Associations of accelerometer-based sedentary bouts with adiposity markers among German adults - results from a cross-sectional study.

BACKGROUND: Long periods of uninterrupted sitting, i.e., sedentary bouts, and their relationship with adverse health outcomes have moved into focus of public health recommendations. However, evidence on associations between sedentary bouts and adiposity markers is limited. Our aim was to investigate associations of the daily number of sedentary bouts with waist circumference (WC) and body mass index (BMI) in a sample of middle-aged to older adults. METHODS: In this cross-sectional study, data were collected from three different studies that took place in the area of Greifswald, Northern Germany, between 2012 and 2018. In total, 460 adults from the general population aged 40 to 75 years and without known cardiovascular disease wore tri-axial accelerometers (ActiGraph Model GT3X+, Pensacola, FL) on the hip for seven consecutive days. A wear time of ≥ 10 h on ≥ 4 days was required for analyses. WC (cm) and BMI (kg m- 2) were measured in a standardized way. Separate multilevel mixed-effects linear regression analyses were used to investigate associations of sedentary bouts (1 to 10 min, >10 to 30 min, and >30 min) with WC and BMI. Models were adjusted for potential confounders including sex, age, school education, employment, current smoking, season of data collection, and composition of accelerometer-based time use. RESULTS: Participants (66% females) were on average 57.1 (standard deviation, SD 8.5) years old and 36% had a school education >10 years. The mean number of sedentary bouts per day was 95.1 (SD 25.0) for 1-to-10-minute bouts, 13.3 (SD 3.4) for >10-to-30-minute bouts and 3.5 (SD 1.9) for >30-minute bouts. Mean WC was 91.1 cm (SD 12.3) and mean BMI was 26.9 kg m- 2 (SD 3.8). The daily number of 1-to-10-minute bouts was inversely associated with BMI (b = -0.027; p = 0.047) and the daily number of >30-minute bouts was positively associated with WC (b = 0.330; p = 0.001). All other associations were not statistically significant. CONCLUSION: The findings provide some evidence on favourable associations of short sedentary bouts as well as unfavourable associations of long sedentary bouts with adiposity markers. Our results may contribute to a growing body of literature that can help to define public health recommendations for interrupting prolonged sedentary periods. TRIAL REGISTRATION: Study 1: German Clinical Trials Register (DRKS00010996); study 2: ClinicalTrials.gov (NCT02990039); study 3: ClinicalTrials.gov (NCT03539237).

The effect of a video-supported assessment to increase the accuracy of self-reported physical activity.

Self-reported physical activity differs from activity levels measured by device. We tested the effect of a video that visualizes the intensity levels of physical activity to increase the agreement between self-reported and accelerometer-based moderate-to-vigorous physical activity (MVPA) within a single-blinded, randomized study. Participants (N = 378, 40-75 years) wore an accelerometer for seven days. Prior to the collection of self-reported data by the IPAQ-SF, participants were randomly assigned (1:1) to a control group (CG) or a video group (VG). The outcome was the absolute difference between self-reported and accelerometer-based time spent in MVPA (Δ MVPAIPAQ-Accelerometry ). To examine the agreement, we used Spearman correlation coefficients and Bland-Altman analysis. To test the video effect, we used Wilcoxon signed-rank test, Bayes factor, and simultaneous-quantile regression. In total, 302 participants fulfilled the accelerometer wear time criteria (≥10 hours/day; ≥6 days) and completed self-reports within three days after the wearing period. The median of Δ MVPAIPAQ-Accelerometry was -9.0 min/day (IQR: -32.0 to 66.6) for CG and -11.5 min/day (IQR: -29.9 to 14.3) for VG. Wilcoxon signed-rank test revealed no differences in Δ MVPAIPAQ-Accelerometry between study groups whereas Bayes factor indicated insensitivity of the data. Simultaneous-quantile regression revealed no relationship between video presentation and Δ MVPAIPAQ-Accelerometry in the 25th percentile. In the 50th (b = -12.4 [95% CI = -23.2 to -1.5] and 75th percentile (b = -45.7 [95% CI = -70.5 to -20.9]), Δ MVPAIPAQ-Accelerometry was negatively associated with video presentation. To conclude, video-supported assessment may increase the accuracy of self-reported MVPA among individuals who slightly underestimated and those who overestimated their MVPA.

Do sociodemographic variables and cardiometabolic risk factors moderate the mere-measurement effect on physical activity and sedentary time?

BACKGROUND: Participation in an assessment may change health behavior. This "mere-measurement effect" may be used for prevention purposes. However, little is known about whether individuals' characteristics moderate the effect. The objective was to explore whether changes of physical activity (PA) and sedentary time (ST) after a cardiovascular assessment depend on sociodemographic variables and cardiometabolic risk factors. METHODS: A sample of n = 175 adults aged 40 to 65 received baseline assessment including self-administered PA and ST questionnaires and standardized measurement of blood pressure, waist circumference, and blood parameters. After 5 weeks, participants again reported PA and ST without any prior treatment or intervention. Linear regression models were used to analyze the dependence of five-week changes in PA and ST on baseline sociodemographic and cardiometabolic variables. RESULTS: Men increased transport-related PA more than women (b = 9.3 MET-hours/week, P = .031). Men with higher triglycerides increased transport-related PA less than men with lower triglycerides (b = - 5.6 MET-hours/week, P = .043). Men with higher systolic blood pressure reduced ST more than those with lower systolic blood pressure (b = - 35.7 min/week, P = .028). However, this linear association ceased to exist at a level of approximately 145 mmHg (b of squared association = 1.0, P = .080). A similar relationship was found for glycated hemoglobin and ST. CONCLUSIONS: The findings suggest that sex and cardiometabolic risk factors moderate mere-measurement effects on PA and ST. Researchers and practitioners using mere measurement for prevention purposes may address PA and ST according to these individual characteristics. TRIAL REGISTRATION: ClinicalTrials.govNCT02990039. Registered 7 December 2016. Retrospectively registered.

Patterns of accelerometer-based sedentary behavior and their association with cardiorespiratory fitness in adults.

We aimed to identify patterns of sedentary behavior (SB) and examined whether cardiorespiratory fitness differs between classes with distinct patterns of SB. One hundred and seventy participants (57% women, mean age = 56.4 years) received accelerometry monitoring for 7 days. Prior to accelerometry assessment, cardiorespiratory fitness was assessed by peak oxygen uptake (VO2peak ). VO2peak was directly measured during a symptom-limited cardiopulmonary exercise testing on a cycle ergometer. Patterns in accelerometer data were classified based on time spent in SB per day using growth mixture modeling. Model-implied class-specific VO2peak means were compared using adjusted equality test of means. Growth mixture modeling revealed four patterns of SB: "High, stable" (n = 120, M = 724.9 min/d), "Low, increase" (n = 14, M = 622.2 min/d), "Low, decrease" (n = 11, M = 540.2 min/d), and "High, decrease" (n = 25, M = 694.8 min/d). Persons in class "High, stable" had significantly lower VO2peak values (M = 25.0 mL/kg/min, SD = 0.6) compared to persons in class "Low, increase" (M = 30.5 mL/kg/min, SD = 3.6; P = 0.001), in class "Low, decrease" (M = 30.1 mL/kg/min, SD = 5.0; P = 0.009), and in class "High, decrease" (M = 29.6 mL/kg/min, SD = 5.9; P = 0.032). No differences among the other classes were found. We identified four classes of individuals with distinct patterns of SB and showed that VO2peak partially differs between classes. Especially, individuals with stable high SB levels throughout the week might be addressed in public health recommendations and interventions.

A cross-sectional analysis of the associations between leisure-time sedentary behaviors and clustered cardiometabolic risk.

BACKGROUND: The aim of this study was to conduct a comprehensive investigation of the association between different types of leisure-time sedentary behavior (watching television, using a computer, reading and socializing) and clustered cardiometabolic risk in apparently healthy adults aged 40 to 65 years. METHODS: One hundred seventy-three participants from the general population (64% women; mean age = 54.4 years) consented to attend a cardiovascular examination program and to complete a questionnaire on leisure-time sedentary behaviors. Waist circumference, blood pressure, glucose, triglycerides, and high-density lipoprotein cholesterol of non-fasting blood samples were assessed, and a clustered cardiometabolic risk score [CMRS] was calculated. Data were collected between February and July 2015. Associations between leisure-time sedentary behaviors and CMRS were analyzed using linear and quantile regression, adjusted for socio-demographic variables and other types of leisure-time sedentary behavior (model 1) and additionally, adjusted for leisure-time physical activity and traveling in motor vehicles (model 2). RESULTS: Linear regression revealed that there was a positive association between watching television and CMRS (model 1: b = 0.27 [CI: 0.03; 0.52]; model 2: b = 0.30 [CI: 0.05; 0.56]). In addition, quantile regression analysis revealed that using a computer was negatively associated with the 50th (model 1: b = - 0.43 [CI: -0.79; - 0.07]) and the 75th percentiles (model 1: b = - 0.71 [CI: -1.27; - 0.14]) of CMRS. Reading and socializing were not associated with CMRS. CONCLUSIONS: Watching television was positively associated with a clustered cardiometabolic risk score, while time spent using a computer revealed inconsistent findings. Our results give reason to consider different types of behaviors in which individuals are sedentary and the associations between these behaviors and cardiometabolic risk, supporting the need for behavior-specific assessments as well as public health recommendations to maintain or enhance adults' health. TRIAL REGISTRATION: Clinical trial registration number: NCT02990039 , Retrospectively registered (December 12, 2016).

Participation and social functioning in patients with fibromyalgia: development and testing of a new questionnaire.

BACKGROUND: While there are numerous instruments for capturing the symptoms of fibromyalgia syndrome (FMS) patients, there is a lack of questionnaires capable of measuring in detail FMS patients' participation and social functioning. It was our aim to develop and methodologically test a new patient questionnaire specific to FMS measuring these concepts (the "Fibromyalgia Participation Questionnaire" FPQ). METHODS: We first conducted a qualitative prestudy (focus groups, N = 38) to identify which impairments FMS patients experience in daily life because of their illness. To analyze the data we developed a coding system that contained 10 supercategories and a total of 105 subcategories. Items for the FPQ were developed from the subcategories. The psychometric analysis was done on a sample of N = 256 FMS patients undergoing inpatient rehabilitation in Germany. RESULTS: The final version of the FPQ contained 27 items and three scales (participation in social life FPQ-S, 11 items; participation in daily life FPQ-D, 11 items, participation in work-life FPQ-W 5 items). The FPQ displays good distribution properties, all the scales are unidimensional, and the scales fit to the Rasch model. Cronbach's Alpha range from 0.85 to 0.94. We noted indications of construct validity in that the FPQ correlates as expected with the Fibromyalgia Impact Questionnaire (physical scale), Pain Disability Index and scales from the PROMIS® item banks for satisfaction with participation. The FPQ scales generally reveal greater responsiveness than other instruments. By linking FPQ items to the categories of the International Classification of Functioning, Disability and Health (ICF) we demonstrate content validity. CONCLUSIONS: The FPQ captures participation and social functioning in FMS patients. As its psychometric properties are good, it can be recommended for use in evaluation studies and clinical trials.

Health education literacy in patients with chronic musculoskeletal diseases: development of a new questionnaire and sociodemographic predictors.

It was our aim to develop a questionnaire for patients with chronic musculoskeletal diseases to self-report their health education literacy, to analyse the psychometric properties of the instrument and to test hypotheses concerning sociodemographic predictors of health education literacy. A total of 577 patients with chronic back pain or osteoarthritis who underwent inpatient rehabilitation were surveyed. The resulting 'HELP questionnaire' (health education literacy of patients with chronic musculoskeletal diseases) consists of 18 items and three scales (comprehension of medical information, applying medical information, communicative competence in provider interactions). The instrument's psychometric properties are good (Cronbach's alpha between 0.88 and 0.95, unidimensionality and Rasch model fit established). Our sample's average level of self-reported health education literacy is quite high. However, 20-30% of the patients admitted to having difficulty understanding important aspects of health education programmes (i.e. comprehending what medical information means in relation to their disease). The variance explained by sociodemographic and basic medical variables is small (4-8%). Greater effort is required to make health education programmes easier to understand. There is a need for more research on interindividual variability of complex aspects of health literacy.

Preliminary results of the cross-sectional associations of sedentary behavior and physical activity with serum brain-derived neurotrophic factor in adults with coronary heart disease.

This is the first study to analyze the association of accelerometer-measured patterns of habitual physical activity (PA) and sedentary behavior (SB) with serum BDNF in individuals with coronary heart disease. A total of 30 individuals (M = 69.5 years; 80% men) participated in this pre-post study that aimed to test a multi-behavioral intervention. All participants underwent standardized measurement of anthropometric variables, blood collection, self-administered survey, and accelerometer-based measurement of PA and SB over seven days. Serum BDNF concentrations were measured using enzyme-linked immunosorbent assay kit. We applied separate multiple linear regression analysis to estimate the associations of baseline SB pattern measures, light and moderate-to-vigorous PA with serum BDNF (n = 29). Participants spent 508.7 ± 76.5 min/d in SB, 258.5 ± 71.2 min/d in light PA, and 21.2 ± 15.2 min/d in moderate-to-vigorous PA. Per day, individuals had 15.5 ± 3.2 numbers of 10-to-30 min bouts of SB (average length: 22.2 ± 2.1 min) and 3.4 ± 1.2 numbers of > 30 min bouts of SB (average length: 43.8 ± 2.4 min). Regression analysis revealed no significant associations between any of the accelerometer-based measures and serum BDNF. The findings of this study did not reveal an association of accelerometer-measured PA and SB pattern variables with serum BDNF in individuals with coronary heart disease. In addition, our data revealed a considerable variation of PA and SB which should be considered in future studies.

Measurement Reactivity of Accelerometer-Based Sedentary Behavior and Physical Activity in 2 Assessment Periods.

BACKGROUND: The purposes of this study were to examine accelerometer measurement reactivity (AMR) in sedentary behavior (SB), physical activity (PA), and accelerometer wear time in 2 measurement periods and to quantify AMR as a human-related source of bias for the reproducibility of SB and PA estimates. METHODS: In total, 136 participants (65% women, mean age = 54.6 y) received 7-day accelerometry at the baseline and after 12 months. Latent growth models were used to identify AMR. Intraclass correlations were calculated to examine the reproducibility using 2-level mixed-effects linear regression analyses. RESULTS: Within each 7-day accelerometry assessment, the participants increased their time spent in SB (b = 2.4 min/d; b = 3.8 min/d) and reduced their time spent in light PA (b = -2.0 min/d; b = -3.2 min/d), but did not change moderate to vigorous PA. The participants reduced their wear time (b = -5.2 min/d) only at the baseline. The intraclass correlations ranged from .42 for accelerometer wear time to .74 for SB. The AMR was not identified as a source of bias in any regression model. CONCLUSIONS: AMR may influence SB and PA estimates differentially. Although 7-day accelerometry seems to be a reproducible measure, our findings highlight accelerometer wear time as a crucial confounder in analyzing SB and PA data.

Influence of different nitrate-N monitoring strategies on load estimation as a base for model calibration and evaluation.

Model-based predictions of the impact of land management practices on nutrient loading require measured nutrient flux data for model calibration and evaluation. Consequently, uncertainties in the monitoring data resulting from sample collection and load estimation methods influence the calibration, and thus, the parameter settings that affect the modeling results. To investigate this influence, we compared three different time-based sampling strategies and four different load estimation methods for model calibration and compared the results. For our study, we used the river basin model Soil and Water Assessment Tool on the intensively managed loess-dominated Parthe watershed (315 km(2)) in Central Germany. The results show that nitrate-N load estimations differ considerably depending on sampling strategy, load estimation method, and period of interest. Within our study period, the annual nitrate-N load estimation values for the daily composite data set have the lowest ranges (between 9.8% and 15.7% maximum deviations related to the mean value of all applied methods). By contrast, annual estimation results for the submonthly and the monthly data set vary in greater ranges (between 24.9% and 67.7%). To show differences between the sampling strategies, we calculated the percentage deviation of mean load estimations of submonthly and monthly data sets as related to the mean estimation value of the composite data set. For nitrate-N, the maximum deviation is 64.5% for the submonthly data set in the year 2000. We used average monthly nitrate-N loads of the daily composite data set to calibrate the model to achieve satisfactory simulation results [Nash-Sutcliffe efficiency (NSE) 0.52]. Using the same parameter settings with submonthly and monthly data set, the NSE dropped to 0.42 and 0.31, respectively. Considering the different results from the monitoring strategy and the load estimation method, we recommend both the implementation of optimized monitoring programs and the use of multiple load estimation methods to improve water quality characterization and provide appropriate model calibration and evaluation data.

Visualization of Intensity Levels to Reduce the Gap Between Self-Reported and Directly Measured Physical Activity.

Physical activity (PA) assessment needs tools that are inexpensive and easy to administer. Common questionnaires inquire time spent in light, moderate, and vigorous PA. However, inaccuracies may occur due to individually different understanding of PA intensity levels. Alternatively used direct measures (e.g., accelerometers) are susceptible to reactivity bias and may lack the ability to capture certain activities. Compared to accelerometer measurement, respondents report more time spent in higher-intensity PA. A video that visualizes PA intensity levels might help to overcome this problem. This report describes the design of a randomized controlled trial as a methodology to investigate the effect of a video on the difference between self-reported and directly measured PA. It is hypothesized that the video reduces the mean difference between the two measures. Individuals from the general population are recruited. Hip-worn accelerometers are used to collect directly measured PA data on seven consecutive days. Afterwards, participants are randomly allocated to the experimental and the control group. The experimental group receives a video demonstration on PA intensity levels and subsequent PA assessment via self-administered computer-assisted questionnaire. The control group receives PA assessment only. Thereafter, the data are processed to compare the difference between self-reported and accelerometer-based moderate-to-vigorous physical activity (MVPA) between the study groups using a two-sample t-test. This methodology is appropriate for investigating the effect of any existing or self-produced video on the difference between the two measurement methods. It can be used not only for persons from the general population, but for a variety of other populations and contexts as accurate measures are needed to evaluate PA levels.

The effect of mere measurement from a cardiovascular examination program on physical activity and sedentary time in an adult population.

BACKGROUND: Measuring physical activity (PA) and sedentary time (ST) by self-report or device as well as assessing related health factors may alter those behaviors. Thus, in intervention trials assessments may bias intervention effects. The aim of our study was to examine whether leisure-time PA, transport-related PA, and overall ST measured via self-report vary after assessments and whether a brief tailored letter intervention has an additional effect. METHODS: Among a sample of subjects with no history of myocardial infarction, stroke, or vascular intervention, a number of 175 individuals participated in a study comprising multiple repeated assessments. Of those, 153 were analyzed (mean age 54.5 years, standard deviation = 6.2; 64% women). At baseline, participants attended a cardiovascular examination (standardized measurement of blood pressure and waist circumference, blood sample taking) and wore an accelerometer for seven days. At baseline and after 1, 6, and 12 months, participants completed the International Physical Activity Questionnaire. A random subsample received a tailored counseling letter intervention at month 1, 3, and 4. Changes in PA and ST from baseline to 12-month follow-up were analyzed using random-effects modelling. RESULTS: From baseline to 1-month assessment, leisure-time PA did not change (Incidence rate ratio = 1.13, p = .432), transport-related PA increased (Incidence rate ratio = 1.45, p = .023), and overall ST tended to decrease (b = - 1.96, p = .060). Further, overall ST decreased from month 6 to month 12 (b = - 0.52, p = .037). Time trends of the intervention group did not differ significantly from those of the assessment-only group. CONCLUSIONS: Results suggest an effect of measurements on PA and ST. Data of random-effects modelling results revealed an increase of transport-related PA after baseline to 1-month assessment. Decreases in overall ST may result from repeated assessments. A brief tailored letter intervention seemed to have no additional effect. Thus, measurement effects should be considered when planning intervention studies and interpreting intervention effects. TRIAL REGISTRATION: ClinicalTrials.gov NCT02990039. Registered 7 December 2016. Retrospectively registered.

Communication preferences in patients with fibromyalgia syndrome: descriptive results and patient characteristics as predictors.

BACKGROUND: Communication with patients with fibromyalgia syndrome (FMS) is often considered difficult. The primary objective of this explorative study was to describe the communication preferences of FMS patients in comparison with other chronic diseases, and the secondary objective was to identify patient-related predictors of those communication preferences. METHODS: A total of 256 FMS patients were asked to fill out the KOPRA [(Kommunikationspraeferenzen), communication preferences of patients with chronic illness] questionnaire at the beginning of their rehabilitation, answering questions about their communication preferences. The KOPRA's descriptive parameters were calculated and compared with other diagnosis groups. In order to include as many influencing factors as possible, data on patient-related sociodemographic, medical, pain impact and psychologic variables were gathered. A hierarchical regression analysis with four steps was performed to identify patient-related predictors of patients' communication preferences. RESULTS: FMS patients consider an open and patient-centered communication style to be especially important. Emotionally supportive communication and communication about personal circumstances are important for FMS patients, but the preferences of individual patients vary widely. FMS patients reveal higher values in all the subdimensions of communication preferences compared with patients with low back pain or chronic ischemic heart disease. Only a few variables appear to predict patient communication preferences. The explained variance ranged from 3.1% to 9.7%. Psychologic variables have been identified as predictors in conjunction with all communication preferences. CONCLUSION: Health care providers who communicate with FMS patients should employ an open and patient-centered communication style, and affective communication components should be adapted to accommodate each patient.

The comprehensibility of health education programs: questionnaire development and results in patients with chronic musculoskeletal diseases.

OBJECTIVE: The objective was to develop a comprehensive questionnaire for measuring the patient-perceived comprehensibility of health education programs (COHEP questionnaire). According to a conceptual model outlined in the article, comprehensibility is considered a context factor of patient health literacy. METHODS: A questionnaire study was carried out on N=577 patients with chronic musculoskeletal diseases. During inpatient rehabilitation, patients participated in standardized, interactive group education programs conducted by clinic personnel. Factorial structure, unidimensionality, reliability, fit to the Rasch model, and construct validity were tested. RESULTS: The COHEP consists of 30 items and 4 scales (comprehension-fostering behavior of program trainers, transferability to everyday life, comprehensibility of medical information, amount of information). All scales are reliable, unidimensional, and meet the requirements of the Rasch model. In addition, there are initial indications of validity. The descriptive results show that the overall rating of the comprehensibility of patient education programs in the German rehabilitation system is good, but that there are clear differences between centers. CONCLUSION: The COHEP can be used to evaluate health education programs, since it measures an important proximal outcome. PRACTICE IMPLICATIONS: An analysis of patient-perceived comprehensibility can help providers adapt education sessions better to the health literacy of patients.