Cross-sectional and longitudinal associations between the 24-hour movement behaviours, including muscle and bone strengthening activity, with bone and lean mass from childhood to adolescence.

BACKGROUND: This study aimed to assess whether moderate-to-vigorous physical activity (MVPA), sport and exercise as a proxy measure of muscle and bone strengthening activity, sedentary behaviour, and sleep were associated with total-body-less-head (TBLH) bone mineral content (BMC) and TBLH lean mass cross-sectionally and longitudinally from age 6 to 9 years and age 9 to 11 years to age 15 to 17 years. METHODS: We used longitudinal data from a population sample of Finnish children from the Physical Activity and Nutrition in Children study (age 6 to 9 years: n = 478, 229 females; age 9 to 11 years: n = 384, 197 females; age 15 to 17 years: n = 222, 103 females). Linear regression analysed the cross-sectional and longitudinal associations between accelerometer-assessed MVPA, sedentary time and sleep, and questionnaire-assessed sport and exercise participation and screen time with dual-energy X-ray absorptiometry-assessed TBLH BMC and lean mass. RESULTS: In females, MVPA at age 6 to 9 years was positively associated with TBLH BMC at age 15 to 17 years (ß = 0.008, p = 0.010). Sport and exercise at age 9 to 11 years was positively associated with TBLH BMC (ß = 0.020, p = 0.002) and lean mass (ß = 0.343, p = 0.040) at age 15 to 17 years. MVPA at age 9 to 11 years was positively associated with TBLH lean mass (ß = 0.272, p = 0.004) at age 15 to 17 years. In males, sleep at age 6 to 9 years was positively associated with TBLH lean mass (ß = 0.382, p = 0.003) at age 15 to 17 years. Sport and exercise at age 9 to 11 years was positively associated with TBLH BMC (ß = 0.027, p = 0.012) and lean mass (ß = 0.721, p < 0.001) at age 15 to 17 years. CONCLUSIONS: Promoting engagement in the 24-hour movement behaviours in childhood, particularly sport and exercise to strengthen muscle and bone, is important in supporting bone and lean mass development in adolescence. TRIAL REGISTRATION: NCT01803776; first trial registration date: 04/03/2013.

Physical activity volume and intensity distribution in relation to bone, lean and fat mass in children.

Considering physical activity (PA) volume and intensity may provide novel insights into the relationships of PA with bone, lean, and fat mass. This study aimed to assess the associations of PA volume, PA intensity distribution, including moderate-to-vigorous PA (MVPA) with total-body-less-head bone mineral content (BMC), lean, and fat mass in children. A population sample of 290 Finnish children (158 females) aged 9-11 years from the Physical Activity and Nutrition in Children (PANIC) Study was studied. PA, including MVPA, was assessed with a combined heart rate and movement sensor, and the uniaxial acceleration was used to calculate average-acceleration (a proxy metric for PA volume) and intensity-gradient (reflective of PA intensity distribution). Linear regression analyzed the associations of PA volume, PA intensity and MVPA with BMC, lean mass, and fat mass assessed by dual-energy X-ray absorptiometry. PA volume was positively associated with BMC in females (unstandardised regression coefficient [ß] = 0.26) and males (ß = 0.47), and positively associated with lean (ß = 7.33) and negatively associated with fat mass in males (ß = -20.62). PA intensity was negatively associated with BMC in males (ß = -0.13). MVPA was positively associated with lean mass in females and males (ß = 0.007 to 0.012), and negatively associated with fat mass in females and males (ß = -0.030 to -0.029). PA volume may be important for improving BMC in females and males, and increasing lean and reducing fat mass in males, whereas MVPA may be important for favorable lean and fat outcomes in both sexes.

Prevalence of Erosive Tooth Wear and Associated Dietary Factors among a Group of Finnish Adolescents.

The aim of this study was to investigate the prevalence and severity of erosive tooth wear (ETW) among Finnish adolescents and to evaluate how frequency as well as amount of the use of erosive products is associated with ETW. The study population consisted of 328 voluntary, >15-year-old secondary school students (males 49.1%, females 50.9%) in three municipalities in Finland. Clinical examination to measure ETW (BEWE index) was carried out by trained and calibrated dentists. Piloted questionnaires included questions on consumption of drinks, fruits and berries, as well as tooth brushing frequency. Means and medians of frequencies and amounts of consumed erosive products were calculated and associations with ETW severity were analysed by logistic regression models. One-third (36.9%) of the participants were in need of at least preventive measures for ETW (BEWE sum score ≥3), but severe ETW (BEWE sum score >9) was rare (2.1%). Boys had severe ETW significantly more frequently than girls (p < 0.001). Habitual consumption of erosive drinks was common especially among boys compared to girls (p = 0.001). ETW was significantly associated with the amount of consumed erosive drinks, fruits, or berries. The prevalence of ETW among adolescences in Finland seems to be at the same level as in other Nordic and European countries. Consumption of erosive products is common and thus, the risk for tooth erosion is high, especially in boys. In addition to erosive drinks, also berries and fruits are associated with ETW and should be included in individual dietary counselling when early signs of ETW are clinically detected.

Associations of diet quality, food consumption, eating frequency and eating behaviour with dental caries experience in Finnish children: a 2-year longitudinal study.

We examined cross-sectional and longitudinal associations of dietary factors with caries experience in a population sample of 487 children aged 6-9 years at baseline examinations of the Physical Activity and Nutrition in Children (PANIC) Study. Altogether, 406 of these children attended 2-year follow-up examinations. Food consumption and eating frequency were assessed using 4-day food records, diet quality using the Baltic Sea Diet Score (BSDS) and eating behaviour using the Children's Eating Behavior Questionnaire. Caries experience was examined clinically. The cross-sectional associations of dietary factors with caries experience at baseline were analysed using linear regression and the longitudinal associations of dietary factors with a change in caries experience over follow-up using generalised mixed-effects regression adjusted for other risk factors. A higher consumption of high-fibre grain products (standardised regression coefficient ß = -0·16, P = 0·003) and milk (ß = -0·11, P = 0·025) and higher BSDS (ß = -0·15, P = 0·007) were associated with lower caries experience, whereas a higher consumption of potatoes (ß = 0·11, P = 0·048) and emotional overeating (ß = 0·12, P = 0·025) were associated with higher caries experience. Higher snacking frequency (fixed coefficient ß = 0·07, P = 0·033), desire to drink (ß = 0·10, P = 0·046), slowness in eating (ß = 0·12, P = 0·027) and food fussiness (ß = 0·12, P = 0·018) were associated with higher caries experience, whereas enjoyment of food (ß = -0·12, P = 0·034) and higher BSDS (ß = -0·02, P = 0·051) were associated with lower caries experience.

The effects of an 8-year individualised lifestyle intervention on food consumption and nutrient intake from childhood to adolescence: the PANIC Study.

We aimed to investigate the effects of a long-term, individualised, family-based lifestyle intervention on food consumption and nutrient intake from childhood to adolescence. We conducted an 8-year diet and physical activity intervention study in a population sample of children aged 7-9 years at baseline in 2007-2009. We allocated the participants to the intervention group (n 306) and the control group (n 198). We assessed diet by 4-d food records at baseline, 2-year follow-up and 8-year follow-up. We analysed the data using linear mixed-effects models adjusted for age at baseline and sex. The consumption of vegetables and vegetable oil-based spreads (fat ≥60 %) increased in the intervention group but did not change in the control group (P < 0⋅001 for time×group interaction). The consumption of fruits and berries increased in the intervention group but decreased in the control group (P = 0⋅036). The consumption of high-fat cheese (P = 0⋅029), butter-based spreads (P = 0⋅001) and salty snacks (P = 0⋅028) increased less, and the consumption of low-fat cheese (P = 0⋅004) increased more in the intervention group than in the control group. Saturated fat intake (P = 0⋅001) increased less, and the intakes of dietary fibre (P = 0⋅003), vitamin D (P = 0⋅042) and vitamin E (P = 0⋅027) increased more in the intervention group than in the control group. The intakes of vitamin C (P < 0⋅001) and folate (P = 0⋅001) increased in the intervention group but decreased in the control group. To conclude, individualised, family-based lifestyle intervention altered food choices towards more recommended diet and resulted in enhanced diet quality from childhood to adolescence.

The Mediating Role of Endocrine Factors in the Positive Relationship Between Fat Mass and Bone Mineral Content in Children Aged 9-11 Years: The Physical Activity and Nutrition in Children Study.

Introduction: We aimed to investigate whether the relationship between fat mass and bone mineral content (BMC) is mediated by insulin, leptin, adiponectin, dehydroepiandrosterone sulphate, testosterone and estradiol in children aged 9-11 years. Materials and Methods: We utilised cross-sectional data from the Physical Activity and Nutrition in Children study (n = 230 to 396; 112 to 203 girls). Fat mass and BMC were assessed with dual-energy X-ray absorptiometry. Endocrine factors were assessed from fasted blood samples. We applied the novel 4-way decomposition method to analyse associations between fat mass, endocrine factors, and BMC. Results: Fat mass was positively associated with BMC in girls (ß = 0.007 to 0.015, 95% confidence interval (CI) 0.005 to 0.020) and boys (ß = 0.009 to 0.015, 95% CI 0.005 to 0.019). The relationship between fat mass and BMC was mediated by free leptin index in girls (ß = -0.025, 95% CI -0.039 to -0.010) and boys (ß = -0.014, 95% CI -0.027 to -0.001). The relationship between fat mass and BMC was partially explained by mediated interaction between fat mass and free leptin index in boys (ß = -0.009, 95% CI -0.013 to -0.004) and by interaction between fat mass and adiponectin in girls (ß = -0.003, 95% CI -0.006 to -0.000). Conclusion: At greater levels of adiponectin and free leptin index, the fat mass and BMC relationship becomes less positive in girls and boys respectively. The positive association between fat mass with BMC was largely not explained by the endocrine factors we assessed. Clinical Trial Registration: [https://clinicaltrials.gov/ct2/show/NCT01803776], identifier NCT01803776.

Associations of physical activity, sedentary time, and diet quality with biomarkers of inflammation in children.

We investigated the associations of physical activity (PA), sedentary time (ST), and diet quality with biomarkers of inflammation in 390 children (192 girls, 198 boys) aged 6-8 years. PA energy expenditure (PAEE), light PA, moderate PA (MPA), vigorous PA (VPA), moderate-to-vigorous PA (MVPA), and ST were assessed by combined movement and heart rate sensor. Finnish Children Healthy Eating Index was calculated using data from 4 d food records. Body fat percentage (BF%) was measured by dual-energy X-ray absorptiometry. High-sensitivity C-reactive protein (Hs-CRP), leptin, interleukin-6 (IL-6), adiponectin, tumour necrosis factor-α, and glycoprotein acetyls were measured from fasting blood samples. PAEE, MPA, VPA, and MVPA were inversely associated with hs-CRP (ß=-191 to -139, 95% CI=-0.294 to -0.024), leptin (ß=-0.409 to -0.301, 95% CI=-0.499 to -0.107), IL-6 (ß=-0.136 to -0.104, 95% CI=-0.240 to -0.001) and PAEE, MPA, and MVPA were inversely associated with glycoprotein acetyls (ß=-0.117 to -0.103, 95% CI=-0.213 to -0.001). ST was directly associated with hs-CRP (ß=0.170, 95% CI=0.070-0.269), leptin (ß=0.355, 95% CI=0.265-0.445), and IL-6 (ß=0.105, 95% CI=0.005-0.205). VPA was inversely associated with hs-CRP, leptin, and IL-6 in children with higher BF% (ß=-0.344 to -0.181, 95% CI=-0.477 to -0.033) but not among children with lower BF% (ß=-0.007-0.033, 95% CI=-0.183-0.184). In conclusion, PA was inversely and ST directly associated with circulating levels of biomarkers of inflammation among children. Furthermore, we observed that PA was inversely associated with these biomarkers for inflammation in children with a higher BF%. HighlightsSystemic inflammation, as indicated by increased circulating concentrations of biomarkers for inflammation, may be important in causal pathways leading to insulin resistance, sub-clinical atherosclerosis, and eventually clinical manifestations of cardiovascular diseases.Higher levels of physical activity and lower levels of sedentary time were associated with more favourable inflammatory profile.Body fat percentage modified these associations and especially vigorous intensity physical activity was inversely associated with biomarkers of inflammation on children with higher body fat percentage but not in children with lower body fat percentage.

Longitudinal and cross-sectional associations of adherence to 24-hour movement guidelines with cardiometabolic risk.

This study aimed to examine (1) adherence to 24 h movement guidelines over a 2 years follow-up in children aged 6-8 years and (2) association of this adherence with cardiometabolic risk factors. Physical activity and sleep were assessed by a monitor combining heart rate and accelerometry measurements. Screen time was reported by the parents. Body fat percentage, waist circumference, blood glucose, serum insulin, plasma lipids, and blood pressure were assessed, and a cardiometabolic risk score was calculated using z-scores. Children were classified as meeting the guidelines if they had on average ≥60 min/day of moderate-to-vigorous physical activity during the valid days; ≤120 min/day of screen time; and 9-11 h/day of sleep. In total, 485 children had valid data at baseline or at 2 years follow-up. Analyses were conducted using adjusted logistic and linear regression models. Most children adhered to the 24 h movement guidelines at baseline, but the adherence decreased over the 2 years follow-up. Meeting physical activity guidelines individually, or in combination with screen time and/or sleep, was longitudinally associated with a lower cardiometabolic risk score, insulin and waist circumference, and cross-sectionally additionally with lower diastolic blood pressure and higher high-density lipoprotein cholesterol. However, these associations became statistically non-significant after adjustment for body fat. In conclusion, meeting 24 h movement guidelines at baseline increases the odds of meeting them at 2 years follow-up in school-aged children. Furthermore, meeting 24 h movement guidelines is associated with lower levels of cardiometabolic risk factors, but these associations are partly explained by lower body fat. Thus, promoting movement behaviors, especially physical activity, and healthy weight in early childhood is important in supporting cardiometabolic health in children.

Dental caries among Finnish teenagers participating in physical activity and diet intervention: association with anthropometrics and behavioural factors.

BACKGROUND: An association between childhood anthropometric measurements and dental caries is conflicting. The prevalence and severity of dental caries and its association with anthropometric and behavioural factors, were investigated among Finnish teenagers. METHODS: The study sample comprised 202 15-17-year-old participants in the Physical Activity and Nutrition in Children (PANIC) Study. Dental caries findings were recorded using International Caries Detection and Assessment System (ICDAS) criteria, including activity estimation; numbers of decayed teeth (DT) and decayed, missing and filled teeth (DMFT) were recorded. Body weight, height and waist circumference were measured and respective body mass index (BMI) was calculated. Body fat percentage was assessed by dual-energy X-ray absorptiometry. Health-related behaviours and consumption of food and drinks were assessed using questionnaires, and intake of nutrients using a 4-day food record. RESULTS: Mean DMFT for all the participants was 2.4 (SD = 2.9), DT 0.6 (SD = 1.3), and 36% had DMFT = 0. No difference between genders was observed. In bivariate analyses, use of sugar-sweetened beverages (SSB) three times or less per week and not having used snuff associated significantly, whereas higher carbohydrate intake (E%), toothbrushing less often than twice a day and higher caries experience at baseline almost significantly with DT > 0. In adjusted regression analyses, frequent use of SSB and higher carbohydrate intake increased the odds for DT > 0. Additionally, higher carbohydrate intake (E%) and infrequent tooth brushing significantly associated with a higher number of DT. CONCLUSION: Caries prevalence is still low and similar in Finnish teenage girls and boys. Behavioural factors are, but anthropometric factors are not associated with dental caries.

Longitudinal associations of physical activity, sedentary time, and cardiorespiratory fitness with arterial health in children - the PANIC study.

We investigated the longitudinal associations of physical activity (PA), sedentary time (ST), and cardiorespiratory fitness (CRF) with arterial health among children. In our primary analyses, we investigated 245 children (girls 51.8%) aged 6-9 years participating in the baseline examinations who had data on arterial health at 2-year follow-up. We also utilized a subsample of 90 children who had a complete arterial health data at baseline and 2-year follow-up. ST (≤1.5 METs), light PA (>1.5-4 METs), moderate PA (>4-7 METs), vigorous PA (>7METs), and moderate-to-vigorous PA (MVPA, >4 METs) were assessed by combined movement and heart rate monitoring and CRF by maximal exercise testing on a cycle ergometer at baseline and 2-year follow-up. Stiffness index (SI) as a measure of arterial stiffness and change in reflection index during exercise test (DRI) as a measure of arterial dilation capacity were assessed by pulse contour analysis. Two-year change in vigorous PA was associated with DRI in boys but not in girls (p=0.021 for interaction). In a subsample analyses, 2-year changes in MPA, VPA, and MVPA were inversely associated with 2-year change in SI. In conclusion, promoting PA at higher intensities may confer larger benefits on arterial health than reducing ST and increasing LPA.

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

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 (ß) = - 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 (ß = - 0.0203, + 47% change in ß) and butter-based spreads (ß = - 0.0294, + 30% change in ß), moderate-to-vigorous physical activity (ß = - 0.0268, + 30% change in ß), light physical activity (ß = - 0.0274, + 29% change in ß) and sedentary time (ß = - 0.0270, + 30% change in ß). 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.

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

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 ß for intervention effect -0.33 [95% CI -0.62, -0.04], p = 0.026) and HOMA-IR (ß 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 abstract.

Cardiorespiratory Fitness, Physical Activity, and Insulin Resistance in 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 (ß = 0.065, 95% confidence interval [CI] = -0.031 to 0.161), insulin (ß = -0.079, 95% CI = -0.172 to 0.015), or HOMA-IR (ß = -0.065, 95% CI = -0.161 to 0.030). Wmax/BM was inversely associated with insulin (ß = -0.289, 95% CI = -0.377 to -0.200) and HOMA-IR (ß = -0.269, 95% CI = -0.359 to -0.180). The BF% was directly associated with insulin (ß = 0.409, 95% CI = 0.325 to 0.494) and HOMA-IR (ß = 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.

Associations of physical activity, sedentary time, and cardiorespiratory fitness with heart rate variability in 6- to 9-year-old children: the PANIC study.

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 (ß = - 0.185 to - 0.146, p ≤ 0.049) and MVPA, VPA, PAEE, and CRF were directly associated (ß = 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 (ß = 0.169 to 0.270, p ≤ 0.046). In girls, ST was inversely associated (ß = - 0.382 to - 0.294, p < 0.001) and LPA, MPA, VPA, MVPA, and PAEE were directly associated with HRV variables (ß = 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.

Associations of Cardiorespiratory Fitness and Adiposity With Arterial Stiffness and Arterial Dilatation Capacity in Response to a Bout of Exercise in Children.

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. Methods: Findings are based on 329 children (177 boys and 152 girls) aged 8-11 years. V˙O2peak was assessed by a maximal cardiopulmonary exercise test on a cycle ergometer and scaled by lean body mass (LM). BF% and LM were measured by bioelectrical impedance. Stiffness index (measure of arterial stiffness) and change in reflection index (ΔRI, measure of arterial dilatation capacity) were assessed by pulse contour analysis. Data were analyzed by linear regression models. Results:V˙O2peak/LM was positively associated with ΔRI in boys adjusted for age and BF% (ß = 0.169, P = .03). Further adjustments for systolic blood pressure, heart rate, and the study group had no effect on this association, but additional adjustment for clinical puberty attenuated it (ß = 0.171, P = .07). BF% was inversely related to ΔRI in boys adjusted for age and V˙O2peak/LM (ß = -0.171, P = .03). V˙O2peak or BF% was not associated with ΔRI in girls or with stiffness index in either boys or girls. Conclusion: Increasing cardiorespiratory fitness and decreasing adiposity may improve arterial health in childhood, especially among boys.

Longitudinal associations of physical activity and sedentary time with cardiometabolic risk factors in children.

BACKGROUND: There are few prospective studies on the associations of changes in objectively measured vigorous physical activity (VPA∆ ), moderate-to-vigorous physical activity (MVPA∆ ), light physical activity (LPA∆ ), and sedentary time (ST∆ ) with changes in cardiometabolic risk factors (∆ ) in children. We therefore investigated these relationships among children. METHODS: The participants were a population sample of 258 children aged 6-8 years followed for 2 years. We assessed PA and ST by a combined heart rate and movement sensor; computed continuous age- and sex-adjusted z-scores for waist circumference, blood pressure, and fasting insulin, glucose, triglycerides, and high-density lipoprotein (HDL) cholesterol; and constructed a cardiometabolic risk score (CRS) of these risk factors. Data were analyzed using linear regression models adjusted for age, sex, the explanatory and outcome variables at baseline, and puberty. RESULTS: VPA∆ associated inversely with CRS∆ (ß = -0.209, P = 0.001), body fat percentage (BF%)∆ (ß = -0.244, P = 0.001), insulin∆ (ß = -0.220, P = 0.001), and triglycerides∆ (ß = -0.164, P = 0.012) and directly with HDL cholesterol∆ (ß = 0.159, P = 0.023). MVPA∆ associated inversely with CRS∆ (ß = -0.178, P = 0.012), BF%∆ (ß = -0.298, P = <0.001), and insulin∆ (ß = -0.213, P = 0.006) and directly with HDL cholesterol∆ (ß = 0.184, P = 0.022). LPA∆ only associated negatively with CRS∆ (ß = -0.163, P = 0.032). ST∆ associated directly with CRS∆ (ß = 0.218, P = 0.003), BF%∆ (ß = 0.212, P = 0.016), and insulin∆ (ß = 0.159, P = 0.049). CONCLUSIONS: Increased VPA and MVPA and decreased ST were associated with reduced overall cardiometabolic risk and major individual risk factors. Change in LPA had weaker associations with changes in these cardiometabolic risk factors. Our findings suggest that increasing at least moderate-intensity PA and decreasing ST decrease cardiometabolic risk in children.

Longitudinal Associations of Fitness, Motor Competence, and Adiposity with Cognition.

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 (ß = -0.161, 95% confidence interval [CI] = -0.314 to -0.009), a shorter 50-m shuttle run test duration (ß = 0.152, 95% CI = 0.007-0.296), and a higher number of cubes moved in the Box and block test (ß = -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.

Health-related correlates of psychological well-being among girls and boys 6-8 years of age: The Physical Activity and Nutrition in Children study.

AIM: Due to limited knowledge on the differences in the correlates of psychological well-being (PSWB) between girls and boys, we compared the correlates of PSWB between primary school girls and boys. METHODS: A population sample of 412 children participated in the Physical Activity and Nutrition in Children study. Parents completed a questionnaire that included 19 questions on the components of PSWB, and a PSWB score was computed. We assessed correlates of PSWB, including physical activity, sedentary behaviour, cardiorespiratory fitness, diet quality, body fat content, sleep duration, sleep disordered breathing, prevalent diseases and parental characteristics. We used logistic regression to analyse the risk of being in the lowest third of the PSWB scores. RESULTS: Low parental education was associated with increased risk (odds ratio (OR) 2.34, P = 0.039) and high cardiorespiratory fitness with decreased risk (OR 0.26, P = 0.006) of poor PSWB in girls. At least 2 h of screen-based sedentary behaviour per day (OR 1.93, P = 0.037), daily parental smoking (OR 2.10, P = 0.034) and sleep disordered breathing (OR 4.24, P = 0.003) were related to increased risk of poor PSWB in boys. CONCLUSIONS: There are large differences in the correlates of PSWB between girls and boys. Most of these correlates are modifiable and related to the health behaviour of children and their parents.

Associations of lifestyle factors with serum dehydroepiandrosterone sulphate and insulin-like growth factor-1 concentration in prepubertal children.

OBJECTIVE: Little is known about the relationships of dietary factors, physical activity and sedentary behaviour to dehydroepiandrosterone sulphate (DHEAS) and insulin-like growth factor-1 (IGF-1) concentrations among prepubertal children. Therefore, we studied the associations of these lifestyle factors with serum DHEAS and IGF-1 in children. DESIGN AND SUBJECTS: Cross-sectional analysis of a population sample of 431 prepubertal children aged 6-9 years. MEASUREMENTS: Assessment of dietary factors by food records and physical activity and sedentary behaviour by a combined heart rate and movement monitor and a questionnaire. Measurement of serum DHEAS and IGF-1. RESULTS: Consumption of low-fibre grain products (standardized regression coefficient ß = .118, P = .017) and intake of vegetable protein (ß = .100, P = .045) was positively and consumption of sugar-sweetened beverages (ß = -.117, P = .018) was inversely associated with DHEAS after adjustment for sex, age and body fat percentage. Energy intake (ß = .160, P = .001) was positively associated with IGF-1 adjusting for sex, age and body fat percentage. Vigorous physical activity was inversely associated with DHEAS after adjustment for sex and age (ß = -.120, P = .027), and total (ß = -.137, P = .007), moderate (ß = -.130, P = .012), vigorous (ß = -.136, P = .011) and moderate to vigorous physical activity (ß = -.160, P = .003) were inversely and total sedentary behaviour (ß = .151, P = .003) was positively associated with IGF-1 adjusting for sex and age. None of physical activity measures was associated with DHEAS or IGF-1 after additional adjustment for body fat percentage. CONCLUSIONS: Lifestyle factors have weak and moderate associations with biochemical markers of adrenarche in prepubertal children. These associations indicate body fat independent and dependent influences of diet and physical activity, respectively.

Physical activity, sedentary behaviour, and socioeconomic status among Finnish girls and boys aged 6-8 years.

We studied differences in physical activity (PA), sedentary behaviour (SB), and the types of PA and SB between Finnish girls and boys and children from different socioeconomic backgrounds (SES). We assessed PA, SB, parental education, and household income using detailed questionnaires in a representative population sample of 486 children (238 girls, 248 boys) aged 6-8 years. Girls spent on average 1.7 h/day and boys 2.0 h/day in total PA (p = 0.002). Altogether 66% of girls and 54% of boys had less than 2 h of total PA per day (p = 0.012). Girls had lower levels of unsupervised PA (45 vs. 54 min/day, p = 0.001), supervised PA (1.5 vs. 1.9 h/week, p = 0.009), and PA during school recess (1.8 vs. 1.9 h/week, p = 0.032) than boys. Girls had higher levels of total SB (3.8 vs. 3.4 h/day, p = 0.015) but lower levels of screen-based SB (1.5 vs. 1.9 h/day, p < 0.001) than boys. Lower parental education and household income were associated with lower levels of supervised PA in girls (p = 0.011 and p = 0.008, respectively) and in boys (p = 0.006 and p = 0.003, respectively). Lower parental education and household income were also related to higher levels of screen-based SB in boys (p = 0.005 and p < 0.001, respectively) but not in girls. Girls have lower levels of total, unsupervised, and supervised PA, PA during recess, and screen-based SB but higher levels of total SB than boys. Lower parental education and household income are associated with lower levels of supervised PA in both genders and higher levels of screen-based SB in boys.