A 2 year physical activity and dietary intervention attenuates the increase in insulin resistance in a general population of children: the PANIC study

Funder: The NIHR Biomedical Research Centre in CambridgeFunder: Finnish Innovation Fund SitraFunder: Foundation for Paediatric ResearchFunder: Ministry of Social Affairs and Health of FinlandFunder: Yrjö Jahnsson FoundationFunder: Research Committee of the Kuopio University Hospital Catchment Area (State Research Funding)Funder: The city of KuopioFunder: The UK Medical Research CouncilFunder: Finnish Cultural FoundationFunder: Ministry of Education and Culture of FinlandFunder: Juho Vainio FoundationFunder: Paavo Nurmi FoundationFunder: Diabetes Research Foundation in FinlandFunder: Finnish Foundation for Cardiovascular ResearchFunder: Social Insurance Institution of FinlandAbstract: Aims/hypothesis: We studied for the first time the long-term effects of a combined physical activity and dietary intervention on insulin resistance and fasting plasma glucose in a general population of predominantly normal-weight children. Methods: We carried out a 2 year non-randomised controlled trial in a population sample of 504 children aged 6–9 years at baseline. The children were allocated to a combined physical activity and dietary intervention group (306 children at baseline, 261 children at 2-year follow-up) or a control group (198 children, 177 children) without blinding. We measured fasting insulin and fasting glucose, calculated HOMA-IR, assessed physical activity and sedentary time by combined heart rate and body movement monitoring, assessed dietary factors by a 4 day food record, used the Finnish Children Healthy Eating Index (FCHEI) as a measure of overall diet quality, and measured body fat percentage (BF%) and lean body mass by dual-energy x-ray absorptiometry. The intervention effects on insulin, glucose and HOMA-IR were analysed using the intention-to-treat principle and linear mixed-effects models after adjustment for sex, age at baseline, and pubertal status at baseline and 2 year follow-up. The measures of physical activity, sedentary time, diet and body composition at baseline and 2 year follow-up were entered one-by-one as covariates into the models to study whether changes in these variables might partly explain the observed intervention effects. Results: Compared with the control group, fasting insulin increased 4.65 pmol/l less (absolute change +8.96 vs +13.61 pmol/l) and HOMA-IR increased 0.18 units less (+0.31 vs +0.49 units) over 2 years in the combined physical activity and dietary intervention group. The intervention effects on fasting insulin (regression coefficient β for intervention effect −0.33 [95% CI −0.62, −0.04], p = 0.026) and HOMA-IR (β for intervention effect −0.084 [95% CI −0.156, −0.012], p = 0.023) were statistically significant after adjustment for sex, age at baseline, and pubertal status at baseline and 2 year follow-up. The intervention had no effect on fasting glucose, BF% or lean body mass. Changes in total physical activity energy expenditure, light physical activity, moderate-to-vigorous physical activity, total sedentary time, the reported consumption of high-fat (≥60%) vegetable oil-based spreads, and FCHEI, but not a change in BF% or lean body mass, partly explained the intervention effects on fasting insulin and HOMA-IR. Conclusions/interpretation: The combined physical activity and dietary intervention attenuated the increase in insulin resistance over 2 years in a general population of predominantly normal-weight children. This beneficial effect was partly mediated by changes in physical activity, sedentary time and diet but not changes in body composition. Trial registration: ClinicalTrials.gov NCT01803776 Graphical abstrac

The effects of a 2-year physical activity and dietary intervention on plasma lipid concentrations in children: the PANIC Study

Funder: Opetus- ja Kulttuuriministeriö; doi: http://dx.doi.org/10.13039/501100003126Funder: Sosiaali- ja Terveysministeriö; doi: http://dx.doi.org/10.13039/501100008487Abstract: Purpose: We studied the effects of a physical activity and dietary intervention on plasma lipids in a general population of children. We also investigated how lifestyle changes contributed to the intervention effects. Methods: We carried out a 2-year controlled, non-randomized lifestyle intervention study among 504 mainly prepubertal children aged 6–9 years at baseline. We assigned 306 children to the intervention group and 198 children to the control group. We assessed plasma concentrations of total, LDL, HDL, and VLDL cholesterol, triglycerides, HDL triglycerides, and VLDL triglycerides. We evaluated the consumption of foods using 4-day food records and physical activity using a movement and heart rate sensor. We analyzed data using linear mixed-effect models adjusted for age at baseline, sex, and pubertal stage at both time points. Furthermore, specific lifestyle variables were entered in these models. Results: Plasma LDL cholesterol decreased in the intervention group but did not change in the control group ( − 0.05 vs. 0.00 mmol/L, regression coefficient (β) = − 0.0385, p = 0.040 for group*time interaction). This effect was mainly explained by the changes in the consumption of high-fat vegetable oil-based spreads (β = − 0.0203, + 47% change in β) and butter-based spreads (β = − 0.0294, + 30% change in β), moderate-to-vigorous physical activity (β = − 0.0268, + 30% change in β), light physical activity (β = − 0.0274, + 29% change in β) and sedentary time (β = − 0.0270, + 30% change in β). The intervention had no effect on other plasma lipids. Conclusion: Lifestyle intervention resulted a small decrease in plasma LDL cholesterol concentration in children. The effect was explained by changes in quality and quantity of dietary fat and physical activity. Clinical Trial Registry Number: NCT01803776, ClinicalTrials.go

Metabolic equivalents of task are confounded by adiposity, which disturbs objective measurement of physical activity

Physical activity refers any bodily movements produced by skeletal muscles that expends energy. Hence the amount and the intensity of physical activity can be assessed by energy expenditure. Metabolic equivalents of task (MET) are multiplies of the resting metabolism reflecting metabolic rate during exercise. The standard MET is defined as 3.5 ml/min/kg. However, the expression of energy expenditure by body weight to normalize the size differences between subjects causes analytical hazards: scaling by body weight does not have a physiological, mathematical, or physical rationale. This review demonstrates by examples that false methodology may cause paradoxical observations if physical activity would be assessed by body weight scaled values such as standard METs. While standard METs are confounded by adiposity, lean mass proportional measures of energy expenditure would enable a more truthful choice to assess physical activity. While physical activity as a behavior and cardiorespiratory fitness or adiposity as a state represents major determinants of public health, specific measurements of health determinants must be understood to enable a truthful evaluation of the interactions and their independent role as a health predictor

Assessment of body composition by dual-energy X-ray absorptiometry, bioimpedance analysis and anthropometrics in children: the Physical Activity and Nutrition in Children study Summary Correspondence Accepted for publication

Objective and methods: We compared InBody 720 segmental multifrequency bioimpedance analysis (SMF-BIA) with Lunar Prodigy Advance dual-energy X-ray absorptiometry (DXA) in assessment of body composition among 178 predominantly prepubertal children. Segmental agreement analysis of body compartments was carried out, and inter-relationships of anthropometric and other measures of body composition were defined. Moreover, the relations of different reference criteria for excess body fat were evaluated. Results: The prevalence of excess body fat varies greatly according to the used criteria. Intraclass and Pearson's correlations between SMF-BIA and DXA were >0Á92 in total body and >0Á74 in regional measures. SMF-BIA underestimated percentage body fat (%BF) and fat mass (FM), and overestimated lean mass (LM) and percentage LM with significant offset trend bias. Higher adiposity increased offsets, and overall agreement was poorer in girls. On average, %BF offsets (girls/boys) and limits of agreement (LA) were 3Á9/1Á6% [(À)1Á4-9Á2%/(À)3Á4-6Á7%]. Interestingly percentage offsets of fat content (%BF: 18Á9/10Á1%, FM: 18Á8/ 11Á1%) showed no significant bias trends indicating that the corresponding absolute methodological offset depends on the amount of fat content. The smallest percentage offset was found with LM: 4Á3/0Á1%, referring offset (LA) of 0Á88/ 0Á03 kg (AE2Á05/AE1Á71 kg). Correspondingly, segmental LM had poorer agreement than total body LM. All anthropometrics except for the waist-to-hip ratio showed strong correlations (r = 0Á76-0Á95) with abdominal and total body fat. Conclusion: Segmental multifrequency bioimpedance analysis is precise enough for total-LM analysis and had also sufficient trueness for total body composition analysis to be used in epidemiological purposes. There is need to generate scientifically and clinically relevant criteria and reference values for excess body fat

Comparison between parameters from maximal cycle ergometer test first without respiratory gas analysis and thereafter with respiratory gas analysis among healthy prepubertal children

It is important to distinguish true and clinically relevant changes and methodological noise from measure to measure. In the clinical practice maximal cycle ergometer tests are typically performed first without respiratory gas analysis, and thereafter, if needed, with respiratory gas analysis. Therefore we report comparison of parameters from maximal cycle ergometer exercise tests which were done first without respiratory gas analysis and thereafter with it in 38 prepubertal and healthy children (20 girls, 18 boys). The Bland-Altman method was used to assess agreement in maximal workload (WMAX) and heart rate (HR) and systolic blood pressure (SBP) between rest and maximum. Girls achieved higher WMAX in the exercise tests with respiratory gas analysis compared with exercise tests without respiratory gas analysis (P=0.016), whereas WMAX was similar in the tests among boys. Maximal HR (proportional offset -1%; CV% 3.3) and highest SBP (proportional offset 3%; CV% 10.6) were similar in the tests among children. Precision and agreement for HR improved and precision for SBP worsened with increasing exercise intensity. Heteroscedasticity was not observed for WMAX, HR or SBP. We conclude that maximal cycle ergometer tests without and with respiratory gas analysis can be used consecutively because measurement of respiratory gases did not impair performance or have significant effect on the maximality of the exercise tests. Our results suggest that similar references can be used for children who accept or refuse using a mask during maximal exercise test.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Associations of physical activity and sedentary behavior with academic skills--a follow-up study among primary school children.

There are no prospective studies that would have compared the relationships of different types of physical activity (PA) and sedentary behavior (SB) with academic skills among children. We therefore investigated the associations of different types of PA and SB with reading and arithmetic skills in a follow-up study among children.The participants were 186 children (107 boys, 79 girls, 6-8 yr) who were followed-up in Grades 1-3. PA and SB were assessed using a questionnaire in Grade 1. Reading fluency, reading comprehension and arithmetic skills were assessed using standardized tests at the end of Grades 1-3.Among all children more recess PA and more time spent in SB related to academic skills were associated with a better reading fluency across Grades 1-3. In boys, higher levels of total PA, physically active school transportation and more time spent in SB related to academic skills were associated with a better reading fluency across the Grades 1-3. Among girls, higher levels of total PA were related to worse arithmetic skills across Grades 1-3. Moreover, total PA was directly associated with reading fluency and arithmetic skills in Grades 1-3 among girls whose parents had a university degree, whereas these relationships were inverse in girls of less educated parents.Total PA, physically active school transportation and SB related to academic skills may be beneficial for the development of reading skills in boys, whereas factors that are independent of PA or SB may be more important for academic skills in girls.ClinicalTrials.gov: NCT01803776

Differences in academic skills in Grades 1–3 between children who were in the upper and lower halves of sedentary behavior related to academic skills (A and B) and computer use and video game playing (C) in Grade 1 among 107 boys and 79 girls.

<p>Data are from analyses of covariance with repeated measures adjusted for age, parental education and the PANIC study group (intervention vs. control). SB = Sedentary behavior; CVG = Computer use and video game playing; SBAS = Sedentary behavior related to academic skills. Error bars represent standard errors of the mean (SEM).</p

The differences in academic skills in Grades 1–3 between children who were in the upper and lower halves of total physical activity (A) and physically active school transportation (B) in Grade 1 among 107 boys and 79 girls.

<p>The data were adjusted for age, parental education, the PANIC study group (intervention vs. control) from the analyses of covariance with repeated measures. Error bars represent standard errors of the mean (SEM).</p

Basic characteristics of 186 children (107 boys and 79 girls).

<p>Basic characteristics are displayed as means (SD), medians (IQRs) or percentages (%). Differences in basic characteristics between girls and boys were analyzed with the Student’s t-test or Mann-Whitney U test for continuous variables and chi-square test for categorical variables.</p><p>Basic characteristics of 186 children (107 boys and 79 girls).</p