Anne Grunseit

Daily Sitting Time and All-Cause Mortality: A Meta-Analysis

Objective To quantify the association between daily total sitting and all-cause mortality risk and to examine dose-response relationships with and without adjustment for moderate-to-vigorous physical activity. Methods Studies published from 1989 to January 2013 were identified via searches of multiple databases, reference lists of systematic reviews on sitting and health, and from authors’ personal literature databases. We included prospective cohort studies that had total daily sitting time as a quantitative exposure variable, all-cause mortality as the outcome and reported estimates of relative risk, or odds ratios or hazard ratios with 95% confidence intervals. Two authors independently extracted the data and summary estimates of associations were computed using random effects models. Results Six studies were included, involving data from 595,086 adults and 29,162 deaths over 3,565,569 person-years of follow-up. Study participants were mainly female, middle-aged or older adults from high-income countries; mean study quality score was 12/15 points. Associations between daily total sitting time and all-cause mortality were not linear. With physical activity adjustment, the spline model of best fit had dose-response HRs of 1.00 (95% CI: 0.98-1.03), 1.02 (95% CI: 0.99-1.05) and 1.05 (95% CI: 1.02-1.08) for every 1-hour increase in sitting time in intervals between 0-3, >3-7 and >7 h/day total sitting, respectively. This model estimated a 34% higher mortality risk for adults sitting 10 h/day, after taking physical activity into account. The overall weighted population attributable fraction for all-cause mortality for total daily sitting time was 5.9%, after adjusting for physical activity. Conclusions Higher amounts of daily total sitting time are associated with greater risk of all-cause mortality and moderate-to-vigorous physical activity appears to attenuate the hazardous association. These findings provide a starting point for identifying a threshold on which to base clinical and public health recommendations for overall sitting time, in addition to physical activity guidelines.

Sedentary behaviour and risk of mortality from all-causes and cardiometabolic diseases in adults: evidence from the HUNT3 population cohort

Background Sedentary behaviour is a potential risk factor for chronic-ill health and mortality, that is, independent of health-enhancing physical activity. Few studies have investigated the risk of mortality associated with multiple contexts of sedentary behaviour. Objective To examine the prospective associations of total sitting time, TV-viewing time and occupational sitting with mortality from all causes and cardiometabolic diseases. Methods Data from 50 817 adults aged ≥20 years from the Nord-Trøndelag Health Study 3 (HUNT3) in 2006–2008 were linked to the Norwegian Cause of Death Registry up to 31 December 2010. Cox proportional hazards models examined all-cause and cardiometabolic disease-related mortality associated with total sitting time, TV-viewing and occupational sitting, adjusting for multiple potential confounders including physical activity. Results After mean follow-up of 3.3 years (137 315.8 person-years), 1068 deaths were recorded of which 388 were related to cardiometabolic diseases. HRs for all-cause mortality associated with total sitting time were 1.12 (95% CI 0.89 to 1.42), 1.18 (95% CI 0.90 to 1.57) and 1.65 (95% CI 1.24 to 2.21) for total sitting time 4−<7, 7−<10 and ≥10 h/day, respectively, relative to <4 h/day after adjusting for confounders (p-trend=0.001). A similar pattern of associations was observed between total sitting time and mortality from cardiometabolic diseases, but TV-viewing time and occupational sitting showed no or borderline significant associations with all-cause or cardiometabolic disease-related mortality over the same follow-up period. Conclusions Total sitting time is associated with all-cause and cardiometabolic disease-related mortality in the short term. However, prolonged sitting in specific contexts (ie, watching TV, at work) do not adversely impact health in the same timeframe. These findings suggest that adults should be encouraged to sit less throughout the day to reduce their daily total sitting time.

Parental influences on child physical activity and screen viewing time: a population based study

BackgroundParents can influence their childrens physical activity participation and screen time.This study examined the relative significance of perceived parental barriers and self-efficacy in relation to childrens physical activity participation and screen time viewing. The associations between these factors and the behaviours were analysed.MethodsCross-sectional population survey in New South Wales, Australia of parents of pre-school (N = 764), younger (Kindergarten, Grades 2 and 4; N = 1557) and older children (Grades 6, 8 and 10; N = 1665). Parents reported barriers and self-efficacy to influence their childs physical activity and screen time behaviours in a range of circumstances. Differences were examined by childs sex and age group, household income, maternal education and location of residence. The duration of physical activity and screen viewing was measured by parental report for pre-school and younger children and self-report for older children. Associations between parental factors and childrens organised, non-organised and total activity and screen time were analysed.ResultsCost, lack of opportunities for participation and transport problems were the barriers most often reported, particularly by low income parents and those in rural areas. The number of barriers was inversely related to childrens time spent in organised activity, but not their non-organised activity. Higher parental self-efficacy was positively associated with organised physical activity in the younger and older childrens groups and the non-organised activity of older children. School-age children (younger and older groups) were less likely to meet physical activity guidelines when parents reported ≥4 barriers (OR 3.76, 95% CI 1.25-11.34 and OR 3.72, 95% CI 1.71-8.11 respectively). Low parental self-efficacy was also associated with the likelihood of children exceeding screen time guidelines for each age group (pre-school OR 0.62, 95% CI 0.43-0.87; young children OR 0.56, 95% CI 0.39-0.80; and older children OR 0.57, 95% CI 0.43-0.74).ConclusionParental barriers are associated with the time that children spend in both active and sedentary pursuits. These findings highlight family, economic and environmental factors that should be addressed in programs to promote child physical activity and tackle sedentary behaviour.

Industry self regulation of television food advertising: responsible or responsive?

INTRODUCTION This study evaluated the impact of the Australian Food and Grocery Council (AFGC) self-regulatory initiative on unhealthy food marketing to children, introduced in January 2009. The study compared patterns of food advertising by AFGC and non-AFGC signatory companies in 2009, 2007 and 2006 on three Sydney commercial free-to-air television channels. METHODS Data were collected across seven days in May 2006 and 2007, and four days in May 2009. Advertised foods were coded as core, non-core and miscellaneous. Regression for counts analyses was used to examine change in rates of advertisements across the sampled periods and differential change between AFGC-signatory or non-signatory companies between 2007 and 2009. RESULTS Of 36 food companies that advertised during the 2009 sample period, 14 were AFGC signatories. The average number of food advertisements decreased significantly from 7.0 per hour in 2007 to 5.9 in 2009. There was a significant reduction in non-core food advertising from 2007 to 2009 by AFGC signatories compared with non-signatory companies overall and during peak times, when the largest numbers of children were viewing. There was no reduction in the rate of non-core food advertisements by all companies, and these advertisements continue to comprise the majority during peak viewing times. DISCUSSION While some companies have responded to pressures to reduce unhealthy food advertising on television, the impact of the self-regulatory code is limited by the extent of uptake by food companies. The continued advertising of unhealthy foods indicates that this self-regulatory code does not adequately protect children.

Advertising of fast food to children on Australian television: the impact of industry self-regulation.

OBJECTIVE To assess the impact of the quick-service restaurant industry (QSRI) self-regulatory initiative on fast-food advertising to children on Australian commercial television. DESIGN AND SETTING Analysis of advertisements for foods on the three main free-to-air commercial television channels (channels 7, 9 and 10) in Sydney, Australia, over 4 days in both May 2009 and April 2010 in terms of: number of advertisements; types of food (coded core [healthy] foods, non-core [unhealthy] foods, miscellaneous foods; or fast foods); whether advertised meals were intended for children; whether advertisements were broadcast during childrens peak viewing times; and whether the company in question was a signatory to the QSRI initiative. MAIN OUTCOME MEASURES Change in the mean frequency and rate of food advertisements per hour from 2009 to 2010; change in the types of fast-food meals (healthier alternatives [at least one nutrient-dense, low-energy food considered part of a healthy diet for children], non-core [high in undesirable nutrients and not considered part of a healthy diet for children], and other) being advertised; and proportion of childrens energy requirements provided by fast-food meals. RESULTS From 2009 to 2010, the mean frequency of fast-food advertisements increased from 1.1 to 1.5 per hour. While non-core fast foods comprised a lesser share of fast-food advertising in 2010 than 2009, the mean frequency at which they were advertised during times when the largest numbers of children were watching television remained the same (1.3 per hour in both 2009 and 2010). Family meals advertised for childrens consumption in 2010 provided energy far in excess of childrens requirements. CONCLUSIONS Childrens exposure to unhealthy fast-food advertising has not changed following the introduction of self-regulation, and some fast foods advertised for childrens consumption contain excessive energy. The limited impact of self-regulation suggests that governments should define the policy framework for regulating fast-food advertising to children.

Temporal trends in non-occupational sedentary behaviours from Australian Time Use Surveys 1992, 1997 and 2006

BackgroundCurrent epidemiological data highlight the potential detrimental associations between sedentary behaviours and health outcomes, yet little is known about temporal trends in adult sedentary time. This study used time use data to examine population trends in sedentary behaviours in non-occupational domains and more specifically during leisure time.MethodsWe conducted secondary analysis of population representative data from the Australian Time Use Surveys 1992, 1997 and 2006 involving respondents aged 20 years and over with completed time use diaries for two days. Weighted samples for each survey year were: n = 5851 (1992), n = 6419 (1997) and n = 5505 (2006). We recoded all primary activities by domain (sleep, occupational, transport, leisure, household, education) and intensity (sedentary, light, moderate). Adjusted multiple linear regressions tested for differences in time spent in non-occupational sedentary behaviours in 1992 and 1997 with 2006 as the reference year.ResultsTotal non-occupational sedentary time was slightly lower in 1997 than in 2006 (mean = 894 min/2d and 906 min/2d, respectively; B = −11.2; 95%CI: -21.5, -0.9). Compared with 2006, less time was spent in 1997 in sedentary transport (B-6.7; 95%CI: -10.4, -3.0) and sedentary education (B = −6.3; 95%CI: -10.5, -2.2) while household and leisure sedentary time remained stable. Time engaged in different types of leisure-time sedentary activities changed between 1997 and 2006: leisure-time computer use increased (B = −26.7; 95%CI: -29.5, -23.8), while other leisure-time sedentary behaviours (e.g., reading, listening to music, hobbies and crafts) showed small concurrent reductions. In 1992, leisure screen time was lower than in 2006: TV-viewing (B = −24.2; 95%CI: -31.2, -17.2), computer use (B = −35.3; 95%CI: -37.7, -32.8). In 2006, 90 % of leisure time was spent sedentary, of which 53 % was screen time.ConclusionsNon-occupational sedentary time has increased slightly from 1997 to 2006 in the Australian adult population. This seems to be the result of small increases in sedentary transport and education time while sedentary household and leisure time were stable over this time period. However, almost all leisure time is spent sedentary and the composition of sedentary leisure time changed between 1992 and 2006 towards a larger proportion being screen-based activities. This could be an important observation for public health, as most of the evidence on the detrimental effects of sedentary behaviour is around watching television and health.

Anxiety, Depression and HIV Related Symptomatology across the Spectrum of HIV Disease

Levels of anxiety and depression were assessed for 207 HIV seropositive homosexual/bisexual men (AIDS = 34, ARC = 72, asymptomatic HIV infection = 101), and 36 seronegative controls. Lymphocyte subset enumeration, history of opportunistic infections, and occurrence of HIV-related symptoms were recorded at the time of assessment. No differences between groups were found on age, educational level, state/trait anxiety or depression scores. Neither the number of symptoms reported, their duration, severity, frequency of occurrence, nor the proportion of patients who reported a specific symptom was different between the three HIV seropositive groups. Severity of anxiety and depression was related to the magnitude of symptomatology, but not associated with either degree of immunodeficiency, number of opportunistic infections or diagnostic group. Principal component analysis extracted five symptom factors (cognitive, affective, psychosocial, neurological and physical), none of which predicted state anxiety scores. However, affective and psychosocial symptom factors predicted trait anxiety and depression scores. The results indicate that ratings of anxiety and depression are independent of stage of HIV infection, may be in part mediated by constitutional and physical symptoms of HIV disease, but are primarily associated with the presence of psychological and psychosocial symptoms.

Cross-sectional associations of total sitting and leisure screen time with cardiometabolic risk in adults. Results from the HUNT Study, Norway

OBJECTIVES To examine associations of total sitting time, TV-viewing and leisure-time computer use with cardiometabolic risk biomarkers in adults. DESIGN Population based cross-sectional study. METHODS Waist circumference, BMI, total cholesterol, HDL cholesterol, blood pressure, non-fasting glucose, gamma glutamyltransferase (GGT) and triglycerides were measured in 48,882 adults aged 20 years or older from the Nord-Trøndelag Health Study 2006-2008 (HUNT3). Adjusted multiple regression models were used to test for associations between these biomarkers and self-reported total sitting time, TV-viewing and leisure-time computer use in the whole sample and by cardiometabolic disease status sub-groups. RESULTS In the whole sample, reporting total sitting time ≥10 h/day was associated with poorer BMI, waist circumference, total cholesterol, HDL cholesterol, diastolic blood pressure, systolic blood pressure, non-fasting glucose, GGT and triglyceride levels compared to those reporting total sitting time <4h/day (all p<0.05). TV-viewing ≥4 h/day was associated with poorer BMI, waist circumference, total cholesterol, HDL cholesterol, systolic blood pressure, GGT and triglycerides compared to TV-viewing <1h/day (all p<0.05). Leisure-time computer use ≥1 h/day was associated with poorer BMI, total cholesterol, diastolic blood pressure, GGT and triglycerides compared with those reporting no leisure-time computing. Sub-group analyses by cardiometabolic disease status showed similar patterns in participants free of cardiometabolic disease, while similar albeit non-significant patterns were observed in those with cardiometabolic disease. CONCLUSIONS Total sitting time, TV-viewing and leisure-time computer use are associated with poorer cardiometabolic risk profiles in adults. Reducing sedentary behaviour throughout the day and limiting TV-viewing and leisure-time computer use may have health benefits.

Building the case for independent monitoring of food advertising on Australian television

OBJECTIVE To provide an independent monitoring report examining the ongoing impact of Australian self-regulatory pledges on food and drink advertising to children on commercial television. DESIGN Analysis of food advertisements across comparable sample time periods in April/May 2006, 2007, 2009, 2010 and 2011. The main outcome measure comprised change in the mean rate of non-core food advertisements from 2006 to 2011. SETTING Sydney free-to-air television channels. SUBJECTS Televised food advertisements. RESULTS In 2011 the rate of non-core food advertisements was not significantly different from that in 2006 or 2010 (3·2/h v. 4·1/h and 3·1/h), although there were variations across the intervening years. The rate of fast-food advertising in 2010 was significantly higher than in 2006 (1·8/h v. 1·1/h, P < 0·001), but the same as that in 2011 (1·5/h). CONCLUSIONS The frequency of non-core food advertising on Sydney television has remained essentially unchanged between 2006 and 2011, despite the implementation of two industry self-regulatory pledges. The current study illustrates the value of independent monitoring as a basic requirement of any responsive regulatory approach.

Co-occurrence of Obesogenic Risk Factors Among Adolescents

PURPOSE The purpose of this study was to determine the prevalence, sociodemographic distribution, and co-occurrence of five potentially obesogenic behavioral risk factors (low physical activity, high screen time, low fruit and vegetable intake, high soft drink consumption, and high snack intake) among adolescents. METHODS Cross-sectional representative population survey (n = 1,568) of grade 6, 8, and 10 students (49% male) randomly selected from 70 primary and secondary schools in New South Wales, Australia, between February and May 2007. Co-occurrence was assessed using an observed-to-expected ratio (O/E) method. RESULTS Only 5% of boys and 9% of girls had none of the five obesogenic behavioral risk factors studied. Overall, 51.4% of boys and 42.9% of girls had three or more risk factors. Prevalence of multiple risk factors (3+) was higher among boys and girls from lower income households and among girls whose mothers had less than grade 12 education. For both boys and girls, the occurrence of all five risk factors was 160% greater than expected (O/E ratio: 2.6). CONCLUSIONS There was clear evidence of a co-occurrence of obesogenic risk factors among adolescents, especially among those from lower socioeconomic backgrounds, indicating this group would benefit from targeted prevention strategies.