Assessment of physical activity in older individuals: a doubly labeled water study

Comparison of total and activity energy expenditure estimates from physical activity questionnaires and doubly labelled water: a systematic review and meta-analysis

Physical activity questionnaires (PAQ) could be suitable tools in free-living people for measures of physical activity, total and activity energy expenditure (TEE and AEE). This meta-analysis was performed to determine valid PAQ for estimating TEE and AEE using doubly labelled water (DLW). We identified data from relevant studies by searching Google Scholar, PubMed and Scopus databases. This revealed thirty-eight studies that had validated PAQ with DLW and reported the mean differences between PAQ and DLW measures of TEE (TEEDLW - TEEPAQ) and AEE (AEEDLW - AEEPAQ). We assessed seventy-eight PAQ consisting of fifty-nine PAQ that assessed TEE and thirty-five PAQ that examined AEE. There was no significant difference between TEEPAQ and TEEDLW with a weighted mean difference of -243·3 and a range of -841·4 to 354·6 kJ/d, and a significant weighted mean difference of AEEDLW - AEE PAQ 414·6 and a range of 78·7-750·5. To determine whether any PAQ was a valid tool for estimating TEE and AEE, we carried out a subgroup analysis by type of PAQ. Only Active-Q, administered in two seasons, and 3-d PA diaries were correlated with TEE by DLW at the population level; however, these two PAQ did not demonstrate an acceptable limit of agreement at individual level. For AEE, no PAQ was correlated with DLW either at the population or at the individual levels. Active-Q and 3-d PA diaries were identified as the only valid PAQ for TEE estimation. Further well-designed studies are needed to verify this result and identify additional valid PAQ.

Polish Adaptation of the Yale Physical Activity Survey: Measurement Properties

The aim of this study was to assess the measurement properties of a Polish adaptation of the Yale Physical Activity Survey (YPAS-PL). The Polish cultural adaptation of the YPAS was administered to a group of 104 people aged 65 to 89 years (mean age 72 ± 5). To assess the reliability of the YPAS-PL, a test-retest procedure was applied. Validity was assessed by comparing the results of the YPAS-PL with accelerometery (ActiGraph wGT3X+). The indicators based on the YPAS-PL activities checklist were characterized by high repeatability and had better reliability values than the YPAS-PL activity dimension indices (energy expenditure interclass correlation coefficient (ICC) = 0.81, total time physical activity ICC = 0.86). We noted a significant positive relationship between energy expenditure measured by an accelerometer and the YPAS-PL (r = 0.23). We can conclude that the YPAS-PL is an adequate tool for assessing energy expenditure related to physical activity in a Polish population of older adults. We also recommend the cautious and well thought-out use of the YPAS-PL activity dimension indices (summary, vigorous, leisurely walking, moving, standing, and sitting indexes).

Refining Low Physical Activity Measurement Improves Frailty Assessment in Advanced Lung Disease and Survivors of Critical Illness

RATIONALE

The frail phenotype has gained popularity as a clinically relevant measure in adults with advanced lung disease and in critical illness survivors. Because respiratory disease and chronic illness can greatly limit physical activity, the measurement of participation in traditional leisure time activities as a frailty component may lead to substantial misclassification of frailty in pulmonary and critical care patients.

OBJECTIVES

To test and validate substituting the Duke Activity Status Index (DASI), a simple 12-item questionnaire, for the Minnesota Leisure Time Physical Activity (MLTA) questionnaire, a detailed questionnaire covering 18 leisure time activities, as the measure of low activity in the Fried frailty phenotype (FFP) instrument.

METHODS

In separate multicenter prospective cohort studies of adults with advanced lung disease who were candidates for lung transplant and older survivors of acute respiratory failure, we assessed the FFP using either the MLTA or the DASI. For both the DASI and MLTA, we evaluated content validity by testing floor effects and construct validity through comparisons with conceptually related factors. We tested the predictive validity of substituting the DASI for the MLTA in the FFP assessment using Cox models to estimate associations between the FFP and delisting/death before transplant in those with advanced lung disease and 6-month mortality in older intensive care unit (ICU) survivors.

RESULTS

Among 618 adults with advanced lung disease and 130 older ICU survivors, the MLTA had a substantially greater floor effect than the DASI (42% vs. 1%, and 49% vs. 12%, respectively). The DASI correlated more strongly with strength and function measures than did the MLTA in both cohorts. In models adjusting for age, sex, comorbidities, and illness severity, substitution of the DASI for the MLTA led to stronger associations of the FFP with delisting/death in lung transplant candidates (FFP-MLTA hazard ratio [HR], 1.42; 95% confidence interval [CI], 0.55-3.65; FFP-DASI HR, 2.99; 95% CI, 1.03-8.65) and with mortality in older ICU survivors (FFP-MLTA HR, 2.68; 95% CI, 0.62-11.6; FFP-DASI HR, 5.71; 95% CI, 1.34-24.3).

CONCLUSIONS

The DASI improves the construct and predictive validity of frailty assessment in adults with advanced lung disease or recent critical illness. This simple questionnaire should replace the more complex MLTA in assessing the frailty phenotype in these populations.

A systematic literature review of reviews on techniques for physical activity measurement in adults: a DEDIPAC study

The links between increased participation in Physical Activity (PA) and improvements in health are well established. As this body of evidence has grown, so too has the search for measures of PA with high levels of methodological effectiveness (i.e. validity, reliability and responsiveness to change). The aim of this “review of reviews” was to provide a comprehensive overview of the methodological effectiveness of currently employed measures of PA, to aid researchers in their selection of an appropriate tool. A total of 63 review articles were included in this review, and the original articles cited by these reviews were included in order to extract detailed information on methodological effectiveness.

Self-report measures of PA have been most frequently examined for methodological effectiveness, with highly variable findings identified across a broad range of behaviours. The evidence-base for the methodological effectiveness of objective monitors, particularly accelerometers/activity monitors, is increasing, with lower levels of variability observed for validity and reliability when compared to subjective measures. Unfortunately, responsiveness to change across all measures and behaviours remains under-researched, with limited information available.

Other criteria beyond methodological effectiveness often influence tool selection, including cost and feasibility. However, researchers must be aware of the methodological effectiveness of any measure selected for use when examining PA. Although no “perfect” tool for the examination of PA in adults exists, it is suggested that researchers aim to incorporate appropriate objective measures, specific to the behaviours of interests, when examining PA in free-living environments.

Comparison of Different Physical Activity Measurement Methods in Adults Aged 45 to 64 Years Under Free-Living Conditions

OBJECTIVE

To compare physical activity (PA) measured by 4 methods in adults under free-living conditions in relation to selected demographic and anthropometric variables.

DESIGN

Cohort study.

SETTING

Department of Sports Medicine.

PARTICIPANTS

Clinically healthy men (81) and women (69) aged 45 to 64 years.

INTERVENTIONS

Physical activity monitoring for 7 consecutive days under free-living conditions by pedometer (P) and accelerometer (A) simultaneously and PA questionnaires: International Physical Activity Questionnaire (IPAQ) and Seven-Day Physical Activity Questionnaire Recall (SDPAR) completed after the 7-day PA.

MAIN OUTCOME MEASURES

Comparison of PA measured by pedometer, IPAQ, and SDPAR with accelerometer with regard to age, body mass, gender, and obesity type.

RESULTS

Total energy expenditure (EE) by IPAQ was higher than A (P < 0.001) in both groups regardless of age, body mass, or obesity type. Mean EE value by P was greater than A (P < 0.001) in central-obesity males and lower than A (P < 0.001) in central-obesity females. There were differences in step counts in women, unnoticed in men. SDPAR overestimated total EE in gynoid-obesity males and in central-obesity females compared with A. Ninety-five percent CI was the largest around IPAQ compared with P and SDPAR, with SDPAR showing the best agreement with A.

CONCLUSIONS

Body mass and obesity type influenced PA measurements. To monitor PA, it is recommended to use pedometer in normal bodyweight and overweight groups while accelerometer is advisable in obese subjects. A combined approach of objective and subjective PA monitoring tools is preferable.

Energy Expenditure in People with Diabetes Mellitus: A Review

Physical activity (PA) is an important non-therapeutic tool in primary prevention and treatment of diabetes mellitus (DM). To improve activity-based health management, patients need to quantify activity-related energy expenditure and the other components of total daily energy expenditure. This review explores differences between the components of total energy expenditure in patients with DM and healthy people and presents various tools for assessing the energy expenditure in subjects with DM. From this review, it appears that patients with uncontrolled DM have a higher basal energy expenditure (BEE) than healthy people which must be considered in the establishment of new BEE estimate equations. Moreover, studies showed a lower activity energy expenditure in patients with DM than in healthy ones. This difference may be partially explained by patient with DMs poor compliance with exercise recommendations and their greater participation in lower intensity activities. These specificities of PA need to be taken into account in the development of adapted tools to assess activity energy expenditure and daily energy expenditure in people with DM. Few estimation tools are tested in subjects with DM and this results in a lack of accuracy especially for their particular patterns of activity. Thus, future studies should examine sensors coupling different technologies or method that is specifically designed to accurately assess energy expenditure in patients with diabetes in daily life.

Minnesota Leisure Time Physical Activity Questionnaire in medical practice and health promotion

The prevention of chronic diseases, especially metabolic disorders, is based on modification of behavioural risk factors, in particular eating habits and physical activity. Numerous population studies have demonstrated a relationship between regular physical activity and decreased levels of risk factors for CVD (cardiovascular disease), type 2 diabetes and some cancers. Increasing the level of physical activity as part of the programs implemented for disease prevention or health promotion for selected populations requires a behavioural diagnosis, whereby an essential element is the preferred leisure-time activity in terms of the structure of negative health indicators. Evaluation of physical activity under population studies requires a simple, validated and inexpensive tool to be used in medical practice or health promotion. The Minnesota Leisure Time Physical Activity Questionnaire (MLTPAQ) is a tool currently often used and validated with laboratory methods. Standard MLTPAQ allows for assessment of the level of physical activity undertaken in leisure time. The authors present an algorithm for assessing leisure-time physical activity level based on MLTPAQ. The paper also reviews the practical application of the MLTPAQ questionnaire on healthy and patient populations in Poland and other countries by specialists in public health, health promotion and in medical practice.

Accelerometer-based measures in physical activity surveillance: current practices and issues

OBJECTIVE

Self-reports of physical activity (PA) have been the mainstay of measurement in most non-communicable disease (NCD) surveillance systems. To these, other measures are added to summate to a comprehensive PA surveillance system. Recently, some national NCD surveillance systems have started using accelerometers as a measure of PA. The purpose of this paper was specifically to appraise the suitability and role of accelerometers for population-level PA surveillance.

METHODS

A thorough literature search was conducted to examine aspects of the generalisability, reliability, validity, comprehensiveness and between-study comparability of accelerometer estimates, and to gauge the simplicity, cost-effectiveness, adaptability and sustainability of their use in NCD surveillance.

CONCLUSIONS

Accelerometer data collected in PA surveillance systems may not provide estimates that are generalisable to the target population. Accelerometer-based estimates have adequate reliability for PA surveillance, but there are still several issues associated with their validity. Accelerometer-based prevalence estimates are largely dependent on the investigators' choice of intensity cut-off points. Maintaining standardised accelerometer data collections in long-term PA surveillance systems is difficult, which may cause discontinuity in time-trend data. The use of accelerometers does not necessarily produce useful between-study and international comparisons due to lack of standardisation of data collection and processing methods. To conclude, it appears that accelerometers still have limitations regarding generalisability, validity, comprehensiveness, simplicity, affordability, adaptability, between-study comparability and sustainability. Therefore, given the current evidence, it seems that the widespread adoption of accelerometers specifically for large-scale PA surveillance systems may be premature.

Validation of a Computerized Use of Time Recall for Activity Measurement in Advanced-Age Adults

Background:

The Multimedia Activity Recall for Children and Adults (MARCA) is a computerized recall instrument that records use of time during 24 hr the previous day and has been developed to address limitations of current self-report physical activity measures for those in advanced age.

Methods:

Test–retest reliability and convergent validity of the adult MARCA were assessed in a sample of 45 advanced-age adults (age 84.9SD ±1.62 yr) as a subsample of the Life and Living in Advanced-Age Cohort Study New Zealand (LiLACS NZ). Test–retest methods required participants to recall the previous day’s activity using the MARCA twice within the same day. Convergent validity was assessed against accelerometry.

Results:

Test–retest reliability was high, with ICCs greater than .99 for moderate to vigorous physical activity (MVPA) and physical activity level (PAL). Compared with accelerometry, the MARCA demonstrated validity comparable to other self-report instruments with Spearman’s coefficients of .34 and .59 for time spent in nonsedentary physical activity and PAL.

Conclusion:

The MARCA is a valid and reliable self-report tool for physical activity behaviors in advanced-age adults.

A systematic review of reliability and objective criterion-related validity of physical activity questionnaires

Physical inactivity is one of the four leading risk factors for global mortality. Accurate measurement of physical activity (PA) and in particular by physical activity questionnaires (PAQs) remains a challenge. The aim of this paper is to provide an updated systematic review of the reliability and validity characteristics of existing and more recently developed PAQs and to quantitatively compare the performance between existing and newly developed PAQs.

A literature search of electronic databases was performed for studies assessing reliability and validity data of PAQs using an objective criterion measurement of PA between January 1997 and December 2011. Articles meeting the inclusion criteria were screened and data were extracted to provide a systematic overview of measurement properties. Due to differences in reported outcomes and criterion methods a quantitative meta-analysis was not possible.

In total, 31 studies testing 34 newly developed PAQs, and 65 studies examining 96 existing PAQs were included. Very few PAQs showed good results on both reliability and validity. Median reliability correlation coefficients were 0.62–0.71 for existing, and 0.74–0.76 for new PAQs. Median validity coefficients ranged from 0.30–0.39 for existing, and from 0.25–0.41 for new PAQs.

Although the majority of PAQs appear to have acceptable reliability, the validity is moderate at best. Newly developed PAQs do not appear to perform substantially better than existing PAQs in terms of reliability and validity. Future PAQ studies should include measures of absolute validity and the error structure of the instrument.

Validity of activity monitors in health and chronic disease: a systematic review

The assessment of physical activity in healthy populations and in those with chronic diseases is challenging. The aim of this systematic review was to identify whether available activity monitors (AM) have been appropriately validated for use in assessing physical activity in these groups. Following a systematic literature search we found 134 papers meeting the inclusion criteria; 40 conducted in a field setting (validation against doubly labelled water), 86 in a laboratory setting (validation against a metabolic cart, metabolic chamber) and 8 in a field and laboratory setting. Correlation coefficients between AM outcomes and energy expenditure (EE) by the criterion method (doubly labelled water and metabolic cart/chamber) and percentage mean differences between EE estimation from the monitor and EE measurement by the criterion method were extracted. Random-effects meta-analyses were performed to pool the results across studies where possible. Types of devices were compared using meta-regression analyses. Most validation studies had been performed in healthy adults (n = 118), with few carried out in patients with chronic diseases (n = 16). For total EE, correlation coefficients were statistically significantly lower in uniaxial compared to multisensor devices. For active EE, correlations were slightly but not significantly lower in uniaxial compared to triaxial and multisensor devices. Uniaxial devices tended to underestimate TEE (−12.07 (95%CI; -18.28 to −5.85) %) compared to triaxial (−6.85 (95%CI; -18.20 to 4.49) %, p = 0.37) and were statistically significantly less accurate than multisensor devices (−3.64 (95%CI; -8.97 to 1.70) %, p<0.001). TEE was underestimated during slow walking speeds in 69% of the lab validation studies compared to 37%, 30% and 37% of the studies during intermediate, fast walking speed and running, respectively. The high level of heterogeneity in the validation studies is only partly explained by the type of activity monitor and the activity monitor outcome. Triaxial and multisensor devices tend to be more valid monitors. Since activity monitors are less accurate at slow walking speeds and information about validated activity monitors in chronic disease populations is lacking, proper validation studies in these populations are needed prior to their inclusion in clinical trials.

Hormone replacement therapy and physical function in healthy older men. Time to talk hormones?

Improving physical function and mobility in a continuously expanding elderly population emerges as a high priority of medicine today. Muscle mass, strength/power, and maximal exercise capacity are major determinants of physical function, and all decline with aging. This contributes to the incidence of frailty and disability observed in older men. Furthermore, it facilitates the accumulation of body fat and development of insulin resistance. Muscle adaptation to exercise is strongly influenced by anabolic endocrine hormones and local load-sensitive autocrine/paracrine growth factors. GH, IGF-I, and testosterone (T) are directly involved in muscle adaptation to exercise because they promote muscle protein synthesis, whereas T and locally expressed IGF-I have been reported to activate muscle stem cells. Although exercise programs improve physical function, in the long-term most older men fail to comply. The GH/IGF-I axis and T levels decline markedly with aging, whereas accumulating evidence supports their indispensable role in maintaining physical function integrity. Several studies have reported that the administration of T improves lean body mass and maximal voluntary strength in healthy older men. On the other hand, most studies have shown that administration of GH alone failed to improve muscle strength despite amelioration of the detrimental somatic changes of aging. Both GH and T are anabolic agents that promote muscle protein synthesis and hypertrophy but work through separate mechanisms, and the combined administration of GH and T, albeit in only a few studies, has resulted in greater efficacy than either hormone alone. Although it is clear that this combined approach is effective, this review concludes that further studies are needed to assess the long-term efficacy and safety of combined hormone replacement therapy in older men before the medical rationale of prescribing hormone replacement therapy for combating the sarcopenia of aging can be established.

Reliability and validity of CHAMPS self-reported sedentary-to-vigorous intensity physical activity in older adults

BACKGROUND

Recent research highlights the potential value of differentiating between categories of physical activity intensities as predictors of health and well-being. This study sought to assess reliability and concurrent validity of sedentary (ie, 1 METs), low-light (ie, >1 and ≤2 METs; eg, playing cards), high-light (ie, >2 and <3 METs; eg, light walking), moderate-to-vigorous physical activity (MVPA, ≥3 METs), and "total activity" (≥2 METs) from the CHAMPS survey. Further, this study explored over-reporting and double-reporting.

METHODS

CHAMPS data were gathered from the Seniors Neighborhood Quality of Life Study, an observational study of adults aged 65+ years conducted in 2 US regions.

RESULTS

Participants (N = 870) were 75.3 ± 6.8 years old, with 56% women and 71% white. The CHAMPS sedentary, low-light, high-light, total activity, and MVPA variables had acceptable test-retest reliability (ICCs 0.56-0.70). The CHAMPS high-light (ρ = 0.27), total activity (ρ = 0.34), and MVPA (ρ = 0.37) duration scales were moderately associated with accelerometry minutes of corresponding intensity, and the sedentary scale (ρ = 0.12) had a lower, but significant correlation. Results suggested that several CHAMPS items may be susceptible to over-reporting (eg, walking, housework).

CONCLUSIONS

CHAMPS items effectively measured high-light, total activity, and MVPA in seniors, but further refinement is needed for sedentary and low-light activity.

Accelerometer use with children, older adults, and adults with functional limitations

Accurately assessing physical activity behavior in children, older adults, and adults with functional limitations is essential to further our understanding of determinants of physical activity behavior in these populations and to design, implement, and evaluate interventions designed to increase physical activity participation. Objective methods to assess physical activity behavior, owing to improvements in accuracy and precision over self-report measures, have become common in research and practice settings. This article reviews the current use of objective methods to assess physical activity in observational, determinant, and intervention studies for children, older adults, and adults with functional limitations. Important considerations are presented when adopting prediction algorithms developed on one population, and using in another population that is markedly different in age, health, and functional status. Best practices are presented, along with future recommendations for research to advance this area of scientific inquiry.

Predicting energy expenditure in elders with the metabolic cost of activities

INTRODUCTION

Measuring free-living energy expenditure in aging human is a considerable challenge. The objective of this study was to predict total energy expenditure (TEE) in elders by combining the metabolic cost of activities and accelerometer outputs.

METHODS

Seventeen elders (7 women, 10 men) aged 60 to 78 yr were recruited. Body composition was measured by dual x-ray absorptiometry. Doubly labeled water was used as the criterion standard to measure TEE on a 7-d time frame. During the same period, participants wore a uniaxial accelerometer (Caltrac) to estimate TEE. Resting metabolic rate and metabolic costs of sitting, standing, and walking (1, 3, and 5 km·h(-1)) were measured by indirect calorimetry.

RESULTS

There was no correlation between Caltrac's outputs and doubly labeled water measurement of TEE. The best predictors of TEE were fat-free mass, the metabolic cost of standing, and the metabolic cost of walking at 3 km·h(-1) (r = 0.78, P < 0.01).

CONCLUSIONS

Our results suggest that TEE may be estimated with good accuracy using fat-free mass, the cost of standing still, and the cost of walking at 3 km·h(-1). These predictors are easy to measure in older adults. Further work is needed to confirm our findings and develop prediction equation with these parameters.

Validity of the International Physical Activity Questionnaire and the Singapore Prospective Study Program physical activity questionnaire in a multiethnic urban Asian population

BACKGROUND

Physical activity patterns of a population remain mostly assessed by the questionnaires. However, few physical activity questionnaires have been validated in Asian populations. We previously utilized a combination of different questionnaires to assess leisure time, transportation, occupational and household physical activity in the Singapore Prospective Study Program (SP2). The International Physical Activity Questionnaire (IPAQ) has been developed for a similar purpose. In this study, we compared estimates from these two questionnaires with an objective measure of physical activity in a multi-ethnic Asian population.

METHODS

Physical activity was measured in 152 Chinese, Malay and Asian Indian adults using an accelerometer over five consecutive days, including a weekend. Participants completed both the physical activity questionnaire in SP2 (SP2PAQ) and IPAQ long form. 43 subjects underwent a second set of measurements on average 6 months later to assess reproducibility of the questionnaires and the accelerometer measurements. Spearman correlations were used to evaluate validity and reproducibility and correlations for validity were corrected for within-person variation of accelerometer measurements. Agreement between the questionnaires and the accelerometer measurements was also evaluated using Bland Altman plots.

RESULTS

The corrected correlation with accelerometer estimates of energy expenditure from physical activity was better for the SP2PAQ (vigorous activity: r = 0.73; moderate activity: r = 0.27) than for the IPAQ (vigorous activity: r = 0.31; moderate activity: r = 0.15). For moderate activity, the corrected correlation between SP2PAQ and the accelerometer was higher for Chinese (r = 0.38) and Malays (r = 0.57) than for Indians (r = -0.09). Both questionnaires overestimated energy expenditure from physical activity to a greater extent at higher levels of physical activity than at lower levels of physical activity. The reproducibility for moderate activity (accelerometer: r = 0.68; IPAQ: r = 0.58; SP2PAQ: r = 0.55) and vigorous activity (accelerometer: 0.52; IPAQ: r = 0.38; SP2PAQ: r = 0.75) was moderate to high for all instruments.

CONCLUSION

The agreement between IPAQ and accelerometer measurements of energy expenditure from physical activity was poor in our Asian study population. The SP2PAQ showed good validity and reproducibility for vigorous activity, but performed less well for moderate activity particularly in Indians. Further effort is needed to develop questionnaires that better capture moderate activity in Asian populations.

Comparative validity of physical activity measures in older adults

PURPOSE

To compare the validity of various physical activity measures with doubly labeled water (DLW)-measured physical activity energy expenditure (PAEE) in free-living older adults.

METHODS

Fifty-six adults aged ≥65 yr wore three activity monitors (New Lifestyles pedometer, ActiGraph accelerometer, and a SenseWear (SW) armband) during a 10-d free-living period and completed three different surveys (Yale Physical Activity Survey (YPAS), Community Health Activities Model Program for Seniors (CHAMPS), and a modified Physical Activity Scale for the Elderly (modPASE)). Total energy expenditure was measured using DLW, resting metabolic rate was measured with indirect calorimetry, the thermic effect of food was estimated, and from these, estimates of PAEE were calculated. The degree of linear association between the various measures and PAEE was assessed, as were differences in group PAEE, when estimable by a given measure.

RESULTS

All three monitors were significantly correlated with PAEE (r=0.48-0.60, P<0.001). Of the questionnaires, only CHAMPS was significantly correlated with PAEE (r=0.28, P=0.04). Statistical comparison of the correlations suggested that the monitors were superior to YPAS and modPASE. Mean squared errors for all correlations were high, and the median PAEE from the different tools was significantly different from DLW for all but the YPAS and regression-estimated PAEE from the ActiGraph.

CONCLUSIONS

Objective devices more appropriately rank PAEE than self-reported instruments in older adults, but absolute estimates of PAEE are not accurate. Given the cost differential and ease of use, pedometers seem most useful in this population when ranking by physical activity level is adequate.

Correlation between the Yale Physical Activity Survey (YPAS) and a submaximal performance-based test: a study in a population of elderly Spanish women

The aim of this study is to research the degree of correlation between the Spanish version of the questionnaire YPAS and the 6-minute walking test (6MWT) in women over 60. In addition, the authors analyzed the relationship between the variables age and body mass index (BMI) and the walked distance. The study was carried out with 44 elderly women (68.1 ± 5.4 years) who filled in the questionnaire and immediately afterwards performed the 6MWT. Total time and energy expenditure (EE) values obtained in the questionnaire are significantly correlated with the 6MWT (p=0.02; p=0.01, respectively), while BMI and age showed an inverse association (r=-0.433; r=-0.318, respectively) with the walked distance. The Spanish version of YPAS is beginning to be considered as a valid and useful tool for habitual physical activity (PA) measurement and can be used among elderly Spanish speaking women.

The usefulness of an accelerometer for monitoring total energy expenditure and its clinical application for predicting body weight changes in type 2 diabetic korean women

BACKGROUND

The purpose of this study was to evaluate the usefulness of an accelerometer in predicting body weight (BW) change during a lifestyle intervention and to find out whether exercise or overall physical activity is associated with change in insulin sensitivity and body composition.

METHODS

A total of 49 overweight (body mass index [BMI] ≥ 23 kg/m(2)) women with diabetes were enrolled and performed lifestyle intervention while monitoring BW, total energy expenditure (TEE) and physical activity energy expenditure (PAEE) using an accelerometer, and energy intake (EI) using a three-day dietary record at baseline and every 2 weeks for 12 weeks. We assessed body composition using bioimpedance analysis and compared the actual BW change to the predicted BW change, which was calculated from the energy deficit (ED) between EI and TEE (ED = EI-TEE).

RESULTS

Mean age was 57.2 years, duration of diabetes was 8.0 years, and BMI was 27.8 kg/m(2). There was no significant difference between EI and TEE at baseline. For 12 weeks, the ED was 474.0 kcal·day(-1), which was significantly correlated with BW change (-3.1 kg) (r = 0.725, P < 0.001). However, the actual BW change was 50% lower than the predicted BW change. Both TEE and PAEE correlated with change in K(ITT) (r = 0.334, P = 0.019; r = 0.358, P = 0.012, respectively), BMI (r = -0.395, P = 0.005; r = -0.347, P = 0.015, respectively), and fat mass (r = -0.383, P = 0.007; r = -0.395, P = 0.005, respectively), but only TEE correlated with fat free mass change (r = -0.314, P = 0.030).

CONCLUSION

The accelerometer appears to be a useful tool for measuring TEE under free-living conditions for both short- and long-term periods.

Objective light-intensity physical activity associations with rated health in older adults

The extent to which light-intensity physical activity contributes to health in older adults is not well known. The authors examined associations between physical activity across the intensity spectrum (sedentary to vigorous) and health and well-being variables in older adults. Two 7-day assessments of accelerometry from 2005 to 2007 were collected 6 months apart in the observational Senior Neighborhood Quality of Life Study of adults aged >65 years in Baltimore, Maryland, and Seattle, Washington. Self-reported health and psychosocial variables (e.g., lower-extremity function, body weight, rated stress) were also collected. Physical activity based on existing accelerometer thresholds for moderate/vigorous, high-light, low-light, and sedentary categories were examined as correlates of physical health and psychosocial well-being in mixed-effects regression models. Participants (N = 862) were 75.4 (standard deviation, 6.8) years of age, 56% female, 71% white, and 58% overweight/obese. After adjustment for study covariates and time spent in moderate/vigorous physical activity and sedentary behavior, low-light and high-light physical activity were positively related to physical health (all P < 0.0001) and well-being (all P < 0.001). Additionally, replacing 30 minutes/day of sedentary time with equal amounts of low-light or high-light physical activity was associated with better physical health (all P < 0.0001). Objectively measured light-intensity physical activity is associated with physical health and well-being variables in older adults.

Patterns of physical activity in different domains and implications for intervention in a multi-ethnic Asian population: a cross-sectional study

Background

The benefits of regular physical activity for quality of life and disease prevention have been well documented. Identification of low activity groups would facilitate interventional programs. Many studies have focussed on leisure time activity, which may not capture the spectrum of physical activity relevant to disease prevention. Furthermore, few studies have been conducted in urban Asian settings.

Methods

We evaluated physical activity in different domains (leisure time, occupational, household and transportation) and its sociodemographic determinants in 4750 adult Chinese, Malay, and Asian Indian Singaporeans. Physical activity was assessed using locally validated questionnaires.

Results

Occupational and household activity contributed substantially more to total physical activity than leisure time or transportation activity. However, when only activity of at least moderate intensity was considered leisure time activity contributed most to total physical activity. Higher socio-economic status was associated with more leisure time activity, but less total physical activity due to reduced activity in the other domains. Chinese ethnicity was also associated with less total physical activity as a result of less activity in non-leisure time domains.

Conclusions

In assessing levels of physical activity and recommending changes, it is important to consider physical activity in different domains. Focus on leisure-time physical activity alone could identify the wrong groups for intervention and miss opportunities for increasing physical activity in populations.

A comparison of questionnaire, accelerometer, and pedometer: measures in older people

PURPOSE

To compare (i) the convergent validity of the self-report Zutphen Physical Activity Questionnaire with the 7-d objective physical activity (PA) measurement by accelerometers and pedometers and (ii) the construct validity of these measures by examining their associations with physical health and psychological and anthropometric variables.

METHODS

Five hundred and sixty community-dwelling people aged > or =65 yr were invited from a UK primary care practice and 238 (43%) participated (mean age = 74, 53% male). PA was assessed subjectively by the Zutphen questionnaire (modified to include housework questions) and objectively by the 7-d accelerometer monitoring: a random half also had a pedometer. A questionnaire assessed health, disability, and psychological factors, and anthropometric assessment was performed.

RESULTS

Mean daily PA levels were as follows: Zutphen = 9.1 kcal x kg(-1) x d(-1) (SD = 6.6 kcal x kg(-1) x d(-1)); accelerometer activity count = 226,648 (SD = 121,966); accelerometer step count = 6495 (SD = 3212); and pedometer step count = 6712 (SD = 3526). Zutphen score was moderately correlated with accelerometer activity count (R = 0.34, P < 0.001) and pedometer step count (R = 0.36, P < 0.001). Pedometer step count was highly correlated with accelerometer activity count (R = 0.82, P< 0.001) and accelerometer step count (R = 0.86, P < 0.001). Objective PA measures showed strong associations with health and anthropometric and psychological variables. Zutphen score was not significantly related to most health or anthropometric measures but was associated with psychological variables and provided information about activity type.

CONCLUSIONS

Convergent validity was strong between accelerometers and pedometers but weaker between these and self-report Zutphen. Pedometers may be preferred to accelerometers for simple studies due to their lower cost. Objective measures had better construct validity, being more strongly associated with established PA determinants, and thus offered better value to researchers than the questionnaire, but the latter provided useful detail on activity type, so a combined approach to PA assessment may be preferable.

Physical activity and years of healthy life in older adults: results from the cardiovascular health study

Little is known about how many years of life and disability-free years seniors can gain through exercise. Using data from the Cardiovascular Health Study, the authors estimated the extra years of life and self-reported healthy life (over 11 years) and years without impairment in activities of daily living (over 6 years) associated with quintiles of physical activity (PA) in older adults from different age groups. They estimated PA from the Minnesota Leisure Time Activities Questionnaire. Multivariable linear regression adjusted for health-related covariates. The relative gains in survival and years of healthy life (YHL) generally were proportionate to the amount of PA, greater among those 75+, and higher in men. Compared with being sedentary, the most active men 75+ had 1.49 more YHL (95% CI: 0.79, 2.19), and the most active women 75+ had 1.06 more YHL (95% CI: 0.44, 1.68). Seniors over age 74 experience the largest relative gains in survival and healthy life from physical activity.

Measures of physical activity using cell phones: validation using criterion methods

Background

Physical activity is associated with reduced risks of many chronic diseases. Data collected on physical activity in large epidemiological studies is often based on paper questionnaires. The validity of these questionnaires is debated, and more effective methods are needed.

Objective

This study evaluates repeated measures of physical activity level (PAL) and the feasibility of using a Java-based questionnaire downloaded onto cell phones for collection of such data. The data obtained were compared with reference estimates based on the doubly labeled water method and indirect calorimetry (PAL_ref).

Method

Using a Java-based cell phone application, 22 women reported their physical activity based on two short questions answered daily over a 14-day period (PAL_cell). Results were compared with reference data obtained from the doubly labeled water method and indirect calorimetry (PAL_ref). Results were also compared against physical activity levels assessed by two regular paper questionnaires completed by women at the end of the 14-day period (PAL_quest1 and PAL_quest2). PAL_cell, PAL_quest1, and PAL_quest2 were compared with PAL_ref using the Bland and Altman procedure.

Results

The mean difference between PAL_cell and PAL_ref was small (0.014) with narrow limits of agreement (2SD = 0.30). Compared with PAL_ref, the mean difference was also small for PAL_quest1 and PAL_quest2 (0.004 and 0.07, respectively); however, the limits of agreement were wider (PAL_quest1, 2SD = 0.50 and PAL_quest2, 2SD = 0.90). The test for trend was statistically significant for PAL_quest1 (slope of regression line = 0.79, P = .04) as well as for PAL_quest2 (slope of regression line = 1.58, P < .001) when compared with PAL_ref.

Conclusion

A Java-based physical activity questionnaire administered daily using cell phones produced PAL estimates that agreed well with PAL reference values. Furthermore, the limits of agreement between PAL obtained using cell phones, and reference values were narrower than for corresponding estimates obtained using paper questionnaires. Java-based questionnaires downloaded onto cell phones may be a feasible and cost-effective method of data collection for large-scale prospective studies of physical activity.

Ability of physical activity measurements to assess health-related risks

The aim of this study is to evaluate if two different physical activity (PA) questionnaires have similar ability to rank individuals, and to examine associations with cardiovascular-metabolic risk factors, compared to an objective measure. In a random sample (n=369, age: 65+/-6 years) from the population-based 'Malmö Diet and Cancer' (MDC) cohort, PA was measured by a leisure-time comprehensive questionnaire (MDC-score), a simple leisure-time questionnaire and by accelerometer-monitoring (CSA). Moderate correlations were observed between MDC-score and CSA in men and women (r=0.35 and 0.24, respectively). In men, both questionnaires and CSA were inversely associated with waist circumference, insulin resistance and metabolic syndrome. In women, the MDC-score was positively associated with high-density lipoprotein-cholesterol, and the simple questionnaire inversely associated with anthropometric indexes, but no association was seen between PA estimates and cardiovascular components. We conclude that both PA questionnaires distinguish health risks associated with anthropometric-metabolic risk factors, particularly in men.

Estimating energy expenditure with the RT3 triaxial accelerometer

The RT3 is a relatively new triaxial accelerometer that has replaced the TniTrac. The aim of this study was to validate the RT3 against doubly labeled water (DLW) in a free-living, mixed weight sample of adults. Total energy expenditure (TEE) was measured over a 15-day period using DLW Activity-related energy expenditure (AEE) was estimated by subtracting resting energy expenditure and thermic effect of feeding from TEE. The RT3 triaxial accelerometer was worn over 14 consecutive days. TEE and AEE were estimated using the RT3 proprietary equation. Thirty-six adults ages 18-56 years (56% women) with an average weight of 75.9 kg (SD = 14.8) completed all measurements. Compared to DLW the RT3 underestimated TEE by 539 kJ (4%) and AEE by 485 kJ (15%) on average. The RT3 provided a relatively accurate assessment of free-living activity-related energy expenditure at the group level and generally underestimated total and activity-related energy expenditure compared to DLW

Age differences in the relation of perceived neighborhood environment to walking

PURPOSE

The strength of the relationship of environment to physical activity may differ by age group. Older adults were expected to be more affected by environmental attributes than younger adults. The present study examined age-related differences in associations between perceived neighborhood environment and physical activity.

METHODS

Participants were 1623 adults aged 20 to 97 yr divided into five groups: ages 20-39, 40-49, 50-65, 66-75, and 76+. They were recruited from King County/Seattle, WA, neighborhoods selected to vary in land use and median income. Participants completed questionnaires about neighborhood environment attributes and walking for transportation and for leisure purposes. Neighborhood environment, within a 15- to 20-min walk from home, was measured on nine attributes with the validated Neighborhood Environment Walkability Scale questionnaire: residential density, proximity to nonresidential land uses, ease of access to nonresidential uses, street connectivity, walking/cycling facilities, esthetics, pedestrian traffic safety, crime safety, and proximity to recreation facilities. Participants reported frequency and duration of walking using the validated International Physical Activity Questionnaire and the Community Healthy Activities Model Program for Seniors. Partial correlations were computed, adjusting for demographics.

RESULTS

Walking for transportation was significantly related to multiple perceived neighborhood attributes in all age groups, although walking for leisure was not. Walking for transportation was significantly related to almost all neighborhood environment variables in the youngest age group. In contrast, only two environmental attributes, proximity to nonresidential uses (like shops) and recreation facilities, were moderately correlated with walking for transportation in the two oldest groups.

CONCLUSION

Communities need to be designed with many favorable environmental attributes to support walking for transportation among younger adults. Having nonresidential destinations and recreation facilities within walking distance may be among the most important attributes to support older adults' physical activity.

The long-term relationship between high-intensity volunteering and physical activity in older African American women

OBJECTIVES

Experience Corps (EC) places older volunteers in public elementary schools in 20 cities across the country. The EC program in Baltimore is a health promotion intervention designed to improve the academic outcomes of children and increase older adult volunteer physical activity. We sought to determine if there were sustained increases in physical activity with participation in EC.

METHODS

Seventy-one African American women volunteers in the Baltimore EC were compared with 150 African American women in the Women's Health and Aging Studies (WHAS) I and II; all were aged 65-86 years with comparable Social Economic Status, frailty, and self-reported health status. Using a regression model, we evaluated physical activity adjusting for a propensity score and time of follow-up over 3 years.

RESULTS

EC volunteers reported a sustained increase in physical activity as compared with the comparison cohort. Baseline physical activity for individuals with a median propensity score was 420 kcal/wk for both groups. At 36 months, EC volunteers reported 670 kcal/week compared with 410 kcal/week in WHAS (p = .04). Discussion These findings suggest that high-intensity senior service programs that are designed as health promotion interventions could lead to sustained improvements in physical activity in high-risk older adults, while simultaneously addressing important community needs.

A comparison of direct versus self-report measures for assessing physical activity in adults: a systematic review

BACKGROUND

Accurate assessment is required to assess current and changing physical activity levels, and to evaluate the effectiveness of interventions designed to increase activity levels. This study systematically reviewed the literature to determine the extent of agreement between subjectively (self-report e.g. questionnaire, diary) and objectively (directly measured; e.g. accelerometry, doubly labeled water) assessed physical activity in adults.

METHODS

Eight electronic databases were searched to identify observational and experimental studies of adult populations. Searching identified 4,463 potential articles. Initial screening found that 293 examined the relationship between self-reported and directly measured physical activity and met the eligibility criteria. Data abstraction was completed for 187 articles, which described comparable data and/or comparisons, while 76 articles lacked comparable data or comparisons, and a further 30 did not meet the review's eligibility requirements. A risk of bias assessment was conducted for all articles from which data was abstracted.

RESULTS

Correlations between self-report and direct measures were generally low-to-moderate and ranged from -0.71 to 0.96. No clear pattern emerged for the mean differences between self-report and direct measures of physical activity. Trends differed by measure of physical activity employed, level of physical activity measured, and the gender of participants. Results of the risk of bias assessment indicated that 38% of the studies had lower quality scores.

CONCLUSION

The findings suggest that the measurement method may have a significant impact on the observed levels of physical activity. Self-report measures of physical activity were both higher and lower than directly measured levels of physical activity, which poses a problem for both reliance on self-report measures and for attempts to correct for self-report - direct measure differences. This review reveals the need for valid, accurate and reliable measures of physical activity in evaluating current and changing physical activity levels, physical activity interventions, and the relationships between physical activity and health outcomes.

Concurrent comparison of energy intake and expenditure among adults in Butajira District, Ethiopia

Objective

To estimate and compare dietary energy intake (DEI) and total energy expenditure (TEE) among adults, using questionnaires.

Design

Comparative, cross-sectional study.

Setting

Community-based, at the demographic surveillance site (DSS) in Butajira District of Ethiopia.

Subjects

A total of 619 adults, 18–64 years of age, were randomly selected from among the urban and rural population of Butajira using the DSS sampling frame. Habitual dietary intake and physical activity were assessed using questionnaires. BMR was estimated using a regression equation, and TEE was calculated from BMR and the metabolic energy equivalent task (MET) and duration of reported activities. Physical activity level (PAL) was calculated as TEE/BMR, while food intake level (FIL) was calculated as DEI/BMR. The mean DEI:TEE ratio was used to evaluate reported DEI at the population level, while individual misreporters were identified by applying the Goldberg cut-off points at three levels of PAL.

Results

Based on the Goldberg method, 57 % of the study participants were identified as acceptable reporters of DEI, among whom mean TEE was 8·21 (95 % CI 8·01, 8·42) MJ (1963 (95 % CI 1914, 2012) kcal), mean DEI was 8·13 (95 % CI 7·93, 8·34) MJ (1944 (95 % CI 1895, 1993) kcal) and mean DEI:TEE was 1·01 (95 % CI 0·99, 1·04).

Conclusion

The dietary history and physical activity questionnaires provide comparable estimates of mean energy intake and expenditure at a population level. Acceptable reporters have to be identified in order to obtain better estimates. Questionnaire-based estimates of energy intake should not be interpreted without an inherent system of comparison or validation.

Physical activity in aging: comparison among young, aged, and nonagenarian individuals

Physical activity (PA) is known to decline with age; however, there is a paucity of data on activity in persons who are in their nineties and beyond. We used objective and reliable methods to measure PA in nonagenarians (>or=90 yr; n=98) and hypothesized that activity would be similar to that of aged (60-74 yr; n=58) subjects but less than in young (20-34 yr; n=53) volunteers. Total energy expenditure (TEE) was measured by doubly labeled water over 14 days and resting metabolic rate (RMR) by indirect calorimetry. Measures of PA included activity energy expenditure adjusted for body composition, TEE adjusted for RMR, physical activity level (PAL), and activity over 14 days by accelerometry expressed as average daily durations of light and moderate activity. RMR and TEE were lower with increasing age group (P<0.01); however, RMR was not different between aged and nonagenarian subjects after adjusting for fat-free mass, fat mass, and sex. Nonagenarians had a lower PAL and were more sedentary than the aged and young groups (P<0.01); however, the nonagenarians who were more active on a daily basis walked further during a timed test, indicating higher physical functionality. For all measures of activity, no differences were found between young and aged volunteers. PA was markedly lower in nonagenarians compared with young and aged adults. Interestingly, PA was similar between young volunteers and those who were in their 60s and 70s, likely due to the sedentary nature of our society, particularly in young adults.

Validity of the modified Baecke questionnaire: comparison with energy expenditure according to the doubly labeled water method

Background

In epidemiological research, physical activity is usually assessed by questionnaires. Questionnaires are suitable for large study populations since they are relatively inexpensive and not very time consuming. However, questionnaire information is by definition subjective and prone to recall bias, especially among elderly subjects. The Modified Baecke Questionnaire, developed by Voorrips and coworkers, measures habitual physical activity in the elderly. The questionnaire includes questions on household activities, sports, and leisure time activities, over a time period of one year. The Modified Baecke Questionnaire results in a score to classify people as high, moderate, or low in daily physical activity, based on tertiles.

Methods

The validity of the Modified Baecke Questionnaire score was assessed among 21 elderly men and women using the doubly labeled water method as the reference criterion. This method is considered to be the gold standard for measuring energy expenditure in free-living individuals. Energy expenditure on physical activity is estimated by the ratio of total energy expenditure measured by the doubly labeled water method and resting metabolic rate measured by indirect calorimetry. This ratio is called the physical activity ratio.

Results

The Spearman correlation coefficient between the questionnaire score and the physical activity ratio (PAR) was 0.54 (95% CI 0.22–0.66). Correct classification by the questionnaire occurred in 71% of participants who were in the lowest tertile of PAR, in 14% of participants in the middle tertile, and in 43% of participants in the highest tertile. Subjects were not wrongly classified in an opposite tertile.

Conclusion

The validity of the Modified Baecke Questionnaire is fair-to-moderate. This study shows that the questionnaire can correctly classify individuals as low or high active, but does a poor job for moderately active individuals.

Construct validation of physical activity surveys in culturally diverse older adults: a comparison of four commonly used questionnaires

The purpose of this study was to establish validity evidence of four physical activity (PA) questionnaires in culturally diverse older adults by comparing self-report PA with performance-based physical function. Participants were 54 older adults who completed the Continuous Scale Physical Functional Performance 10-item Test (CS-PFP10), Physical Activity Scale for the Elderly (PASE), HAMPS Physical Activity Questionnaire for Older Adults, Yale Physical Activity Survey (YPAS), and modified Baecke questionnaire. The total PASE score, three outcome scores for the CHAMPS, and three summary indices for the YPAS were significantly correlated with total CS-PFP10 score. The modified Baecke exhibited no correlations with CS-PFP10 scores. The PASE, CHAMPS, and YPAS appear to be the most valid PA self-report questionnaires for culturally diverse older adults.

Estimating activity energy expenditure: how valid are physical activity questionnaires?

Activity energy expenditure (AEE) is the modifiable component of total energy expenditure (TEE) derived from all activities, both volitional and nonvolitional. Because AEE may affect health, there is interest in its estimation in free-living people. Physical activity questionnaires (PAQs) could be a feasible approach to AEE estimation in large populations, but it is unclear whether or not any PAQ is valid for this purpose. Our aim was to explore the validity of existing PAQs for estimating usual AEE in adults, using doubly labeled water (DLW) as a criterion measure. We reviewed 20 publications that described PAQ-to-DLW comparisons, summarized study design factors, and appraised criterion validity using mean differences (AEE(PAQ) - AEE(DLW), or TEE(PAQ) - TEE(DLW)), 95% limits of agreement, and correlation coefficients (AEE(PAQ) versus AEE(DLW) or TEE(PAQ) versus TEE(DLW)). Only 2 of 23 PAQs assessed most types of activity over the past year and indicated acceptable criterion validity, with mean differences (TEE(PAQ) - TEE(DLW)) of 10% and 2% and correlation coefficients of 0.62 and 0.63, respectively. At the group level, neither overreporting nor underreporting was more prevalent across studies. We speculate that, aside from reporting error, discrepancies between PAQ and DLW estimates may be partly attributable to 1) PAQs not including key activities related to AEE, 2) PAQs and DLW ascertaining different time periods, or 3) inaccurate assignment of metabolic equivalents to self-reported activities. Small sample sizes, use of correlation coefficients, and limited information on individual validity were problematic. Future research should address these issues to clarify the true validity of PAQs for estimating AEE.

Physical activity assessment with accelerometers: an evaluation against doubly labeled water

This review focuses on the ability of different accelerometers to assess daily physical activity as compared with the doubly labeled water (DLW) technique, which is considered the gold standard for measuring energy expenditure under free-living conditions. The PubMed Central database (U.S. NIH free digital archive of biomedical and life sciences journal literature) was searched using the following key words: doubly or double labeled or labeled water in combination with accelerometer, accelerometry, motion sensor, or activity monitor. In total, 41 articles were identified, and screening the articles' references resulted in one extra article. Of these, 28 contained sufficient and new data. Eight different accelerometers were identified: 3 uniaxial (the Lifecorder, the Caltrac, and the CSA/MTI/Actigraph), one biaxial (the Actiwatch AW16), 2 triaxial (the Tritrac-R3D and the Tracmor), one device based on two position sensors and two motion sensors (ActiReg), and the foot-ground contact pedometer. Many studies showed poor results. Only a few mentioned partial correlations for accelerometer counts or the increase in R(2) caused by the accelerometer. The correlation between the two methods was often driven by subject characteristics such as body weight. In addition, standard errors or limits of agreement were often large or not presented. The CSA/MTI/Actigraph and the Tracmor were the two most extensively validated accelerometers. The best results were found for the Tracmor; however, this accelerometer is not yet commercially available. Of those commercially available, only the CSA/MTI/Actigraph has been proven to correlate reasonably with DLW-derived energy expenditure.

Is overweight/obesity associated with short sleep duration in older women?

BACKGROUND AND AIM

No study to date has documented the association between short sleep duration and the risk for obesity in older people. Therefore, the aim of this study was to examine cross-sectional associations between short sleep duration and variations in body fat indices in older women.

METHODS

Anthropometric and body composition measurements, resting energy expenditure, daily energy expenditure, daily energy intake, plasma lipid-lipoprotein profile, and self-reported sleep duration were determined in a sample of 90 women of 50 years and above.

RESULTS

The odds ratios for overweight/obesity were comparable in subjects reporting <7 hours and >or=7 hours of sleep per day, with or without adjustment for age, daily energy expenditure and daily energy intake. The results did not permit to observe any significant difference between the two sleeper groups for all the variables investigated. The correlations between sleep duration and adiposity indices were also non significant.

CONCLUSIONS

Short sleep duration does not predict an increased risk of being overweight/obese in older women. This observation, together with our previously reported results in younger subjects, suggests that the sleep-body fat relationship progressively becomes less detectable with increasing in age.

Activity monitoring and energy expenditure in COPD patients: a validation study

There is increasing interest in the objective measurement of physical activity in chronic obstructive pulmonary disease (COPD) patients due to the close relationship between physical activity level, health, disability and mortality. We aimed to (a) determine the validity and reproducibility of an activity monitor that integrates accelerometry with multiple physiologic sensors in the determination of energy expenditure in COPD subjects and (b) to document the independent contribution of the additional physiologic sensors to accelerometry measures in improving true energy expenditure determination. Eight subjects (4 male, FEV(1) 56.4 +/- 14.1%, RV 145.0 +/- 75.7%) performed 2 separate 6-minute walk and 2 incremental shuttle walk exercise tests. Energy expenditure was calculated during each exercise test using the physiologic activity monitor and compared to a validated exhaled breath metabolic system. Test-retest reproducibility of physiologic activity monitor during the walking tests was comparable to an exhaled breath metabolic system. Physiologic sensor data significantly improved the explained variance in energy expenditure determination (r(2)=0.88) compared to accelerometry data alone (r(2)=0.68). This physiologic activity monitor provides a valid and reproducible estimate of energy expenditure during slow to moderate paced walking in a laboratory setting and represents an objective method to assess activity in COPD subjects.

Physical activity-related energy expenditure with the RT3 and TriTrac accelerometers in overweight adults

OBJECTIVE

The objective was to evaluate two accelerometers, the RT3 and the TriTrac-R3D for their ability to produce estimates of physical activity-related energy expenditure (PAEE) in overweight/obese adults.

RESEARCH METHODS AND PROCEDURES

PAEE estimates from both accelerometers were obtained in two experiments. In Experiment 1, 13 overweight/obese subjects (BMI 34.2+/-6.4 kg/m2) were monitored over 2 weeks in everyday life, PAEE being simultaneously measured by the doubly labeled water method (DLW). In Experiment 2, 8 overweight/obese subjects (BMI 34.3+/-5.0 kg/m2) and 10 normal-weight subjects (BMI 20.8+/-2.1 kg/m2) were monitored during a treadmill walking protocol, PAEE being simultaneously measured by indirect calorimetry.

RESULTS

In Experiment 1, there was no significant difference between methods in mean PAEE (DLW: 704+/-223 kcal/d, RT3: 656+/-140 kcal/d, TriTrac-R3D 624+/-419 kcal/d). The relative difference between methods (accelerometer vs. DLW) was -17.1%+/-16.7% for the RT3 and -20.0+/-44.6% for the TriTrac-R3D. Correlation for PAEE between RT3 and DLW was higher than between TriTrac-R3D and DLW (r=0.67, p<0.05 and r=0.36, p=0.25, respectively). The 95% confidence interval (CI) (kcal/d) of the mean difference between methods was large, amounting to -385 to 145 for the RT3 and -887 to 590 for the TriTrac-R3D. In Experiment 2, both accelerometers were sensitive to the changes in treadmill speed, with no significant difference in mean PAEE between methods in overweight/obese subjects.

CONCLUSIONS

Although both accelerometers did not provide accurate estimates of PAEE at individual levels, the data suggest that RT3 has the potential to assess PAEE at group levels in overweight/obese subjects.

Comparing different measures of energy expenditure in human subjects resident in a metabolic facility

OBJECTIVE

To compare energy expenditure (EE) measured by doubly labeled water (DLW) with other measures, both physical and based on subjective questionnaires.

DESIGN

A comparison of methods in a stratified sample of adult volunteers.

SETTING

The feeding behaviour suite (FBS) at the Rowett Research Institute, Aberdeen.

SUBJECTS

A total of 59 subjects, stratified for age, sex and body mass index (BMI).

INTERVENTIONS

EE was assessed by DLW (validated using measurements of energy balance), heart rate monitor (HRM), activity monitor (Caltrac), 24-h physical activity diary (PAD) and 7-day physical activity recall. Energy intake was assessed using covert (investigator-weighed) food intake (EI). Data were collected over a 12-day period of residence in the Rowett's FBS.

RESULTS

No methods correlated highly with physical activity assessed by DLW. Physical methods correlated more closely than did subjective recording. All methods (except EI) significantly underestimated EE, estimated by DLW. There were no significant differences in association between methods and sex, age, BMI or fat-free mass.

CONCLUSION

EE is difficult to measure precisely or accurately with current approaches but physical methods are slightly better than subjective accounts.

Effect of sarcopenia on cardiovascular disease risk factors in obese postmenopausal women

OBJECTIVE

To compare sarcopenic-obese and obese postmenopausal women for risk factors predisposing to cardiovascular disease (CVD) and determine whether there may be a relationship between muscle mass and metabolic risk in obese postmenopausal women.

RESEARCH METHODS AND PROCEDURES

In this cross-sectional study, 22 healthy obese postmenopausal women (mean age, 66 +/- 5 years; mean BMI, 27 +/- 3 kg/m(2)) were divided into two groups matched for age (+/-2 years) and fat mass (FM) (+/-2%). Sarcopenia was defined as a muscle mass index of <14.30 kg fat-free mass (FFM)/m(2) (which corresponds to 1 standard deviation below the values of a young reference population), and obesity was defined as an FM of >35% (which corresponds to the World Health Organization guidelines). FM, FFM (measured by DXA), daily energy expenditure (accelerometry), dietary intake (3-day dietary record), and blood biochemical analyses (lipid profile, insulin, glucose, and C-reactive protein) were obtained. Visceral fat mass (VFM) was calculated by the equation of Bertin, which estimates VFM from DXA measurements.

RESULTS

Obese women had more FFM (p = 0.006), abdominal FM (p = 0.047), and VFM (p = 0.041) and a worse lipid profile [p = 0.040 for triglycerides; p = 0.004 for high-density lipoprotein (HDL); p = 0.026 for total cholesterol/HDL] than sarcopenic-obese postmenopausal women. Obese women also ingested significantly more animal (p = 0.001) and less vegetal proteins (p = 0.013), although both groups had a similar total protein intake (p = 0.967).

DISCUSSION

Sarcopenia seems to be associated with lower risk factors predisposing to CVD in obese postmenopausal women. With the increase in the number of aging people, the health implications of being sarcopenic-obese merit more attention.

Comparison of activity level in daily life with heart rate: Application to elderly persons of different ambulatory abilities

OBJECTIVES

Normal activity monitoring methods are mainly useful for relatively healthy and ablebodied people, but are not necessarily appropriate for elderly persons who may have difficulty in walking, or for the frail who may be bedridden. The purpose of this study was to examine 24-hour heart rate recording for the comparison of activity levels in daily life of elderly persons of different ambulatory abilities.

METHODS

Forty-two elderly females (mean, 82.1 years old) volunteered to participate in this study. The subjects were divided into four groups on the basis of their ambulatory status, and their 24-hour heart rate recordings were compared with their results of activity assessments.

RESULTS

The results of activity assessments showed a tendency to decrease as the ambulatory ability of the group decreased. The "total heart beats", calculated as the sum of all heart rates over 24 hours, were almost the same among the four groups, and therefore did not show a similar tendency. However, the "total excess-beats product (TEBP)" correlated with the results of activity assessments. TEBP was calculated as the sum of all differences in beats between each heart rate in 24 hours and the mean heart rate during sleeping at night. Therefore, TEBP may reflect a more active state than the bedridden state.

CONCLUSIONS

These results suggest that comparison of activity levels in daily life using 24-hour heart rate recording might be possible by the calculation of TEBP, and that this method might be useful for the comparison of the activity levels of elderly persons of diffent ambulatory abilities.

Volunteering: a physical activity intervention for older adults--The Experience Corps program in Baltimore

There is compelling evidence supporting the benefits of increased regular physical activity in older adults. The Experience Corps program in Baltimore MD was designed in part as a community based approach to increasing physical activity that would also appeal to older adults who have historically not utilized health promotion programs. The Baltimore Experience Corps program places older volunteers in public elementary schools for 15 h a week in roles designed to improve the academic outcomes of children and, simultaneously, increase the physical, cognitive and social activity of volunteers. This paper reports on the change in physical activity levels among older adults associated with participation in the Baltimore Experience Corps. In a pilot randomized controlled evaluation, older adults were randomly assigned to Experience Corps (EC participants) or a waiting list control group. Ages ranged from 59-86 years, 96% were African American, 94% were women, and 84% had annual incomes less than $15,000. EC participants were required to serve >/=15 h a week. At follow-up after 4-8 months, an analysis of 113 randomized volunteers revealed 53% of the EC participants were more active than the previous year by self-report, as compared to 23% of the controls (p<0.01). When adjusted for age, gender and education, there was a trend toward increased physical activity in the EC participants as calculated by a kilocalorie per week increase of 40%, versus a 16% decrease in the controls (p=0.49). EC participants who reported "low activity" at baseline experienced an average 110% increase in their physical activity at follow-up. Among the controls who were in the "low activity" group at baseline, there was, on average, only a 12% increase in physical activity (p=0.03). Among those who were previously active, there was no significant difference (p=0.30). The pilot results suggest that a high intensity volunteer program that is designed as a health promotion intervention can lead, in the short-term, to significant improvements in the level of physical activity of previously inactive older adult volunteers.

Comparison of energy expenditure estimates from 4 physical activity questionnaires with doubly labeled water estimates in postmenopausal women

BACKGROUND

Physical activity energy expenditure (EE) is an important determinant of health, and epidemiologists have used various methods, such as physical activity and energy intake recalls and records, to estimate energy cost. However, most epidemiologic studies have not validated these methods against the doubly labeled water (DLW) technique for measuring EE.

OBJECTIVE

The aim was to compare EE estimated by 4 physical activity questionnaires with that obtained with the DLW technique in free-living postmenopausal women.

DESIGN

We measured EE in kcal/d using the DLW method, the Harvard Alumni questionnaire, the Five City Project questionnaire, the Cross-Cultural Activity Participation Study (CAPS) Four Week Activity Recall, and the CAPS Typical Week Activity Survey in 65 healthy postmenopausal women.

RESULTS

Compared with DLW, the Harvard Alumni questionnaire, the Five City Project questionnaire, and the CAPS Four Week Activity Recall overestimated (P < 0.05) daily EE by 62%, 16%, and 11%, respectively, whereas the CAPS Typical Week Activity Recall underestimated (P < 0.05) EE by 31%. Both the Harvard Alumni and Five City Project questionnaires overestimated EE in obese and overweight women.

CONCLUSIONS

When using 3 of the 4 questionnaire methods, postmenopausal women overestimated EEs. Of all women, obese women overestimated daily EE the most.

Physical Activity and Hospitalization for Exacerbation of COPD

BACKGROUND

Acute exacerbations (AEs) have a negative impact on various aspects of the progression of COPD, but objective and detailed data on the impact of hospitalizations for an AE on physical activity are not available. Objective and measurements: We aimed to investigate physical activity using an activity monitor (DynaPort; McRoberts; the Hague, the Netherlands), pulmonary function, muscle force, 6-min walking distance, and arterial blood gas levels in 17 patients (mean age, 69 +/- 9 years [+/- SD]; body mass index, 24 +/- 5 kg/m(2)) at the beginning and end of a hospitalization period for an AE and 1 month after discharge.

RESULTS

Time spent on weight-bearing activities (walking and standing) was markedly low both at day 2 and day 7 of hospitalization (median, 7%; interquartile range [IQR], 3 to 18% of the time during the day; and median, 9%; IQR, 7 to 21%, respectively) and 1 month after discharge (median, 19% [IQR, 10 to 34%]; Friedman test, p = 0.13). Time spent on weight-bearing activities was positively correlated to quadriceps force at the end of the hospitalization period (r = 0.47; p = 0.048). Patients with hospitalization for an AE in the previous year had an even lower activity level when compared to those without a recent hospitalization. In addition, patients with a lower activity level at 1 month after discharge were more likely to be readmitted in the following year.

CONCLUSIONS

Patients with COPD are markedly inactive during and after hospitalization for an AE. Efforts to enhance physical activity should be among the aims of the disease management during and following the AE periods.

Activity monitoring for assessment of physical activities in daily life in patients with chronic obstructive pulmonary disease

OBJECTIVE

To investigate the degree of agreement between different methods of assessing physical activities in daily life in patients with chronic obstructive pulmonary disease (COPD): video recordings (criterion standard), the DynaPort Activity Monitor (DAM), and patient self-report.

DESIGN

Study A: outcomes from video recordings were compared with DAM outcomes and with patient estimation of time spent on each activity after a 1-hour protocol including walking, cycling, standing, sitting, and lying. Study B: DAM outcomes and patient self-report were compared during 1 day in real life.

SETTING

Outpatient clinic in a university hospital.

PARTICIPANTS

Study A: 10 patients with COPD (mean age, 62+/-6 y; forced expiratory volume in the first second [FEV1]=40%+/-16% of predicted). Study B: 13 patients with COPD (mean age, 61+/-8 y; FEV1=33%+/-10% of predicted).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Time spent on different activities and movement intensity during walking and cycling.

RESULTS

Study A: time estimated by the patients in the sitting position was significantly lower than the time showed by the video recordings and the DAM (both P<.001). For the other variables, there were no statistically significant differences (all P>.05). However, Bland and Altman plots and intraclass correlation coefficients showed large disagreement between video recordings and patients' estimations, in contrast to the high degree of agreement between video recordings and DAM. Changes in walking speed correlated highly to changes in DAM movement intensity (r=.81, P<.01). Study B: patients significantly overestimated walking time (22+/-47 min, P=.04) and underestimated standing time (-45+/-71 min, P=.04).

CONCLUSIONS

The DAM showed high accuracy in objectively assessing time spent on different activities and changes in walking speed in patients with COPD. Patients' estimations of time spent on physical activities in daily life disagreed with objective assessment.