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Objectives Cardiorespiratory fitness (CRF) has been inversely associated with risk of cardiometabolic diseases. However, there are no studies comparing the independent associations of CRF scaled by body size and composition using different approaches with cardiometabolic risk factors between children and adults. We therefore investigated these associations in children and adults using same measures for CRF and cardiometabolic risk factors. Design Cross-sectional. Methods A total of 352 children (47.2 % girls) and 572 men were included in the study. Peak oxygen uptake (V̇O2peak) was measured during a maximal exercise test on a cycle ergometer and was scaled by total body mass (BM−1), total fat free mass (FFM−1), and allometrically modelled BM, FFM, and stature. Insulin, glucose, triglycerides, HDL cholesterol, and LDL cholesterol were assessed from fasting blood samples and systolic and diastolic blood pressure were measured. HOMA-IR and continuous metabolic risk score were computed. Results V̇O2peak scaled by BM−1 was inversely associated with insulin, HOMA-IR, triglycerides, diastolic blood pressure, the cardiometabolic risk score and the number of cardiometabolic risk factors in children and adults. However, these associations attenuated remarkably when V̇O2peak was scaled by total FFM or allometrically modelled BM, FFM, or stature. V̇O2peak was consistently and positively associated with HDL cholesterol in children and adults irrespective of the scaling approach. Conclusions The inverse associations of CRF with cardiometabolic risk factors among children and adults attenuated remarkably when body size and composition were appropriately controlled for. However, the positive association between CRF and HDL cholesterol was consistent irrespective of the scaling approach. peerReviewed

Obesity in early childhood is associated with increased risk of chronic diseases, but studies of body composition at preschool ages are sparse. Therefore, we examined differences in body composition by sex and obesity status in Finnish preschool-aged children and within-individual changes in body composition in normal and overweight children. Body composition was measured using segmental multifrequency bioimpedance analysis (BIA) in 476 children and in 781 children at age 3 and 5 years, respectively. Of those, 308 had repeated BIA measurements at both ages. BMI-SDS was used for classification of normal weight and overweight children. Sex difference in the amount of lean mass (LM) was already seen at 3 years of age (boys 11.7 kg, girls 11.3 kg; p

Funder: Opetus- ja Kulttuuriministeriö; doi: http://dx.doi.org/10.13039/501100003126, Funder: Sosiaali- ja Terveysministeriö; doi: http://dx.doi.org/10.13039/501100008487, 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.gov

We investigated the associations of motor competence (MC) with peak oxygen uptake (V.O-2peak), peak power output (W-max), and body fat percentage (BF%) and whether measures of cardiorespiratory fitness (CRF) modify the associations between MC and BF%. Altogether, 35 children (aged 7-11 years) in the CHIPASE Study and 297 in PANIC Study (aged 9-11 years) participated in the study. MC was assessed using KTK and modified Eurofit tests. V.O-2peak and W-max were measured by maximal exercise test on a cycle ergometer and scaled by lean mass (LM) or body mass (BM). BF% was assessed either by bioimpedance (CHIPASE) or DXA (PANIC). MC was not associated with V.O-2peak/LM (standardized regression coefficient beta = 0.073-0.188, P > .083). V.O-2peak/BM and W-max/LM and BM were positively associated with MC (beta = 0.158-0.610, P < .05). MC ( = -0.186 to -0.665, P < .01), but not V.O-2peak/LM ( = -0.169-0.035, P > .381), was inversely associated with BF%. Furthermore, the associations of MC with BF% were not modified by CRF. These results suggest that the positive associations between MC and CRF scaled by BM are a function of adiposity and not peak aerobic power and that CRF is not modifying factor in the associations of MC and BF%.

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

Obesity in early childhood is associated with increased risk of chronic diseases, but studies of body composition at preschool ages are sparse. Therefore, we examined differences in body composition by sex and obesity status in Finnish preschool-aged children and within-individual changes in body composition in normal and overweight children.Body composition was measured using segmental multifrequency bioimpedance analysis (BIA) in 476 children and in 781 children at age 3 and 5 years, respectively. Of those, 308 had repeated BIA measurements at both ages. BMI-SDS was used for classification of normal weight and overweight children.Sex difference in the amount of lean mass (LM) was already seen at 3 years of age (boys 11.7 kg, girls 11.3 kg; p 0.001). At 5 years of age, boys had lower fat mass (FM; 3.6 kg vs. 3.9 kg, p 0.001), lower percent fat mass (%FM; 17.2% vs. 19.1%; p 0.001), and higher LM (16.0 kg vs. 15.2 kg; p 0.001) than girls. Overweight children had higher values in FM, %FM, and LM compared with normal weight peers at both ages. Among normal weight children, the increase of LM by age was associated with only minor changes in FM, whereas children who were or became overweight both LM and FM was substantially increased between 3 and 5 years of age.BIA-assessed body composition differs by sex and obesity status already at age of 3 years. For children who are or become overweight at very young age, the patterns for the changes in LM and FM by age are different than for normal weight children.

Purpose Few studies have investigated the independent and joint associations of cardiorespiratory fitness (CRF) and body fat percentage (BF%) with insulin resistance in children. We investigated the independent and combined associations of CRF and BF% with fasting glycemia and insulin resistance and their interactions with physical activity (PA) and sedentary time among 452 children age 6 to 8 yr. Methods We assessed CRF with a maximal cycle ergometer exercise test and used allometrically scaled maximal power output (Wmax) for lean body mass (LM) and body mass (BM) as measures of CRF. The BF% and LM were measured by dual-energy X-ray absorptiometry, fasting glycemia by fasting plasma glucose, and insulin resistance by fasting serum insulin and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). The PA energy expenditure, moderate-to-vigorous PA (MVPA), and sedentary time were assessed by combined movement and heart rate sensor. Results Wmax/LM was not associated with glucose (β = 0.065, 95% confidence interval [CI] = -0.031 to 0.161), insulin (β = -0.079, 95% CI = -0.172 to 0.015), or HOMA-IR (β = -0.065, 95% CI = -0.161 to 0.030). Wmax/BM was inversely associated with insulin (β = -0.289, 95% CI = -0.377 to -0.200) and HOMA-IR (β = -0.269, 95% CI = -0.359 to -0.180). The BF% was directly associated with insulin (β = 0.409, 95% CI = 0.325 to 0.494) and HOMA-IR (β = 0.390, 95% CI = 0.304 to 0.475). Higher Wmax/BM, but not Wmax/LM, was associated with lower insulin and HOMA-IR in children with higher BF%. Children with higher BF% and who had lower levels of MVPA or higher levels of sedentary time had the highest insulin and HOMA-IR. Conclusions Children with higher BF% together with less MVPA or higher levels of sedentary time had the highest insulin and HOMA-IR. Cardiorespiratory fitness appropriately controlled for body size and composition using LM was not related to insulin resistance among children.

SummaryPurpose Exercise testing by cycle ergometer allows to observe the interaction between oxygen uptake (VO2) and workload (W), and VO2/W-slope can be used as a diagnostic tool. Respectively, peak oxygen uptake (VO2PEAK) can be estimated by maximal workload. We aim to determine reference for VO2/W-slope among prepubertal children and define agreement between estimated and measured VO2PEAK. Methods A total of 38 prepubertal children (20 girls) performed a maximal cycle ergometer test with respiratory gas analysis. VO2/W-slopes were computed using linear regression. Agreement analysis by Bland and Altman for estimated and measured VO2PEAK was carried out including limits of agreement (LA). Determinants for VO2/W-slopes and estimation bias were defined. Results VO2/W-slope was in both girls and boys ≥9·4 and did not change with exercise level, but the oxygen cost of exercise was higher among physically more active children. Estimated VO2PEAK had 6·4% coefficient of variation, and LA varied from 13% underestimation to 13% overestimation. Bias had a trend towards underestimation along lean mass proportional VO2PEAK. The primary determinant for estimation bias was VO2/W-slope (β = −0·65; P

Purpose To study the associations of physical activity (PA), sedentary time (ST), and cardiorespiratory fitness (CRF) with heart rate variability (HRV) in children. Methods The participants were a population sample of 377 children aged 6–9 years (49% boys). ST, light PA (LPA), moderate PA (MPA), vigorous PA (VPA), and moderate-to-vigorous PA (MVPA), and PA energy expenditure (PAEE) were assessed using a combined heart rate and movement sensor, maximal power output per kilograms of lean body mass as a measure of CRF by maximal cycle ergometer exercise test, and HRV variables (SDNN, RMSSD, LF, and HF) using 5 min resting electrocardiography. Data were analysed by linear regression adjusted for years from peak height velocity. Results In boys, ST was inversely associated (β = − 0.185 to − 0.146, p ≤ 0.049) and MVPA, VPA, PAEE, and CRF were directly associated (β = 0.147 to 0.320, p ≤ 0.048) with HRV variables. CRF was directly associated with all HRV variables and PAEE was directly associated with RMSSD after mutual adjustment for ST, PAEE, and CRF (β = 0.169 to 0.270, p ≤ 0.046). In girls, ST was inversely associated (β = − 0.382 to − 0.294, p β = 0.144 to 0.348, p ≤ 0.049). After mutual adjustment for ST, PAEE, and CRF, only the inverse associations of ST with HRV variables remained statistically significant. Conclusions Higher ST and lower PA and CRF were associated with poorer cardiac autonomic nervous system function in children. Lower CRF in boys and higher ST in girls were the strongest correlates of poorer cardiac autonomic function.

Purpose: To investigate the associations of directly measured peak oxygen uptake (V˙O2peak) and body fat percentage (BF%) with arterial stiffness and arterial dilatation capacity in children. Metho...

Purpose: The purpose of this study was to investigate the longitudinal associations of cardiorespiratory fitness (CRF), motor competence (MC), and body fat percentage (BF%) with cognition in children. Methods: Altogether, 371 children (188 boys and 183 girls) 6–9 yr of age at baseline participated in this 2-yr follow-up study. We assessed CRF by maximal cycle ergometer test, computed the MC score from the z-scores of the 50-m shuttle run, static balance, and box and block test results, measured BF% by dual-energy x-ray absorptiometry, and assessed cognition using the Raven’s Coloured Progressive Matrices (RCPM) score. The associations were studied by linear regression analysis and repeated-measures ANCOVA. Results: In boys, a higher MC score (β = −0.161, 95% confidence interval [CI] = −0.314 to −0.009), a shorter 50-m shuttle run test duration (β = 0.152, 95% CI = 0.007–0.296), and a higher number of cubes moved in the Box and block test (β = −0.161, 95% CI = −0.309 to −0.013) at baseline were associated with a smaller increase in the RCPM score during follow-up. These associations were largely explained by the RCPM score at baseline. However, boys in the highest third (mean difference = 2.5, 95% CI for difference = 0.66–4.33) and the middle third (mean difference = 2.1, 95% CI for difference = 0.39–3.82) of the MC score at baseline had a higher RCPM score over the 2-yr follow-up than boys in the lowest third. CRF, MC, or adiposity was not associated with the RCPM score in girls. Changes in CRF, MC, or BF% were not associated with changes in cognition. Conclusions: Higher MC at baseline predicted better cognition during the first two school years in boys but not in girls. CRF or adiposity was not associated with cognition in boys or girls. peerReviewed

Background:There are few studies on determinants of cardiorespiratory fitness (CRF) among girls and boys separately in population samples of children.Methods:We therefore investigated the determinants of CRF, assessed by maximal workload per height using allometric scaling, in a population sample of 162 girls and 177 boys aged 6 to 8 years. We used automated bootstrap feature selection and linear regression models.Results:The strongest determinants of CRF among girls were maximal heart rate (HR; standardized regression coefficient [β] = 0.31, P < .001), unsupervised physical activity (β = 0.29, P < .001), lean body mass (β = 0.23, P = .001), and errors in static balance test (β = –0.16, P = .02), accounting altogether for 25.7% of variation in CRF. In boys, unsupervised physical activity (β = 0.24, P < .001), resting HR (β = –0.25, P < .001), hand grip strength (β = 0.21, P = .001), errors in static balance test (β = –0.16, P = .01), organized football (β = 0.16, P = .01), and unsupervised trampoline jumping (β = 0.14, P = .04) were the strongest determinants of CRF, accounting altogether for 29.7% of variation in CRF.Conclusions:These findings suggest that unsupervised physical activity is sufficient in improving CRF in both sexes. Furthermore, larger muscle mass and better balance are associated with higher CRF that has to be taken into account when assessing CRF using maximal cycle ergometer exercise test among 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 a comparison of parameters from maximal cycle ergometer exercise tests that 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), 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%; coefficients of variation, 3.3%) and highest SBP (proportional offset, 3%; coefficients of variation, 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 a 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 a maximal exercise test.

We aimed to develop cut -points for directly measured peak oxygen uptake (VO2peak ) to identify boys and girls at increased cardiometabolic risk using different scaling methods to control for body size and composition. Altogether 352 children (186 boys, 166 girls) aged 9 – 11 years were included in the analyses. We measured VO2peak directly during a maximal cycle ergometer exercise test and lean body mass (LM) by bioelectrical impedance. We computed a sex - and age -specific cardiometabolic risk score (CRS) by summing important cardiometabolic risk factors and defined increased cardiometabolic risk as >1 standard deviation above the mean of CRS. Receiver operating characteristics curves were used to detect O2peak cut -points for increased cardiometabolic risk. Boys with VO2peak

Associations of cardiorespiratory fitness (CRF), physical activity (PA), sedentary behavior, and body fat percentage (BF%) with arterial stiffness and dilation capacity were investigated in 160 prepubertal children (83 girls) 6-8 years of age. We assessed CRF (watts/lean mass) by maximal cycle ergometer exercise test, total PA, structured exercise, unstructured PA, commuting to and from school, recess PA and total and screen-based sedentary behavior by questionnaire, BF% using dual-energy X-ray absorptiometry, and arterial stiffness and dilation capacity using pulse contour analysis. Data were adjusted for sex and age. Poorer CRF (standardized regression coefficient β = -0.297, P

Adrenarche refers to the onset of increased production of adrenal androgens in childhood leading variably to clinical signs of androgen action. The prevalence and presentation of adrenarche in prepubertal girls and boys is not well known.Our objective was to examine the prevalence and clinical presentation of adrenarche in a population sample of prepubertal children aged less than 9 years.This cross-sectional study included prepubertal children (209 girls and 228 boys; median age 7.6 [range 6.8-8.9] years) taking part in The Physical Activity and Nutrition in Children (PANIC) Study.The prevalence of adrenarche was assessed.The prevalence of any clinical sign of androgen action was higher in girls than in boys (26.1% vs 10.0%; P.001) and biochemical adrenarche without any clinical sign was less common in girls than in boys (8.1% vs 16.7%; P = .007). When premature adrenarche was defined by serum dehydroepiandrosterone sulfate concentration ≥1 μmol/L (≥37 μg/dL) and any clinical sign before the age of 8 years in girls and 9 years in boys, its total prevalence was 8.6% in girls and 1.8% in boys. The risk of having any clinical sign increased with higher body fat percentage in boys and with higher serum dehydroepiandrosterone sulfate concentration in girls.Clinical signs of androgen action are more common, but biochemical adrenarche without any clinical sign is less common in prepubertal girls than boys. This sexual dimorphism of adrenarche might be explained by sex-dependent differences in peripheral androgen metabolism or action that are modified by body fat.

We validated the metabolic syndrome (MetS) score by confirmatory factor analysis (CFA) in children, middle-aged men, and older women and men and by investigating the relationships of the MetS score to incident type 2 diabetes, myocardial infarction, and cardiovascular and overall death in middle-aged men.We assessed the core features of MetS, calculated the MetS score using z scores for waist circumference, insulin, glucose, triacylglycerols, HDL-cholesterol and blood pressure, and carried out CFA to investigate whether MetS represents a single entity in population samples of 491 children, 1,900 middle-aged men, 614 older women and 555 older men from Finland. We also followed-up incident type 2 diabetes for 11 years and other outcomes for 17-18 years in middle-aged men.We carried out second-order CFAs in which the MetS was represented by a second-order latent variable underlying four latent variables characterised by abdominal obesity, insulin resistance, dyslipidaemia and raised blood pressure in different age groups. These second-order factors and factors derived from first-order CFA using previously proposed models were strongly associated with a composite MetS score in all age groups (r = 0.84-0.94) and similarly predicted type 2 diabetes, cardiovascular outcomes and mortality in middle-aged men. The risk of type 2 diabetes, myocardial infarction, cardiovascular death and overall death increased 3.67-, 1.38-, 1.56- and 1.44-fold, respectively, for a 1 SD increase in the MetS score.The MetS can be described as a single entity in all age groups. The MetS score is a valid tool for research evaluating cardiometabolic risk in different age groups. Further research is needed to define cut-off points for risk estimation in clinical practice.

Summary Objective and methods We compared InBody720 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 >0·92 in total body and >0·74 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 3·9/1·6% [(−)1·4–9·2%/(−)3·4–6·7%]. Interestingly percentage offsets of fat content (%BF: 18·9/10·1%, FM: 18·8/11·1%) 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: 4·3/0·1%, referring offset (LA) of 0·88/0·03 kg (±2·05/±1·71 kg). Correspondingly, segmental LM had poorer agreement than total body LM. All anthropometrics except for the waist-to-hip ratio showed strong correlations (r = 0·76–0·95) 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.

Background Measurement of heart rate variability (HRV) is a useful method for examining cardiac autonomic control. HRV has been measured in many studies among adults, but research on this topic among children is limited. We therefore defined reference values for a large number of HRV parameters among children. Methods The subjects were a population sample of 465 mainly prepubertal children 6–8 years of age. Electrocardiogram (ECG) was recorded at rest, and 1- and 5min ECG samples were selected for HRV analyses. HRV data were analysed in boys and girls separately to study possible gender differences in HRV parameters. Pearson’s coefficients for correlation of age, maturity stage, height, weight and body mass index – standard deviation score (BMI-SDS) with HRV parameters were computed to study whether these factors confounded the definition of the reference values for HRV parameters. Results We found no statistically significant differences in HRV parameters between genders. Therefore, we defined the reference values for all HRV parameters as 5th, 25th, 50th, 75th and 95th percentiles from the ECG samples in all children, but not in boys and girls separately. Age, maturity stage, height, weight and BMISDS had weak, if any, associations with HRV parameters, suggesting that they did not confound the definition of the reference values. Conclusion Same reference values for HRV parameters can be used in boys and girls. Although 5-min ECG recordings are preferable for measuring HRV, also 1-min recordings provide reliable data on most HRV parameters, especially those that mainly describe cardiac parasympathetic regulation.

We investigated the associations of body fat percentage, objectively assessed moderate-to-vigorous physical activity (MVPA), and different types of physical activity assessed by a questionnaire with neuromuscular performance. The participants were 404 children aged 6–8 years. Body fat percentage (BF%) was assessed using dual-energy x-ray absorptiometry and physical activity by combined heart rate and movement sensing and a questionnaire. The results of 50-metre shuttle run, 15-metre sprint run, hand grip strength, standing long jump, sit-up, modified flamingo balance, box and block, and sit-and-reach tests were used as measures of neuromuscular performance. Children who had a combination of higher BF% and lower levels of physical activity had the poorest performance in 50-metre shuttle run, 15-metre sprint run, and standing long jump tests. Higher BF% was associated with slower 50-metre shuttle run and 15-metre sprint times, shorter distance jumped in standing long jump test, fewer sit-ups, more errors in balance test, and less cubes moved in box and block test. Higher levels of physical activity and particularly MVPA assessed objectively by combined accelerometer and heart rate monitor were related to shorter 50-metre shuttle run and 15-metre sprint times. In conclusion, higher BF% and lower levels of physical activity and particularly the combination of these two factors were associated with worse neuromuscular performance.

We studied the associations of clustering of metabolic risk factors with plasma levels of alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) in healthy prepubertal children.The subjects were a representative population sample of 492 children 6-8 years of age. We assessed body fat percentage (dual-energy X-ray absorptiometry), body mass index, waist circumference, systolic and diastolic blood pressure, glucose, insulin, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides, ALT, GGT, and high-sensitivity C-reactive protein (hsCRP) and calculated a continuous metabolic syndrome score variable. We also used factor analysis to examine whether high-normal liver enzymes are a feature of metabolic syndrome among children.Children with overweight or obesity, defined by International Obesity Task Force (IOTF) criteria, had a 2.1-times higher risk of having ALT and a 4.5-times higher risk of having GGT in the highest fifth of its distribution than normal weight children. Children in the highest sex-specific third of metabolic syndrome score, body fat percentage, waist circumference, and insulin had a two to three times higher risk of being in the highest fifth of ALT and GGT. Moreover, children in the highest third of glucose and hsCRP had a 2.5-fold risk of being in the highest fifth of GGT. First-order factor analysis yielded three factors; the first included insulin, glucose, and triglycerides; the second waist circumference, insulin, GGT, and hsCRP; and the third HDL-C, triglycerides, waist circumference, and insulin. Second-order factor analysis yielded a single metabolic syndrome factor, explaining 64.1% of the variance.Clustering of metabolic risk factors, particularly excess body fat, is associated with high-normal levels of ALT and GGT in prepubertal children. High-normal levels of liver enzymes, especially GGT, and systemic low-grade inflammation could be considered features of metabolic syndrome among children. Subtle changes in liver function may play an important role in the pathogenesis of metabolic syndrome beginning in childhood.

We investigated the associations of dental occlusion, other craniofacial features and body fat with paediatric sleep-disordered breathing (SDB) in a representative population sample of 491 Finnish children 6–8 years of age. Overweight and obesity were defined using age- and sex-specific body mass index cutoffs by International Obesity Task Force (IOTF) criteria. Body fat percentage was assessed by dual-energy X-ray absorptiometry. Facial proportions, dental occlusion and soft tissue structures were evaluated by an orthodontist. Sleep was assessed by a sleep questionnaire administered by the parents. SDB was defined as apnoeas, frequent or loud snoring or nocturnal mouth breathing observed by the parents. The prevalence of SDB was 9.9 % with no difference between boys and girls. The median (interquartile range) of body fat percentage was 20.6 (17.4–27.1) in girls and 15.0 (11.4–21.6) in boys. Altogether 11.4 % of boys and 15.6 % of girls were classified as having overweight or obesity according to the IOTF criteria. There was no difference in the prevalence of overweight, obesity or body fat percentage between children with SDB and those without it. Children with tonsillar hypertrophy had a 3.7 times higher risk of suffering SDB than those with normal size tonsils after adjustment for age, sex and body fat percentage. Furthermore, children with cross bite had a 3.3 times higher risk of having SDB than those without cross bite, and children with a convex facial profile had a 2.6 times higher risk of having SDB than those with a normal facial profile. Conclusion: Abnormal craniofacial morphology, but not excess body fat, is associated with an increased risk of having SDB in 6–8-year-old children. A simple model of necessary clinical examinations (i.e. facial profile, dental occlusion and tonsils) is recommended to recognize children with an increased risk of SDB.

SummaryBackground In the exercise testing measures of cardiorespiratory fitness need to be scaled by body size or composition to enable comparison between individuals. Traditionally used weight-proportional measures are potentially confounded by body adiposity that hampers their interpretation and applicability in the clinical assessment of cardiorespiratory fitness. Objective We aimed to find the most appropriate measure of body size or composition for scaling of measures of cardiorespiratory fitness among children. Methods We assessed body weight and height, maximal workload (WMAX) and maximal oxygen uptake (VO2MAX) using cycle ergometer exercise test with respiratory gas analysis and body lean mass (LM) and fat mass (FM) by dual-energy X-ray absorptiometry and by bioimpedance analysis among 38 children. The data were analysed using Pearson's coefficients for correlation and stepwise linear regression models. Results Lean mass (r > 0·54) and height (r > 0·51) had stronger positive correlations with absolute WMAX and VO2MAX than weight (r > 0·30) in girls and boys. None of the measures of body size or composition correlated with LM-proportional WMAX or VO2MAX in girls or boys. Only LM correlated positively with height-proportional WMAX (r = 0·65) and VO2MAX (r = 0·71) in boys. FM correlated negatively with weight-proportional WMAX (r

We investigated cardiovascular fitness and haemodynamic responses to maximal cycle ergometer exercise test in children. The participants were a population sample of 425 children (204 girls, 221 boys) aged 6-8 years. Heart rate (HR) and systolic blood pressure (SBP) were measured from the beginning of pre-exercise rest to the end of recovery period. We provided reference values for peak workload and changes in HR and SBP during and after maximal exercise test in girls and boys. Girls had a lower cardiovascular fitness, indicated by peak workload per body weight [mean (2 s) 2.7 (0.9) vs. 3.1 (1.0) W · kg(-1), P0.001] and lean mass [mean (2 s) 3.5 (0.9) vs. 3.8 (1.0) W · kg(-1), P0.001] than boys. Plateau or decline in SBP close to the end of the test was found in about third of children and was considered a normal SBP response. Girls had a slower HR decrease within 2 min after the test than boys [mean (2 s) 53 (18) vs. 59 (22) beats · min(-1), P0.001]. The results are useful for physicians and exercise physiologists to evaluate cardiovascular fitness and haemodynamic responses to exercise in children and to detect children with low exercise tolerance or abnormal haemodynamic responses to exercise.

To investigate the associations of dietary factors with overweight, body fat percentage (BF%), waist circumference (WC) and hip circumference (HC) among children.Cross-sectional analysis of the Physical Activity and Nutrition in Children (PANIC) Study among 510 children (263 boys, 247 girls) aged 6-8 years from Kuopio, Finland.The children's weight, height, WC and HC were measured. Overweight was defined by International Obesity Task Force body mass index cutoffs. The BF% was measured by dual-energy X-ray absorptiometry, nutrient intakes and meal frequency by 4-day food records and eating behaviour by Children's Eating Behaviour Questionnaire.Daily consumption of all the three main meals was inversely associated with overweight (odds ratio (OR) 0.37, 95% confidence interval (CI) 0.18-0.75), BF% (β -0.12, P = 0.012), WC (β -0.16, P = 0.002) and HC (β -0.15, P = 0.002). Enjoyment of food, food responsiveness and emotional overeating were directly associated with overweight (OR 1.57, 95% CI 1.04-2.35; OR 4.68, 95% CI 2.90-7.54; OR 2.60, 95% CI 1.52-4.45, respectively), BF% (β 0.13, P = 0.004; β 0.30, P0.001; β 0.09, P = 0.035, respectively), WC (β 0.14, P = 0.003; β 0.40, P0.001; β 0.19, P0.001, respectively) and HC (β 0.15, P = 0.001; β 0.38, P0.001; β 0.15, P = 0.001, respectively). Satiety responsiveness was inversely associated with overweight (OR 0.42, 95% CI 0.26-0.67), BF% (β -0.20, P0.001), WC (β -0.26, P0.001) and HC (β -0.26, P0.001). Slowness in eating was inversely associated with overweight (OR 0.61, 95% CI 0.41-0.92), WC (β -0.16, P = 0.001) and HC (β -0.17, P0.001). Protein intake was directly associated with BF% (β 0.11, P = 0.017), WC (β 0.11, P = 0.020) and HC (β 0.13, P = 0.008).Promoting regular consumption of main meals and healthy eating behaviours should be emphasized in the prevention of overweight among children. More research is needed on the association of protein-rich foods with body adiposity in children.

Arterial stiffness index (SI) and reflection index (RI) from digital pulse contour analysis have been shown to be good measures of arterial stiffness and may be useful in the evaluation of endothelial function. Finger skin temperature (FST) is also considered to reflect peripheral circulatory functions. We evaluated the reproducibility of SI, RI and FST before and after the exercise stress test. The subjects were 36 children (16 boys, 20 girls) 6-8 years of age. We measured SI, RI and FST at rest both before and after the exercise stress test on a cycle ergometer and repeated these measurements within 5-14 days. The reproducibility of SI, RI and FST was evaluated by calculating intraclass correlation coefficients (ICC), coefficients of variation (CV%) and 95% limits of agreements. SI had a greater reproducibility after the exercise stress test than before it (CV% 4·8 versus 6·3%, ICC 0·548 versus 0·438). RI had a better ICC (0·689 versus 0·416) but a higher CV% (28·6 versus 18·7%) after the exercise stress test than before it. Relative change in response to the exercise stress test in SI (-1·5% at first visit and 0·4% at second visit) was not as dramatic as in RI (-49·3% at first visit and -46·5% at second visit). The reproducibility of FST was also better after the exercise test than before it (CV% 5·7 versus 10·0%, ICC 0·509 versus 0·503). In healthy children, the reproducibility of SI, RI and FST was relatively good, especially after the exercise stress test.

Summary Objective: Arterial stiffness index (SI) and reflection index (RI) from digital pulse contour analysis have been shown to be good measures of arterial stiffness and may be useful in the evaluation of endothelial function. Finger skin temperature (FST) is also considered to reflect peripheral circulatory functions. We evaluated the reproducibility of SI, RI and FST before and after the exercise stress test. Methods: The subjects were 36 children (16 boys, 20 girls) 6–8 years of age. We measured SI, RI and FST at rest both before and after the exercise stress test on a cycle ergometer and repeated these measurements within 5–14 days. The reproducibility of SI, RI and FST was evaluated by calculating intraclass correlation coefficients (ICC), coefficients of variation (CV%) and 95% limits of agreements. Results: SI had a greater reproducibility after the exercise stress test than before it (CV% 4·8 versus 6·3%, ICC 0·548 versus 0·438). RI had a better ICC (0·689 versus 0·416) but a higher CV% (28·6 versus 18·7%) after the exercise stress test than before it. Relative change in response to the exercise stress test in SI (−1·5% at first visit and 0·4% at second visit) was not as dramatic as in RI (−49·3% at first visit and −46·5% at second visit). The reproducibility of FST was also better after the exercise test than before it (CV% 5·7 versus 10·0%, ICC 0·509 versus 0·503). Conclusion: In healthy children, the reproducibility of SI, RI and FST was relatively good, especially after the exercise stress test.

Background 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. Methods 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. Results 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. Conclusions 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. Trial Registration ClinicalTrials.gov: NCT01803776

Background Lower levels of physical activity (PA) and sedentary behaviour (SB) have been associated with increased cardiometabolic risk among children. However, little is known about the independent and combined associations of PA and SB as well as different types of these behaviours with cardiometabolic risk in children. We therefore investigated these relationships among children. Methods The subjects were a population sample of 468 children 6–8 years of age. PA and SB were assessed by a questionnaire administered by parents and validated by a monitor combining heart rate and accelerometry measurements. We assessed body fat percentage, waist circumference, blood glucose, serum insulin, plasma lipids and lipoproteins and blood pressure and calculated a cardiometabolic risk score using population-specific Z-scores and a formula waist circumference + insulin + glucose + triglycerides - HDL cholesterol + mean of systolic and diastolic blood pressure. We analysed data using multivariate linear regression models. Results Total PA was inversely associated with the cardiometabolic risk score (β = -0.135, p = 0.004), body fat percentage (β = -0.155, p Conclusions The results of our study emphasise increasing total and unstructured PA and decreasing watching TV and videos and other sedentary behaviours to reduce cardiometabolic risk among children. Trial registration ClinicalTrials.gov Identifier: NCT01803776.

HAAPALA, E. A., A.-M. POIKKEUS, T. TOMPURI, K. KUKKONEN-HARJULA, P. H. T. LEPPANEN, V. LINDI, and T. A. LAKKA. Associations of Motor and Cardiovascular Performance with Academic Skills in Children. Med. Sci. Sports Exerc. ,V ol. 46, No. 5, pp. 1016-1024, 2014. Purpose: We investigated the associations of cardiovascular and motor performance in grade 1 with academic skills in grades 1-3. Methods: The participants were 6- to 8-yr-old children with complete data in grades 1-2 for 174 children and in grade 3 for 167 children. Maximal workload during exercise test was used as a measure of cardiovascular performance. The shuttle run test (SRT) time, the errors in balance test, and the number of cubes moved in box and block test (BBT) were measures of motor performance. Academic skills were assessed using reading fluency, reading comprehension, and arithmetic skill tests. Results: Among boys, longer SRT time was associated with poorer reading fluency in grades 1-3 (A = j0.29 to j0.39, P G 0.01), reading comprehension in grades 1-2 (A = j0.25 to j0.29, P G 0.05), and arithmetic skills in grades 1-3 (A = j0.33 to j0.40, P G 0.003). Poorer balance was related to poorer read- ing comprehension (A = j0.20, P = 0.042). The smaller number of cubes moved in BBT was related to poorer reading fluency in grades 1-2 (A = 0.23-0.28, P G 0.03), reading comprehension in grade 3 (A =0 .23,P = 0.037), and arithmetic skills in grades 1-2 (A = 0.21-0.23, P G 0.043). Among girls, longer SRT time was related to poorer reading fluency in grade 3 (A = j0.27, P = 0.027) and arithmetic skills in grade 2 (A = j0.25, P = 0.040). The smaller number of cubes moved in BBT was associated with worse reading fluency in grade 2 (A =0 .26, P = 0.030). Cardiovascular performance was not related to academic skills. Conclusions: Poorer motor performance was associated with worse academic skills in children, especially among boys. These findings emphasize early identification of children with poor motor perfor