Gendered relations? Associations between Swedish parents, siblings, and adolescents' time spent sedentary and physically active.

Introduction: The family is assumed to be fundamental in youth socialization processes and development, connected to social and cultural practices such as healthy lifestyles and physical activity. However, gender patterns in physical activity among adolescents and the structural drivers of gender inequality (e.g., parentage and siblingship) are poorly understood. The aim of this study was to explore further how gender structures relate to adolescents' time spent being sedentary and physically active, using contemporary gender theory. Methods: This cross-sectional study involved 1,139 adolescents aged 13-14 and their parents, including 815 mothers and 572 fathers. Physical activity and time spent sedentary were assessed through accelerometry among adolescents and through a self-report questionnaire for parents validated against accelerometry. Results: The results showed significant relationships between mothers' moderate-to-vigorous physical activity (MVPA) and girls' MVPA on weekdays and weekends, and fathers' MVPA was significantly related to girls' MVPA on weekdays. Our results imply that the relationship between Swedish parents' and adolescent girls' physical activity in higher intensities are to some extent gendered practices. However, time spent sedentary does not seem to show any patterns of being performed according to binary ideas of gender. Further, our exploratory analyses suggest that these results somewhat intersect with parents' educational level and relate to intra-categorical aspects of doing gender. The results also indicate slight gendered patterns in the "doing" of brotherhood for time spent sedentary, however, for boys only on weekends. Discussion: The study contributes to the understanding of gender norms as constraints and enablers for adolescents' participation in physical activity. The results can spur public health and physical activity research to apply a contemporary gender theory approach, and to expand the research agenda connected to what relates to gender inequalities in physical activity practices.

Adolescents' experiences of a school-based health promotion intervention in socioeconomically advantaged and disadvantaged areas in Sweden: a qualitative process evaluation study.

BACKGROUND: Adolescence is a transition period in which positive experiences of physical activity have the potential to last into later adulthood. These experiences are influenced by socioeconomic determinants, leading to health inequalities. This study aims to explore adolescents' experiences and participation in a multi-component school-based intervention in schools located in socioeconomically advantaged and disadvantaged areas in Sweden. METHODS: A qualitative design was used to evaluate how participants experienced the intervention. The intervention was a multi-component school-based intervention. It was conducted in six schools (four control and two intervention schools) with a total of 193 students and lasted one school year. It was teacher-led and consisted of three 60-minute group sessions per week: varied physical activities, homework support with activity breaks, and walks while listening to audiobooks. In total, 23 participant observations were conducted over eight months and 27 students participated in focus groups. A content analysis was conducted. RESULTS: The results describe a main category 'Engaging in activities depending on socioeconomic status' and three generic categories: 1. Variations in participation in PA together with classmates and teachers; 2. Variations in engagement in PA after school; and 3. Differences in time and place allocated to do homework and listen to audiobooks. These categories illustrate how participants looked forward to the physical activities but used the time spent during the walks and homework support differently depending on how busy they were after school. Frequently, those who were busiest after school were also those from the advantaged area, and those who had little to do after school were from the disadvantaged area. CONCLUSION: Socioeconomic factors influence participants' possibilities to engage in the intervention activities as well as how they use their time in the activities. This study showed that it is crucial to support adolescents' participation in physical activities by providing structure and engaging well-known teachers in the activities, especially in schools located in disadvantaged areas.

Acute effects of nitrate and breakfast on working memory, cerebral blood flow, arterial stiffness, and psychological factors in adolescents: Study protocol for a randomised crossover trial.

BACKGROUND: Inorganic nitrate has been shown to acutely improve working memory in adults, potentially by altering cerebral and peripheral vasculature. However, this remains unknown in adolescents. Furthermore, breakfast is important for overall health and psychological well-being. Therefore, this study will investigate the acute effects of nitrate and breakfast on working memory performance, task-related cerebral blood flow (CBF), arterial stiffness, and psychological outcomes in Swedish adolescents. METHODS: This randomised crossover trial will recruit at least 43 adolescents (13-15 years old). There will be three experimental breakfast conditions: (1) none, (2) low-nitrate (normal breakfast), and (3) high-nitrate (concentrated beetroot juice with normal breakfast). Working memory (n-back tests), CBF (task-related changes in oxygenated and deoxygenated haemoglobin in the prefrontal cortex), and arterial stiffness (pulse wave velocity and augmentation index) will be measured twice, immediately after breakfast and 130 min later. Measures of psychological factors and salivary nitrate/nitrite will be assessed once before the conditions and at two-time points after the conditions. DISCUSSION: This study will provide insight into the acute effects of nitrate and breakfast on working memory in adolescents and to what extent any such effects can be explained by changes in CBF. This study will also shed light upon whether oral intake of nitrate may acutely improve arterial stiffness and psychological well-being, in adolescents. Consequently, results will indicate if nitrate intake from beetroot juice or if breakfast itself could acutely improve cognitive, vascular, and psychological health in adolescents, which can affect academic performance and have implications for policies regarding school meals. TRIAL REGISTRATION: The trial has been prospectively registered on 21/02/2022 at https://doi.org/10.1186/ISRCTN16596056. Trial number: ISRCTN16596056.

COVID-19 and unfavorable changes in mental health unrelated to changes in physical activity, sedentary time, and health behaviors among Swedish adolescents: A longitudinal study.

Background: The COVID-19 pandemic has had major impact on the daily lives of adolescents. This study examined whether mental health outcomes had changed over the pandemic, and if such changes were related to changes in physical activity (PA), sedentary time, sleep, screen time, and participation in organized sports. Materials and methods: In this longitudinal study, data were collected in autumn 2019 with follow-up measurements in spring 2021. In total, 558 schools were invited and 34 schools around Stockholm with a variation in socioeconomic background were included. Physical activity and sedentary time were measured for seven consecutive days by accelerometry (Actigraph). Anxiety, health-related quality of life (HRQoL), psychosomatic health, stress, sleep duration, screen time, and organized sports participation were self-reported in questionnaires. Linear models were applied to estimate associations between changes in mental health outcomes and exposures. Results: From the baseline sample of 1,139 participants, 585 (55% girls), mean (SD) age 14.9 (0.3) years, participated in the follow-up. Between 2019 and 2021, there was a decrease in HRQoL [mean difference -1.7 (-2.3, -1.2), p < 0.001], increase in psychosomatic health problems [mean difference 1.8 (1.3, 2.3), p < 0.001], and an increase in the number of participants with high stress [from 94 (28%) to 139 (42%), p < 0.001]. Weekly light PA and sleep duration decreased and weekly sedentary time and screen time increased unrelated to changes in mental health outcomes. An increase in sleep duration during weekdays was significantly related to both a decrease in anxiety (B = -0.71, CI: -1.36, -0.06) and an increase in HRQoL (B = 1.00, CI: 0.51, 1.49). Conclusion: During the COVID-19 pandemic, mental health appears to have been impaired in Swedish adolescents, but unrelated to changes in PA, sedentary time, screen time, or participation in organized sports. However, increased sleep duration on weekdays was related to less anxiety and better HRQoL. The results may help policy makers and other stakeholders comprehend the differential effects of the COVID-19 pandemic on mental health outcomes and help guiding the planning of policy actions. Trial registration: ISRCTN15689873.

Effects of prolonged sitting and physical activity breaks on measures of arterial stiffness and cortisol in adolescents.

AIM: In adults, prolonged periods of sitting have been linked to acute negative effects on vascular structure and function. The aim of this study was to evaluate the acute effects of physical activity (PA) breaks during prolonged sitting on arterial stiffness, cortisol and psychological factors in adolescents. METHODS: Adolescents underwent different short (3-min) breaks starting every 20 min, during 80 min of sitting on three separate days. Breaks were (A) social seated breaks (SOC), (B) low-intensity simple resistance activity PA breaks (SRA) and (C) moderate-intensity step-up PA breaks (STEP). The arterial stiffness measures were augmentation index (AIx), AIx@75 and pulse wave velocity (PWV). Cortisol was measured from saliva. Psychological factors were self-reported. RESULTS: Eleven girls and six boys (average age 13.6 ± 0.7 years) participated, with average baseline heart rates of 72 ± 11 bpm, systolic/diastolic blood pressure 111 ± 7/64 ± 6 mmHg and cortisol 10.9 ± 5.8 nmoL/L. PWV, cortisol and psychological factors did not change after any of the conditions. AIx@75 increased significantly (4.9 ± 8.7-9.2 ± 13.2) after the STEP intervention compared with SOC and SRA (time × condition p < 0.05). CONCLUSION: Arterial stiffness increased after prolonged sitting with frequent, short step-up activity breaks. The results indicate potential important intensity-dependent effects of physical activity on vascular regulation in youth.

COVID-19 induced changes in physical activity patterns, screen time and sleep among Swedish adolescents - a cohort study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic had a huge impact on daily life, even in countries such as Sweden where the restrictions were relatively mild. This paper assesses the effects of the COVID-19 pandemic restrictions on physical activity (PA) patterns, screen time, and sleep among Swedish adolescents. The exposures explored include gender, parental education, anthropometrics, and cardiovascular fitness (CVF). METHODS: Cohort data were collected from September 26th to December 6th, 2019, and from April 12th to June 9th, 2021. Participants were 13-14 years-old (7th graders) at baseline with 585 participating at both baseline and follow-up. At both baseline and follow-up PA and sedentary time were measured with accelerometers, and sleep and screen time with questionnaires. The exposure variables (gender, parental education, anthropometrics and CVF) were collected at baseline. Multilevel linear regression analyses were performed. RESULTS: Moderate-to-vigorous-physical activity (MVPA) remained unchanged while light physical activity (LiPA) decreased and sedentary time increased. Sleep duration decreased and screen time increased. Girls, adolescents with overweight/obesity (BMI and percent body fat), and those with lower CVF at baseline had less favourable changes in PA patterns, sleep and screen time. CONCLUSIONS: Although no significant (α = 0.05) changes were seen in MVPA, both LiPA and sedentary time as well as sleep and screen time changed in unfavourable ways. More intense activities are often organised and seem to have withstood the pandemic, while less intense activities decreased. Some groups were more vulnerable and will need directed intervention in the post-pandemic period as well as when future pandemics hit.

Associations between organised sports participation, general health, stress, screen-time and sleep duration in adolescents.

AIM: Physical activity patterns in adolescents have been associated with general health. Stress, screen-time and sleep are other factors associated with physical activity that influence health in adolescents. Physical activity accounts for several health benefits; however, the impact of organised sports participation to achieve the same health benefits are less explored. This study explored the associations of organised sports participation with general health, stress, screen-time and sleep-duration in adolescents. METHODS: For this cross-sectional study, data from 1139 adolescents (age 13-14 years) from 34 schools were analysed. Data were collected during autumn 2019. Data collection consisted of self-reported questionnaires and standard methods for height and weight measurements. RESULTS: Adolescents with organised sports participation ≥3 times/week were twice as likely to report better general health (OR: 2.11, CI: 1.45-3.07) and lower screen-time (OR: 1.98, CI: 1.43-2.74). Adolescents with organised sports participation ≥3 times/week were less likely to meet the recommended sleep-duration on weekdays (OR: 0.43, 95% CI: 0.29-0.65). CONCLUSIONS: Adolescents with frequent organised sports participation had better general health, lower amounts of screen-time and shorter sleep-duration on weekdays than those with no participation. Although the causal relationships remain unknown, these results can be relevant when developing strategies promoting physical activity and health in adolescents.

Quantitative Measurements for Factors Influencing Implementation in School Settings: Protocol for A Systematic Review and A Psychometric and Pragmatic Analysis.

INTRODUCTION: In order to address the effectiveness and sustainability of school-based interventions, there is a need to consider the factors affecting implementation success. The rapidly growing field of implementation-focused research is struggling to determine how to assess and measure implementation-relevant constructs. Earlier research has identified the need for strong psychometric and pragmatic measures. The aims of this review are therefore to (i) systematically review the literature to identify measurements of the factors influencing implementations which have been developed or adapted in school settings, (ii) describe each measurement's psychometric and pragmatic properties, (iii) describe the alignment between each measurement and the corresponding domain and/or construct of the Consolidated Framework for Implementation Research (CFIR). METHODS: Six databases (Medline, ERIC, PsycInfo, Cinahl, Embase, and Web of Science) will be searched for peer-reviewed articles reporting on school settings, published from the year 2000. The identified measurements will be mapped against the CFIR, and analyzed for their psychometric and pragmatic properties. DISCUSSION: By identifying measurements that are psychometrically and pragmatically impactful in the field, this review will contribute to the identification of feasible, effective, and sustainable implementation strategies for future research in school settings.

Cross-sectional associations between physical activity pattern, sports participation, screen time and mental health in Swedish adolescents.

OBJECTIVES: To investigate the associations between physical activity pattern, sports participation, screen time and mental health in Swedish adolescents. DESIGN, SETTING AND PARTICIPANTS: A total of 1139 Swedish adolescents (mean age 13.4) from 34 schools participated in the cross-sectional study 'Physical Activity for Healthy Brain Functions in School Youth' in 2019. METHODS: Time spent sedentary and in moderate-to-vigorous physical activity (MVPA) was measured using accelerometers for seven consecutive days. Screen time and sports participation were self-reported. Anxiety and health-related quality of life (HRQoL) were assessed using a Short version of the Spence Children's Anxiety Scale and Kidscreen-10. RESULTS: MVPA was positively associated (95% CI 0.01 to 0.05 in girls and 0.02 to 0.07 in boys) whereas screen time on weekdays was inversely associated with HRQoL (-4.79 to -2.22 in girls and -2.66 to -0.41 in boys). The largest effect sizes were observed between the high/low MVPA group in boys (Cohen's d=0.51) and screen time groups in girls (Cohen's d=0.59 on weekdays). With regards to anxiety, high compared with lower time spent in MVPA during leisure time on weekdays was associated with lower anxiety scores (95% CI -0.13 to -0.05 in girls and -0.07 to -0.01 in boys). Gender differences were observed, boys who participated in organised sports had low anxiety scores (95% CI -3.49 to -0.13) whereas girls who reported 5 hours or more of screen time had high scores (95% CI 1.94 to 6.18 on weekdays and 1.39 to 5.29 on weekend days). CONCLUSIONS: This study showed that MVPA was associated with better mental health, whereas the opposite was seen for screen time. These associations were not consistently significant throughout all time domains, between the genders and mental health outcomes. Our results could create a paradigm for future studies to decide which types of PA patterns and time domains to target in intervention studies with the aim improve mental health among adolescents.

Investigation of the Associations between Diet Quality and Health-Related Quality of Life in a Sample of Swedish Adolescents.

Most adolescents do not consume a high-quality diet, while self-reported mental health problems within this group are increasing. This study aimed to investigate the association between diet quality and health-related quality of life, and to explore the differences in diet quality and health-related quality of life between gender and parental education status. In this cross-sectional study, a detailed web-based recall method was implemented to determine dietary intake, which was analysed using the newly developed Swedish Healthy Eating Index for Adolescents 2015 (SHEIA15) and the Riksmaten Adolescents Diet Diversity Score (RADDS), to determine diet quality. The KIDSCREEN-10 questionnaire was used to measure health-related quality of life, and parental education was self-reported through questionnaires. Parental education was divided into two groups: ≤12 years or >12 years. The study included 1139 adolescents from grade 7 (13−14 years old), 51% were girls. The results showed that girls had higher scores for healthy eating and diet diversity but lower scores for health-related quality of life. A positive association was found between diet diversity and health-related quality of life (Adj R2 = 0.072, p = 0.001), between vegetable/fruit consumption and health-related quality of life (Adj R2 = 0.071, p = 0.002), and between healthy eating and diet diversity (Adj R2 = 0.214, p < 0.001). No association was found between healthy eating and health-related quality of life for all participants. The mean scores for healthy eating and diet diversity were significantly higher in the higher education parental group. In conclusion, higher diet diversity and increased fruit and vegetable consumption could be a strategy to improve health-related quality of life among adolescents. There is a need to promote better diet quality, especially in households of low parental education. In addition, there is a further need to investigate the potential benefits of improved diet quality on mental health and overall well-being.

ABBaH teens: Activity Breaks for Brain Health in adolescents: study protocol for a randomized crossover trial.

BACKGROUND: Physical activity breaks are widely being implemented in school settings as a solution to increase academic performance and reduce sitting time. However, the underlying physiological mechanisms suggested to improve cognitive function from physical activity and the frequency, intensity, and duration of the breaks remain unknown. This study will investigate the effects of frequent, short physical activity breaks during prolonged sitting on task-related prefrontal cerebral blood flow, cognitive performance, and psychological factors. Additionally, the moderating and mediating effects of arterial stiffness on changes in cerebral blood flow will be tested. METHODS: This is a protocol for a randomized crossover study that will recruit 16 adolescents (13-14 years old). Participants will undergo three different conditions in a randomized order, on three separate days, involving sitting 80 min with a different type of break every 17 min for 3 min. The breaks will consist of (1) seated social breaks, (2) simple resistance activities, and (3) step-up activities. Before and after the 80-min conditions, prefrontal cerebral blood flow changes will be measured using functional near-infrared spectroscopy (primary outcome), while performing working memory tasks (1-, 2-, and 3-back tests). Arterial stiffness (augmentation index and pulse wave velocity) and psychological factors will also be assessed pre and post the 80-min interventions. DISCUSSION: Publication of this protocol will help to increase rigor in science. The results will inform regarding the underlying mechanisms driving the association between physical activity breaks and cognitive performance. This information can be used for designing effective and feasible interventions to be implemented in schools. TRIAL REGISTRATION: www.ClinicalTrials.gov , NCT04552626 . Retrospectively registered on September 21, 2020.

Breakfast Habits and Associations with Fruit and Vegetable Intake, Physical Activity, Sedentary Time, and Screen Time among Swedish 13-14-Year-Old Girls and Boys.

This study explored whether breakfast habits were associated with intake of fruits and vegetables, minutes in moderate-to-vigorous physical activity (MVPA), minutes spent sedentary, and screen time among adolescents. Cross-sectional data were collected among 13-14-year-old boys and girls (n = 1139). Breakfast habits and screen time were determined via questionnaire, fruit and vegetable intake were determined through dietary recall, and physical activity and sedentary time were determined via accelerometers. Multilevel mixed models and general estimation equation models were applied. Almost 40% of participants skipped breakfast at least one day of the week. Participants with irregular breakfast habits on weekdays had lower fruit and vegetable consumption by 26.7 g (95% CI = -49.3, -5.9) while irregular breakfast habits during the whole week were associated with higher levels of screen time (OR = 1.5, 95% CI = 1.1, 2.1) compared to regular breakfast habits. Girls with irregular breakfast habits on weekdays had 7.7 min more sedentary time (95% CI = 0.8, 15.7) than girls with regular breakfast habits, while the opposite was found in boys (ß = -13.3, 95% CI = -25.3, -2.6)). No significant associations were found for MVPA. Regular breakfast habits should be encouraged, as they might contribute to a higher intake of fruit and vegetables and are associated with lower levels of screen time, although further studies are necessary to establish causation.

Associations between Physical Activity Patterns, Screen Time and Cardiovascular Fitness Levels in Swedish Adolescents.

Cardiovascular fitness (CVF) has been associated with cardiovascular risk factors in adolescents. CVF levels are determined by non-modifiable and modifiable factors; one modifiable factor is physical activity (PA). There is a lack of studies investigating the associations between PA patterns and CVF and how gender, parental education, BMI status and country of birth are associated with CVF. The aim of this study was to explore the cross-sectional associations between PA patterns and CVF in Swedish 13-14-year-old adolescents. CVF was estimated using the Ekblom-Bak submaximal test, data on PA patterns were collected using hip-worn accelerometers and a questionnaire. The mean CVF was 44.8 mL/kg/min in girls (n = 569) and 55.5 mL/kg/min in boys (n = 451) p < 0.01. The results showed a significant association between participation in organised sports (ß = 3.32 CI: 2.14, 4.51, ß = 4.38, CI: 2.80, 5.96), MVPA (ß = 0.07, CI: 0.04, 0.11, ß = 0.07, CI: 0.03, 0.11), a high proportion of SED (ß = -0.47, CI: -0.70, -0.25, ß = -0.41, CI: -0.64, -0.18) and CVF in girls and boys, respectively. More than five hours of screen time on weekdays was associated with lower CVF (ß = -2.32 CI: -3.92, -0.71 in girls and boys ß = -2.82, CI: -5.14, -0.50). While causal relations remain unknown, these findings could be relevant when designing future interventions with the aim to improve CVF.

Associations between the School Environment and Physical Activity Pattern during School Time in Swedish Adolescents.

Knowledge about associations between school-based initiatives and physical activity patterns is limited. The purpose of this paper was to examine associations between factors in the school environment, physical activity and sedentary time during school time. The cross-sectional study included 1139 adolescents aged 13-14 from 34 schools. Physical activity and sedentary time were measured using hip-worn accelerometers. Factors in the school environment included health policy, a mobile phone ban during breaks, organized physical activities during breaks and activity breaks during lessons reported by teachers. The frequency and duration of breaks and physical education (PE) lessons were collected from school schedules. The results showed significant associations between health policy (ß = 3.87, 95% confidence interval (CI): 2.37, 5.23), the mobile phone ban (ß = 2.51, 95% CI: 1.29, 3.94) and PE; total duration (ß = 0.08, 95% CI: 0.05, 0.11), average duration (ß = 0.08, 95% CI: 0.01, 0.13) and frequency (ß = 1.73, 95% CI: 0.50, 3.04) and moderate-vigorous physical activity. There were negative associations between health policy (ß = -6.41, 95% CI: -10.24, -2.67), the mobile phone ban (ß = -3.75, 95% CI: -7.25, -0.77) and PE; total duration (ß = -0.15, 95% CI: -0.23, -0.08) and average duration (ß = -0.14, 95% CI: -0.27, -0.03) and time spent sedentary. Adolescents attending schools with health policies, mobile phone bans and more time for PE showed higher levels of physical activity and lower sedentary time.

Adverse outcomes of chronic widespread pain and common mental disorders in individuals with sickness absence - a prospective study of Swedish twins.

BACKGROUND: Chronic widespread pain (CWP) and common mental disorders (CMDs) are common public health problems, but little is known about the role of CWP and CMDs on future adverse outcomes among work disabled individuals. The aims of the study were to investigate the associations between CWP and CMDs with subsequent disability pension (DP), long-term unemployment (> 90 days) and all-cause mortality in individuals with sickness absence (SA) and whether the associations were explained by familial factors. METHODS: In this prospective cohort study, 7884 Swedish twins born between 1933 and 1985 were included and baseline data were gathered from a questionnaire in 1998 to 2006. Register data were used for obtaining information regarding demographics, SA, DP, unemployment and mortality. Cox proportional hazards regressions were used to calculate Hazard Ratios (HR) with 95% Confidence Intervals (CI) for the associations between CWP and/or CMDs with DP, unemployment and mortality, while conditional Cox models for twin pairs provided control for familial confounding. RESULTS: Having either CWP or CMDs among those with a history of SA was associated with a higher risk of DP and all-cause mortality than individuals without CWP and CMDs after controlling for socio-demographic and health factors. Moreover, sick-listed individuals with both CWP and CMDs had a higher risk of DP while those who only had CMDs had a higher risk of long-term unemployment compared to those without CWP and CMDs. The association between CMDs with DP and long-term unemployment was no longer significant when controlling for familial factors. CONCLUSIONS: CMDs was a risk factor for DP, unemployment and mortality among individuals with SA, while CWP seems to be important in relation to future DP and mortality. Familial factors played a role in the associations between CMDs and DP and CMDs and unemployment.

Transitioning from sickness absence to disability pension-the impact of poor health behaviours: a prospective Swedish twin cohort study.

OBJECTIVES: To investigate the association between three poor health behaviours (current smoker, high consumption of alcohol and low physical activity levels) and the transition to disability pension (DP) among individuals who have recently been sickness absent. Furthermore, we aimed to explore whether having multiple poor health behaviours increased the risk of transitioning from sickness absence (SA) to DP. DESIGN: Prospective twin cohort study. SETTING: Sweden. PARTICIPANTS: Twins aged 20-46 who had participated in a survey and been on SA (>14 days) in the year preceding baseline (date of answering the questionnaire). MAIN OUTCOME MEASURE: Incident DP during the follow-up which ended on 31 December 2012 (mean 5.2 years). A national register with full coverage provided data on DP. RESULTS: The Cox proportional-hazards regression analyses showed that current smokers had a higher risk of transitioning from SA to DP compared with never smokers (HR 1.76; 95% CI 1.08 to 2.84). Alcohol use and lack of physical activity as well as poor health behaviour sum score showed no significant associations. CONCLUSIONS: Being a current smoker influences the transition from SA to DP. Although non-significant, there were indications that more physical activity and fewer poor health behaviours could reduce the risk of exiting the labour market through DP. Improving health behaviours among people on SA could be a valuable tool for preventing the transition to DP.

The role of occupational class on the association between sickness absence and disability pension: A Swedish register-based twin study.

Objectives The aim of this study was to examine the association between long-term sickness absence (LTSA) due to mental disorders and musculoskeletal disorders and all-cause disability pension (DP) among blue- and white-collar workers. A secondary objective was to examine the influence of familial factors on the associations. Methods This was a prospective twin cohort study of 42 984 individuals (21-64 years at baseline), 3017 of whom had a new LTSA spell (>14 days) due to mental or musculoskeletal disorders in 2005-2006. Average follow-up time was 5.4 years. Survey data on occupational class and register data on LTSA and DP were used. Cox proportional hazards regression was applied to calculate hazards ratios (HR) with 95% confidence intervals (CI). Results During follow-up, 989 participants went on disability. LTSA due to mental disorders and musculoskeletal disorders led to similar HR for DP among both white- and blue-collar workers when compared to white-collar workers not on LTSA (reference group). LTSA ≥6 months due to musculoskeletal disorders was associated with a higher risk of DP for white-collar (HR 31.50, 95% CI 20.45-48.52) than blue-collar (HR 17.64, 95% CI 13.08-23.78) workers when compared to the reference group. HR were lower in the discordant twin pair models for LTSA due to mental disorders than in the whole cohort. Conclusions White-collar workers on LTSA due to musculoskeletal disorders are especially vulnerable to all-cause DP. This pattern was not present for LTSA due to mental disorders. Familial factors seem to influence the association between LTSA due to mental disorders and all-cause DP.

The association between part-time and temporary employment and sickness absence: a prospective Swedish twin study.

Background: Sickness absence (SA) is becoming a major economic problem in many countries. Our aim was to investigate whether type of employment, including temporary employment or part-time employment, is associated with SA while controlling for familial factors (genetic and shared environment). Differences between men and women and across employment sectors were explored. Methods: This is a prospective twin study based on 21 105 twins born in Sweden 1959-85. The participants completed a survey in 2005 with follow-up of SA (≥15 days), using register data, until end of 2013. The data were analyzed with logistic regression, with results presented as odds ratios (OR) with 95% confidence intervals (CI). Results: Temporary employment involved higher odds of SA (OR=1.21 95% CI=1.04-1.40) compared to full-time employment. Both part-time workers (OR=0.84 95% CI=0.74-0.95) and the self-employed (OR=0.77 95%CI=0.62-0.94) had lower odds of SA. Stratifying by sex showed lower odds for part-timers (OR=0.82 95% CI=0.73-0.94) and self-employed women (OR=0.65 95% CI=0.47-0.90), but higher odds for men in temporary employment (OR=1.33 95% CI=1.03-1.72). Temporary employees in county councils (OR=1.73 95% CI=1.01-2.99) and municipalities (OR=1.41 95% CI=1.02-1.96) had higher odds while part-timers employed in the private sector had lower odds (OR=0.77 95% CI=0.64-0.93). Familial factors did not confound the association between employment type and SA. Conclusions: Employment type is associated with SA, with temporary employment involving a higher risk compared to permanent full-time employment while both part-time employment and self-employment involved a lower risk. The associations vary between women and men and across sectors.

Cardiorespiratory fitness and response to exercise treatment in depression.

BACKGROUND: Exercise improves cardiorespiratory fitness (CRF) and reduces depressive symptoms in people with depression. It is unclear if changes in CRF are a predictor of the antidepressant effect of exercise in people with depression. AIMS: To investigate whether an increase in CRF is a predictor of depression severity reduction after 12 weeks of exercise (trial registration: DRKS study ID, DRKS00008745). METHOD: The present study includes participants who took part in vigorous (n = 33), moderate (n = 38) and light (n = 39) intensity exercise and had CRF information (as predicted maximal oxygen uptake, V̇O2max) collected before and after the intervention. Depression severity was measured with the Montgomery-Åsberg Depression Rating Scale (MADRS). V̇O2max (L/min) was assessed with the Åstrand-Rhyming submaximal cycle ergometry test. The main analysis was conducted pooling all exercise intensity groups together. RESULTS: All exercise intensities improved V̇O2max in people with depression. Regardless of frequency and intensity of exercise, an increase in post-treatment V̇O2max was significantly associated with reduced depression severity at follow-up (B = -3.52, 95% CI -6.08 to -0.96); adjusting for intensity of exercise, age and body mass index made the association stronger (B = -3.89, 95% CI -6.53 to -1.26). Similarly, increased V̇O2max was associated with higher odds (odds ratio = 3.73, 95% CI 1.22-11.43) of exercise treatment response (≥50% reduction in MADRS score) at follow-up. CONCLUSIONS: Our data suggest that improvements in V̇O2max predict a greater reduction in depression severity among individuals who were clinically depressed. This finding indicates that improvements in V̇O2max may be a marker for the underpinning biological pathways for the antidepressant effect of exercise. DECLARATION OF INTEREST: None.

Long-term effects of exercise at different intensity levels on depression: A randomized controlled trial.

Previous research has shown positive effects of exercise on depression but studies have mainly focused on the short-term effects; few have examined the long-term effect, especially with regard to differences in intensity. The aim of this study was to examine the long-term effects of prescribed exercise on depression, performed at three intensity levels. People aged 18-67years with mild to moderate depression (Patient Health Questionnaire-9 score of ≥10) participated in a single-blind, parallel randomized control trial lasting 12weeks (Sweden 2011-2013). Four arms were included: Treatment as usual (TAU, n=310), light (n=106), moderate (n=105) and vigorous exercise (n=99). Severity of depression was measured at baseline, post-treatment and 12-month follow-up using the Montgomery-Åsberg Depression Rating Scale (MADRS). Coefficients (ß) and odds ratios were estimated using linear mixed models with time×group interactions. The results showed that at the 12month follow-up the light exercise group had significantly lower depression severity scores than the TAU (-1.9, 95% CI: -3.7, -0.04) and the moderate exercise group (-2.94 95% CI: -5.2, -0.7). The vigorous exercise group had significantly lower scores than the moderate exercise group only (-2.7, 95% CI: -4.9, -0.4). In conclusion, compared to usual care for depression, only light exercise resulted in significantly lower depression severity at 12-month follow-up. Both light and vigorous exercise was more effective than moderate exercise. TRIAL REGISTRATION: The study was registered with the German Clinical Trial Register (DRKS study ID: DRKS00008745).