Physical activity and sedentary time are related to clinically relevant health outcomes among adults with obstructive lung disease

The purpose of the current study was to determine the association between sedentary time and physical activity with clinically relevant health outcomes among adults with impaired spirometry and those with or without self-reported obstructive lung disease (asthma or COPD).Data from participants of the Canadian Longitudinal Study on Aging were used for analysis (n = 4156). Lung function was assessed using spirometry. Adults were said to have impaired spirometry if their Forced Expiratory Volume in 1\ua0s wa

Sedentary time in older men and women: an international consensus statement and research priorities

Sedentary time is a modifiable determinant of poor health, and in older adults, reducing sedentary time may be an important first step in adopting and maintaining a more active lifestyle. The primary purpose of this consensus statement is to provide an integrated perspective on current knowledge and expert opinion pertaining to sedentary behaviour in older adults on the topics of measurement, associations with health outcomes, and interventions. A secondary yet equally important purpose is to suggest priorities for future research and knowledge translation based on gaps identified. A five-step Delphi consensus process was used. Experts in the area of sedentary behaviour and older adults (n=15) participated in three surveys, an in-person consensus meeting, and a validation process. The surveys specifically probed measurement, health outcomes, interventions, and research priorities. The meeting was informed by a literature review and conference symposium, and it was used to create statements on each of the areas addressed in this document. Knowledge users (n=3) also participated in the consensus meeting. Statements were then sent to the experts for validation. It was agreed that self-report tools need to be developed for understanding the context in which sedentary time is accumulated. For health outcomes, it was agreed that the focus of sedentary time research in older adults needs to include geriatric-relevant health outcomes, that there is insufficient evidence to quantify the dose-response relationship, that there is a lack of evidence on sedentary time from older adults in assisted facilities, and that evidence on the association between sedentary time and sleep is lacking. For interventions, research is needed to assess the impact that reducing sedentary time, or breaking up prolonged bouts of sedentary time has on geriatric-relevant health outcomes. Research priorities listed for each of these areas should be considered by researchers and funding agencies

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Sedentary Behavior and Physical Activity Are Independent Predictors of Successful Aging in Middle-Aged and Older Adults

Background. Sedentary behavior is emerging as an important risk factor for poor health. Physical activity has proven to be important in determining overall successful aging (SA) among older adults; however, no data exists on the influence of sedentary behavior on SA. The purpose of this analysis was to determine whether there is an association between sedentary behavior and successful aging, independent of physical activity levels. Methods. 9,478 older (M = 4,245; F = 5,233) and 10,060 middle-aged (M = 4.621; F = 5,439) adults from the Healthy Aging cycle of the Canadian Community Health Survey were analyzed. Multivariate logistic regressions were conducted with SA and its three components as outcomes while physical activity and sedentary behavior were entered as main exposures. Results. Among older adults, compared to those who were sedentary (4 hours or more/day), those who were moderately (2–4 hours/day) and least sedentary (<2 hours/day) were 38% (OR: 1.38; CI: 1.12–1.69) and 43% (OR: 1.43; CI: 1.23–1.67) more likely to age successfully, respectively. Among middle-aged adults, those who were least sedentary were 43% (OR: 1.43; CI: 1.25–1.63) more likely to age successfully. Conclusions. These novel findings suggest that sedentary activities are significantly associated with lower odds of SA among middle-aged and older adults, potentially in a dose-dependent manner

Novel Predictors of Age-Related Changes in Lung Function

Smoking and air pollution exposure are modifiable predictors of age-related declines in lung function. There is some evidence to suggest that physical inactivity may be a predictor of age-related changes in lung function; however, the independent contribution of sitting time, physical activity, and cardiorespiratory fitness have not been investigated to date. PURPOSE: To determine the association between age-related declines in lung function with sitting time, physical activity and cardiorespiratory fitness in a population of healthy adults. METHODS: Data from the Fels Longitudinal Study (1999-2015) were used for analysis (n=996), with serial data available for up to five study visits. Forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) were measured using a metabolic cart (SensorMedics VMax). Physical activity was measured using the Baecke questionnaire and TV time was self-reported as either never, seldom, sometimes, often, and very often. Cardiorespiratory fitness was determined by calculating VO2max from a submaximal treadmill test. Data were analyzed using repeated measures hierarchical linear models in SAS. RESULTS: The sample was middle-aged (45.0 ±17 years), overweight (BMI: 27.1 ± 5.6 kg/m2), and their VO2max was 36.6±9.8 ml/kg/min. Approximately 53% of the sample reported watching TV often and only 3% of the sample reported engaging in regular physical activity often. In models adjusted for age, BMI, physical functioning and smoking status, there was a significant TV time x sex interaction (p\u3c0.0001) when modeling FEV1, such that higher TV time in females was associated with worse FEV1 compared to males. A physical activity x sex interaction (p\u3c0.0001) was also observed in adjusted models of FEV1. When TV time, physical activity and cardiorespiratory fitness were included in the same model, only the association between cardiorespiratory fitness and FEV1 remained significant (p\u3c0.001). CONCLUSION: Cardiorespiratory fitness is a predictor of age-related changes in lung function. Among deconditioned adults, particularly in females, reducing sedentary time and increasing physical activity may lead to an increase in cardiorespiratory fitness and thus may attenuate the age-related decline in lung function

Factors Influencing Sedentary Behaviour in Older Adults: An Ecological Approach

Sedentary behaviour is negatively associated with several health outcomes and is particularly problematic among older adults. Knowledge translation tools and public health promotion strategies are needed; however, little evidence is available to inform framing of such tools or development of intervention programs. The aim of the present study was to use data on the perceptions of sedentary time and the programs or supports older adults identify as important for reducing their sedentary time, to inform knowledge translation strategies targeting this population. Focus groups were conducted with four groups of older adults (n = 26) at local seniors' centres (Ontario, Canada). Participants were 74 ± 8.5 years old and were engaging in both sedentary and physical activities in a social environment. Using the Ecological Model for sedentary time in adults, we categorized data into leisure time, household, transport and occupation domains. Intrinsic and extrinsic factors that worked to either discourage or promote sedentary behaviour were identified. Drawing on both groupings of data, results were synthesized to inform public health strategies on appropriate messaging and better uptake of programming and guidelines. For example, successful programs developed on the topic will need to include a social component and a mentally stimulating component, as these were identified as critical for enjoyment and motivation. It was clear from this analysis that sedentary time reduction strategies will need to consider the different domains in which older adults accumulate sedentary time

Role of age at asthma diagnosis in the asthma-obesity relationship

OBJECTIVE: To determine whether age at asthma diagnosis has an impact on the previously described relationship between asthma and obesity

Objectively measured and self-reported sedentary time in older Canadians

Objective: The aim of this study was to examine objectively measured total and self-reported leisure sedentary time among older Canadians by work status. Methods: The analysis was based on 1729 older adults (60–79 years) from the 2007/09 and 2010/11 Canadian Health Measures Survey. Work status, functional limitations, smoking, and perceived health were assessed by self-report and waist circumference (WC) was measured. Total sedentary time (ST) and physical activity (PA) were objectively measured by accelerometer and leisure sedentary activities were assessed by questionnaire. Results: 93.6% of individuals were sedentary for 8 or more hours per day. Measured ST did not differ by work status, while self-reported leisure ST was higher in those not working compared to those working (239 vs. 207 minutes/day, p < 0.05). Correlates of measured ST were fair/poor perceived health (β: 28.76, p < 0.01), smoking (β: 17.12, p < 0.05), high-risk WC (β: 13.14, p < 0.05), and not meeting PA guidelines (β: 35.67, p < 0.001). For self-reported leisure ST, working status (β: 33.80, p < 0.001) and functional limitations (β: 16.31, p < 0.05) were significant correlates. Conclusions: Older adults accumulate substantial ST regardless of their working status and ST is correlated with indicators of health risk. Older adults are an important target population for interventions to reduce ST

Novel Predictors of Age-Related Changes in Lung Function

Smoking and air pollution exposure are modifiable predictors of age-related declines in lung function. There is some evidence to suggest that physical inactivity may be a predictor of age-related changes in lung function; however, the independent contribution of sitting time, physical activity, and cardiorespiratory fitness have not been investigated to date. PURPOSE: To determine the association between age-related declines in lung function with sitting time, physical activity and cardiorespiratory fitness in a population of healthy adults. METHODS: Data from the Fels Longitudinal Study (1999-2015) were used for analysis (n=996), with serial data available for up to five study visits. Forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) were measured using a metabolic cart (SensorMedics VMax). Physical activity was measured using the Baecke questionnaire and TV time was self-reported as either never, seldom, sometimes, often, and very often. Cardiorespiratory fitness was determined by calculating VO2max from a submaximal treadmill test. Data were analyzed using repeated measures hierarchical linear models in SAS. RESULTS: The sample was middle-aged (45.0 ±17 years), overweight (BMI: 27.1 ± 5.6 kg/m2), and their VO2max was 36.6±9.8 ml/kg/min. Approximately 53% of the sample reported watching TV often and only 3% of the sample reported engaging in regular physical activity often. In models adjusted for age, BMI, physical functioning and smoking status, there was a significant TV time x sex interaction (p\u3c0.0001) when modeling FEV1, such that higher TV time in females was associated with worse FEV1 compared to males. A physical activity x sex interaction (p\u3c0.0001) was also observed in adjusted models of FEV1. When TV time, physical activity and cardiorespiratory fitness were included in the same model, only the association between cardiorespiratory fitness and FEV1 remained significant (p\u3c0.001). CONCLUSION: Cardiorespiratory fitness is a predictor of age-related changes in lung function. Among deconditioned adults, particularly in females, reducing sedentary time and increasing physical activity may lead to an increase in cardiorespiratory fitness and thus may attenuate the age-related decline in lung function