Jakob Tarp

Aarhus University | AU · Department of Clinical Epidemiology

Objective To examine the joint associations between physical activity and abdominal obesity with the risk of cardiovascular disease (CVD) events. Methods We included 70 830 UK Biobank participants (mean age±SD=61.6 ± 7.9 years; 56.4% women) with physical activity measured by wrist-worn accelerometers and without major chronic diseases. Participant...

Objectives To examine whether moderate-to-vigorous physical activity (MVPA) modifies the association between sedentary time and mortality and vice versa, and estimate the joint associations of MVPA and sedentary time on mortality risk. Methods This study involved individual participant data analysis of four prospective cohort studies (Norway, Swed...

Objective: The aim of this study was to determine dose-response associations, including the minimal effective level, between leisure-time physical activity and risk of incident neuropathy, nephropathy, and retinopathy. Research design and methods: This cohort study included 18,092 individuals with type 2 diabetes from the UK Biobank. Self-report...

Background How the association between adiposity and the risk of death changes with age, and which is the optimal level of adiposity to reduce mortality in older ages, is still not completely understood. We aimed to ascertain the age-specific risks of mortality associated with different measures of adiposity. Methods This was a prospective UK Biob...

Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6 . Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural an...

Introduction Habitual physical activity behaviors of individuals with new-onset type 2 diabetes are largely unknown. We aimed to investigate accelerometer-derived physical activity behaviors in individuals with newly diagnosed type 2 diabetes. We also examined sociodemographic and health-related correlates of a high-risk physical activity profile....

Device‐measured physical activity and sedentary time are suggested to be more important determinants of all‐cause mortality compared to body mass index (BMI) in mainly older adults. However, the joint associations of physical activity and sedentary time with BMI in relation to mortality risk in relatively healthy middle‐aged individuals are unclear...

Background Physical activity behaviors among children and adolescents are socioeconomically patterned. Understanding if, and how, the built environment contributes to socioeconomic inequalities in physical activity and for whom built environments are most important, can lead to the identification of intervention entry points to reduce inequalities...

Context: There is a rise in overweight and obesity among children and adolescents with type 1 diabetes (T1D) in parallel with the rise in the metabolic syndrome (MetS) among children and adolescents. Objective: The aim of the study was to describe the prevalence and characteristics of MetS in children and adolescents with T1D compared to their h...

Background Access to screen-based media has been revolutionized during the past two decades. How this has affected sedentary time (ST) accumulation in children is poorly understood. Methods This study, based on the Physical Activity among Norwegian Children Study (PANCS), uses accelerometer data from population-based samples of 9- and 15-year-olds...

Background Consumer wearables and smartphone devices commonly offer an estimate of energy expenditure (EE) to assist in the objective monitoring of physical activity to the general population. Alongside consumers, healthcare professionals and researchers are seeking to utilise these devices for the monitoring of training and improving human health....

Background The joint associations of total and intensity-specific physical activity with obesity in relation to all-cause mortality risk are unclear. Methods We included 34 492 adults (72% women, median age 62.1 years, 2034 deaths during follow-up) in a harmonised meta-analysis of eight population-based prospective cohort studies with mean follow-...

Background Studies suggest that high occupational physical activity increases mortality risk. However, it is unclear whether this association is causal or can be explained by a complex network of socioeconomic and behavioural factors. We aimed to examine the association between occupational physical activity and longevity, taking a complex network...

Background Cardiorespiratory fitness may moderate the association between obesity and all‐cause mortality (ie, the “fat‐but‐fit” hypothesis), but unaddressed sources of bias are a concern. Methods and Results Cardiorespiratory fitness was estimated as watts per kilogram from a submaximal bicycle test in 77 169 men and women from the UK Biobank coh...

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in di...

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in di...

Background: Regular stair climbing has the potential to lower the risk of premature death, but current evidence is scarce. We aimed to examine whether daily stair climbing is associated with lower risk of all-cause, cancer, and cardiovascular disease (CVD) mortality. Methods: Using the UK Biobank cohort, we extracted information of self-reported...

It remains unclear whether the provision of additional physical activity in school improves academic outcomes. We conducted a secondary analysis of the Childhood Health, Activity, and Motor Performance School Study Denmark (CHAMPS-study DK), a natural experiment based on a trebling of curricular physical education, to investigate whether children r...

Objectives To determine if subpopulations of students benefit equally from school-based physical activity interventions in terms of cardiorespiratory fitness and physical activity. To examine if physical activity intensity mediates improvements in cardiorespiratory fitness. Design Pooled analysis of individual participant data from controlled tria...

Objectives To examine the joint associations of accelerometer-measured physical activity and sedentary time with all-cause mortality. Methods We conducted a harmonised meta-analysis including nine prospective cohort studies from four countries. 44 370 men and women were followed for 4.0 to 14.5 years during which 3451 participants died (7.8% morta...

Objective To examine the combined and stratified associations of physical activity and adiposity measures, modelled as body mass index (BMI), abdominal adiposity (waist circumference), and body fat percentage (BF) with all-cause mortality. Patients and Methods Using the UK Biobank cohort, we extracted quintiles of self-reported weekly physical act...

Physical activity and cardiorespiratory fitness are inversely associated with markers of cardiometabolic risk in children and adolescents, but the interplay between these variables in relation to the cardiometabolic risk profile is unclear. We systematically reviewed the literature to examine whether the association between physical activity and ca...

Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled ana...

Background: Adolescents' health-related behavior varies from weekday to weekend. Only few studies, however, have examined to which degree such variation will affect markers of cardiometabolic health. Therefore, the primary aim of this study is to examine if markers of cardiometabolic health differ between different days of the week in adolescents....

Introduction Walking is free, does not require special training, and can be done almost everywhere. Therefore, walking is a feasible behavior on which to tailor public health messages. This study assess the prospective association and dose‐response relationship between daily steps and all‐cause mortality. Materials and Methods Daily steps were mea...

Physical activity was recently reiterated as 'the miracle cure' for health because of its positive influence on numerous chronic disease conditions and very low risk of negative outcomes

Background: Observational studies linking physical activity with mortality are susceptible to reverse causation bias from undiagnosed and prevalent diseases. Researchers often attempt to deal with reverse causation bias by excluding deaths occurring within the first 1 or 2 years from the analysis, but it is unclear if excluding deaths within this...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Objective To examine the dose-response associations between accelerometer assessed total physical activity, different intensities of physical activity, and sedentary time and all cause mortality. Design Systematic review and harmonised meta-analysis. Data sources PubMed, PsycINFO, Embase, Web of Science, Sport Discus from inception to 31 July 201...

Aims/hypothesis The study aimed to quantitatively summarise the dose–response relationships between cardiorespiratory fitness and muscular strength on the one hand and risk of type 2 diabetes on the other and estimate the hypothetical benefits associated with population-wide changes in the distribution of fitness. Methods We performed a systematic...

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities1,2. This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity3–6. Here we use 2,009 population-based studies, with measurements of height and...

Purpose: Insulin resistance may exert a negative influence on bone mass in childhood and adolescence. The objective was to assess the association between insulin resistance and total body less head (TBLH) bone mineral content (BMC) and to investigate whether body composition, physical activity or osteocalcin levels may influence this association....

Background: The role of muscle fitness in controlling cardiometabolic risk factors during childhood is incompletely understood. Methods: A prospective observational design including 6- to 11-year-old children (n = 512) was used to study associations between 1.5-year changes in handgrip strength, standing vertical jump displacement, the short shu...

This longitudinal study examined associations of bone mass with physical activity and vitamin D level over more than 6 years through puberty. A total of 663 participants (320 boys) with mean age 9.6 years at baseline (10–17 years at follow-up), underwent dual energy X-ray absorptiometry, anthropometry and blood samples for vitamin D at least twice...

Background The extent of the obesity epidemic among youth is an important public health statistic which provides an indication of the future burden of non-communicable diseases. Many developing countries, including Albania, do not have systematic and repeated monitoring systems in operation. Methods The Balkan Survey of Inactivity in Children stud...

Objectives: To determine the role of physical activity intensity and bout-duration in modulating associations between physical activity and cardiometabolic risk markers. Methods: A cross-sectional study using the International Children's Accelerometry Database (ICAD) including 38,306 observations (in 29,734 individuals aged 4-18 years). Accelero...

Previous research has found positive associations between cognitive control and aerobic fitness in preadolescents and adults; however, fewer studies have investigated these associations in adolescents. Adolescence is of particular interest due to continued maturation of the prefrontal cortex; an area that subserves cognitive control. This study inv...

Methods: The study was cross-sectional and included 558 adolescents (mean age 14.2 years). Anthropometrics and systolic blood pressure (sysBP) were measured and fasting blood samples were analyzed for metabolic risk factors. A metabolic risk factor cluster score (MetS-cluster score) was computed from the sum of standardized sysBP, triglycerides (T...

Purpose: The main objective of the study was to investigate the effect of short bouts of aerobic exercise with various exercise intensities on inhibitory control using a flanker task in adolescents. Methods: The study used a randomized controlled crossover design with 52 adolescents (mean age 17.7 years). On separate days, participants completed fo...

Background: Schools are a key setting for large-scale primordial non-communicable disease prevention in young people, but little data on sustainability of impacts on cardiometabolic risk markers is available. Methods: Six and a half year follow-up of a natural experiment. In 2008, six public schools in the municipality of Svendborg (Denmark) augmen...

Our objective was to determine associations between retinal vascular caliber and physical activity (PA) in a school‐based child cohort. In a prospective study we created a childhood cumulative average PA‐index using objectively measured PA (accelerometry) assessed at four periods between 2009 and 2015. Cumulative exposure to PA intensities was esti...

Underweight, overweight, and obesity in childhood and adolescence are associated with adverse health consequences throughout the life-course. Our aim was to estimate worldwide trends in mean body-mass index (BMI) and a comprehensive set of BMI categories that cover underweight to obesity in children and adolescents, and to compare trends with those...

BACKGROUND:Underweight, overweight, and obesity in childhood and adolescence are associated with adverse health consequences throughout the life-course. Our aim was to estimate worldwide trends in mean body-mass index (BMI) and a comprehensive set of BMI categories that cover underweight to obesity in children and adolescents, and to compare trends...

Worldwide trends in body-mass index, underweight, overweight, and obesity from 1975 to 2016: a pooled analysis of 2416 population-based measurement studies in 128•9 million children, adolescents, and adults NCD Risk Factor Collaboration (NCD-RisC)* Summary Background Underweight, overweight, and obesity in childhood and adolescence are associated w...

Background and objective Cardiovascular disease and type 2 diabetes pose a global health burden. Therefore, clarifying the pathology of these risk factors is essential. Previous studies have found positive and negative associations between one or more cardiovascular risk factors and brain-derived neurotrophic factor (BDNF) probably due to diverse m...

Differences between analytic sample and participants with missing data. Characteristics presented as percentages, mean (SD) or median (interquartile range). a: Variables expressed as median (interquartile range) due to non-normality. *: Significant difference between samples. (DOCX)

Partial correlation coefficients between cardiovascular risk factors and the composite z-score. All variables are represented as z-scores adjusted for age, gender and pubertal status. SysBP and WC were adjusted for height. All non-BDNF blood measurements were adjusted for weekday. *and bold values = Significant correlation. (DOCX)

Background Underweight, overweight, and obesity in childhood and adolescence are associated with adverse health consequences throughout the life-course. Our aim was to estimate worldwide trends in mean body-mass index (BMI) and a comprehensive set of BMI categories that cover underweight to obesity in children and adolescents, and to compare tr...

Background/objectives: To model the association between accumulating 60 daily minutes of moderate-to-vigorous physical activity and a composite score of biological risk factors into a direct and an indirect effect, using abdominal obesity as the mediator. Subjects/methods: Cross-sectional data from the International Children's Accelerometry Data...

Aim: To investigate the influence of a school-based intervention with a tripling of physical education (PE) lessons from two (90 min) to six lessons per week (270 min) on scholastic performance. Methods: This study is part of the CHAMPS study-DK, a quasi-experimental study that began in 2008. The intervention group consisted of six schools and t...

Objective: The purpose of this study was to examine the associations between objectively measured physical activity and serum brain-derived neurotrophic factor (BDNF) in adolescents. Methods: Cross-sectional analyses were performed using data from 415 adolescents who participated in the 2015 follow-up of the Childhood Health Activity and Motor Perf...

Objective: The purpose of this study was to examine the associations between objectively measured physical activity and serum brain-derived neurotrophic factor (BDNF) in adolescents. Methods: Cross-sectional analyses were performed using data from 415 adolescents who participated in the 2015 follow-up of the Childhood Health Activity and Motor P...

Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in S...

Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in S...

Background: Physical activity is associated not only with health-related parameters, but also with cognitive and academic performance. However, no large scale school-based physical activity interventions have investigated effects on cognitive performance in adolescents. The aim of this study was to describe the effectiveness of a school-based phys...

Implementation of intervention components. SMS-tracking from students at intervention schools. (DOCX)

Trial protocol_Danishversion. Approved trial protocol (Danish). (PDF)

Trial protocol_englishVersion. Approved trial protocol (English translation). (PDF)