Paula Gardiner

Measurement of adults' sedentary time in population-based studies.

Sedentary time (too much sitting) increasingly is being recognized as a distinct health risk behavior. This paper reviews the reliability and validity of self-reported and device-based sedentary time measures and provides recommendations for their use in population-based studies. The focus is on instruments that have been used in free-living, population-based research in adults. Data from the 2003-2006 National Health and Nutrition Examination Survey are utilized to compare the descriptive epidemiology of sedentary time that arises from the use of different sedentary time measures. A key recommendation from this review is that, wherever possible, population-based monitoring of sedentary time should incorporate both self-reported measures (to capture important domain- and behavior-specific sedentary time information) and device-based measures (to measure both total sedentary time and patterns of sedentary time accumulation).

Occupational sitting and health risks: a systematic review

CONTEXT Emerging evidence suggests that sedentary behavior (i.e., time spent sitting) may be negatively associated with health. The aim of this study was to systematically review the evidence on associations between occupational sitting and health risks. EVIDENCE ACQUISITION Studies were identified in March-April 2009 by literature searches in PubMed, PsycINFO, CENTRAL, CINAHL, EMBASE, and PEDro, with subsequent related-article searches in PubMed and citation searches in Web of Science. Identified studies were categorized by health outcome. Two independent reviewers assessed methodologic quality using a 15-item quality rating list (score range 0-15 points, higher score indicating better quality). Data on study design, study population, measures of occupational sitting, health risks, analyses, and results were extracted. EVIDENCE SYNTHESIS 43 papers met the inclusion criteria (21% cross-sectional, 14% case-control, 65% prospective); they examined the associations between occupational sitting and BMI (n=12); cancer (n=17); cardiovascular disease (CVD, n=8); diabetes mellitus (DM, n=4); and mortality (n=6). The median study-quality score was 12 points. Half the cross-sectional studies showed a positive association between occupational sitting and BMI, but prospective studies failed to confirm a causal relationship. There was some case-control evidence for a positive association between occupational sitting and cancer; however, this was generally not supported by prospective studies. The majority of prospective studies found that occupational sitting was associated with a higher risk of DM and mortality. CONCLUSIONS Limited evidence was found to support a positive relationship between occupational sitting and health risks. The heterogeneity of study designs, measures, and findings makes it difficult to draw definitive conclusions at this time.

Safety of green tea extracts : a systematic review by the US Pharmacopeia.

Green tea [Camellia sinensis (L.) Kuntze] is the fourth most commonly used dietary supplement in the US. Recently, regulatory agencies in France and Spain suspended market authorization of a weight-loss product containing green tea extract because of hepatotoxicity concerns. This was followed by publication of adverse event case reports involving green tea products. In response, the US Pharmacopeia (USP) Dietary Supplement Information Expert Committee (DSI EC) systematically reviewed the safety information for green tea products in order to re-evaluate the current safety class to which these products are assigned. DSI EC searched PubMed (January 1966–June 2007) and EMBASE (January 1988–June 2007) for clinical case reports and animal pharmacological or toxicological information. Reports were also obtained from a diverse range of other sources, including published reviews, the US FDA MedWatch programme, USP’s MEDMARX® adverse event reporting system, the Australian Therapeutic Goods Administration, the UK Medicines and Healthcare products Regulatory Agency, and Health Canada’s Canadian Adverse Drug Reaction Monitoring Program. Case reports pertaining to liver damage were evaluated according to the Naranjo causality algorithm scale. In addition, the Committee analysed information concerning historical use, regulatory status, and current extent of use of green tea products. A total of 216 case reports on green tea products were analysed, including 34 reports concerning liver damage. Twenty-seven reports pertaining to liver damage were categorized as possible causality and seven as probable causality. Clinical pharmacokinetic and animal toxicological information indicated that consumption of green tea concentrated extracts on an empty stomach is more likely to lead to adverse effects than consumption in the fed state. Based on this safety review, the DSI EC determined that when dietary supplement products containing green tea extracts are used and formulated appropriately the Committee is unaware of significant safety issues that would prohibit monograph development, provided a caution statement is included in the labelling section. Following this decision, USP’s DSI ECs may develop monographs for green tea extracts, and USP may offer its verification programmes related to that dietary ingredient.

Prolonged sedentary time and physical activity in workplace and non-work contexts: a cross-sectional study of office, customer service and call centre employees

BackgroundTo examine sedentary time, prolonged sedentary bouts and physical activity in Australian employees from different workplace settings, within work and non-work contexts.MethodsA convenience sample of 193 employees working in offices (131), call centres (36) and customer service (26) was recruited. Actigraph GT1M accelerometers were used to derive percentages of time spent sedentary (<100 counts per minute; cpm), in prolonged sedentary bouts (≥20 minutes or ≥30 minutes), light-intensity activity (100–1951 cpm) and moderate-to-vigorous physical activity (MVPA; ≥1952 cpm). Using mixed models adjusted for confounders, these were compared for: work days versus non-work days; work hours versus non-work hours (work days only); and, across workplace settings.ResultsWorking hours were mostly spent sedentary (77.0%, 95%CI: 76.3, 77.6), with approximately half of this time accumulated in prolonged bouts of 20 minutes or more. There were significant (p<0.05) differences in all outcomes between workdays and non-work days, and, on workdays, between work- versus non-work hours. Results consistently showed “work” was more sedentary and had less light-intensity activity, than “non-work”. The period immediately after work appeared important for MVPA. There were significant (p<0.05) differences in all sedentary and activity outcomes occurring during work hours across the workplace settings. Call-centre workers were generally the most sedentary and least physically active at work; customer service workers were typically the least sedentary and the most active at work.ConclusionThe workplace is a key setting for prolonged sedentary time, especially for some occupational groups, and the potential health risk burden attached requires investigation. Future workplace regulations and health promotion initiatives for sedentary occupations to reduce prolonged sitting time should be considered.

Reallocating Time to Sleep, Sedentary Behaviors, or Active Behaviors: Associations With Cardiovascular Disease Risk Biomarkers, NHANES 2005–2006

Sleep and sedentary and active behaviors are linked to cardiovascular disease risk biomarkers, and across a 24-hour day, increasing time in 1 behavior requires decreasing time in another. We explored associations of reallocating time to sleep, sedentary behavior, or active behaviors with biomarkers. Data (n = 2,185 full sample; n = 923 fasting subanalyses) from the cross-sectional 2005-2006 US National Health and Nutrition Examination Survey were analyzed. The amounts of time spent in sedentary behavior, light-intensity activity, and moderate-to-vigorous physical activity (MVPA) were derived from ActiGraph accelerometry (ActiGraph LLC, Pensacola, Florida), and respondents reported their sleep duration. Isotemporal substitution modeling indicated that, independent of potential confounders and time spent in other activities, beneficial associations (P < 0.05) with cardiovascular disease risk biomarkers were associated with the reallocation of 30 minutes/day of sedentary time with equal time of either sleep (2.2% lower insulin and 2.0% lower homeostasis model assessment of β-cell function), light-intensity activity (1.9% lower triglycerides, 2.4% lower insulin, and 2.2% lower homeostasis model assessment of β-cell function), or MVPA (2.4% smaller waist circumference, 4.4% higher high-density lipoprotein cholesterol, 8.5% lower triglycerides, 1.7% lower glucose, 10.7% lower insulin, and 9.7% higher homeostasis model assessment of insulin sensitivity. These findings provide evidence that MVPA may be the most potent health-enhancing, time-dependent behavior, with additional benefit conferred from light-intensity activities and sleep duration when reallocated from sedentary time.

Feasibility of Reducing Older Adults' Sedentary Time

BACKGROUND Sedentary time (too much sitting, as distinct from lack of exercise) is a prevalent risk to health among older adults. PURPOSE Examine the feasibility of an intervention to reduce and break up sedentary time in older adults. DESIGN A pre-experimental (pre-post) study. SETTING/PARTICIPANTS A total of 59 participants aged ≥60 years from Brisbane, Australia. Data were collected between May and December 2009 and analyzed in 2010. INTERVENTION One face-to-face goal-setting consultation and one individually tailored mailing providing feedback on accelerometer-derived sedentary time, grounded in social cognitive theory and behavioral choice theory. MAIN OUTCOME MEASURES Program reach and retention; changes in accelerometer-derived sedentary time, light-intensity physical activity (LIPA), and moderate-to-vigorous-intensity physical activity (MVPA) (assessed over 6 days in pre- and post-intervention periods); and participant satisfaction. RESULTS Reach was 87.5% of those screened and eligible; retention was 100%. From pre- to post-intervention, participants decreased their sedentary time [-3.2% (95% CI= -4.18, -2.14), p<0.001], increased their breaks in sedentary time per day [4.0 (1.48, 6.52), p=0.003], and increased their LIPA [2.2% (1.40, 2.99), p<0.001] and MVPA [1.0% (0.55, 1.38), p<0.001]. Significantly greater reductions in sedentary time were made after 10:00am, with significantly greater number of breaks occurring between 7:00pm and 9:00pm. Participants reported high satisfaction with the program (median 9/10). CONCLUSIONS Sedentary time in older adults can be reduced following a brief intervention based on goal setting and behavioral self-monitoring.

Associations between television viewing time and overall sitting time with the metabolic syndrome in older men and women: the Australian Diabetes, Obesity and Lifestyle study.

OBJECTIVES: To examine associations between self‐reported television (TV) viewing time and overall sitting time with the metabolic syndrome and its components.

Healthier women, healthier reproductive outcomes: recommendations for the routine care of all women of reproductive age

By addressing the reproductive intentions and contraceptive practices and needs of every patient, providers may be able to decrease womens chances of experiencing unintended pregnancies and support women in achieving planned and well-timed pregnancies. By addressing the health promotion needs of every patient and examining and addressing her health profile for reproductive risks, irrespective of her desires for pregnancy, it is likely that more women will enter pregnancy with high levels of preconception wellness and that healthier women and healthier pregnancies and infants will result. The importance of the integration of reproductive planning and health promotion into womens routine healthcare is further emphasized when the potentially far-reaching effects of reproductive outcomes (such as unintended pregnancies, adverse pregnancy outcomes, pregnancy complications, and sexually transmitted infections) on womens health, well-being, and life circumstances are considered.

Clinical Applications of Yoga for the Pediatric Population: A Systematic Review

OBJECTIVE The aim of this study was to evaluate the evidence for clinical applications of yoga among the pediatric population. METHODS We conducted an electronic literature search including CINAHL, Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE, Medline, PsycINFO, and manual search of retrieved articles from inception of each database until December 2008. Randomized controlled trials (RCTs) and nonrandomized controlled trials (NRCTs) were selected that included yoga or yoga-based interventions for individuals aged 0 to 21 years. Data were extracted and articles critically reviewed using a modified Jadad score and descriptive methodological criteria, with summarization in tables. RESULTS Thirty-four controlled studies published from 1979 to 2008 were identified, with 19 RCTS and 15 NRCTs. Many studies were of low methodological quality. Clinical areas for which yoga has been studied include physical fitness, cardiorespiratory effects, motor skills/strength, mental health and psychological disorders, behavior and development, irritable bowel syndrome, and birth outcomes following prenatal yoga. No adverse events were reported in trials reviewed. Although a large majority of studies were positive, methodological limitations such as randomization methods, withdrawal/dropouts, and details of yoga intervention preclude conclusive evidence. CONCLUSIONS There are limited data on the clinical applications of yoga among the pediatric population. Most published controlled trials were suggestive of benefit, but results are preliminary based on low quantity and quality of trials. Further research of yoga for children by using a higher standard of methodology and reporting is warranted.

Associations of Leisure-Time Internet and Computer Use With Overweight and Obesity, Physical Activity and Sedentary Behaviors: Cross-Sectional Study

Background Internet and computer use are increasingly common leisure-time sedentary behaviors, which have the potential to impact negatively on health outcomes. However, little is known about the extent to which adults’ Internet and computer use is associated with weight status and time spent in leisure-time physical activity. Objective The objective is to examine associations of leisure-time Internet and computer use with overweight and obesity, leisure-time physical activity, and other sedentary behaviors. Methods Participants (2650 adults living in Adelaide, Australia) completed a mail-back questionnaire including items on their height and weight, past seven day recall of leisure-time physical activity, Internet and computer use, and other leisure-time sedentary behaviors. Leisure-time Internet and computer use was categorized into no use, low use (less than three hours per week), or high use (three hours or more per week). Results Participants with low leisure-time Internet and computer use had the highest levels of educational attainment and employment, and engaged in less other sedentary behaviors when compared to participants with no or high Internet and computer use. Multinomial logistic regression, adjusted for gender, age, employment, education, other sedentary behaviors and physical activity, determined that participants with a high leisure-time Internet and computer use were 1.46 (95% CI = 1.10 - 1.93) times more likely to be overweight (BMI≥25 and < 30 kg/m2) and 2.52 times more likely (95% CI = 1.82 - 3.52) to be obese (BMI≥30 kg/m2), compared to those who reported no Internet and computer use in their leisure-time. Adults with high leisure-time Internet and computer use were more likely to be overweight or obese even if they were highly active in their leisure time (OR = 1.86; 95% CI = 1.21 - 2.88), as compared to participants who did not use the Internet or computer. Leisure-time physical activity levels were largely independent of Internet and computer use. Conclusion These findings suggest that, apart from nutritional and physical activity interventions, it may also be necessary to decrease time spent in sedentary behaviors, such as leisure-time Internet and computer use, in order to reduce the prevalence of overweight and obesity. Future Internet interventions to reduce weight or increase physical activity may need to differentiate between participants with different levels of Internet use in order to increase their effectiveness. Longitudinal studies are required to examine further the potential causal relationships between the development of overweight and specific sedentary behaviors such as Internet and computer use.