Elin Kolle

Accelerometer-Determined Physical Activity in Adults and Older People

PURPOSE There is a lack of large-scale comparable data on the population levels of physical activity (PA) and sedentary activity. We conducted a cross-sectional population-based multicenter study to describe the levels of PA and sedentary activity and to determine adherence to current national PA recommendations in Norwegian adults and older people. METHODS In 2008 and 2009, PA was assessed objectively for seven consecutive days using the ActiGraph GT1M accelerometer in 3867 participants age 20-85 yr. A total of 3267 participants provided valid PA assessments that met all inclusion criteria. RESULTS Women and men did not differ in the overall activity levels (335 and 342 counts per minute, respectively) or in steps per day (8113 and 7951 steps per day, respectively). However, for intensity-specific PA, men accumulated significantly more minutes of sedentary activity and moderate-to-vigorous PA (MVPA) compared with women (557 vs 533 min of sedentary activity, P ≤ 0.001 and 35 vs 33 min of MVPA, P = 0.01). Both overall activity levels and steps per day remained steady with age, until 65 yr, after which activity levels declined. CONCLUSIONS Overall, the study sample spent 62% of their time being sedentary, 25% in low-intensity PA, 9% in lifestyle activity, and 4% in MVPA. One in five people met current national PA recommendations. These results suggest that adults and older people spend the majority of their time being sedentary and that adherence to PA recommendations is low.

Low Muscle Fitness Is Associated with Metabolic Risk in Youth

PURPOSE To examine the independent associations of muscle fitness and cardiorespiratory fitness with clustered metabolic risk in youth. METHODS In 2005-2006, a cohort of 9- and 15-yr-olds (N = 2818) was randomly selected from all regions of Norway. The participation rate was 89% and 74% among the 9-and 15-yr-olds, respectively. We assessed muscular strength by measuring explosive, isometric, and endurance strength. Cardiorespiratory fitness was measured directly as peak oxygen uptake during a cycle ergometry test. Risk factors included in the composite risk factor score (sum of z-scores) were systolic blood pressure, triglyceride, high-density lipoprotein cholesterol, insulin resistance, and waist circumference. RESULTS Muscle fitness was negatively associated with clustered metabolic risk, independent of cardiorespiratory fitness, and after adjustment for age, sex, and pubertal stage (beta = -0.112, P < 0.001). Independent of muscle fitness, an inverse association was found between cardiorespiratory fitness and clustered metabolic risk (beta = -0.337, P < 0.001). Moreover, the odds ratios for having clustered risk in the least fit quartile compared with the most fit quartile were 7.2 (95% confidence interval (CI)=4.3-12.0) and 17.3 (95% CI = 9.2-32.7) for muscle fitness and cardiorespiratory fitness, respectively. CONCLUSIONS Our results show that muscle fitness and cardiorespiratory fitness are independently associated with metabolic risk in youth.

Objectively assessed physical activity and aerobic fitness in a population‐based sample of Norwegian 9‐ and 15‐year‐olds

The present study described current physical activity, determined compliance with physical activity guidelines and assessed aerobic fitness in a nationally representative sample of 9‐ and 15‐year‐olds in Norway. In 2005–2006, 2299 children and adolescents were randomly recruited. The participation rate was 89% and 74% among the 9‐ and 15‐year‐olds, respectively. Physical activity was assessed objectively by accelerometry, and aerobic fitness was measured directly as peak oxygen uptake during a cycle ergometry test. Boys were more physically active than girls, and 9‐year‐olds were substantially more active than 15‐year‐olds. Physical activity was higher during weekdays than weekends, and 9‐year‐olds were most active during spring. While four out of five children met current physical activity guidelines, only half of the adolescents did. The mean (SD) values for peak VO2 were: 9‐year‐old boys, 48.2 (7.1) mL/min/kg; 9‐year‐old girls, 42.9 (6.7) mL/min/kg; and 15‐year‐old girls 41.1 (6.0) mL/min/kg and 15‐year‐old boys 51.9 (8.0) mL/min/kg. Because of the high participation rate, this study provides a good description of the physical activity and aerobic fitness in the young population. Finally, girls and adolescents seem appropriate targets when promoting physical activity in order to increase the proportion meeting the recommendations.

Seasonal variation in objectively assessed physical activity among children and adolescents in Norway: a cross-sectional study.

BackgroundThe literature on seasonality in children and youths physical activity participation is inconsistent. The aims of this study were to: 1) compare physical activity across seasons and describe activity patterns within seasons, and 2) to determine compliance with current physical activity recommendations across seasons among 9- and 15-year-olds living in a climatically diverse country.MethodsParticipants were 2,299 9- and 15-year-olds from all regions in Norway. Physical activity was assessed using the Actigraph accelerometer for 4 consecutive days. Physical activity data were collected during winter, spring and fall. General linear models were used to study the associations between physical activity and season.ResultsNine-year-old children had significantly higher mean physical activity levels in spring than in winter and fall. In the two latter seasons, physical activity levels were especially low after school hours and on weekends. Logistic regression models demonstrated that 9-year-olds had 3.3 times (95% Confidence Interval (CI): 2.08, 5.18) higher odds of meeting recommended levels of physical activity in spring than in winter. No associations were found between mean physical activity level and season among the 15-year-olds. However, the adolescents also had higher odds (OR = 1.56; 95% CI: 1.05, 2.32) of meeting the physical activity recommendations in spring than in winter.ConclusionIn a large population-based sample, we observed substantial seasonal differences in physical activity among 9-year-olds, and the activity pattern varied across the seasons. The results emphasize the need to take season into account when developing physical activity interventions for children. Season appears to have less influence on adolescents physical activity; interventions for increasing physical activity in this group could therefore be implemented throughout the year.

Recommended aerobic fitness level for metabolic health in children and adolescents: a study of diagnostic accuracy

Objective To define the optimal cut-off for low aerobic fitness and to evaluate its accuracy to predict clustering of risk factors for cardiovascular disease in children and adolescents. Design Study of diagnostic accuracy using a cross-sectional database. Setting European Youth Heart Study including Denmark, Portugal, Estonia and Norway. Participants 4500 schoolchildren aged 9 or 15 years. Main Outcome Measure Aerobic fitness was expressed as peak oxygen consumption relative to bodyweight (mlO2/min/kg). Results Risk factors included in the composite risk score (mean of z-scores) were systolic blood pressure, triglyceride, total cholesterol/HDL-cholesterol ratio, insulin resistance and sum of four skinfolds. 14.5% of the sample, with a risk score above one SD, were defined as being at risk. Receiver operating characteristic analysis was used to define the optimal cut-off for sex and age-specific distribution. In girls, the optimal cut-offs for identifying individuals at risk were: 37.4 mlO2/min/kg (9-year-old) and 33.0 mlO2/min/kg (15-year-old). In boys, the optimal cut-offs were 43.6 mlO2/min/kg (9-year-old) and 46.0 mlO2/min/kg (15-year-old). Specificity (range 79.3–86.4%) was markedly higher than sensitivity (range 29.7–55.6%) for all cut-offs. Positive predictive values ranged from 19% to 41% and negative predictive values ranged from 88% to 90%. The diagnostic accuracy for identifying children at risk, measured by the area under the curve (AUC), was significantly higher than what would be expected by chance (AUC >0.5) for all cut-offs. Conclusions Aerobic fitness is easy to measure, and is an accurate tool for screening children with clustering of cardiovascular risk factors. Promoting physical activity in children with aerobic fitness level lower than the suggested cut-points might improve their health.

Secular trends in adiposity in Norwegian 9-year-olds from 1999-2000 to 2005

BackgroundDue to the negative health consequences of childhood obesity monitoring trends in body mass and adiposity is essential. The purpose of this study was to describe secular trends in the prevalence of overweight and obesity among 9-year-old children, and to study changes in adiposity and fat distribution by investigating changes in waist circumference (WC) and skinfold thicknesses.MethodsA total of 859 9-year-olds were included in two cross-sectional studies conducted in 1999-2000 and 2005. Measurements of body mass index (BMI; in kg/m2), WC and skinfold thicknesses were taken by trained investigators. The International Obesity Task Force cut-offs were used to define overweight and obese subjects.ResultsThe overall prevalence of overweight (including obesity) did not change over the five year period. However, a shift may have occurred as the prevalence of overweight (including obesity) increased by 6.4% in girls and 5.5% in boys over the five year period. In both study periods, logistic regression analyses revealed that children of non-Western origin had 2 times higher odds of being overweight/obese than those of Western origin. However, neither the children of Western origin nor the children of non-Western origin showed a significant increase in the prevalence of overweight over the five-year period. No changes were observed for mean BMI, while a significant increase in WC was reported for both girls and boys, and an increase in all skinfold measurements was observed in girls only. Shifts in percentile distribution were observed for BMI, WC and sum of 4 skinfold thickness, however, the shift appeared to be faster in the upper end of the population distribution (p < 0.001 for interactions).ConclusionFrom 1999-2000 to 2005, there have been increases in 9-year-olds measures of adiposity even though the BMI did not change. The results indicate the need of a large-scale monitoring of adiposity, in addition to BMI, in children.

Patterns of objectively measured physical activity in normal weight, overweight, and obese individuals (20-85 years): a cross-sectional study.

Background The magnitude of the association between physical activity (PA) and obesity has been difficult to establish using questionnaires. The aim of the study was to evaluate patterns of PA across BMI-defined weight categories and to examine the independent contribution of PA on weight status, using accelerometers. Methods The study was a cross-sectional population-based study of 3,867 adults and older people aged 20–85 years, living in Norway. PA was assessed for seven consecutive days using the ActiGraph GT1M accelerometer. Anthropometrical data was self-reported and overweight and obesity was defined as having a body mass index (BMI) of 25–<30 and ≥30 kg/m2, respectively. Results Overweight and obese participants performed less overall PA and PA of at least moderate intensity and took fewer steps, compared to normal weight participants. Although overall PA did not differ between weekdays and weekends, an interaction between BMI category and type of day was present, indicating a larger difference in overall PA between BMI categories on weekends compared to weekdays. Obese participants displayed 19% and 25% lower overall physical activity compared to normal weight participants, on weekdays and weekends, respectively. Participants in the most active quintile of overall PA had a 53% lower risk (OR 0.47, 95% CI: 0.37 to 0.60) for having a BMI above or below 25 kg/m2, and a 71% lower risk (OR: 0.29, 95% CI: 0.20 to 0.44) for having a BMI above or below 30 kg/m2. Conclusions Overweight and obese participants engaged in less overall PA and moderate and vigorous PA compared with normal weight individuals. The weight related differences in overall PA were most pronounced on the weekend and the risk of being overweight or obese decreases across quintiles of PA.

Reliability and validity of the Physical Activity Scale for the Elderly (PASE) in patients with hip osteoarthritis

BackgroundPhysical activity (PA) is beneficial in reducing pain and improving function in lower limb osteoarthritis (OA), and is recommended as a first line treatment. Self-administered questionnaires are used to assess PA, but knowledge about reliability and validity of these PA questionnaires are limited, in particular for patients with OA. The purpose of this study was to evaluate the reliability and validity of the Physical Activity Scale for the Elderly (PASE) in patients with hip OA.MethodsForty patients with hip OA (20 men and 20 women, mean age 61.3 ± 10 years) were included. For test-retest reliability PASE was administered twice with a mean time between tests of 9 ± 4 days. Intraclass correlation coefficient (ICC), standard error of measurement (SEM) and minimal detectable change (MDC) were calculated for the total score and for the particular items assessing different PA intensity levels. In addition a Bland-Altman analysis for the total PASE score was performed. Construct validity was evaluated by comparing the PASE results with the Actigraph GT1M accelerometer and the International Physical Activity Questionnaire (IPAQ), using the Spearman rank correlation coefficient.ResultsICC for the total PASE score was 0.78, with relatively large error of measurement; SEM = 31 and MDC = 87. ICC for the intensity items was 0.20 for moderate PA intensity, 0.46 for light PA intensity and to 0.68 for vigorous PA intensity. The Spearman rank correlation coefficient between the Actigraph GT1M total counts per minute and the total PASE score was 0.30 (p = 0.089), and ranging from 0.20-0.38 for the different PA intensity categories. The Spearman rank correlation between IPAQ and PASE was 0.61 (p = 0.001) for the total scores.ConclusionsIn patients with hip OA the test-retest reliability of the total PASE score was moderate, with acceptable ICC, but with large measurement errors. The construct validity of the PASE was poor when compared to the Actigraph GT1M accelerometer. Test-retest reliability and construct validity revealed that the PASE was unable to assess PA intensity levels. PASE is not recommended as a valid tool to examine PA level for patients with hip OA.

Cross sectional analysis of the association between mode of school transportation and physical fitness in children and adolescents

ObjectiveTo investigate the associations between body composition, cardiorespiratory and muscular fitness in relation to travel mode to school in children and adolescents.MethodChildren and adolescents from 40 elementary schools and 23 high schools representing all regions in Norway were invited to participate in the study. Anthropometry, cardiorespiratory and muscular fitness were tested at the school location. Questionnaires were used in order to register mode of transport to school, age, gender and levels of leisure time physical activity.ResultsA total of 1694 (i.e. 60% of all invited participants) children and adolescents at a mean age of 9.6 and 15.6 respectively (SD = 0.4 for both groups) were analyzed for associations with physical fitness variables. Males cycling to school had lower sum of skin folds than adolescents walking to school. Higher cardiorespiratory fitness in adolescents and male cyclists compared to walkers and passive commuters were observed. Among children, cycling and walking to school, higher isometric muscle endurance in the back extensors compared to passive commuters was observed.ConclusionBased on this national representative cross-sectional examination of randomly selected children and adolescents there is evidence that active commuting, especially cycling, is associated with a favourable body composition and better cardiorespiratory and muscular fitness as compared to passive commuting.

Three-year follow-up of physical activity in Norwegian youth from two ethnic groups: associations with socio-demographic factors

BackgroundMore research on factors associated with physical activity and the decline in participation during adolescence is needed. In this paper, we investigate the levels, change, and stability of physical activity during the late teens among ethnic Norwegians and ethnic minorities, and we examine the associations between physical activity and socio-demographic factors.MethodsThe baseline (T1) of this longitudinal study included 10th graders who participated in the youth part of the Oslo Health Study, which was carried out in schools in 2000–2001. The follow-up (T2) in 2003–2004 was conducted partly at school and partly by mail. A total of 2489 (1112 boys and 1377 girls) participated both at baseline and at follow-up. Physical activity level was measured by a question on weekly hours of physical activity outside of school. Socio-demographic variables were collected by questionnaire and from data obtained from Statistics Norway. Analysis of variance was used to study the level of and changes (T1 to T2) in physical activity, and the associations between physical activity and socio-demographic factors. Stability in physical activity was defined as the percentage of students reporting the same physical activity both times.ResultsBoys were more active than girls at age 15 and 18 years, independent of ethnic background. Among girls, ethnic Norwegians were more active than ethnic minorities. Hours per week spent on physical activity declined in all groups during the follow-up period. Few associations were found between physical activity and socio-demographic factors in both cross-sectional and longitudinal data. Among the ethnic minority girls, 65% reported being physically active 0–2 hours per week at baseline, and 82% of these girls reported the same level at follow up.ConclusionThe association between physical activity and ethnicity at age 15 years remained the same during the follow-up. Few associations were found between physical activity and socio-demographic variables. A large proportion of ethnic minority girls reported a persistently low physical activity level, and this low participation rate may need special attention.