models were used to evaluate the effect of metabolic group on physical limitations and disability changes over time.

RESULTS

Diabetes, with or without MetS, was associated with a higher percent rate of increase over 3 years in ADL and IADL disability than was no diabetes, even after controlling for demographics, body mass index (BMI), and incident disease. The mean ADL score had a 35% higher rate of increase (higher = more impairment) for the MetS+DM+ group and 68% higher for the MetS-DM+ group. Results for IADL were similar. The baseline MetS, without or with diabetes, was associated with a significantly higher rate of increase in mobility/strength limitations (8% and 36.5%, respectively).

CONCLUSIONS

In older Mexican Americans, MetS is associated with progressive limitations in mobility and strength. Preventing progressive mobility/strength limitations may require assessing and treating these impairments in people with MetS regardless of the presence of diabetes. However, preventing the progression of MetS without to MetS with diabetes may be important to limit the progression of ADL and IADL disability found in people with MetS and diabetes.

Physical activity and body mass index in elderly Iranians in Sweden: a population-based study

BACKGROUND/OBJECTIVES

To analyze whether elderly Iranians in Sweden have a higher mean body mass index (BMI) and are less physically active than elderly Swedes after adjustment for possible confounders.

SUBJECTS/METHODS

A total of 402 men and women (167 Iranian-born and 235 Swedish-born) aged 60-84 years residing in Stockholm, Sweden, were included in this population-based survey. Iranian participants were weighed and their height was measured. BMI values from the Swedish participants were based on self-reported data adjusted for the known discrepancy between objectively measured and self-reported weight and height. The outcome variables, BMI and self-reported leisure-time physical activity, were analyzed by linear regression and unconditional logistic regression.

RESULTS

Overall, Iranian women had the highest mean BMI (29.2) of all subgroups. The model that included an interaction between sex and length of time in Sweden showed that there was no significant difference in BMI between Swedish men (reference) and Swedish women or Iranian men. In contrast, Iranian women had significantly higher BMI than the reference group after adjustment for age, education and marital status. The largest difference in BMI compared to the reference group was found among Iranian women who immigrated to Sweden in 1989 or later (beta-coefficient=3.41, 95% CI=1.99-4.83). Iranians and Swedes had almost the same odds of >or= once-weekly leisure-time physical activity.

CONCLUSIONS

Elderly Iranian immigrants and especially women who immigrated to Sweden in 1989 or later must be targeted in order to decrease their burden of risk factors for cardiovascular disease.

Adiposity and Alzheimer's disease

The objective of this manuscript is to provide a comprehensive review of the relation between adiposity and Alzheimer's disease (AD), its potential mechanisms, and issues in its study. Adiposity represents the body fat tissue content. When the degree of adiposity increases it can be defined as being overweight or obese by measures such as the body mass index. Being overweight or obese is a cause of hyperinsulinemia and diabetes, both of which are risk factors for AD. However, the epidemiologic evidence linking the degree of adiposity and AD is conflicting. Traditional adiposity measures such as body mass index have decreased validity in the elderly. Increased adiposity in early or middle adult life leads to hyperinsulinemia which may lead to diabetes later in life. Thus, the timing of ascertainment of adiposity and its related factors is critical in understanding how it might fit into the pathogenesis of AD. We believe that the most plausible mechanism relating adiposity to AD is hyperinsulinemia, but it is unclear whether specific products of adipose tissue also have a role. Being overweight or obese is increasing in children and adults, thus understanding the association between adiposity and AD has important public health implications.

Alternative definitions of sarcopenia, lower extremity performance, and functional impairment with aging in older men and women

OBJECTIVES

To compare two methods for classifying an individual as sarcopenic for predicting decline in physical function in the Health, Aging and Body Composition Study.

DESIGN

Observational cohort study with 5 years of follow-up.

SETTING

Communities in Memphis, Tennessee, and Pittsburgh, Pennsylvania.

PARTICIPANTS

Men and women aged 70 to 79 (N=2,976, 52% women, 41% black).

MEASUREMENTS

Appendicular lean mass (aLM) was measured using dual energy x-ray absorptiometry, and participants were classified as sarcopenic first using aLM divided by height squared and then using aLM adjusted for height and body fat mass (residuals). Incidence of persistent lower extremity limitation (PLL) was measured according to self-report, and change in objective lower extremity performance (LEP) measures were observed using the Short Physical Performance Battery.

RESULTS

There was a greater risk of incident PLL in women who were sarcopenic using the residuals sarcopenia method than in women who were not sarcopenic (hazard ratio (HR)=1.34, 95% confidence interval (CI)=1.11-1.61) but not in men. Those defined as sarcopenic using the aLM/ht(2) method had lower incident PLL than nonsarcopenic men (HR=0.76, 95% CI=0.60-0.96) and women (HR=0.75, 95% CI=0.60-0.93), but these were no longer significant with adjustment for body fat mass. Using the residuals method, there were significantly poorer LEP scores in sarcopenic men and women at baseline and Year 6 and greater 5-year decline, whereas sarcopenic men defined using the aLM/ht(2) method had lower 5-year decline. Additional adjustment for fat mass attenuated this protective effect.

CONCLUSION

These findings suggest that sarcopenia defined using the residuals method, a method that considers height and fat mass together, is better for predicting disability in an individual than the aLM/ht(2) method, because it considers fat as part of the definition.

The Cardiometabolic Syndrome and Sarcopenic Obesity in Older Persons

The aging of the world's population is a major contributor to the growing prevalence of the cardiometabolic syndrome (CMS) because older persons are more affected by the constellation of cardiovascular risk factors that constitute the syndrome. The prevalence of CMS has been related to the increasing prevalence of obesity, which is growing progressively even among older age groups. Indeed, obesity and aging are 2 overlapping mounting public health problems. It is currently accepted that CMS predicts cardiovascular mortality and/or the development of type 2 diabetes mellitus, and this is also true in studies including older persons. CMS is further complicated by modifications in body composition and fat redistribution during aging; older adults are at higher risk for developing central obesity and sarcopenia or sarcopenic obesity, a condition characterized by an important reduction in lean body mass associated with obesity, linked to an increased production of inflammatory adipokines that may alter insulin sensitivity and muscle mass and strength. A better understanding of the pathophysiologic mechanisms of sarcopenic obesity may help to elucidate the complex relationship between CMS and mortality/morbidity in older adults.

The epidemiology of obesity

In the United States, obesity among adults and overweight among children and adolescents have increased markedly since 1980. Among adults, obesity is defined as a body mass index of 30 or greater. Among children and adolescents, overweight is defined as a body mass index for age at or above the 95th percentile of a specified reference population. In 2003-2004, 32.9% of adults 20-74 years old were obese and more than 17% of teenagers (age, 12-19 y) were overweight. Obesity varies by age and sex, and by race-ethnic group among adult women. A higher body weight is associated with an increased incidence of a number of conditions, including diabetes mellitus, cardiovascular disease, and nonalcoholic fatty liver disease, and with an increased risk of disability. Obesity is associated with a modestly increased risk of all-cause mortality. However, the net effect of overweight and obesity on morbidity and mortality is difficult to quantify. It is likely that a gene-environment interaction, in which genetically susceptible individuals respond to an environment with increased availability of palatable energy-dense foods and reduced opportunities for energy expenditure, contributes to the current high prevalence of obesity. Evidence suggests that even without reaching an ideal weight, a moderate amount of weight loss can be beneficial in terms of reducing levels of some risk factors, such as blood pressure. Many studies of dietary and behavioral treatments, however, have shown that maintenance of weight loss is difficult. The social and economic costs of obesity and of attempts to prevent or to treat obesity are high.

Muscle quality, aerobic fitness and fat mass predict lower-extremity physical function in community-dwelling older adults

BACKGROUND

Muscle mass, strength and fitness play a role in lower-extremity physical function (LEPF) in older adults; however, the relationships remain inadequately characterized.

OBJECTIVE

This study aimed to examine the relationships between leg mineral free lean mass (MFLM(LEG)), leg muscle quality (leg strength normalized for MFLM(LEG)), adiposity, aerobic fitness and LEPF in community-dwelling healthy elderly subjects.

METHODS

Fifty-five older adults (69.3 +/- 5.5 years, 36 females, 19 males) were assessed for leg strength using an isokinetic dynamometer, body composition by dual energy X-ray absorptiometry and aerobic fitness via a treadmill maximal oxygen consumption test. LEPF was assessed using computerized dynamic posturography and stair ascent/descent, a timed up-and-go task and a 7-meter walk with and without an obstacle.

RESULTS

Muscle strength, muscle quality and aerobic fitness were similarly correlated with static LEPF tests (r range 0.27-0.40, p < 0.05); however, the strength of the independent predictors was not robust with explained variance ranging from 9 to 16%. Muscle quality was the strongest correlate of all dynamic LEPF tests (r range 0.54-0.65, p < 0.001). Using stepwise linear regression analysis, muscle quality was the strongest independent predictor of dynamic physical function explaining 29-42% of the variance (p < 0.001), whereas aerobic fitness or body fat mass explained 5-6% of the variance (p < 0.05) depending on performance measure.

CONCLUSIONS

Muscle quality is the most important predictor, and aerobic fitness and fat mass are secondary predictors of LEPF in community-dwelling older adults. These findings support the importance of exercise, especially strength training, for optimal body composition, and maintenance of strength and physical function in older adults.

High baseline values of fat mass, independently of appendicular skeletal mass, predict 2-year onset of disability in elderly subjects at the high end of the functional spectrum

BACKGROUND AND AIMS

To evaluate the relation between baseline body composition and 2- year onset of functional limitation in elderly subjects at the high end of the functional spectrum.

METHODS

Anthropometric measurements, physical functioning as measured by a modified version of the Activities of Daily Living Scale, and baseline albumin, were evaluated in 145 men and women aged 66-78 years, free of functional limitations, selected from the general population of Verona. In each subject, total body fat mass (FM) and appendicular FFM (ASMM) were measured by dual-energy X-ray absorptiometry; the FM (FMI) and ASMM indexes (ASMMI) were also calculated by dividing each body composition variable by height squared.

RESULTS

After 2 years of follow-up, 48.2% of women and 40% of men had developed mild levels of disability, with limitations in kneeling, bending and climbing stairs. In women, but not in men, a BMI higher than 25 Kg/m2 or values of FMI higher than the 50th percentile, were significantly associated with a 3 to 5 times increased risk of limitations in climbing stairs and lower body performance. In men, a trend was found between low values of ASMMI and an increased risk of limitations in kneeling and bending. After cross-tabulating categories based on the 50th percentile of ASMMI and FMI, high values of FMI, independently of ASMMI, were significantly related with higher incidence of limitation in climbing stairs in women. In women, the highest 2-year incidence of limitation in climbing stairs was found in the group of obese subjects.

CONCLUSIONS

High body fat and high BMI values were associated with a greater probability of developing functional limitations 2 years later in a population of elderly subjects at the high end of the functional spectrum. Moreover, in women, high baseline values of fat mass, independently of appendicular fat-free mass, were more likely to predict the future onset of functional limitations.

Birth size, adult body composition and muscle strength in later life

OBJECTIVE

Low birth weight has been linked to lower lean body mass and abdominal obesity later in life, whereas high birth weight has been suggested to predict later obesity as indicated by high body mass index (BMI). We examined how birth weight was related to adult body size, body composition and grip strength.

DESIGN/SUBJECTS

Cross-sectional study on 928 men and 1075 women born in 1934-1944, with measurements at birth recorded.

MEASUREMENTS

Height, weight, waist and hip circumference and isometric grip strength were measured. Lean and fat body mass were estimated by bioelectrical impedance with an eight-polar tactile electrode system.

RESULTS

A 1 kg increase in birth weight corresponded in men to a 4.1 kg (95% CI: 3.1, 5.1) and in women to a 2.9 kg (2.1, 3.6) increase in adult lean mass. This association remained significant after adjustment for age, adult body size, physical activity, smoking status, social class and maternal size. Grip strength was positively related to birth weight through its association with lean mass. The positive association of birth weight with adult BMI was explained by its association with lean mass. Low birth weight was related to higher body fat percentage only after adjustment for adult BMI. Abdominal obesity was not predicted by low birth weight.

CONCLUSIONS

Low birth weight is associated with lower lean mass in adult life and thus contributes to the risk of relative sarcopenia and the related functional inability at the other end of the lifespan. At a given level of adult BMI, low birth weight predicts higher body fat percentage.

Effects of birth cohort and age on body composition in a sample of community-based elderly

BACKGROUND

The effect of the recent obesity epidemic on body composition remains unknown. Furthermore, age-related changes in body composition are still unclear.

OBJECTIVE

The objective was to simultaneously examine the effects of birth cohort and age on body composition.

DESIGN

A total of 1786 well-functioning, community-based whites and blacks (52% women and 35% blacks) aged 70-79 y from the Health, Aging, and Body Composition Study underwent dual-energy X-ray absorptiometry annually from 1997 to 2003.

RESULTS

At baseline, mean +/- SD percentage body fat, fat mass, and lean mass (bone-free) were 28 +/- 5%, 24 +/- 7 kg, and 56 +/- 7 kg, respectively, for men and 39 +/- 6%, 28 +/- 9 kg, and 40 +/- 6 kg for women. Mixed models were used to assess the effects of cohort and age-related changes on body composition. Later cohorts in men had a greater percentage body fat (0.32% per birth year, P < 0.0001) than did earlier cohorts. This cohort effect was due to a greater increase in fat mass than in lean mass (0.45 kg and 0.17 kg/birth year, respectively). With increasing age, percentage body fat in men initially increased and then leveled off. This age-related change was due to an accelerated decrease in lean mass and an initial increase and a later decrease in fat mass. Similar but less extreme effects of cohort and age were observed in women.

CONCLUSIONS

The combination of effects of both birth cohort and age leads to bigger body size and less lean mass in the elderly.

Unhealthy lifestyles during the life course: association with physical decline in late life

BACKGROUND AND AIMS

This study aimed at examining the association between unhealthy lifestyle in young age, midlife and/or old age and physical decline in old age, and between chronic exposure to an unhealthy lifestyle throughout life and physical decline in old age.

METHODS

The study sample included 1297 respondents of the Longitudinal Aging Study Amsterdam (LASA). Lifestyle in old age (55-85 y) was assessed at baseline, whereas lifestyle in young age (around 25 y) and midlife (around 40 y) were assessed retrospectively. Lifestyle factors included physical activity, body mass index (BMI), number of alcohol drinks per week and smoking. Physical decline was calculated as a change in physical performance score between baseline and six-year followup.

RESULTS

Of the lifestyle factors present in old age, a BMI of 25-29 vs BMI < 25 kg/m2 (OR=1.6; 95% CI: 1.1-2.2) and a BMI of > or = 30 vs BMI < 25 kg/m2 (OR=1.8; 95% CI: 1.2-2.7) were associated with physical decline in old age. Being physically inactive in old age was not significantly associated with an increased risk of physical decline, although, being physically inactive in both midlife and old age increased the odds of physical decline in old age to 1.6 (95% CI: 1.1-2.4), compared with respondents who were physically inactive in midlife and physically active in old age. Being overweight in both age periods was associated with an OR of 1.5 (95% CI: 1.1-2.2).

CONCLUSIONS

These data suggest that overweight in old age, and chronic exposure to physical inactivity or overweight throughout life, increases the risk of physical decline in old age. Therefore, physical activity and prevention of excessive weight at all ages should be stimulated, to prevent physical decline in old age.

The new Geriatric Nutritional Risk Index is a good predictor of muscle dysfunction in institutionalized older patients

BACKGROUND & AIMS

The validity of Geriatric Nutritional Risk Index (GNRI), in predicting nutrition-related risk of complications in the elderly, has been recently underscored. Malnutrition may results also in muscle function impairment. Thus, the present study aims to investigate if GNRI might be a reliable detector of muscle dysfunction in institutionalized older people.

METHODS

In total, 153 institutionalized elderly (71 males, 82 females; mean age+/-SD: 75.2+/-8.4; range: 65-96) were studied in anthropometric parameters, serum albumin concentration and total score on GNRI. Muscle function was assessed by handgrip strength (HG).

RESULTS

Women were significantly older than men and presented lower values of HG and arm muscle area (AMA). In overall population, GNRI was significantly correlated with AMA, HG and strength for centimeter of muscle area (HG/AMA); however, in gender-separated analysis, men presented higher degrees of correlation. After dividing patients in four categories according to GNRI, a more significant difference was detected in HG and HG/AMA rather than the other clinical and anthropometric parameters. Moreover, ANOVA analysis between HG quartiles was highly significant for GNRI, AMA and HG/AMA.

CONCLUSIONS

GNRI is a good predictor of muscle dysfunction, particularly in men, and useful in identifying patients suitable for nutritional support and physical activity.

Body composition and functional limitation in COPD

Background

Low body mass index has been associated with increased mortality in severe COPD. The impact of body composition earlier in the disease remains unclear. We studied the impact of body composition on the risk of functional limitation in COPD.

Methods

We used bioelectrical impedance to estimate body composition in a cohort of 355 younger adults with COPD who had a broad spectrum of severity.

Results

Among women, a higher lean-to-fat ratio was associated with a lower risk of self-reported functional limitation after controlling for age, height, pulmonary function impairment, race, education, and smoking history (OR 0.45 per 0.50 increment in lean-to-fat ratio; 95% CI 0.28 to 0.74). Among men, a higher lean-to-fat ratio was associated with a greater distance walked in 6 minutes (mean difference 40 meters per 0.50 ratio increment; 95% CI 9 to 71 meters). In women, the lean-to-fat ratio was associated with an even greater distance walked (mean difference 162 meters per 0.50 increment; 95% CI 97 to 228 meters). In women, higher lean-to-fat ratio was also associated with better Short Physical Performance Battery Scores. In further analysis, the accumulation of greater fat mass, and not the loss of lean mass, was most strongly associated with functional limitation among both sexes.

Conclusion

Body composition is an important non-pulmonary impairment that modulates the risk of functional limitation in COPD, even after taking pulmonary function into account. Body composition abnormalities may represent an important area for screening and preventive intervention in COPD.

Rural-urban differences in health and health behaviour: a baseline description of a community health-promotion programme for the elderly

STUDY OBJECTIVE

To (1) describe the setting and design of the Good Ageing in Lahti Region (GOAL) programme; (2) by using the baseline results of the GOAL cohort study, to examine whether living in urban, semi-urban, or rural communities is related to risk factors for chronic diseases and functional disability in ageing individuals.

DESIGN

The baseline data of a cohort study of ageing individuals living in three community types (urban, semi-urban, rural). Data were collected by two questionnaires and laboratory assessments.

SETTING

Fourteen municipalities in the Lahti region (Päijät-Häme County) in Finland.

PARTICIPANTS

A regionally and locally stratified random sample of men and women born in 1946-50, 1936-40, and 1926-30. A total of 4,272 were invited and 2,815 (66%) participated.

MAIN RESULTS

Elevated serum cholesterol, obesity, disability, sedentary lifestyle (<2 times/week walking), and high fat intake were more prevalent in rural vs. urban and semi-urban communities. After adjustment for sex, age, education, obesity, diet, physical activity, smoking, and alcohol use, rural communities remained the only community type with increased (p<0.05) probability for high BMI (OR 1.33) and high waist circumference (OR 1.43).

CONCLUSIONS

The unfavourable health and lifestyle profile, together with an old population, makes health promotion for elderly citizens a special challenge for rural communities such as those in Päijät-Häme County, Finland. Most, if not all, of the differences in health between the three community types were explained by educational background, physical activity, and smoking.

Waist circumference as a predictor of disability among older adults

OBJECTIVE

Few studies have addressed the association between abdominal obesity, as measured by waist circumference (WC), and disability in the elderly. Moreover, those studies were cross-sectional and yielded inconsistent results. The objective of this study was to examine longitudinally the association between WC and self-reported disability among older adults.

RESEARCH METHODS AND PROCEDURES

A prospective cohort study was conducted from 2001 to 2003 in 3235 persons (1411 men and 1824 women) representative of the non-institutionalized Spanish population ages 60 years and older. Baseline information was collected by home-based personal interviews and measurement of WC, weight, and height. Two years later, information on disability was obtained by telephone interview. The association of interest was summarized with odds ratios obtained by logistic regression.

RESULTS

Among persons reporting no disability at baseline, WC predicted disability 2 years later. After adjustment for age, education, tobacco use, alcohol consumption, and physical activity, men in the highest WC quintile had 2.17 (95% confidence interval, 1.15 to 4.09) times more risk of mobility disability and 4.77 (95% confidence interval, 2.50 to 9.13) times more risk of agility disability than those in the lowest quintile. Additional adjustment for BMI, chronic diseases, and cognitive function led to only a slight reduction in this association. Results were similar for women. No statistically significant association was observed between WC and restriction of daily activities, limitation in instrumental activities of daily living, and limitation in bathing or dressing, in either men or women.

DISCUSSION

WC predicts mobility and agility disability in old age. Avoidance of the highest values of WC might decrease the risk of disability in older adults.

The relations of body composition and adiposity measures to ill health and physical disability in elderly men

Although body build is related to disability and mortality in older people, the independent contributions of adiposity and lean mass are not fully defined. The authors examined the relations of body composition (fat mass index, fat-free mass index) and adiposity (body mass index, waist circumference) to ill health and physical disability in a cross-sectional study of 4,252 British men aged 60-79 years in 1998-2000. Increased body mass index, waist circumference, and fat mass index were associated with increased prevalence of cardiovascular disease, overall ill health, and disability. Adjusted odds ratios of cardiovascular disease (top vs. bottom fifth) were 1.58 (95% confidence interval (CI): 1.23, 2.03) for fat mass index, 1.45 (95% CI: 1.14, 1.86) for body mass index, and 1.27 (95% CI: 0.99, 1.62) for waist circumference. For overall "poor/fair" health, the corresponding odds ratios were 1.71 (95% CI: 1.33, 2.21), 1.49 (95% CI: 1.17, 1.90), and 1.64 (95% CI: 1.28, 2.09) and, for mobility limitation, they were 1.56 (95% CI: 1.17, 2.06), 1.96 (95% CI: 1.48, 2.56), and 1.88 (95% CI: 1.42, 2.49). A high fat-free mass index was associated with only a decreased prevalence of respiratory problems and cancer (odds ratios=0.45 (95% CI: 0.33, 0.62) and 0.62 (95% CI: 0.42, 0.94), respectively). Body fatness, not fat-free mass, is associated with cardiovascular disease and disability in older men. Simple measures of overweight, such as body mass index and waist circumference, are good indicators of the likelihood of morbidity in older men. Prevention of weight gain with increasing age is likely to reduce morbidity and disability among older men.

Fat mass rather than muscle strength is the major determinant of physical function and disability in postmenopausal women younger than 75 years of age

OBJECTIVE

Few studies have investigated the relationships between body composition, functional ability, and age-related disability in postmenopausal women. We investigated the relative role of fat mass, lean mass, and muscle strength in the development of disability in a group of healthy postmenopausal women younger than 75 years.

DESIGN

We performed a cross-sectional study among 396 independently living women aged 56-73 years, randomly selected between 8 and 30 years after menopause. Lean mass and fat mass were assessed by dual-energy x-ray absorptiometry. Muscle strength (grip and leg extensors) was assessed using dynamometry. Functional ability was estimated by Physical Performance Score, physical activity during the preceding year, and impairment in activities of daily living.

RESULTS

Of the participants, 43.7 % were overweight (25 > or = BMI < 30 kg/m2), and 17.7% were obese (BM I > or = 30 kg/m2). Higher muscle strength was observed with increasing lean body mass, and participants with higher muscle strength scored better in the physical performance score and activities of daily living. Higher fat mass was significantly associated with a lower physical performance score, lower physical activity, and a higher frequency of disability. Increasing fat mass was associated with increasing lean mass and decreasing lean/fat ratio. The increase in lean mass and muscle strength associated with higher fat mass was mainly localized in the legs.

CONCLUSIONS

Our results support the role of fat mass as the primary risk marker for disability, which might later accelerate by the age-related decrease in lean mass and the development of sarcopenia after the age of 75 years.

Relative weight and mobility: a longitudinal study in a biracial population of older adults

PURPOSE

We examined the association of relative weight with mobility and changes in mobility over time and whether these associations differed by race.

METHODS

Data come from a prospective, population-based, observational study of adults aged 65 years or older. Mobility outcomes were assessed at baseline and two follow-up interviews at 3-year intervals. The study included 4195 participants with a mean age of 73.8 +/- 6.3 (SD) years; 61.4% were women, and 60.9% were black. Assessment of mobility included a brief self-report instrument and a performance-based walk test. Body mass index (BMI, kilograms per square meter) was used as a measure of relative weight. We used generalized estimating equation models to examine change in mobility outcomes over time as a function of BMI.

RESULTS

Average BMI was 26.6 +/- 5.7 kg/m(2), with 34.0% overweight and 23.4% obese. BMI showed a significant curvilinear association with mobility outcomes at baseline (p < 0.001), but was not associated with change in mobility during follow-up. Maximum mobility levels occurred at a significantly higher level of BMI among blacks than whites.

CONCLUSIONS

Higher levels of BMI may lead to mobility impairments earlier in life, but there is little evidence that they increase the rate of decline in mobility in older age itself.

Intensive weight loss program improves physical function in older obese adults with knee osteoarthritis

OBJECTIVE

Physical function and body composition in older obese adults with knee osteoarthritis (OA) were examined after intensive weight loss.

RESEARCH METHODS AND PROCEDURES

Older obese adults (n = 87; > or = 60 years; BMI > or = 30.0 kg/m2) with symptomatic knee OA and difficulty with daily activities were recruited for a 6-month trial. Participants were randomized into either a weight stable (WS) or weight loss (WL) program. Participants in WL (10% weight loss goal) were prescribed a 1000 kcal/d energy deficit diet with exercise 3 d/wk. WS participants attended health information sessions. Body composition and physical function (Western Ontario and McMaster University Osteoarthritis Index, 6-minute walking distance, and stair climb time) were assessed at baseline and 6 months. Statistical analysis included univariate analysis of covariance on 6-month measurements using baseline values as covariates. Associations between physical function and body composition were performed.

RESULTS

Body weight decreased 8.7 +/- 0.8% in WL and 0.0 +/- 0.7% in WS. Body fat and fat-free mass were lower for WL than WS at 6 months (estimated means: fat = 38.1 +/- 0.4% vs. 40.9 +/- 0.4%, respectively; fat-free mass = 56.7 +/- 0.4 vs. 58.8 +/- 0.4 kg, respectively). WL had better function than WS, with lower Western Ontario and McMaster University Osteoarthritis Index scores, greater 6-minute walk distance, and faster stair climb time (p < 0.05). Changes in function were associated with weight loss in the entire cohort.

DISCUSSION

An intensive weight loss intervention incorporating energy deficit diet and exercise training improves physical function in older obese adults with knee OA. Greater improvements in function were observed in those with the most weight loss.

Transitions to mobility difficulty associated with lower extremity osteoarthritis in high functioning older women: longitudinal data from the Women's Health and Aging Study II

OBJECTIVE

To assess the impact of lower extremity osteoarthritis (OA) on transitions to mobility difficulty, and to assess the influence of pain, excess weight, and quadriceps strength on these transitions.

METHODS

We analyzed longitudinal data acquired from 199 participants in the Women's Health and Aging Study II (ages 70-79 years) who initially reported no lower extremity limitation (e.g., difficulty walking one-quarter mile) or difficulty in activities of daily living (ADL; e.g., transferring). Prevalent lower extremity OA was determined from validated algorithms encompassing multiple data sources. Markov transition models were created to analyze the first transition from no difficulty at baseline to lower extremity limitations, ADL difficulty, or both 18, 36, and 72 months later.

RESULTS

Compared with women without OA (n = 140), a higher proportion of women with lower extremity OA (n = 59) initially reported pain on most days and more severe pain while walking (P < 0.05). Women with OA were also heavier, with a higher proportion being obese or overweight (P < 0.001). Lower extremity OA, higher body mass index, and lower knee extensor strength independently increased the risk of transition to combined lower extremity and ADL difficulty first over 72 months.

CONCLUSION

Lower extremity OA increased the likelihood of developing difficulty in both lower extremity tasks and ADL over 72 months in a cohort of initially high functioning older women. Two modifiable factors, higher relative weight and lower knee extensor strength, substantially impacted these transitions, and therefore warrant increased attention in the management of lower extremity OA.

Obesity, weight change, and functional decline in peripheral arterial disease

BACKGROUND

Our objectives were to determine whether obesity is associated with a greater functional decline compared with the ideal body mass index (BMI) among persons with peripheral arterial disease (PAD) and to determine the associations between weight gain and loss and functional declines in PAD. We hypothesized that baseline obesity and weight gain during follow-up would each be associated with functional declines in persons with PAD.

METHODS

The design was a prospective cohort study. The subjects were 389 men and women with PAD (mean ankle-brachial index, 0.65 +/- 0.14) who were followed up prospectively for a median of 48 months. The main outcome measures were functional assessments (6-minute walk, usual- and rapid-paced 4-m walking speed, and summary performance score). Weight and height were measured at baseline and annually. Results were adjusted for age, sex, race, comorbidities, ankle-brachial index, education, leg symptoms, exercise status, depressive symptoms, pack-years of cigarette smoking, prior-year functioning, and patterns of missing data.

RESULTS

Compared with those with a baseline BMI between 20 and 25 kg/m2, PAD participants with baseline BMI greater than 30 kg/m2 had a significantly greater average annual decline in 6-minute walk performance (-13.1 vs -26.5 m/y; P = .004), usual-paced 4-m walking velocity (-0.028 vs -0.055 m/s per year; P = .024), and fast-paced 4-m walking velocity (-0.053 vs -0.086 m/s per year; P = .012). Persons with weight gain between 5 and 10 pounds after baseline who walked for exercise regularly had significantly less decline in the 6-minute walk than persons without significant weight change who did not walk for exercise (P = .04).

CONCLUSIONS

Obesity is associated with functional decline in persons with PAD. Walking exercise may protect against functional decline in PAD persons with modest weight gain.

Influence of sarcopenia on the development of physical disability: the Cardiovascular Health Study

OBJECTIVES

To examine the temporal relationship between sarcopenia and disability in elderly men and women.

DESIGN

Cardiovascular Health Study, a longitudinal study of cardiovascular disease and its risk factors in older people.

SETTING

Four U.S. communities.

PARTICIPANTS

Five thousand thirty-six men and women aged 65 and older.

MEASUREMENTS

Whole-body skeletal muscle mass was measured at baseline, and subjects were classified as having normal muscle mass, moderate sarcopenia, or severe sarcopenia based on previously established thresholds. Disability was measured via questionnaire at baseline in up to eight annual follow-up examinations. The cross-sectional relationship between sarcopenia and prevalent disability at baseline was examined using logistic regression models. The longitudinal relation between sarcopenia and incident disability over 8 years of follow-up was examined using Cox proportional hazards models.

RESULTS

At baseline, the likelihood of disability was 79% greater in those with severe sarcopenia (P<.001) but was not significantly greater in those with moderate sarcopenia (P=.38) than in those with normal muscle mass. During the 8-year follow-up, the risk of developing disability was 27% greater in those with severe sarcopenia (P=.006) but was not statistically greater in those with moderate sarcopenia (P=.23) than in those with normal muscle mass.

CONCLUSION

Severe sarcopenia was a modest independent risk factor for the development of physical disability. The effect of sarcopenia on disability was considerably smaller in the longitudinal analysis than in the cross-sectional analysis.

Health consequences of obesity in the elderly: a review of four unresolved questions

Obesity prevalence is growing progressively even among older age groups. Controversy exists about the potential harms of obesity in the elderly. Debate persists about the relation between obesity in old age and total or disease-specific mortality, the definition of obesity in the elderly, its clinical relevance, and about the need for its treatment. Knowledge of age-related body composition and fat distribution changes will help us to better understand the relationships between obesity, morbidity and mortality in the elderly. Review of the literature supports that central fat and relative loss of fat-free mass may become relatively more important than BMI in determining the health risk associated with obesity in older ages. Weight gain or fat redistribution in older age may still confer adverse health risks (for earlier mortality, comorbidities conferring independent adverse health risks, or for functional decline). Evaluation of comorbidity and weight history should be performed in the elderly in order to generate a comprehensive assessment of the potential adverse health effects of overweight or obesity. The risks of obesity in the elderly have been underestimated by a number of confounders such as survival effect, competing mortalities, relatively shortened life expectancy in older persons, smoking, weight change and unintentional weight loss. Identification of elderly subjects with sarcopenic obesity is probably clinically relevant, but the definition of sarcopenic obesity, the benefits of its clinical identification, as well as its relation to clinical consequences require further study. Studies on the effect of voluntary weight loss in the elderly are scarce, but they suggest that even small amounts of weight loss (between 5-10% of initial body weight) may be beneficial. In older as well as in younger adults, voluntary weight loss may help to prevent the adverse health consequences of obesity.

Angiotensin-converting enzyme inhibition intervention in elderly persons: effects on body composition and physical performance

The disablement process is often accompanied by sarcopenia or muscle loss, which is associated with virtually all identified disability risk factors. Clinically, the association between body composition and physical performance has been documented by several studies. However, loss of strength is greater than loss of muscle mass with age implying that the quality of remaining muscle may be reduced. Although there are limited data explaining potential physiological mechanisms that contribute to muscle quality, sarcopenia is frequently associated with fat accumulation, and the percentage of body fat increases with age even if weight does not. However, the relationship between fat and muscle function may not be linear, suggesting that there may be an optimal ratio of lean to fat mass for physical function. There are no definitive pharmacological interventions proven to prevent decline in physical function either by modulating body composition or by other means. One exception may be angiotensin-converting enzyme inhibitors (ACEIs). ACE is an important component of the renin-angiotensin system, the central hormonal regulator of blood pressure. Recent evidence suggests that ACEIs may improve physical function by means of direct effects on body composition in older persons, rather than through its blood-pressure-lowering effects. Clinical and genetic studies in humans and experimental evidence in animals suggest that modulation of the renin-angiotensin system is associated with metabolic and biochemical changes in skeletal muscle and fat, changes that are associated with declining physical function. ACEIs may modulate this process through a variety of molecular mechanisms including their influence on oxidative stress and on metabolic and inflammation pathways. This review describes potential biological mechanisms of ACE inhibition and its contribution to declining physical performance and changing body composition. Promising pharmacoepidemiological studies and experimental evidence in animals suggest that there are appropriate models in which to study this effect.

Waist circumference and BMI are independently associated with the variation of cardio-respiratory and neuromuscular fitness in young adult men

OBJECTIVE

To test two hypotheses: (1) cardiorespiratory (CRF) and neuromuscular (NMF) fitness is associated with body mass index (BMI) and waist circumference (WC), independent of each other and of leisure-time physical activity; (2) individuals with high CRF and NMF have lower WC for a given BMI, compared with those with low CRF and NMF.

DESIGN

Cross-sectional study.

SETTING

Men participating in refresher training organized by the Finnish Defence Forces.

PARTICIPANTS

A total of 951 men (mean age 29.1, s.d. 4.2 years; BMI 25.3 kg/m(2), s.d. 3.8; WC 91, s.d. 11 cm).

MAIN OUTCOME MEASURES

Body mass index, WC, maximal oxygen uptake (VO(2)max), height of vertical jump, number of push-ups and sit-ups during a 1-min test, static back extension endurance, isometric grip strength, self-reported leisure-time vigorous physical activity. Multiple linear regressions were used to explain the variation in fitness.

RESULTS

Waist circumference had significant (P<0.001) negative association with all test results (standardized beta coefficients from -0.23 to -0.77), except for grip strength. Body mass index had significant negative association with VO(2)max (-0.12; P<0.05), but positive association (P<0.01) with grip strength (0.28), vertical jump (0.21) and push-ups (0.55). For a given BMI, the estimated WC was highest among those with the poorest results for VO(2)max, vertical jump, sit-ups and push-ups.

CONCLUSIONS

Despite stronger isometric grip strength, the functional muscle fitness of the upper body, trunk and lower extremities is impaired in individuals with abdominal obesity. Although the known loss of CRF is a serious consequence of obesity, the deterioration of NMF deserves increased attention.

Reliability of bioimpedance analysis compared with other adiposity measurements in children: The FLVS II Study

OBJECTIVE

To evaluate the reproducibility of the measurement of% body fat by bipedal biometrical impedance analysis (BIA) compared with anthropometric measurements of adiposity in children and the correlations between these methods in children and adults.

METHODS

A cross-sectional study in a total of 1080 adults and children enrolled in 1999 in the Fleurbaix-Laventie Ville Santé II (FLVS II) population-based study in northern France. The reproducibility of anthropometrical and BIA methods was determined by a nested analysis of variance of repeated measurements by 2 investigators and a bipedal BIA device (Tanita TBF 310) in 64 pupils of two 5th grade classes. The correlation of BIA and anthropometric adiposity measurements with the unknown relative fat mass or volume of the body estimated by a latent adiposity variable (LAV) was established by the triads' method in 1080 subjects of the FLVS II cohort.

RESULTS

The reproducibility was similar for the sum of skinfolds, waist circumference and BIA% fat measurements (intraclass correlation coefficients: 0.979-0.992). Correlation coefficient between BIA body fat% and the LAV was higher than 0.86 in all sex and Tanner stage related groups, and similar in children and adults, except in pubertal boys (0.76).

CONCLUSION

With a high level of reproducibility, foot-to-foot BIA analysis provides a valuable measurement of total% fat for epidemiologic studies in children. However further studies are needed before extrapolating these results to overweight children.

Obesity and functional decline: epidemiology and geriatric consequences

Obesity is growing in prevalence among older Americans and is accompanied by an unfortunate burden of chronic disease, functional decline, and poor quality of life. Elevated past or current body mass index (BMI) is strongly associated with increased self-reported functional limitations. Supportive findings have also related decreased physical performance test scores with elevated BMI. Body composition analyses have explored which body compartment is most strongly associated with obesity-related functional impairments. Studies have suggested possible contributions of decreased muscle mass and increased fat mass. Weight reduction intervention studies that have examined functional outcomes among older persons are limited.

Dietary Management for Older Subjects with Obesity

In recent years, obesity has been recognized as a form of malnutrition in older adults and a continuing risk factor for serious health problems. Weight reduction in older adults is not as reliable a recommendation as it is for younger adults; a decreased body mass index (BMI) seems to be associated with a higher incidence of stroke, and a normal or slightly elevated BMI has been linked to greater reserve capacity. Weight loss in older adults requires strategies that consider health status, functional ability, and rational targets. Strategies may include behavior modification, dietary alterations, exercise or physical activity, and reasonable goals that do not put the individual at nutritional risk. Studies that examine different approaches to weight reduction rarely include older subjects, so it is difficult to make judgments about various interventions (surgery, exercise, drugs, or diet) and their efficacy in this population. Fad diets may be lacking in essential nutrients and may prove to be risky for elderly people. Weight loss programs for older adults should focus on maintaining adequate intake of essential nutrients while reducing calories by controlling dietary fat intake.

Obesity in older adults: technical review and position statement of the American Society for Nutrition and NAASO, The Obesity Society

Obesity causes serious medical complications and impairs quality of life. Moreover, in older persons, obesity can exacerbate the age-related decline in physical function and lead to frailty. However, appropriate treatment for obesity in older persons is controversial because of the reduction in relative health risks associated with increasing body mass index and the concern that weight loss could have potential harmful effects in the older population. This joint position statement from the American Society for Nutrition and the NAASO, The Obesity Society reviews the clinical issues related to obesity in older persons and provides health professionals with appropriate weight-management guidelines for obese older patients. The current data show that weight-loss therapy improves physical function, quality of life, and the medical complications associated with obesity in older persons. Therefore, weight-loss therapy that minimizes muscle and bone losses is recommended for older persons who are obese and who have functional impairments or medical complications that can benefit from weight loss.

Health ramifications of the obesity epidemic

For the first time in human history, the numbers of overweight and underweight individuals are about the same, at 2.1 billion each. Along with the current worldwide obesity epidemic is the explosion of obesity- and overweight-related health problems, including diabetes and the metabolic syndrome, musculoskeletal disorders,cardiovascular disease, pulmonary disorders, and certain forms of cancer. Obesity and overweight account for a significant percentage of overall health care costs and contribute significantly to morbidity and mortality in the United States and around the world.

From a postal questionnaire of older men, healthy lifestyle factors reduced the onset of and may have increased recovery from mobility limitation

BACKGROUND AND OBJECTIVE

We have examined predictors of the onset of and recovery from mobility limitation and the association between lifestyle changes in later life and mobility status.

STUDY DESIGN AND SETTING

From a cohort of 7,735 men recruited at ages 40-59 years (1978-1980), 5,075 men completed follow-up postal questionnaires in 1992 (Q92), then aged 52-73 years, and again in 1996 (Q96). Mobility limitation was defined as reported difficulty in any one or more of the following: getting outdoors, walking 400 yards, or climbing stairs.

RESULTS

Lifestyle factors (smoking, obesity, physical inactivity, and heavy drinking) and manual worker social class were significantly and independently associated with onset of mobility limitation and with the exception of physical activity remained significant after further adjustment for chronic diseases. Smoking cessation and taking up physical activity in later life are associated with reduced onset of mobility limitation. Among men with mobility limitation at Q92 (n=645), light or moderate levels of physical activity were associated with significantly increased odds of recovery at Q96 (light activity, OR=2.43, 95% CI 1.48, 4.00; moderate activity, OR=2.57, 95% CI 1.31, 5.02).

CONCLUSION

Maintaining and adopting a healthy lifestyle in later life reduces the onset of mobility limitation in old age. Maintaining physical activity may improve recovery.

Frailty: Emergence and Consequences in Women Aged 65 and Older in the Women's Health Initiative Observational Study

OBJECTIVES

To define frailty using simple indicators; to identify risk factors for frailty as targets for prevention; and to investigate the predictive validity of this frailty classification for death, hospitalization, hip fracture, and activity of daily living (ADL) disability.

DESIGN

Prospective study, the Women's Health Initiative Observational Study.

SETTING

Forty U.S. clinical centers.

PARTICIPANTS

Forty thousand six hundred fifty-seven women aged 65 to 79 at baseline.

MEASUREMENTS

Components of frailty included self-reported muscle weakness/impaired walking, exhaustion, low physical activity, and unintended weight loss between baseline and 3 years of follow-up. Death, hip fractures, ADL disability, and hospitalizations were ascertained during an average of 5.9 years of follow-up.

RESULTS

Baseline frailty was classified in 16.3% of participants, and incident frailty at 3-years was 14.8%. Older age, chronic conditions, smoking, and depressive symptom score were positively associated with incident frailty, whereas income, moderate alcohol use, living alone, and self-reported health were inversely associated. Being underweight, overweight, or obese all carried significantly higher risk of frailty than normal weight. Baseline frailty independently predicted risk of death (hazard ratio (HR)=1.71, 95% confidence interval (CI)=1.48-1.97), hip fracture (HR=1.57, 95% CI=1.11-2.20), ADL disability (odds ratio (OR)=3.15, 95% CI=2.47-4.02), and hospitalizations (OR=1.95, 95% CI=1.72-2.22) after adjustment for demographic characteristics, health behaviors, disability, and comorbid conditions.

CONCLUSION

These results support the robustness of the concept of frailty as a geriatric syndrome that predicts several poor outcomes in older women. Underweight, obesity, smoking, and depressive symptoms are strongly associated with the development of frailty and represent important targets for prevention.

Burden of disease associated with overweight and obesity among U.S. military retirees and their dependents, aged 38-64, 2003

PURPOSE

The prevalence of overweight and obesity is increasing in the general US population and in beneficiaries of the Department of Defense (DoD) Military Healthcare System. The purpose of this study was to describe the prevalence and correlation of overweight, obesity and associated co-morbidities in the DoD beneficiary population.

METHODS

A cross-sectional analysis was preformed on data from the DoD's 2003 Population Health Survey. Prevalence odds ratios (POR) were used to describe the association between overweight and obesity categories and prevalence of co-morbidities.

RESULTS

Eighty percent of men and 60% of women were overweight or obese and 33% of men and 29% of women were obese. The PORs increased in magnitude corresponding to increasing BMI categories for all co-morbidities. The percent of individuals reporting between 2 and 4 co-morbidities also increased with increasing weight class.

CONCLUSIONS

Overweight, obesity and associated co-morbidities are prevalent among DoD beneficiaries. Overweight and obese individuals have an increased prevalence of co-morbidities compared to normal weight individuals. Twenty plus years of active duty in the military does not confer any long-term protection against overweight, obesity or the associated co-morbidities. The DoD should emphasize prevention in order to reduce healthcare costs and the disease burden in this cohort.

Relationships between leisure-time physical activity, obesity and disability in elderly men

BACKGROUND AND AIMS

Relationships have already been shown between leisure-time physical activity, obesity and body composition in young adults. However, this association needs to be confirmed in the elderly. The aim of this study was to investigate the relationship between leisure-time physical activity, obesity, preservation of muscle mass and disability in elderly men.

METHODS

Cross-sectional analysis of a sample of 85 community-dwelling men, 68 to 79 years of age. Body mass index (BMI) was used to quantify obesity. Body composition was evaluated using Dual Energy X-ray Absorptiometry. Disability was measured using a modified version of the Activities of Daily Living scale. Leisure-time physical activity was evaluated by a validated self-administered questionnaire.

RESULTS

A negative relation between obesity and weekly walking was observed. Walking less than 30 minutes per day was associated with a 2.7 greater probability of being obese (95% CI 1.1-6.7). High-intensity exercise, such as brisk walking or gardening, was inversely correlated with body fat (R = -0.296, p < 0.01) and directly correlated with appendicular skeletal mass (R = 0.238, p < 0.05). The prevalence of disability was the highest (58%) among overweight elderly subjects at the lowest tertile of exercise. Multiple logistic regression selected BMI as a positive predictor and high-intensity exercise as a negative predictor of disability.

CONCLUSIONS

Our study shows that, in elderly men, leisure-time physical activity is inversely associated with body fat, BMI, and reported disability, but positively associated with appendicular fat-free mass. The highest prevalence of reported disability was observed in sedentary subjects with BMI higher than 25 kg/m2.

Low skeletal muscle mass is associated with poor structural parameters of bone and impaired balance in elderly men--the MINOS study

In 796 men, 50-85 years of age, decreased relative skeletal muscle mass index was associated with narrower bones, thinner cortices, and a consequent decreased bending strength (lower section modulus), as well as with impaired balance and an increased risk of falls.

INTRODUCTION

In men, appendicular skeletal muscle mass (ASM) is correlated positively with BMC and areal BMD (aBMD). In elderly men, low muscle mass and strength (sarcopenia) is associated with difficulties in daily living activities. The aim of this study was to evaluate if ASM is correlated with bone size, mechanical properties of bones, balance, and risk of falls in elderly men.

MATERIALS AND METHODS

This study used 796 men, 50-85 years of age, belonging to the MINOS cohort. Lifestyle factors were evaluated by standardized questionnaires. Estimates of mechanical bone properties were derived from aBMD measured by DXA. ASM was estimated by DXA. The relative skeletal muscle mass index (RASM) was calculated as ASM/(body height)(2.3).

RESULTS

After adjustment for age, body size, tobacco smoking, professional physical activity, and 17beta-estradiol concentration, RASM was correlated positively with BMC, aBMD, external diameter, and cortical thickness (r = 0.17-0.34, p < 0.0001) but not with volumetric BMD. Consequently, RASM was correlated with section modulus (r = 0.29-0.39, p < 0.0001). Men in the lowest quartile of RASM had section modulus of femoral neck and distal radius lower by 12-18% in comparison with men in the highest quartile of RASM. In contrast, bone width was not correlated with fat mass, reflecting the load of body weight (except for L(3)), which suggests that the muscular strain may exert a direct stimulatory effect on periosteal apposition. After adjustment for confounding variables, a decrease in RASM was associated with increased risk of falls and of inability to accomplish clinical tests of muscle strength, static balance, and dynamic balance (odds ratio per 1 SD decrease in RASM, 1.31-2.23; p < 0.05-0.001).

CONCLUSIONS

In elderly men, decreased RASM is associated with narrower bones and thinner cortices, which results in a lower bending strength. Low RASM is associated with impaired balance and with an increased risk of falls in elderly men. It remains to be studied whether low RASM is associated with decreased periosteal apposition and with increased fracture risk in elderly men, and whether the difference in skeletal muscle mass between men and women contributes to the between-sex difference in fracture incidence.

Physical frailty and body composition in obese elderly men and women

OBJECTIVE

To evaluate the prevalence of frailty and interrelationships among body composition, physical function, and quality of life in community-dwelling obese elderly (OE) persons.

RESEARCH METHODS AND PROCEDURES

Fifty-two OE, 52 nonobese frail, and 52 nonobese nonfrail subjects, matched for age and sex, were studied. Subjective and objective measures of functional status were evaluated by using the physical performance test, exercise stress test, lower extremity (LE) strength, gait speed, static and dynamic balance, functional status questionnaires, and health-related quality-of-life questionnaire (Medical Outcomes Short Form). Body composition was evaluated by using DXA, and muscle quality was evaluated by determining the ratio of LE strength to LE lean mass.

RESULTS

Among OE subjects, 96% met our standard criteria for mild to moderate frailty. Compared with the nonobese nonfrail group, the OE and nonobese frail groups had lower and similar scores in physical performance test, peak aerobic power, and functional status questionnaire, and exhibited similar impairments in strength, walking speed, balance, and health-related quality of life. Although absolute fat-free mass (FFM) was greater, the percentage body weight as FFM and muscle quality was lower in the OE group than in the other two groups.

DISCUSSION

Physical frailty, which predisposes to loss of independence, is common in community-living OE men and women. Physical frailty in OE subjects was associated with low percentage FFM, poor muscle quality, and decreased quality of life. These findings suggest that weight loss therapy may be particularly important in OE persons to improve physical function, in addition to improving the medical complications associated with obesity.

Effects of physical activity and body composition on functional limitation in the elderly: application of the marginal structural model

BACKGROUND

Study of the influence of physical activity and body composition in the context of the disablement process requires analytic techniques that can address time-dependent confounding related to exposures for the occurrence of functional limitation and disability.

METHODS

We applied logistic marginal structural models to explore causal relationships between leisure time physical activity and a measure of relative muscle mass (the lean:fat mass ratio) and self-reported functional limitation. Subjects (n = 1655) were members of a population-based cohort recruited in Sonoma, California, in 1993-1994 (median age 70 years); they were surveyed 3 times over 6.5 years.

RESULTS

Based on the marginal structural model, the causal odds ratio for functional limitation with a 0.5-unit increment in relative muscle mass was 0.56 in women (95% CI = 0.46-0.67). This reduction in odds was not altered by adjustment for baseline covariates. The corresponding causal odds ratio in men was 0.77 (0.65-0.92). This also was not influenced by baseline covariates or levels of physical activity. There was evidence for an independent causal effect of increased levels of physical activity on reduction of odds of functional limitation for men but not for women. Obese women experienced no protective effect of increased lean-to-fat mass. Normal-weight women experienced a benefit with increasing levels of physical activity.

CONCLUSIONS

Marginal structural models provide a means to address time-dependent confounding, which can occur in longitudinal studies. These analyses indicate that leisure time physical activity exerts its beneficial effects through reductions in fat mass relative to lean body mass.

Overweight and obesity and the burden of disease and disability in elderly men

OBJECTIVE

To examine the prevalence of disease burden and disability associated with overweight and obesity in men aged 60-79 y and to assess whether the current WHO weight guidelines are appropriate in the elderly.

DESIGN

Cross-sectional survey 20 y after enrollment.

SETTING

General practices in 24 British towns.

PARTICIPANTS

In total, 4232 men aged 60-79 y (77% of survivors) with measured weight and height.

MAIN OUTCOME MEASURES

Cardiovascular (CV) risk factors, prevalence of diabetes, cardiovascular disease, cancer, disability and regular medication.

RESULTS

In total, 17% of the men were obese (body mass index (BMI) >/=30 kg/m(2)) and a further 52% were overweight (BMI 25-29.9 kg/m(2)). Prevalence of hypertension, low HDL-cholesterol, high triglycerides and insulin resistance and the prevalence of most disease outcomes increased with increasing degrees of overweight/obesity. Men in the normal weight range (18.5-24.9 kg/m(2)) had the lowest prevalence of ill health. Compared with normal weight men, obese men showed a two-fold risk of major CVD (odds ratio (OR)=1.96, 95% CI 1.44-2.67) and locomotor disability (OR=2.26, 95% CI 1.66, 3.09) and were nearly three times as likely to have diabetes, CV interventions or to be on CV medication. Over 60% of the prevalence of high insulin resistance was attributable to overweight and obesity as was over a third of diabetes and hypertension, a quarter of locomotor disability and a fifth of major CVD.

CONCLUSION

In elderly men, overweight and obesity are associated with a significantly increased burden of disease, in particular CV-related disorders and disability. The current guidelines for overweight and obesity appear to be appropriate in elderly men.

Angiotensin-converting enzyme inhibition, body composition, and physical performance in aged rats

This study was designed to test the effects of angiotensin-converting enzyme (ACE) inhibition on body composition and physical performance in aged rats. Male Brown Norway x F344 rats were randomized to receive daily injections of enalapril (40 mg/kg or 80 mg/kg) or saline from 24 to 30 months of age. Body composition was determined using dual-energy X-ray absorptiometry (DXA), and physical performance was assessed using the grip strength and inclined plane procedures. Performance measures were assessed at baseline and monthly thereafter. DXA was performed at baseline, 3 months, and 6 months of follow-up. Compared with the enalapril groups, the saline group experienced a greater 6-month decline in the physical performance measures. Lean body mass declined in both groups; however, the enalapril groups also experienced a significant loss of fat mass. These results suggest that ACE inhibition may prevent age-related declines in physical performance, which may be mediated by a reduction in body fat mass.

The relationship among physical activity, obesity, and physical function in community-dwelling older women

BACKGROUND

The relationship between obesity and physical function is not well understood. Physical activity may be a key factor impacting on the relationship between obesity and physical function.

METHODS

Subjects included 171 community-dwelling women (mean age = 74.3, SD = 4.3) participating in a 14-year follow-up study to a walking intervention trial. Measures of obesity [body mass index (BMI)] and physical activity (Modified Paffenbarger Questionnaire) were collected in 1982, 1985, 1995, and 1999. Physical function was assessed in 1999 using the Functional Status Questionnaire (FSQ) and gait speed.

RESULTS

Measures of obesity from 1982 to 1995 and measures of physical activity from 1982 to 1995 were related to physical function in 1999. However, hierarchical regression analysis to predict physical function in 1999 controlling for the presence of chronic conditions indicated that physical activity from 1982 to 1995, and not obesity from 1982 to 1995, was an independent predictor of physical function (FSQ: adjusted R2 = 0.09, F = 4.68, P < 0.001; gait speed: adjusted R2 = 18.0, F = 9.41, P < 0.0001.

CONCLUSION

Physical activity appears to be as important if not more important than body weight in predicting future physical function.

Age-associated changes in skeletal muscles and their effect on mobility: an operational diagnosis of sarcopenia

Sarcopenia, the reduction of muscle mass and strength that occurs with aging, is widely considered one of the major causes of disability in older persons. Surprisingly, criteria that may help a clinician to identify persons with impaired muscle function are still lacking. Using data from a large representative sample of the general population, we examined how muscle function and calf muscle area change with aging and affect mobility in men and women free of neurological conditions. We tested several putative indicators of sarcopenia, including knee extension isometric torque, handgrip, lower extremity muscle power, and calf muscle area. For each indicator, sarcopenia was considered to be present when the measure was >2 SDs below the mean. For all four measures, the prevalence of sarcopenia increased with age, both in men and women. The age-associated gradient in prevalence was maximum for muscle power and minimum for calf-muscle area. However, lower extremity muscle power was no better than knee-extension torque or handgrip in the early identification of poor mobility, defined either as walking speed <0.8 m/s or inability to walk at least 1 km without difficulty and without developing symptoms. Optimal cutoff values that can be used in the clinical practice to identify older persons with poor mobility were developed. The findings of the study lay the basis for a cost-effective, clinical marker of sarcopenia based on a measure of isometric handgrip strength. Our findings should be verified in a longitudinal study.

Exercise and aging

There is increasing evidence that the black box we have referred to as"biologic aging" is composed of genetic factors and many types of environmental exposures. Some of the most potentially modifiable elements of this syndrome are those attributable to disuse or insufficient exposure to certain kinds or intensities of physical stressors during the course of the life span. Beneficial adaptations to exercise once thought restricted to genetically endowed master athletes now are seen to occur just as predictably in frail elders with chronic disease, opening the door to vastly improved physical function and associated health benefits. Knowledge of the benefits of physical activity, however well substantiated, may be necessary, but it is not sufficient to change either physician-prescribing habits or the likelihood of adoption and long-term adherence to exercise on the part of patients. Ultimately, the penetration of an exercise prescription to optimize aging into the most inactive cohorts in the community,who have the most to gain from increases in levels of physical activity and fitness, will depend on a combination of clear evidence-based guidelines coupled with health professional training and behavioral programs tailored to age-specific barriers and motivational factors.

Physical disability and muscular strength in relation to obesity and different body composition indexes in a sample of healthy elderly women

OBJECTIVES

The aim of the present study was to test the association between muscular strength, functional limitations, body composition measurements and indexes of sarcopenia in a sample of community-dwelling, elderly women at the high end of the functional spectrum.

DESIGN

Cross-sectional.

SUBJECTS

In all, 167 women aged 67-78 y were selected from the general population in central Verona. A group of 120 premenopausal healthy women aged 20-50 y represented the young reference group.

MEASUREMENTS

Body weight, height, body mass index (BMI) and the presence of acute and chronic conditions were evaluated in each subject. Body composition was measured by dual-energy X-ray absorptiometry (DXA). Physical functioning was assessed using a modified version of the Activities of Daily Living Scale. Dominant leg isometric strength was measured with a Spark Handheld Dynamometer.

RESULTS

Elderly women with BMI higher than 30 kg/m(2) and in the highest quintile of body fat percent showed a significantly higher prevalence of functional limitation. In our population study, about 40% of sarcopenic elderly women and 50% of elderly women with high body fat and normal muscle mass were functionally limited. The prevalence of functional limitation significantly increased in subjects with class II sarcopenia, defined according to the skeletal muscle mass index (SMI=skeletal muscle mass/body mass x 100). In logistic regression models, after adjusting for age and different chronic health conditions, subjects with BMI higher than 30 kg/m(2), in the highest quintile of body fat, or with high body fat and normal muscle mass or class II sarcopenia according to SMI, had a 3-4 times increased risk of functional limitations. Finally, isometric leg strength was significantly lower in subjects in the lowest quintile of relative muscle mass and in sarcopenic and sarcopenic obese women.

CONCLUSIONS

High body fat and high BMI values were associated with a greater probability of functional limitation in a population of elderly women at the high end of the functional spectrum. Among the different indexes of sarcopenia used in this study, only SMI predicted functional impairment and disability. Isometric leg strength was significantly lower in subjects with sarcopenia and sarcopenic obesity.

Muscle strength in obese elderly women: effect of recreational physical activity in a cross-sectional study

BACKGROUND

Muscle strength (MS) may be impaired in obese persons, and this impairment may be a consequence of both obesity and low physical fitness.

OBJECTIVE

We investigated whether MS differed between obese [body mass index (BMI; in kg/m2 > 29], normal-weight (BMI = 24-29), and lean (BMI < 24) elderly subjects and compared the MS of sedentary and active subjects according to their BMI group.

DESIGN

The study included 215 obese [ (+/- SD) age: 80.0 +/- 3.5 y; BMI: 31.9 +/- 2.6], 630 normal-weight (age: 80.2 +/- 3.7 y; BMI: 26.3 +/- 1.4), and 598 lean (age: 80.7 +/- 3.5 y; BMI: 21.6 +/- 1.8) women with good functional ability. A cross-sectional design was used. Anthropometric measures (weight, height); measures of appendicular skeletal muscle mass (by dual-energy X-ray absorptiometry), isometric knee and elbow extension (by statergometer), and isometric handgrip strength (by dynamometer); and data on health status and self-reported recreational physical activity (RPA: walking, gymnastics, cycling, swimming, gardening) were collected.

RESULTS

Absolute (unadjusted) MS was higher in obese than in lean women (P < 0.01), except for handgrip strength (P > 0.05). When adjusted for age, height, RPA, pain, depression, and appendicular skeletal muscle mass, MS did not differ significantly between obese, normal-weight, and lean subjects, except for knee extension (significant interaction effect with RPA; P = 0.01). With increasing BMI, lower limb strength did not change in the sedentary women but increased in active (> or = 1 h/wk in > or = 1 RPA for > or = 1 mo) women. All adjusted MS measures in active participants were significantly higher (P < 0.001) than those in their sedentary peers.

CONCLUSION

The adjusted MS of elderly women is not associated with obesity but is higher in active subjects than in sedentary ones, especially in the lower limbs of obese subjects.

Traditional and Novel Risk Factors in Older Adults: Cardiovascular Risk Assessment Late in Life

As a population-based, longitudinal study of nearly 6000 older American adults, the Cardiovascular Health Study provides an excellent opportunity to assess the roles of traditional and novel cardiovascular risk factors in the development of coronary heart disease. Cardiovascular Health Study investigators have analyzed both traditional risk factors, such as diabetes, hypertension, and smoking, and new risk factors, such as hemostatic factors, inflammatory markers, exposure to infectious agents, and genetic determinants. These analyses have led to several important conclusions. First, older adults without previous cardiovascular events have a tremendous burden of subclinical vascular disease, which may change how physicians view risk factor modification in this age group. Second, some traditional cardiovascular risk factors lose importance as predictors of cardiovascular disease among older adults. Third, even modest elevations in fasting blood glucose or systolic blood pressure-below the levels used to define diabetes or hypertension-may have prognostic implications. Fourth, novel cardiovascular risk factors may add further information about cardiovascular disease risk in older adults. Promising potential candidates identified in the Cardiovascular Health Study include markers of hemostatic activation, fibrinogen, factor VIII coagulant activity, C-reactive protein, and exposure to herpes simplex virus-1 and possibly chlamydia. Future Cardiovascular Health Study investigations will help to clarify which combination of traditional and newer risk factors provides the best estimate of cardiovascular risk for older adults.

Sarcopenia: alternative definitions and associations with lower extremity function

OBJECTIVES

To compare two sarcopenia definitions and examine the relationship between them and lower extremity function and other health related factors using data from the baseline examination of the Health Aging and Body Composition (Health ABC) Study.

DESIGN

Observational cohort study.

SETTING

Two U.S. communities in Memphis, Tennessee, and Pittsburgh, Pennsylvania.

PARTICIPANTS

Participants were aged 70 to 79 (N=2984, 52% women, 41% black).

MEASUREMENTS

Participants were assessed using dual energy x-ray absorptiometry and were classified as sarcopenic using two different approaches to adjust lean mass for body size: appendicular lean mass divided by height-squared (aLM/ht2) and appendicular lean mass adjusted for height and body fat mass (residuals).

RESULTS

These methods differed substantially in the classification of individuals as being sarcopenic, especially those who were more obese. The former method was highly correlated with body mass index and identified fewer overweight or obese individuals as sarcopenic. In both men and women, none of the obese group would be considered sarcopenic using the aLM/ht2 method, compared with 11.5% of men and 21.0% of women using the residuals method. In men, both classifications of sarcopenia were associated with smoking, poorer health, lower activity, and impaired lower extremity function. Fewer associations with health factors were noted in women, but the classification based on both height and fat mass was more strongly associated with lower extremity functional limitations (odds ratio (OR)=0.9, 95% confidence interval (CI)=0.7-1.2 for low kg/ht2; OR=1.9, 95% CI=1.4-2.5 for lean mass adjusted for height and fat mass).

CONCLUSION

These findings suggest that fat mass should be considered in estimating prevalence of sarcopenia in women and in overweight or obese individuals.

Análisis de la composición corporal por parámetros antropométricos y bioeléctricos

BACKGROUND

Interest in the study of body composition in childhood is increasing. Bioelectrical impedance analysis (BIA) is an accurate and reliable method.

OBJECTIVES

To determine anthropometric parameters, fat-free body mass and fat body mass using BIA and anthropometry, and to establish their relationship.

MATERIAL AND METHOD

A total of 365 healthy children (188 boys, 177 girls) aged 6.0 to 14.9 years were studied. Weight, height, arm circumference, skinfolds (bicipital, tricipital, subscapular and suprailiac) and bioelectrical parameters were measured. Body density was calculated from the four skinfold measurements using Brook's formula. Bioelectrical impedance was measured with a BIA-101 S (RJL Systems) using a fixed frequency (50 kHz). Fat-free body mass from BIA was calculated using Deurenberg's equation (FFM = 0.82 x height2/resistance).

RESULTS

We present the mean, standard deviation and 3rd, 5th, 10th, 25th, 50th, 75th, 90th, 95th and 97th percentiles of anthropometric variables and fat mass and fat-free mass estimated using BIA. Correlations were found between fat-free mass estimated using BIA and anthropometric variables. The reliability of BIA in estimating fat mass was assessed with intraclass correlation coefficients, which were excellent (0.948 in boys, and 0.945 in girls).

CONCLUSIONS

BIA is an easy, low-cost, and highly reliable method, making it a useful technique for studying human body composition. This method shows excellent correlation with anthropometric variables.