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

Plasma 25-Hydroxyvitamin D3 Levels in Colorectal Cancer Patients and Associations with Physical Activity

Physical activity (PA) and vitamin D are thought to affect colorectal cancer prognosis. The present study investigates associations between 25(OH)D₃ and PA in prospectively followed colorectal cancer patients in the ColoCare study. At 6, 12, and 24 mo after surgery, patients donated a blood sample, wore an accelerometer for 10 consecutive days, and completed a PA questionnaire. Plasma 25-hydroxyvitamin D₃ (25(OH)D₃) levels were measured by high-performance liquid chromatography. We tested associations using partial correlations and multivariate linear regression analysis, adjusted for season, age, and body mass index. A total of 137 assessments of 25(OH)D₃ levels and PA were conducted (58 at 6 mo, 51 at 12 mo, and 28 at 24 mo). More than 60% of the patients were vitamin D-deficient (25(OH)D₃ ≤20 ng/ml), independent of study time point. At 6-mo follow-up, accelerometry-based vigorous and moderate-to-vigorous PAs were positively associated with 25(OH)D₃ levels (P = 0.04; P = 0.006,). PA together with season was a significant predictor of elevated 25(OH)D₃ levels. Our results suggest that the majority of colorectal cancer patients may suffer from vitamin D deficiency. Engaging in PA may be an effective approach to increase their 25(OH)D₃ levels.

Measuring Habitual Physical Activity in Neuromuscular Disorders: A Systematic Review

BACKGROUND

Free-living or habitual physical activity (HPA) refers to someone's performance in his or her free-living environment. Neuromuscular disorders (NMD) manifest through HPA, and the observation of HPA can be used to identify clinical risks and to quantify outcomes in research. This review summarizes and analyses previous studies reporting the assessment of HPA in NMD, and may serve as the basis for evidence-based decision-making when considering assessing HPA in this population.

METHODS

A systematic review was performed to identify all studies related to HPA in NMD, followed by a critical appraisal of the assessment methodology and a final review of the identified HPA tools.

RESULTS

A total of 22 studies were selected, reporting on eight different direct tools (or activity monitors) and ten structured patient-reported outcomes. Overall, HPA patterns in NMD differ from healthy control populations. There was a noticeable lack of validation studies for these tools and outcome measures in NMD. Very little information regarding feasibility and barriers for the application of these tools in this population have been published.

CONCLUSIONS

The variety and heterogeneity of tools and methods in the published literature makes the comparison across different studies difficult, and methodological guidelines are warranted. We propose a checklist of considerations for the assessment and reporting of HPA in NMD.

Accelerometry and physical activity questionnaires - a systematic review

Background

The aim of this study is to review accelerometer wear methods and correlations between accelerometry and physical activity questionnaire data, depending on participant characteristics.

Methods

We included 57 articles about physical activity measurement by accelerometry and questionnaires. Criteria were to have at least 100 participants of at least 18 years of age with manuscripts available in English. Accelerometer wear methods were compared. Spearman and Pearson correlation coefficients between questionnaires and accelerometers and differences between genders, age categories, and body mass index (BMI) categories were assessed.

Results

In most investigations, requested wear time was seven days during waking hours and devices were mostly attached on hips with waist belts. A minimum of four valid days with wear time of at least ten hours per day was required in most studies. Correlations (r = Pearson, ρ = Spearman) of total questionnaire scores against accelerometer measures across individual studies ranged from r = 0.08 to ρ = 0.58 (P < 0.001) for men and from r = −0.02 to r = 0.49 (P < 0.01) for women. Correlations for total physical activity among participants with ages ≤65 ranged from r = 0.04 to ρ = 0.47 (P < 0.001) and from r = 0.16 (P = 0.02) to r = 0.53 (P < 0.01) among the elderly (≥65 years). Few studies investigated stratification by BMI, with varying cut points and inconsistent results.

Conclusion

Accelerometers appear to provide slightly more consistent results in relation to self-reported physical activity among men. Nevertheless, due to overall limited consistency, different aspects measured by each method, and differences in the dimensions studied, it is advised that studies use both questionnaires and accelerometers to gain the most complete physical activity information.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3172-0) contains supplementary material, which is available to authorized users.

Reliability of Physical Activity Measures During Free-Living Activities in People After Total Knee Arthroplasty

BACKGROUND

Few instruments that measure physical activity (PA) can accurately quantify PA performed at light and moderate intensities, which is particularly relevant in older adults. The evidence of their reliability in free-living conditions is limited.

OBJECTIVE

The study objectives were: (1) to determine the test-retest reliability of the Actigraph (ACT), SenseWear Armband (SWA), and Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire in assessing free-living PA at light and moderate intensities in people after total knee arthroplasty; (2) to compare the reliability of the 3 instruments relative to each other; and (3) to determine the reliability of commonly used monitoring time frames (24 hours, waking hours, and 10 hours from awakening).

DESIGN

A one-group, repeated-measures design was used.

METHODS

Participants wore the activity monitors for 2 weeks, and the CHAMPS questionnaire was completed at the end of each week. Test-retest reliability was determined by using the intraclass correlation coefficient (ICC [2,k]) to compare PA measures from one week with those from the other week.

RESULTS

Data from 28 participants who reported similar PA during the 2 weeks were included in the analysis. The mean age of these participants was 69 years (SD=8), and 75% of them were women. Reliability ranged from moderate to excellent for the ACT (ICC=.75-.86) and was excellent for the SWA (ICC=.93-.95) and the CHAMPS questionnaire (ICC=.86-.92). The 95% confidence intervals (95% CI) of the ICCs from the SWA were the only ones within the excellent reliability range (.85-.98). The CHAMPS questionnaire showed systematic bias, with less PA being reported in week 2. The reliability of PA measures in the waking-hour time frame was comparable to that in the 24-hour time frame and reflected most PA performed during this period.

LIMITATIONS

Reliability may be lower for time intervals longer than 1 week.

CONCLUSIONS

All PA measures showed good reliability. The reliability of the ACT was lower than those of the SWA and the CHAMPS questionnaire. The SWA provided more precise reliability estimates. Wearing PA monitors during waking hours provided sufficiently reliable measures and can reduce the burden on people wearing them.

MEDIDA DA ATIVIDADE FÍSICA EM JOVENS BRASILEIROS: REPRODUTIBILIDADE E VALIDADE DO PAQ-C E DO PAQ-A

Introdução: O Physical Activity Questionnaire for Children (PAQ-C) e o Physical Activity Questionnaire for Adolescents (PAQ-A) foram originalmente propostos para oferecer medidas autorrelatadas da prática de atividade física de jovens. Objetivos: Traduzir para o idioma português, realizar adaptação transcultural e analisar reprodutibilidade e validade concorrente do PAQ-C e do PAQ-A em amostra de jovens brasileiros. Métodos: Versões originais foram traduzidas de acordo com recomendações internacionais. Os questionários traduzidos foram administrados em amostra de 528 jovens (285 moças e 243 rapazes) com idades entre oito e 18 anos. Reprodutibilidade foi obtida por intermédio de réplicas de aplicação dos questionários, com intervalo de uma semana, envolvendo coeficiente de correlação intraclasse (CCI) e técnica de Bland-Altman. A consistência interna foi analisada mediante coeficiente alfa de Cronbach. Para análise da validade concorrente foram consideradas informações apresentadas pelo acelerômetro RT3 durante sete dias como critério de referência. Atividade física total (AFtotal) e atividade física de intensidades moderada a vigorosa (AFMV) derivadas do acelerômetro foram comparadas mediante coeficiente de correlação de Spearman com pontuações apresentadas pelos questionários. Resultados: Após discretas modificações apontadas no processo de tradução, um comitê de juízes considerou que as versões traduzidas do PAQ-C e do PAQ-A apresentaram equivalências semântica, idiomática, cultural e conceitual. Reprodutibilidade teste-reteste mostrou CCI entre 0,68 e 0,88. A técnica de Bland-Altman evidenciou elevada capacidade de concordância entre réplicas de aplicação dos questionários. A consistência interna mostrou α = 0,71 e α = 0,76, respectivamente. A pontuação dos questionários demostrou correlações moderadas com AFtotal (rho = 0,40; rho = 0,50) e AFMV (rho = 0,48; rho = 0,54) estimadas pelo acelerômetro. Conclusão: A tradução, adaptação transcultural, reprodutibilidade e validade concorrente do PAQ-C e do PAQ-A foram satisfatórias, o que viabiliza sua aplicação em futuros estudos no Brasil.

Physical Activity Is Associated With Reduced Risk of Executive Function Impairment in Older Women

Objective: To examine whether baseline levels of physical activity, measured by total caloric expenditure, predicted domain-specific cognitive impairments over a 9-year period. Method: Participants included 376 community-dwelling older women aged 70 to 80 years at baseline from the Women’s Health and Aging Study II. Cox proportional hazard models were used to evaluate the associations between self-reported physical activity and risk of cognitive impairments in psychomotor speed, executive function, and verbal memory. Models were adjusted for age, race, education, number of chronic illnesses, and number of depressive symptoms at baseline. Results: Greater baseline levels of caloric expenditure were associated with better executive function in the most active quintile of adults compared with the least active quintile. Caloric expenditure was not associated with improved scores for any of the other domains assessed. Discussion: The results of this study suggest that higher levels of physical activity modified risk of incident impairment in executive function.

Concurrent and predictive validity of physical activity measurement items commonly used in clinical settings--data from SCAPIS pilot study

BACKGROUND

As the understanding of how different aspects of the physical activity (PA) pattern relate to health and disease, proper assessment is increasingly important. In clinical care, self-reports are the most commonly used assessment technique. However, systematic comparisons between questions regarding concurrent or criterion validity are rare, as are measures of predictive validity. The aim of the study was to examine the concurrent (using accelerometry as reference) and predictive validity (for metabolic syndrome) of five PA questions.

METHODS

A sample of 948 middle-aged Swedish men and women reported their PA patterns via five different questions and wore an accelerometer (Actigraph GT3X) for a minimum of 4 days. Concurrent validity was assessed as correlations and ROC-analyses. Predictive validity was assessed using logistic regression, controlling for potential confounders.

RESULTS

Concurrent validity was low-to-moderate (r <0.35 and ROC AUC <0.7) with large misclassifications regarding time spent sitting/sedentary and in moderate-to vigorous PA. The predictive validity of the questions was good, and one question (PHAS) showed an 80 % decreased odds-ratio of having metabolic syndrome, after taking potential confounders into consideration.

DISCUSSION

In this mixed sample of adults, both concurrent and predictive validity vaired between items and between measures of the physical activity pattern. The PHAS and WALK items are proposed for assessment of adherence to PA recommendations.

CONCLUSION

Assessing PA patterns using self-report measures results in methodological problems when trying to predict individual risk for the metabolic syndrome, as the concurrent validity generally was low. However, several of the investigated questions may be useful for assessing risk at a group level, showing better predictive validity.

Repeat physical activity measurement by accelerometry among colorectal cancer patients--feasibility and minimal number of days of monitoring

Background

Physical activity plays an important role in colorectal cancer and accelerometry is more frequently used to measure physical activity. The aim of this study was to evaluate feasibility of physical activity measurement by accelerometry in colorectal cancer patients under free-living conditions at 6, 12 and 24 months after surgery, to evaluate the appropriate wear time and to compare results to pedometry.

Methods

Colorectal cancer patients (stage 0/I–IV) from the ColoCare study were asked to optionally wear an accelerometer and a pedometer for ten consecutive days 6, 12 and 24 months post-surgery. Participants completed a feedback questionnaire about the accelerometer measurement. The course of moderate-to-vigorous physical activity over the 10 days was investigated. Additionally, daily step counts from accelerometers and pedometers were compared.

Results

In total, there were 317 individual time points, at which 198 participants were asked to wear an accelerometer. Fifty-nine% initially agreed to participate and of these, 83% (n = 156) completed the assessment with at least 4 days of data. Twenty-one% more consents were obtained when participants were asked on a face-to-face basis compared to recruitment by telephone (P = 0.0002). There were no significant differences in time spent in moderate-to-vigorous physical activity between different wear-time lengths of accelerometry. Both Spearman and intraclass correlation coefficients showed strong correlations (0.92–0.99 and 0.84–0.99, respectively) of moderate-to-vigorous physical activity across 3, 4, 7 and 10 days measurement. Step counts measured by accelerometry and pedometry were strongly correlated (ρ = 0.91, P < 0.0001).

Conclusion

This study suggest that accelerometry is a feasible method to assess physical activity in free-living colorectal cancer patients and that three valid days of physical activity measurement are sufficient for an accurate assessment.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-015-1168-y) contains supplementary material, which is available to authorized users.

Food and Nutrient Intake in African American Children and Adolescents Aged 5 to 16 Years in Baltimore City

OBJECTIVE

This study aimed to describe food and nutrient intake for low-income, urban African American children and adolescents, to highlight the need for further nutrition intervention programs and appropriate tools to address overweight and obesity.

METHODS

This was a cross-sectional study using interviewer-administered single 24-hour dietary recalls. Participants were low-income African American boys and girls aged 5-16 years or their caregivers in Baltimore City. Frequency of food consumption and dietary intakes were analyzed by gender and age groups.

RESULTS

Eighty-one participants were included for analysis. Mean daily energy intakes exceeded Dietary Reference Intakes (DRIs) from 10% to 71% across all gender-age groups: 2304 kcal for children aged 5-8 years; 2429 kcal and 2732 kcal for boys and girls aged 9-13 years, respectively; and 3339 kcal and 2846 kcal for boys and girls aged 14-16 years, respectively. The most frequently reported consumed foods were sweetened drinks, chips, candies, and milk across all age groups. The majority of participants (79-100%) did not meet the DRIs for dietary fiber and vitamin E across all gender-age groups. Milk accounted for 14%, 17%, and 21% of energy, fat, and protein intake, respectively, among children 5-8 years of age, while pizza was the top source of energy, fat, and protein (11%, 13%, and 18%, respectively) among 14-to 16-year-old adolescents. Sweetened drinks and sweetened juices were major sources of sugar, contributing 33% for 5-8 year olds, 29% for 9-13 year olds, and 35% for 14-16 year olds.

CONCLUSIONS

Mean daily energy intake exceeded dietary recommendations across all gender-age groups. This study has provided previously unavailable information on diet and highlights foods to be targeted in nutrition intervention programs.

Prevalência de estilo de vida sedentário entre adolescentes

Objetivo: Identificar a prevalência de estilo de vida sedentário entre adolescentes e conhecer a concordância entre os resultados obtidos por dois instrumentos padronizados de medida. Métodos: Estudo descritivo, transversal, que avaliou 132 estudantes de 14 a 18 anos. As variáveis de estudo foram: sexo, idade, níveis de atividade física com a utilização do Questionário Internacional de Atividade Física em sua versão curta, e média diária de passos com a utilização do pedômetro por, no mínimo, 4 dias consecutivos. Resultados: A prevalência de sedentarismo avaliada pelo questionário foi de 19,7% e a identificada pelo pedômetro foi de 8,3% (p=0,021). Não foi identificada correlação entre os resultados dos diferentes instrumentos. A concordância entre os métodos foi fraca (k=0,021). Conclusão: A prevalência do sedentarismo foi menor quando avaliada pelo pedômetro e não houve correlação com os resultados da avaliação pelo questionário. A concordância foi fraca entre os dois instrumentos de medida.

Use of a Web-based physical activity record system to analyze behavior in a large population: cross-sectional study

Background

The use of Web-based physical activity systems has been proposed as an easy method for collecting physical activity data. We have developed a system that has exhibited high accuracy as assessed by the doubly labeled water method.

Objective

The purpose of this study was to collect behavioral data from a large population using our Web-based physical activity record system and assess the physical activity of the population based on these data. In this paper, we address the difference in physical activity for each urban scale.

Methods

In total, 2046 participants (aged 30-59 years; 1105 men and 941 women) participated in the study. They were asked to complete data entry before bedtime using their personal computer on 1 weekday and 1 weekend day. Their residential information was categorized as urban, urban-rural, or rural. Participant responses expressed the intensity of each activity at 15-minute increments and were recorded on a Web server. Residential areas were compared and multiple regression analysis was performed.

Results

Most participants had a metabolic equivalent (MET) ranging from 1.4 to 1.8, and the mean MET was 1.60 (SD 0.28). The median value of moderate-to-vigorous physical activity (MVPA, ≥3 MET) was 7.92 MET-hours/day. A 1-way ANCOVA showed that total physical activity differed depending on the type of residential area (F_2,2027=5.19, P=.006). The urban areas (n=950) had the lowest MET-hours/day (mean 37.8, SD, 6.0), followed by urban-rural areas (n=432; mean 38.6, SD 6.5; P=.04), and rural areas (n=664; mean 38.8, SD 7.4; P=.002). Two-way ANCOVA showed a significant interaction between sex and area of residence on the urban scale (F_2,2036=4.53, P=.01). Men in urban areas had the lowest MET-hours/day (MVPA, ≥3 MET) at mean 7.9 (SD 8.7); men in rural areas had a MET-hours/day (MVPA, ≥3 MET) of mean 10.8 (SD 12.1, P=.002). No significant difference was noted in women among the 3 residential areas. Multiple regression analysis showed that physical activity consisting of standing while working was the highest contributor to MVPA, regardless of sex.

Conclusions

We were able to compile a detailed comparison of physical activity because our Web-based physical activity record system allowed for the simultaneous evaluation of physical activity from 2046 Japanese people. We found that rural residents had greater total physical activity than urban residents and that working and transportation behaviors differed depending on region type. Multiple regression analysis showed that the behaviors affected MVPA. People are less physically active while working, and sports and active transportation might be effective ways of increasing physical activity levels.

"Are You Sure?": Lapses in Self-Reported Activities Among Healthy Older Adults Reporting Online

Accurate retrospective reporting of activities and symptoms has been shown to be problematic for older adults, yet standard clinical care relies on self-reports to aid in assessment and management. Our aim was to examine the relationship between self-report and sensor-based measures of activity. We administered an online activity survey to participants in our ongoing longitudinal study of in-home ubiquitous monitoring. We found a wide range of accuracies when comparing self-report with time-stamped sensor-based data. Of the 95 participants who completed the 2-hr activity log, nearly one quarter did not complete the task in a way that could potentially be compared with sensor data. Where comparisons were possible, agreement between self-reported and sensor-based activity was achieved by a minority of participants. The findings suggest that capture of real-time events with unobtrusive activity monitoring may be a more reliable approach to describing behavioral patterns and meaningful changes in older adults.

Perceived personal importance of exercise and fears of re-injury: a longitudinal study of psychological factors related to activity after anterior cruciate ligament reconstruction

BACKGROUND

Psychological perceptions are increasingly being recognized as important to recovery and rehabilitation post-surgery. This research longitudinally examined perceptions of the personal importance of exercise and fears of re-injury over a three-year period post anterior cruciate ligament (ACL) reconstruction. Stability and change in psychological perceptions was examined, as well as the association of perceptions with time spent in different types of physical activity, including walking, household activities, and lower and higher risk for knee injury activities.

METHODS

Participants were athletes, 18-40 years old, who underwent ACL reconstruction for first-time ACL injuries. They were recruited from a tertiary care centre in Toronto, Canada. Participants completed interviewer-administered questionnaires pre-surgery and at years one, two and three, postoperatively. Questions assessed demographics, pain, functional limitations, perceived personal importance of exercise, fear of re-injury and physical activities (i.e., walking; household activities; lower risk for knee injury activities; higher risk for knee injury activities). Analyses included fixed-effect longitudinal modeling to examine the association of a fear of re-injury and perceived personal importance of exercise and changes in these perceptions with the total hours spent in the different categories of physical activities, controlling for other factors.

RESULTS

Baseline participants were 77 men and 44 women (mean age = 27.6 years; SD = 6.2). At year three, 78.5% of participants remained in the study with complete data. Fears of re-injury decreased over time while personal importance of exercise remained relatively stable. Time spent in walking and household activities did not significantly change with ACL injury or surgery. Time spent in lower and higher risk of knee injury physical activity did not return to pre-injury levels at three years, post-surgery. Greater time spent in higher risk of knee injury activities was predicted by decreases in fears of re-injury and by greater personal importance of exercise.

CONCLUSIONS

This study highlights not only fears of re-injury, which has been documented in previous studies, but also the perceived personal importance of exercise in predicting activity levels following ACL reconstructive surgery. The findings can help in developing interventions to aid individuals make decisions about physical activities post knee injury and surgery.

Reliability and validity of the modifiable activity questionnaire for an Iranian urban adolescent population

BACKGROUND

The purpose of this study was to evaluate the validity and reliability on the Persian translation of the Modifiable Activity Questionnaire (MAQ) in a sample of Tehranian adolescents.

METHODS

Of a total of 52 subjects, a sub-sample of 40 participations (55.0% boys) was used to assess the reliability and the validity of the physical activity questionnaire. The reliability of the two MAQs was calculated by intraclass correlation coefficients, and validation was evaluated using Pearson correlation coefficients to compare data between mean of the two MAQs and mean of four physical activity records.

RESULTS

Intraclass correlation coefficient was calculated to assess the reliability between two MAQs and the results of leisure time physical activity over the past year were 0.97. Pearson correlation coefficients between mean of two MAQs and mean of four physical activity records were 0.49 (P < 0.001), for leisure time physical activities.

CONCLUSIONS

High reliability and relatively moderate validity were found for the Persian translation of the MAQ in a Tehranian adolescent population. Further studies with large sample size are suggested to assess the validity more precisely.

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.

Body mass index, physical activity, and serum markers of inflammation, immunity, and insulin resistance

BACKGROUND

Epidemiologic studies examining circulating levels of inflammatory markers in relation to obesity and physical inactivity may aid in our understanding of the role of inflammation in obesity-related cancers. However, previous studies on this topic have focused on a limited set of markers.

METHODS

We evaluated associations between body mass index (BMI) and vigorous physical activity level, based on self-report, and serum levels of 78 inflammation-related markers. Markers were measured using a bead-based multiplex method among 1,703 men and women, ages 55-74 years, and with no prior history of cancer at blood draw, and selected for case-control studies nested within the Prostate, Lung, Ovarian, and Colorectal Cancer Screening Trial. Analyses were adjusted for age, sex, smoking, case-control study, physical activity, and BMI.

RESULTS

Twelve markers were positively associated with BMI after FDR correction. ORs and 95% confidence interval (CI) for highest versus lowest levels of CCL2/MCP-1, CXCL5/ENA-78, sTNFRII, CXCL10/IP-10, CXCL6/GCP2, CCL13/MCP-4, amylin, CRP, C-peptide, CCL19/MIP-3b, insulin, and leptin were: 1.50 (1.14-1.98), 1.52 (1.12-2.05), 1.61 (1.17-2.20), 1.69 (1.25-2.28), 1.74 (1.24-2.44), 1.75 (1.22-2.50), 1.91 (1.31-2.78), 2.41 (1.36-4.25), 2.78 (1.83-4.24), 3.30 (2.28-4.78), 4.05 (2.51-6.55), and 50.03 (19.87-125.99) per 5 kg/m(2), respectively. Only CXCL12/SDF-1a was associated with physical activity (≥3 vs. <1 h/wk; OR, 3.28; 95% CI, 1.55-6.94) after FDR correction.

CONCLUSIONS

BMI was associated with a wide range of circulating markers involved in the inflammatory response.

IMPACT

This cross-sectional analysis identified serum markers could be considered in future studies aimed at understanding the underlying mechanisms linking inflammation with obesity and obesity-related cancers.

The Sedentary Time and Activity Reporting Questionnaire (STAR-Q): reliability and validity against doubly labeled water and 7-day activity diaries

We determined measurement properties of the Sedentary Time and Activity Reporting Questionnaire (STAR-Q), which was designed to estimate past-month activity energy expenditure (AEE). STAR-Q validity and reliability were assessed in 102 adults in Alberta, Canada (2009-2011), who completed 14-day doubly labeled water (DLW) protocols, 7-day activity diaries on day 15, and the STAR-Q on day 14 and again at 3 and 6 months. Three-month reliability was substantial for total energy expenditure (TEE) and AEE (intraclass correlation coefficients of 0.84 and 0.73, respectively), while 6-month reliability was moderate. STAR-Q-derived TEE and AEE were moderately correlated with DLW estimates (Spearman's ρs of 0.53 and 0.40, respectively; P < 0.001), and on average, the STAR-Q overestimated TEE and AEE (median differences were 367 kcal/day and 293 kcal/day, respectively). Body mass index-, age-, sex-, and season-adjusted concordance correlation coefficients (CCCs) were 0.24 (95% confidence interval (CI): 0.07, 0.36) and 0.21 (95% CI: 0.11, 0.32) for STAR-Q-derived versus DLW-derived TEE and AEE, respectively. Agreement between the diaries and STAR-Q (metabolic equivalent-hours/day) was strongest for occupational sedentary time (adjusted CCC = 0.76, 95% CI: 0.64, 0.85) and overall strenuous activity (adjusted CCC = 0.64, 95% CI: 0.49, 0.76). The STAR-Q demonstrated substantial validity for estimating occupational sedentary time and strenuous activity and fair validity for ranking individuals by AEE.

Measuring the Ability to Tolerate Activity-Related Discomfort: Initial Validation of the Physical Activity Acceptance Questionnaire (PAAQ)

BACKGROUND

Physical activity (PA) is essential for health, but many adults find PA adherence challenging. Acceptance of discomfort related to PA may influence an individual's ability to begin and sustain a program of exercise. The aim of this study was to evaluate the psychometric properties of the Physical Activity Acceptance Questionnaire (PAAQ).

METHODS

The PAAQ was administered to 3 distinct samples (N = 418). Each sample completed additional self-report measures; 1 sample also wore accelerometers for 7 days (at baseline and 6 months later).

RESULTS

The PAAQ demonstrated high internal validity for its total score (α = .89) and 2 subscales (Cognitive Acceptance α = .86, Behavioral Commitment α = .85). The PAAQ also showed convergent validity with measures of mindfulness, self-reported physical activity levels, and accelerometer-verified levels of moderate-to-vigorous PA (MVPA; P-values < .05). The Cognitive Acceptance subscale showed predictive validity for objectively-verified PA levels among individuals attempting to increase PA over 6 months (P = .05). Test-retest reliability for a subset of participants (n = 46) demonstrated high consistency over 1 week (P < .0001).

CONCLUSIONS

The PAAQ demonstrates sound psychometric properties, and shows promise for improving the current understanding of PA facilitators and barriers among adults.

Assessment of physical activity and energy expenditure: an overview of objective measures

The ability to assess energy expenditure (EE) and estimate physical activity (PA) in free-living individuals is extremely important in the global context of non-communicable diseases including malnutrition, overnutrition (obesity), and diabetes. It is also important to appreciate that PA and EE are different constructs with PA defined as any bodily movement that results in EE and accordingly, energy is expended as a result of PA. However, total energy expenditure, best assessed using the criterion doubly labeled water (DLW) technique, includes components in addition to physical activity energy expenditure, namely resting energy expenditure and the thermic effect of food. Given the large number of assessment techniques currently used to estimate PA in humans, it is imperative to understand the relative merits of each. The goal of this review is to provide information on the utility and limitations of a range of objective measures of PA and their relationship with EE. The measures discussed include those based on EE or oxygen uptake including DLW, activity energy expenditure, physical activity level, and metabolic equivalent; those based on heart rate monitoring and motion sensors; and because of their widespread use, selected subjective measures.

Physical activity monitoring in patients with peripheral arterial disease: validation of an activity monitor

OBJECTIVES

The daily life physical activity (PA) of patients with peripheral arterial disease (PAD) may be severely hampered by intermittent claudication (IC). From a therapeutic, as well as research, point of view, it may be more relevant to determine improvement in PA as an outcome measure in IC. The aim of this study was to validate daily activities using a novel type of tri-axial accelerometer (Dynaport MoveMonitor) in patients with IC.

METHODS

Patients with IC were studied during a hospital visit. Standard activities (locomotion, lying, sitting, standing, shuffling, number of steps and "not worn" detection) were video recorded and compared with activities scored by the MoveMonitor. Inter-rater reliability (expressed in intraclass correlation coefficients [ICC]), sensitivity, specificity, and positive predictive values (PPV) were calculated for each activity.

RESULTS

Twenty-eight hours of video observation were analysed (n = 21). Our video annotation method (the gold standard method) appeared to be accurate for most postures (ICC > 0.97), except for shuffling (ICC = 0.38). The MoveMonitor showed a high sensitivity (>86%), specificity (>91%), and PPV (>88%) for locomotion, lying, sitting, and "not worn" detection. Moderate accuracy was found for standing (46%), while shuffling appeared to be undetectable (18%). A strong correlation was found between video recordings and the MoveMonitor with regard to the calculation of the "number of steps" (ICC = 0.90).

CONCLUSIONS

The MoveMonitor provides accurate information on a diverse set of postures, daily activities, and number of steps in IC patients. However, the detection of low amplitude movements, such as shuffling and "sitting to standing" transfers, is a matter of concern. This tool is useful in assessing the role of PA as a novel, clinically relevant outcome parameter in IC.

Cross-sectional associations of objectively measured physical activity, cardiorespiratory fitness and anthropometry in European adults

OBJECTIVE

To quantify the independent associations between objectively measured physical activity (PA), cardiorespiratory fitness (CRF), and anthropometry in European men and women.

METHODS

2,056 volunteers from 12 centers across Europe were fitted with a heart rate and movement sensor at 2 visits 4 months apart for a total of 8 days. CRF (ml/kg/min) was estimated from an 8 minute ramped step test. A cross-sectional analysis of the independent associations between objectively measured PA (m/s(2)/d), moderate and vigorous physical activity (MVPA) (%time/d), sedentary time (%time/d), CRF, and anthropometry using sex stratified multiple linear regression was performed.

RESULTS

In mutually adjusted models, CRF, PA, and MVPA were inversely associated with all anthropometric markers in women. In men, CRF, PA, and MVPA were inversely associated with BMI, whereas only CRF was significantly associated with the other anthropometric markers. Sedentary time was positively associated with all anthropometric markers, however, after adjustment for CRF significant in women only.

CONCLUSION

CRF, PA, MVPA, and sedentary time are differently associated with anthropometric markers in men and women. CRF appears to attenuate associations between PA, MVPA, and sedentary time. These observations may have implications for prevention of obesity.

Estimating energy expenditure from heart rate in older adults: a case for calibration

Background

Accurate measurement of free-living energy expenditure is vital to understanding changes in energy metabolism with aging. The efficacy of heart rate as a surrogate for energy expenditure is rooted in the assumption of a linear function between heart rate and energy expenditure, but its validity and reliability in older adults remains unclear.

Objective

To assess the validity and reliability of the linear function between heart rate and energy expenditure in older adults using different levels of calibration.

Design

Heart rate and energy expenditure were assessed across five levels of exertion in 290 adults participating in the Baltimore Longitudinal Study of Aging. Correlation and random effects regression analyses assessed the linearity of the relationship between heart rate and energy expenditure and cross-validation models assessed predictive performance.

Results

Heart rate and energy expenditure were highly correlated (r = 0.98) and linear regardless of age or sex. Intra-person variability was low but inter-person variability was high, with substantial heterogeneity of the random intercept (s.d. = 0.372) despite similar slopes. Cross-validation models indicated individual calibration data substantially improves accuracy predictions of energy expenditure from heart rate, reducing the potential for considerable measurement bias. Although using five calibration measures provided the greatest reduction in the standard deviation of prediction errors (1.08 kcals/min), substantial improvement was also noted with two (0.75 kcals/min).

Conclusion

These findings indicate standard regression equations may be used to make population-level inferences when estimating energy expenditure from heart rate in older adults but caution should be exercised when making inferences at the individual level without proper calibration.

Validity of electronically administered Recent Physical Activity Questionnaire (RPAQ) in ten European countries

OBJECTIVE

To examine the validity of the Recent Physical Activity Questionnaire (RPAQ) which assesses physical activity (PA) in 4 domains (leisure, work, commuting, home) during past month.

METHODS

580 men and 1343 women from 10 European countries attended 2 visits at which PA energy expenditure (PAEE), time at moderate-to-vigorous PA (MVPA) and sedentary time were measured using individually-calibrated combined heart-rate and movement sensing. At the second visit, RPAQ was administered electronically. Validity was assessed using agreement analysis.

RESULTS

RPAQ significantly underestimated PAEE in women [median(IQR): 34.9 (22.3, 52.8) vs. 40.6 (32.4, 50.9) kJ/kg/day, 95%LoA: -44.4, 66.1 kJ/kg/day) and overestimated PAEE in men [45.9 (30.6, 71.1) vs. 45.5 (34.1, 57.6) kJ/kg/day, 95%LoA: -44.8, 102.6 kJ/kg/day]. Using individualised definition of 1MET, RPAQ significantly underestimated MVPA in women [median(IQR): 63.7 (30.5, 126.9) vs. 73.6 (47.8, 107.2) min/day, 95%LoA: -127.4, 311.9 min/day] and overestimated MVPA in men [90.0 (42.3, 188.6) vs. 83.3 (55.1, 125.0) min/day, 95%LoA: -134.8, 427.3 min/day]. Correlations (95%CI) between subjective and objective estimates were statistically significant [PAEE: women, rho = 0.20 (0.15-0.26); men, rho = 0.37 (0.30-0.44); MVPA: women, rho = 0.18 (0.13-0.24); men, rho = 0.31 (0.24-0.38)]. When using non-individualised definition of 1MET (3.5 mlO2/kg/min), MVPA was substantially overestimated (16 min/day, and 32 min/day in women and men, respectively). Revisiting occupational intensity assumptions in questionnaire estimation algorithms with occupational group-level empirical distributions reduced median PAEE-bias in manual (38.8 kJ/kg/day vs. 6.8 kJ/kg/day, p<0.001) and heavy manual workers (63.6 vs. -2.8 kJ/kg/day, p<0.001) in an independent hold-out sample [corrected].

CONCLUSION

Relative validity of RPAQ-derived PAEE and MVPA is comparable to previous studies but underestimation of PAEE is smaller. Electronic RPAQ may be used in large-scale epidemiological studies including surveys, providing information on all domains of PA.

Evaluation of Actiheart and a 7 d activity diary for estimating free-living total and activity energy expenditure using criterion methods in 1·5- and 3-year-old children

Accurate and easy-to-use methods to assess free-living energy expenditure in response to physical activity in young children are scarce. In the present study, we evaluated the capacity of (1) 4 d recordings obtained using the Actiheart (mean heart rate (mHR) and mean activity counts (mAC)) to provide assessments of total energy expenditure (TEE) and activity energy expenditure (AEE) and (2) a 7 d activity diary to provide assessments of physical activity levels (PAL) using three sets of metabolic equivalent (MET) values (PALTorun, PALAdolphand PALAinsworth) in forty-four and thirty-one healthy Swedish children aged 1·5 and 3 years, respectively. Reference TEE, PALrefand AEE were measured using criterion methods, i.e. the doubly labelled water method and indirect calorimetry. At 1·5 years of age, mHR explained 8 % (P= 0·006) of the variation in TEE above that explained by fat mass and fat-free mass. At 3 years of age, mHR and mAC explained 8 (P= 0·004) and 6 (P= 0·03) % of the variation in TEE and AEE, respectively, above that explained by fat mass and fat-free mass. At 1·5 and 3 years of age, average PALAinsworthvalues were 1·44 and 1·59, respectively, and not significantly different from PALrefvalues (1·39 and 1·61, respectively). By contrast, average PALTorun(1·5 and 3 years) and PALAdolph(3 years) values were lower (P< 0·05) than the corresponding PALrefvalues. In conclusion, at both ages, Actiheart recordings explained a small but significant fraction of free-living energy expenditure above that explained by body composition variables, and our activity diary produced mean PAL values in agreement with reference values when using MET values published by Ainsworth.

Comparison of the EPIC Physical Activity Questionnaire with combined heart rate and movement sensing in a nationally representative sample of older British adults

Objectives

To compare physical activity (PA) subcomponents from EPIC Physical Activity Questionnaire (EPAQ2) and combined heart rate and movement sensing in older adults.

Methods

Participants aged 60–64y from the MRC National Survey of Health and Development in Great Britain completed EPAQ2, which assesses self-report PA in 4 domains (leisure time, occupation, transportation and domestic life) during the past year and wore a combined sensor for 5 consecutive days. Estimates of PA energy expenditure (PAEE), sedentary behaviour, light (LPA) and moderate-to-vigorous PA (MVPA) were obtained from EPAQ2 and combined sensing and compared. Complete data were available in 1689 participants (52% women).

Results

EPAQ2 estimates of PAEE and MVPA were higher than objective estimates and sedentary time and LPA estimates were lower [bias (95% limits of agreement) in men and women were 32.3 (−61.5 to 122.6) and 29.0 (−39.2 to 94.6) kJ/kg/day for PAEE; −4.6 (−10.6 to 1.3) and −6.0 (−10.9 to −1.0) h/day for sedentary time; −171.8 (−454.5 to 110.8) and −60.4 (−367.5 to 246.6) min/day for LPA; 91.1 (−159.5 to 341.8) and 55.4 (−117.2 to 228.0) min/day for MVPA]. There were significant positive correlations between all self-reported and objectively assessed PA subcomponents (rho  = 0.12 to 0.36); the strongest were observed for MVPA (rho = 0.30 men; rho = 0.36 women) and PAEE (rho = 0.26 men; rho = 0.25 women).

Conclusion

EPAQ2 produces higher estimates of PAEE and MVPA and lower estimates of sedentary and LPA than objective assessment. However, both methodologies rank individuals similarly, suggesting that EPAQ2 may be used in etiological studies in this population.

Measuring physical activity in children and adolescents for dietary surveys: practicalities, problems and pitfalls

Physical inactivity is an important risk factor for many chronic diseases and contributes to obesity and poor mental well-being. The present paper describes the main advantages and disadvantages, practical problems, suggested uses, and future developments regarding self-reported and objective data collection in the context of dietary surveys. In dietary surveys, physical activity is measured primarily to estimate energy expenditure. Energy expenditure surveillance is important for tracking changes over time, particularly given the debates over the role of the relative importance of energy intake and expenditure changes in the aetiology of obesity. It is also important to assess the extent of underreporting of dietary intake in these surveys. Physical activity data collected should include details on the frequency, duration and relative intensity of activity for each activity type that contributes considerably to overall activity and energy expenditure. Problems of validity and reliability, associated with inaccurate assessment, recall bias, and social desirability bias, are well-known; children under 10 years cannot report their activities accurately. However, despite such limitations, questionnaires are still the dominant method of physical activity assessment in dietary surveys due to their low cost and relatively low participant burden. Objective, time-stamped measures that monitor heart rate and/or movement can provide more comprehensive, quantitative assessment of physical activity but at greater cost and participant burden. Although overcoming many limitations of questionnaires, objective measures also have drawbacks, including technical, practical and interpretational issues.

Frailty assessment in the cardiovascular care of older adults

Due to the aging and increasingly complex nature of our patients, frailty has become a high-priority theme in cardiovascular medicine. Despite the recognition of frailty as a pivotal element in the evaluation of older adults with cardiovascular disease (CVD), there has yet to be a road map to facilitate its adoption in routine clinical practice. Thus, we sought to synthesize the existing body of evidence and offer a perspective on how to integrate frailty into clinical practice. Frailty is a biological syndrome that reflects a state of decreased physiological reserve and vulnerability to stressors. Upward of 20 frailty assessment tools have been developed, with most tools revolving around the core phenotypic domains of frailty-slow walking speed, weakness, inactivity, exhaustion, and shrinking-as measured by physical performance tests and questionnaires. The prevalence of frailty ranges from 10% to 60%, depending on the CVD burden, as well as the tool and cutoff chosen to define frailty. Epidemiological studies have consistently demonstrated that frailty carries a relative risk of >2 for mortality and morbidity across a spectrum of stable CVD, acute coronary syndromes, heart failure, and surgical and transcatheter interventions. Frailty contributes valuable prognostic insights incremental to existing risk models and assists clinicians in defining optimal care pathways for their patients. Interventions designed to improve outcomes in frail elders with CVD such as multidisciplinary cardiac rehabilitation are being actively tested. Ultimately, frailty should not be viewed as a reason to withhold care but rather as a means of delivering it in a more patient-centered fashion.

Energy expenditure compared to physical activity measured by accelerometry and self-report in adolescents: a validation study

Background

Physical inactivity is responsible for 5.3 million deaths annually worldwide. To measure physical activity energy expenditure, the doubly labeled water (DLW) method is the gold standard. However, questionnaires and accelerometry are more widely used. We compared physical activity measured by accelerometer and questionnaire against total (TEE) and physical activity energy expenditure (PAEE) estimated by DLW.

Methods

TEE, PAEE (TEE minus resting energy expenditure) and body composition were measured using the DLW technique in 25 adolescents (16 girls) aged 13 years living in Pelotas, Brazil. Physical activity was assessed using the Actigraph accelerometer and by self-report. Physical activity data from accelerometry and self-report were tested against energy expenditure data derived from the DLW method. Further, tests were done to assess the ability of moderate-to-vigorous intensity physical activity (MVPA) to predict variability in TEE and to what extent adjustment for fat and fat-free mass predicted the variability in TEE.

Results

TEE varied from 1,265 to 4,143 kcal/day. It was positively correlated with physical activity (counts) estimated by accelerometry (rho  = 0.57; p = 0.003) and with minutes per week of physical activity by questionnaire (rho  = 0.41; p = 0.04). An increase of 10 minutes per day in moderate-to-vigorous intensity physical activity (MVPA) relates to an increase in TEE of 141 kcal/day. PAEE was positively correlated with accelerometry (rho  = 0.64; p = 0.007), but not with minutes per week of physical activity estimated by questionnaire (rho  = 0.30; p = 0.15). Physical activity by accelerometry explained 31% of the vssariability in TEE. By incorporating fat and fat-free mass in the model, we were able to explain 58% of the variability in TEE.

Conclusion

Objectively measured physical activity significantly contributes to the explained variance in both TEE and PAEE in Brazilian youth. Independently, body composition also explains variance in TEE, and should ideally be taken into account when using accelerometry to predict energy expenditure values.

Sedentary time and markers of chronic low-grade inflammation in a high risk population

Background

Sedentary behaviour has been identified as a distinct risk factor for several health outcomes. Nevertheless, little research has been conducted into the underlying mechanisms driving these observations. This study aimed to investigate the association of objectively measured sedentary time and breaks in sedentary time with markers of chronic low-grade inflammation and adiposity in a population at a high risk of type 2 diabetes mellitus.

Methods

This study reports data from an ongoing diabetes prevention programme conducted in Leicestershire, UK. High risk individuals were recruited from 10 primary care practices. Sedentary time (<25counts per 15s) was measured using Actigraph GT3X accelerometers (15s epochs). A break was considered as any interruption in sedentary time (≥25counts per 15s). Biochemical outcomes included interleukin-6 (IL-6), C-reactive protein (CRP), leptin, adiponectin and leptin:adiponectin ratio (LAR). A sensitivity analysis investigated whether results were affected by removing participants with a CRP level >10 mg/L, as this can be indicative of acute inflammation.

Results

558 participants (age = 63.6±7.7years; male = 64.7%) had complete adipokine and accelerometer data. Following adjustment for various confounders, sedentary time was detrimentally associated with CRP (β = 0.176±0.057, p = 0.002), IL-6 (β = 0.242±0.056, p = <0.001), leptin (β = 0.146±0.043, p = <0.001) and LAR (β = 0.208±0.052, p = <0.001). Associations were attenuated after further adjustment for moderate-to-vigorous physical activity (MVPA) with only IL-6 (β = 0.231±0.073, p = 0.002) remaining significant; this result was unaffected after further adjustment for body mass index and glycosylated haemoglobin (HbA_1c). Similarly, breaks in sedentary time were significantly inversely associated with IL-6 (β = −0.094±0.047, p = 0.045) and leptin (β = −0.075±0.037, p = 0.039); however, these associations were attenuated after adjustment for accelerometer derived variables. Excluding individuals with a CRP level >10 mg/L consistently attenuated the significant associations across all markers of inflammation.

Conclusion

These novel findings from a high risk population recruited through primary care suggest that sedentary behaviour may influence markers associated with inflammation, independent of MVPA, glycaemia and adiposity.

Effects and costs of home-based training with telemonitoring guidance in low to moderate risk patients entering cardiac rehabilitation: The FIT@Home study

Background

Physical training has beneficial effects on exercise capacity, quality of life and mortality in patients after a cardiac event or intervention and is therefore a core component of cardiac rehabilitation. However, cardiac rehabilitation uptake is low and effects tend to decrease after the initial rehabilitation period. Home-based training has the potential to increase cardiac rehabilitation uptake, and was shown to be safe and effective in improving short-term exercise capacity. Long-term effects on physical fitness and activity, however, are disappointing. Therefore, we propose a novel strategy using telemonitoring guidance based on objective training data acquired during exercise at home. In this way, we aim to improve self-management skills like self-efficacy and action planning for independent exercise and, consequently, improve long-term effectiveness with respect to physical fitness and physical activity. In addition, we aim to compare costs of this strategy with centre-based cardiac rehabilitation.

Methods/design

This randomized controlled trial compares a 12-week telemonitoring guided home-based training program with a regular, 12-week centre-based training program of equal duration and training intensity in low to moderate risk patients entering cardiac rehabilitation after an acute coronary syndrome or cardiac intervention. The home-based group receives three supervised training sessions before they commence training with a heart rate monitor in their home environment. Participants are instructed to train at 70-85% of their maximal heart rate for 45–60 minutes, twice a week. Patients receive individual coaching by telephone once a week, based on measured heart rate data that are shared through the internet. Primary endpoints are physical fitness and physical activity, assessed at baseline, after 12 weeks and after one year. Physical fitness is expressed as peak oxygen uptake, assessed by symptom limited exercise testing with gas exchange analysis; physical activity is expressed as physical activity energy expenditure, assessed by tri-axial accelerometry and heart rate measurements. Secondary endpoints are training adherence, quality of life, patient satisfaction and cost-effectiveness.

Discussion

This study will increase insight in long-term effectiveness and costs of home-based cardiac rehabilitation with telemonitoring guidance. This strategy is in line with the trend to shift non-complex healthcare services towards patients’ home environments.

Trial registration

Dutch Trial Register: NTR3780. Clinicaltrials.gov register: NCT01732419

Evaluations of Actiheart, IDEEA® and RT3 monitors for estimating activity energy expenditure in free-living women

Activity energy expenditure (AEE) during free-living conditions can be assessed using devices based on different principles. To make proper comparisons of different devices' capacities to assess AEE, they should be evaluated in the same population. Thus, in the present study we evaluated, in the same group of subjects, the ability of three devices to assess AEE in groups and individuals during free-living conditions. In twenty women, AEE was assessed using RT3 (three-axial accelerometry) (AEERT3), Actiheart (a combination of heart rate and accelerometry) (AEEActi) and IDEEA (a multi-accelerometer system) (AEEIDEEA). Reference AEE (AEEref) was assessed using the doubly labelled water method and indirect calorimetry. Average AEEActi was 5760 kJ per 24 h and not significantly different from AEEref (5020 kJ per 24 h). On average, AEERT3 and AEEIDEEA were 2010 and 1750 kJ per 24 h lower than AEEref, respectively (P < 0·001). The limits of agreement (± 2 sd) were 2940 (Actiheart), 1820 (RT3) and 2650 (IDEEA) kJ per 24 h. The variance for AEERT3 was lower than for AEEActi (P = 0·006). The RT3 classified 60 % of the women in the correct activity category while the corresponding value for IDEEA and Actiheart was 30 %. In conclusion, the Actiheart may be useful for groups and the RT3 for individuals while the IDEEA requires further development. The results are likely to be relevant for a large proportion of Western women of reproductive age and demonstrate that the procedure selected to assess physical activity can greatly influence the possibilities to uncover important aspects regarding interactions between physical activity, diet and health.

Employing virtual advisors in preventive care for underserved communities: results from the COMPASS study

Electronically delivered health promotion programs that are aimed primarily at educated, health-literate individuals have proliferated, raising concerns that such trends could exacerbate health disparities in the United States and elsewhere. The efficacy of a culturally and linguistically adapted virtual advisor that provides tailored physical activity advice and support was tested in low-income older adults. Forty inactive adults (92.5% Latino) 55 years of age and older were randomized to a 4-month virtual advisor walking intervention or a waitlist control. Four-month increases in reported minutes of walking/week were greater in the virtual advisor arm (mean increase = 253.5 ± 248.7 minutes/week) relative to the control (mean increase = 26.8 ± 67.0 minutes/week; p = .0008). Walking increases in the virtual advisor arm were substantiated via objectively measured daily steps (slope analysis p = .002). All but one intervention participant continued some interaction with the virtual advisor in the 20-week poststudy period (mean number of poststudy sessions = 14.0 ± 20.5). The results indicate that a virtual advisor delivering culturally and linguistically adapted physical activity advice led to meaningful 4-month increases in walking relative to control among underserved older adults. This interactive technology, which requires minimal language and computer literacy, may help reduce health disparities by ensuring that all groups benefit from e-health opportunities.

Validation of a previous-day recall measure of active and sedentary behaviors

PURPOSE

A previous-day recall (PDR) may be a less error-prone alternative to traditional questionnaire-based estimates of physical activity and sedentary behavior (e.g., past year), but the validity of the method is not established. We evaluated the validity of an interviewer administered PDR in adolescents (12-17 yr) and adults (18-71 yr).

METHODS

In a 7-d study, participants completed three PDR, wore two activity monitors, and completed measures of social desirability and body mass index. PDR measures of active and sedentary time was contrasted against an accelerometer (ActiGraph) by comparing both to a valid reference measure (activPAL) using measurement error modeling and traditional validation approaches.

RESULTS

Age- and sex-specific mixed models comparing PDR to activPAL indicated the following: 1) there was a strong linear relationship between measures for sedentary (regression slope, β1 = 0.80-1.13) and active time (β1 = 0.64-1.09), 2) person-specific bias was lower than random error, and 3) correlations were high (sedentary: r = 0.60-0.81; active: r = 0.52-0.80). Reporting errors were not associated with body mass index or social desirability. Models comparing ActiGraph to activPAL indicated the following: 1) there was a weaker linear relationship between measures for sedentary (β1 = 0.63-0.73) and active time (β1 = 0.61-0.72), (2) person-specific bias was slightly larger than random error, and (3) correlations were high (sedentary: r = 0.68-0.77; active: r = 0.57-0.79).

CONCLUSIONS

Correlations between the PDR and the activPAL were high, systematic reporting errors were low, and the validity of the PDR was comparable with the ActiGraph. PDR may have value in studies of physical activity and health, particularly those interested in measuring the specific type, location, and purpose of activity-related behaviors.

Lifestyle factors and inflammation: associations by body mass index

Chronic inflammation, which is associated with obesity, may play a role in the etiology of several diseases. Thus, reducing inflammation may offer a disease-prevention strategy, particularly among the obese. Several modifiable factors have been associated with inflammation, including: dietary fiber intake, saturated fat intake, physical activity, smoking, alcohol, and use of certain supplements and medications (glucosamine, chondroitin, fish oil, vitamin E, statins and aspirin). To study whether these associations differ by body mass index (BMI), we used data on 9,895 adults included in the 1999-2004 cycles of the National Health and Nutrition Examination Survey (NHANES). Survey-weighted linear regression was used to evaluate the associations between modifiable factors and serum high-sensitivity C-reactive protein (hsCRP) concentrations across the following groups: underweight/normal weight (BMI<25 kg/m(2)), overweight (25-<30 kg/m(2)) and obese (30+ kg/m(2)). While several factors were significantly associated with decreased hsCRP among the normal weight or overweight groups (increased fiber intake, lower saturated fat intake, physical activity, not smoking, and use of chondroitin, fish oil and statins), only increasing dietary fiber intake and moderate alcohol consumption were associated with reduced hsCRP among the obese. Effect modification by BMI was statistically significant for the saturated fat-hsCRP and smoking-hsCRP associations. These results suggest that posited anti-inflammatory drugs and behaviors may be less strongly associated with inflammation among the obese than among lower weight persons.

Ultrasound estimates of visceral and subcutaneous-abdominal adipose tissues in infancy

Other imaging techniques to quantify internal-abdominal adiposity (IA-AT) and subcutaneous-abdominal adiposity (SCA-AT) are frequently impractical in infants. The aim of this study was twofold: (a) to validate ultrasound (US) visceral and subcutaneous-abdominal depths in assessing IA-AT and SCA-AT from MRI as the reference method in infants and (b) to analyze the association between US abdominal adiposity and anthropometric measures at ages 3 months and 12 months. Twenty-two infants underwent MRI and US measures of abdominal adiposity. Abdominal US parameters and anthropometric variables were assessed in the Cambridge Baby Growth Study (CBGS), n = 487 infants (23 girls) at age 3 months and n = 495 infants (237 girls) at 12 months. US visceral and subcutaneous-abdominal depths correlated with MRI quantified IA-AT (r = 0.48, P < 0.05) and SCA-AT (r = 0.71, P < 0.001) volumes, respectively. In CBGS, mean US-visceral depths increased by ~20 % between ages 3 and 12 months (P < 0.0001) and at both ages were lower in infants breast-fed at 3 months than in other infants. US-visceral depths at both 3 and 12 months were inversely related to skinfold thickness at birth (P = 0.03 and P = 0.009 at 3 and 12 months, resp.; adjusted for current skinfold thickness). In contrast, US-subcutaneous-abdominal depth at 3 months was positively related to skinfold thickness at birth (P = 0.004). US measures can rank infants with higher or lower IA-AT and SCA-AT. Contrasting patterns of association with visceral and subcutaneous-abdominal adiposities indicate that they may be differentially regulated in infancy.

Physical activity assessment: biomarkers and self-report of activity-related energy expenditure in the WHI

We used a biomarker of activity-related energy expenditure (AREE) to assess measurement properties of self-reported physical activity and to determine the usefulness of AREE regression calibration equations in the Women's Health Initiative. Biomarker AREE, calculated as the total energy expenditure from doubly labeled water minus the resting energy expenditure from indirect calorimetry, was assessed in 450 Women's Health Initiative participants (2007-2009). Self-reported AREE was obtained from the Arizona Activity Frequency Questionnaire (AAFQ), the 7-Day Physical Activity Recall (PAR), and the Women's Health Initiative Personal Habits Questionnaire (PHQ). Eighty-eight participants repeated the protocol 6 months later. Reporting error, measured as log(self-report AREE) minus log(biomarker AREE), was regressed on participant characteristics for each instrument. Body mass index was associated with underreporting on the AAFQ and PHQ but overreporting on PAR. Blacks and Hispanics underreported physical activity levels on the AAFQ and PAR, respectively. Underreporting decreased with age for the PAR and PHQ. Regressing logbiomarker AREE on logself-reported AREE revealed that self-report alone explained minimal biomarker variance (R(2) = 7.6, 4.8, and 3.4 for AAFQ, PAR, and PHQ, respectively). R(2) increased to 25.2, 21.5, and 21.8, respectively, when participant characteristics were included. Six-month repeatability data adjusted for temporal biomarker variation, improving R(2) to 79.4, 67.8, and 68.7 for AAFQ, PAR, and PHQ, respectively. Calibration equations "recover" substantial variation in average AREE and valuably enhance AREE self-assessment.

Lower physical activity is a risk factor for a clustering of metabolic risk factors in non-obese and obese Japanese subjects: the Takahata study

In several countries including Japan, people without obesity but with a clustering of metabolic risk factors (MetRFs) were not considered to have the metabolic syndrome (MetS). Here, we examined whether lifestyle characteristics differed between non-obese and obese subjects with or without a clustering of MetRFs. From a population-based cross-sectional study of Japanese subjects aged ≥ 40 years, 1,601 subjects (age: 61.9 ± 10.3 years; 710/891 men/women) were recruited. Physical activity status and daily nutritional intake were estimated using questionnaires. A clustering of MetRFs was defined based on the presence of at least two non-essential risk factors for the diagnosis of the MetS in Japan. Energy intake was not higher in subjects with a clustering of MetRFs compared with those without. Among men, energy expenditure at work was significantly lower in non-obese (9.0 ± 8.2 vs. 11.3 ± 9.3 metabolic equivalents (METs), P = 0.025) and obese (9.0 ± 7.9 vs. 11.6 ± 9.4 METs, P = 0.017) subjects with a clustering of MetRFs than in those without. Multiple logistic regression analysis showed that energy expenditure at work was significantly associated with a clustering of MetRFs after adjusting for possible confounding factors including total energy intake. The ORs (per 1 METs) were 0.970 (95% CI, 0.944-0.997; P = 0.032) in non-obese men and 0.962 (0.926- 0.999; P = 0.043) in obese men. Similar associations were not observed in women. In Japanese males, lower physical activity, but not excessive energy intake, is a risk factor for a clustering of MetRFs independent of their obesity status.

Direct and indirect measurement of physical activity in older adults: a systematic review of the literature

BACKGROUND

Due to physiological and cognitive changes that occur with aging, accurate physical activity (PA) measurement in older adults represents a unique challenge. The primary purpose of this study was to systematically review measures of PA and their use and appropriateness with older adults. A secondary aim was to determine the level of agreement between PA measures in older adults.

METHODS

Literature was identified through electronic databases. Studies were eligible if they examined the correlation and/or agreement between at least 2 measures, either indirect and/or direct, of PA in older adults (> 65 years of age).

RESULTS

Thirty-six studies met eligibility criteria. The indirect and direct measures of PA across the studies differed widely in their ability to address the key dimensions (i.e., frequency, intensity, time, type) of PA in older adults. The average correlation between indirect and direct measures was moderate (r=0.38). The correlation between indirect and other indirect measures (r=0.29) was weak, while correlations between direct measures with other direct measures were high (real world: r= 0.84; controlled settings: r=0.92). Agreement was strongest between direct PA measures with other direct measures in both real world and laboratory settings. While a clear trend regarding the agreement for mean differences between other PA measures (i.e., direct with indirect, indirect with indirect) did not emerge, there were only a limited number of studies that reported comparable units.

CONCLUSIONS

Despite the lack of a clear trend regarding the agreement between PA measures in older adults, the findings underscore the importance of valid, accurate and reliable measurement. To advance this field, researchers will need to approach the assessment of PA in older adults in a more standardized way (i.e., consistent reporting of results, consensus over cut-points and epoch lengths, using appropriate validation tools). Until then researchers should be cautious when choosing measures for PA that are appropriate for their research questions and when comparing PA levels across various studies.

Prevalence, risk factors, activity limitation and health care utilization of an obese, population-based sample with chronic obstructive pulmonary disease

BACKGROUND

To estimate the prevalence and determine the risk factors and health associations among individuals with combined chronic obstructive pulmonary disease and obesity.

METHODS

Canadian national health survey data from 1994 to 2007 (n=650,000) were used. The presence of COPD was based on health professional-diagnosed self-report. The presence of obesity, defined by body mass index ≥ 30 kg⁄m2, was identified using self-reported and measured height and weight. Hospitalization, homecare use, physical activity assessments and socioeconomic data were all self-reported.

RESULTS

In 2005, the prevalence of obesity in COPD (n=3470) and non-COPD (n=92,237) individuals was 24.6% and 17.1%, respectively (P<0.0001). In contrast to the non-COPD group, in which obesity prevalence increased by 38% over 14 years, obesity prevalence increased by only 5% in people with COPD over this same time period. Female sex was the only independent risk factor for obesity in COPD. Previous smoking, residing in Atlantic Canada and the Territories, and low education level were independent risk factors for obesity in the non-COPD group, but not in the COPD group. The odds of physical activity limitation and health care utilization were significantly higher among obese individuals with COPD compared with nonobese COPD and obese non-COPD groups.

CONCLUSIONS

The prevalence of obesity was higher in COPD, and exceeded that of the larger non-COPD group throughout the 13-year observation period. The presence of obesity in COPD was associated with significantly higher risk of severe activity limitation and increased health care utilization. The combination of obesity and COPD has major implications for health care delivery that has not been previously appreciated.

Declared and real physical activity in patients with type 2 diabetes mellitus as assessed by the International Physical Activity Questionnaire and Caltrac accelerometer monitor: a potential tool for physical activity assessment in patients with type 2 diabetes mellitus

AIMS

The aims of this study were to assess and compare declared and real volume of physical activity (PA), and to evaluate correlations of these measurements with glycemic control (HbA1c) and body mass index (BMI), in patients with type 2 diabetes mellitus (T2DM).

MATERIAL AND METHODS

A group of 31 (16 women and 15 men) type 2 diabetic patients treated with insulin monotherapy, from (mean age=54 ± 3.6 years, BMI=29.7 ± 4.8 kg/m(2), T2DM treatment=9 ± 8 years, HbA1c 7 ± 1%) and not professionally active (unemployed or retired) was recruited. An assessment of energy cost (EC) of their weekly PA using International Physical Activity Questionnaire (IPAQ), and an accelerometer assessment was performed.

RESULTS

Total energy expenditure of the declared weekly PA, calculated from the IPAQ (DPA) was 2513 ± 1349 METmin/week, and 2428 ± 1348, for male and female participants, respectively (p > 0.05). EC of the real PA (RPA), registered with the accelerometer was 4552 ± 2028 kcal/week, and 4032 ± 2288 kcal/week, for males, and females, respectively. Patients who demonstrated a high DPA, based on their IPAQ score, showed a significantly higher RPA, as registered by the accelerometer (p < 0.05). HbA1c and BMI did not correlate with their PA measurements.

CONCLUSIONS

Our findings indicate that the IPAQ may serve as a potential tool for physical activity assessment with no further requirement for more sophisticated methods. Our results suggest that habitual physical activity has no impact on glycemic control and BMI in type 2 diabetic patients. However, further studies on a larger population are needed to explore these issues.

Validation of Web-based physical activity measurement systems using doubly labeled water

BACKGROUND

Online or Web-based measurement systems have been proposed as convenient methods for collecting physical activity data. We developed two Web-based physical activity systems-the 24-hour Physical Activity Record Web (24hPAR WEB) and 7 days Recall Web (7daysRecall WEB).

OBJECTIVE

To examine the validity of two Web-based physical activity measurement systems using the doubly labeled water (DLW) method.

METHODS

We assessed the validity of the 24hPAR WEB and 7daysRecall WEB in 20 individuals, aged 25 to 61 years. The order of email distribution and subsequent completion of the two Web-based measurements systems was randomized. Each measurement tool was used for a week. The participants' activity energy expenditure (AEE) and total energy expenditure (TEE) were assessed over each week using the DLW method and compared with the respective energy expenditures estimated using the Web-based systems.

RESULTS

The mean AEE was 3.90 (SD 1.43) MJ estimated using the 24hPAR WEB and 3.67 (SD 1.48) MJ measured by the DLW method. The Pearson correlation for AEE between the two methods was r = .679 (P < .001). The Bland-Altman 95% limits of agreement ranged from -2.10 to 2.57 MJ between the two methods. The Pearson correlation for TEE between the two methods was r = .874 (P < .001). The mean AEE was 4.29 (SD 1.94) MJ using the 7daysRecall WEB and 3.80 (SD 1.36) MJ by the DLW method. The Pearson correlation for AEE between the two methods was r = .144 (P = .54). The Bland-Altman 95% limits of agreement ranged from -3.83 to 4.81 MJ between the two methods. The Pearson correlation for TEE between the two methods was r = .590 (P = .006). The average input times using terminal devices were 8 minutes and 10 seconds for the 24hPAR WEB and 6 minutes and 38 seconds for the 7daysRecall WEB.

CONCLUSIONS

Both Web-based systems were found to be effective methods for collecting physical activity data and are appropriate for use in epidemiological studies. Because the measurement accuracy of the 24hPAR WEB was moderate to high, it could be suitable for evaluating the effect of interventions on individuals as well as for examining physical activity behavior.

Advantage of distance- versus time-based estimates of walking in predicting adiposity

PURPOSE

Physical activity recommendations are defined in terms of time spent being physically active (e.g., 30 min of brisk walking, 5 d · wk(-1)). However, walking volume may be more naturally assessed by distance than by time. Analyses were therefore performed to test whether time or distance provides the best metric for relating walking volume to estimated total and regional adiposity.

METHODS

Linear and logistic regression analyses were used to relate exercise dose to body mass index (BMI), body circumferences, and obesity in a cross-sectional sample of 12,384 female and 3434 male walkers who reported both usual distance walked and time spent walking per week on survey questionnaires. Metabolic equivalent hours per day (MET · h · d(-1), 1 MET = 3.5 mL O2 · kg(-1) · min(-1)) were calculated from the time and pace, or distance and pace, using published compendium values.

RESULTS

Average MET-hours per day walked was 37% greater when calculated from time spent walking versus usual distance in women and was 32% greater in men. Per MET-hours per day, declines in BMI and circumferences (slope ± SE) were nearly twice as great, or greater, for distance- versus time-derived estimates for kilograms per squared meter of BMI (females = -0.58 ± 0.03 vs -0.31 ± 0.02, males = -0.35 ± 0.04 vs -0.15 ± 0.02), centimeter of waist circumference (females = -1.42 ± 0.07 vs -0.72 ± 0.04, males = -0.96 ± 0.10 vs -0.45 ± 0.07), and reductions in the odds for total obesity (odds ratio: females = 0.72 vs 0.84, males = 0.84 vs 0.92) and abdominal obesity (females = 0.74 vs 0.85, males = 0.79 vs 0.91, all comparisons significant).

CONCLUSIONS

Distance walked may provide a better metric of walking volume for epidemiologic obesity research, and better public health targets for weight control, than walking duration. Additional research is required to determine whether these results, derived in a sample that regularly walks for exercise, apply more generally.

Omega 3 polyunsaturated fatty acids and body weight

In animal studies, n-3 PUFA have been shown to influence body composition and to reduce the accumulation of body fat, thereby affecting body weight homeostasis. In addition, it has been suggested that an additional supply of n-3 PUFA during pregnancy or lactation, or both, would have a beneficial effect on birth weight and infant growth and development. The purpose of the present study was to systematically review interventional clinical trials on the effects of dietary n-3 PUFA supplementation on body weight in adult subjects and in infants whose mothers were supplemented with these fatty acids during pregnancy and/or lactation. A systematic search, focused on n-3 PUFA and body weight, and limited to controlled clinical trials, was performed in different databases. The quality of all included studies was assessed against set criteria, and results of eligible trials were compared. There were few studies targeting this topic. In adults, all of the five studies included, except for one, show no change in body weight by dietary supplementation with n-3 PUFA. Within those trials conducted in pregnant and/or lactating women in which a main outcome was birth weight or growth in infancy, two showed a modest increase in birth weight and the rest showed no effect. None of the trials showed an effect of maternal n-3 PUFA supplementation on infant's weight at the short term. However, it should be noted that a number of limitations, including a variety of experimental designs, type and doses of n-3 PUFA, and high attrition rates, among others, make impossible to draw robust conclusions from this review.

Validity and reproducibility of a physical activity questionnaire for older adults: questionnaire versus accelerometer for assessing physical activity in older adults

Background

Physical activity (PA) is important in older adults for the maintenance of functional ability. Assessing PA may be difficult. Few PA questionnaires have been compared to activity monitors. We examined reproducibility and validity of the self-administered Longitudinal Ageing Study Amsterdam Physical Activity Questionnaire (LAPAQ) against a triaxial accelerometer (ACTR) (Sensewear^® Pro) in older adults.

Methods

Participants wore the ACTR continuously for two weeks. After 2 (T [time] = 1) and 4 (T = 2) weeks, participants completed the LAPAQ. Since the LAPAQ asks about 2 weeks’ worth of physical activity, the ACTR and LAPAQ coincided at T1. T2 was used to assess the reproducibility of the LAPAQ results only. We calculated Pearson’s correlation coefficients (PCC) to examine reproducibility and validity. For visualization, we used scatterplots and Bland–Altman plots. With a receiver operating characteristics (ROC) curve we assessed how well the LAPAQ identifies older adults whose activity level is below official recommendations.

Results

A total of 89 persons were included. Of the participants, 48% were men; median age was 73, and median body mass index was 25. The 2-week mean total duration of activity was 2788 (ACTR, T = 1), 2439 (LAPAQ T = 1), and 1994 (LAPAQ T = 2) minutes. As a reference, 2 full weeks contained 20,160 minutes. Reproducibility of the LAPAQ was moderate (PCC 0.68, 95% CI 0.55–0.80). The median difference between LAPAQ at T = 1 and the ACTR (LAPAQ minus ACTR) was –510 minutes and the PCC was 0.25 (95% CI 0.07–0.44). The area under the ROC curve was 0.73 (95% CI 0.59–0.86).

Conclusion

LAPAQ underestimates PA and seems unsuitable for exact measurement in older adults. However, it may be used to determine if a person’s PA level is below the recommended level.

Improving self-reports of active and sedentary behaviors in large epidemiologic studies

Questionnaires that assess active and sedentary behaviors in large-scale epidemiologic studies are known to contain substantial errors. We present three options for improving measures of physical activity behaviors in large-scale epidemiologic studies, discuss the problems and prospects for each of these options, and highlight a new direction for measuring these behaviors in such studies.