Comparison of actigraphy-measured and parent-reported sleep in association with weight status among preschool children.

This study compared weekday and weekend actigraphy-measured and parent-reported sleep in relation to weight status among preschool-aged children. Participants were 3-6 years old preschoolers from the cross-sectional DAGIS-study with sleep data for ≥2 weekday and ≥2 weekend nights. Parents-reported sleep onset and wake-up times were gathered alongside 24 h hip-worn actigraphy. An unsupervised Hidden-Markov Model algorithm provided actigraphy-measured night time sleep without the guidance of reported sleep times. Waist-to-height ratio and age-and-sex-specific body mass index characterised weight status. Comparison of methods were assessed with consistency in quintile divisions and Spearman correlations. Associations between sleep and weight status were assessed with adjusted regression models. Participants included 638 children (49% girls) with a mean ± SD age of 4.76 ± 0.89. On weekdays, 98%-99% of actigraphy-measured and parent-reported sleep estimates were classified in the same or adjacent quintile and were strongly correlated (rs = 0.79-0.85, p < 0.001). On weekends, 84%-98% of actigraphy-measured and parent-reported sleep estimates were respectively classified and correlations were moderate to strong (rs = 0.62-0.86, p < 0.001). Compared with actigraphy-measured sleep, parent-reported sleep had consistently earlier onset, later wake-up, and greater duration. Earlier actigraphy-measured weekday sleep onset and midpoint were associated with a higher body mass index (respective ß-estimates: -0.63, p < 0.01 and -0.75, p < 0.01) and waist-to-height ratio (-0.004, p = 0.03 and -0.01, p = 0.02). Though the sleep estimation methods were consistent and correlated, actigraphy measures should be favoured as they are more objective and sensitive to identifying associations between sleep timing and weight status compared with parent reports.

How energy balance-related behaviours, temperament, stress and overweight associate: a cross-sectional study of Finnish preschoolers.

OBJECTIVE: This study aimed to (1) examine the clustering of energy balance-related behaviours (EBRB) and (2) investigate whether EBRB clusters, temperament and hair cortisol concentration (HCC) associate with overweight. DESIGN: We assessed food consumption using food records, screen time (ST) using sedentary behaviour diaries, sleep consistency and temperament (negative affectivity, surgency, effortful control) using questionnaires and HCC using hair samples. Accelerometers were used to assess physical activity (PA) intensities, sleep duration and sleep efficiency. Researchers measured each child's weight and height. We used finite mixture models to identify EBRB clusters and multilevel logistic regression models to examine the associations between EBRB clusters, temperament, HCC and overweight. SETTING: The cross-sectional DAGIS survey, data collected in 2015-2016. PARTICIPANTS: Finnish 3-6-year-olds (n 864) recruited through preschools. RESULTS: One-third of the participants were categorised into the cluster labelled 'Unhealthy diet, excessive screen time', characterised by unhealthy dietary choices (e.g. greater consumption of high-fat, high-sugar dairy products) and longer ST. Two-thirds were categorised into the second cluster, labelled 'Healthy diet, moderate screen time'. PA and sleep were irrelevant for clustering. Higher negative affectivity and lower effortful control associated with the 'Unhealthy diet, excessive screen time' cluster. EBRB clusters and HCC did not associate with overweight, but surgency was positively associated with overweight (OR = 1·63, 95 % CI 1·17, 2·25). CONCLUSIONS: Of the EBRB, food consumption and ST seem to associate. As temperament associates with EBRB clusters and overweight, tailored support acknowledging the child's temperament could be profitable in maintaining a healthy weight.

Longitudinal associations of movement behaviours with body composition and physical fitness from 4 to 9 years of age: structural equation and mediation analysis with compositional data.

BACKGROUND: The associations of movement behaviours (physical activity [PA], sedentary behaviour [SB], and sleep) with body composition and physical fitness from pre-school to childhood, as well as the direction of the associations, could provide important information for healthy lifestyle promotion in children. This study investigated the longitudinal and bidirectional associations of movement behaviours with body composition and physical fitness measured at 4 and 9 years of age. METHODS: This longitudinal study included baseline (n = 315, 4.5 [SD = 0.1] years) and follow-up data (n = 231, 9.6 [SD = 0.1] years) from the MINISTOP study. Movement behaviours were measured for 7 days using wrist-worn accelerometers, body composition with air-displacement plethysmography, and physical fitness with the ALPHA health-related fitness test battery. Cross-lagged panel models and mediation analyses were performed in combination with compositional data analysis. RESULTS: We did not observe direct associations of the movement behaviours at 4 years with either body composition or physical fitness at 9 years (all P > 0.05). However, fat mass index at 4 years was negatively associated with vigorous PA (VPA), relative to remaining behaviours (VPA, ß = - 0.22, P = 0.002) and light PA (LPA), relative to SB and sleep (ß = - 0.19, P = 0.016) at 9 years. VPA (relative to remaining), moderate PA (MPA) (relative to LPA, SB, and sleep), and SB (relative to sleep) tracked from 4 to 9 years (all ß ≥ 0.17, all P < 0.002), and these behaviours shared variance with fat mass index (all|ß| ≥ 0.19, all P < 0.019), and aerobic, motor, and muscular fitness (all|ß| ≥ 0.19, all P < 0.014) at 9 years. Mediation analysis suggested that the tracking of VPA (relative to remaining behaviours) from 4 to 9 years was negatively associated with fat mass index (ß ≥ - 0.45, P = 0.012), and positively with aerobic fitness at 9 years (ß ≥ 1.64, P = 0.016). CONCLUSION: PA and SB tracked from the pre-school years into childhood. Fat mass index at 4 years of age was negatively associated with VPA (relative to remaining behaviours) and LPA (relative to SB and sleep) at 9 years of age. The tracking of VPA was associated with lower fat mass index and higher aerobic fitness at 9 years of age. These findings suggest that higher levels of VPA in pre-school age, if maintained throughout childhood, may support the development of healthy body composition and aerobic fitness levels in later childhood.

Cross-sectional associations between physical fitness and biomarkers of inflammation in children-The PANIC study.

BACKGROUND: Systemic low-grade inflammation has been proposed as an underlying pathophysiological mechanism for cardiometabolic diseases. We investigated the associations of physical fitness with a systemic low-grade inflammatory state in a population sample of children. METHODS: Altogether 391 children aged 6-9 years were examined. Cardiorespiratory fitness (maximal power output, Wmax ) was assessed by a maximal cycle ergometer test and neuromuscular fitness by hand grip strength, sit-up, standing long jump, 50-meter shuttle run, static balance, sit-and-reach, and box and block tests. Body fat percentage (BF%) and lean mass (LM) were assessed by dual-energy X-ray absorptiometry (DXA). High sensitivity C-reactive protein (hs-CRP), leptin, leptin receptor, high molecular weight adiponectin (HMW-adiponectin), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and glycoprotein acetyls (GlycA) were assessed from fasting blood samples. The modified inflammatory score (IS) was calculated using the population-specific z-scores and formula (z hs-CRP + z leptin + z IL-6 + z TNF-α + z GlycA)-z leptin receptor-z HMW-adiponectin. The data were analyzed using linear regression analyses. RESULTS: Higher Wmax /kg of body mass (ß = -0.416, 95% CI = -0.514 to -0.318), higher number of completed sit-ups (ß = -0.147, 95% CI = -0.244 to -0.049), a longer distance jumped in the standing long jump test (ß = -0.270, 95% CI = -0.371 to -0.169), and a shorter time in the 50-meter shuttle run test (ß = 0.123, 95% CI = 0.022 to 0.223) were associated with lower IS. None of these associations remained statistically significant after adjustment for BF%. CONCLUSIONS: Higher physical fitness is associated with a more favorable inflammatory biomarker profile in children. However, the associations were explained by BF%.

The role of parental congruence in pre-school children's screen time, moderated by parental education.

AIM: This study investigated whether parental congruency regarding screen time (ST) is associated with ST in pre-school children. In addition, we investigated whether parental education levels moderated this relationship. METHODS: A cross-sectional study was conducted in 2015-2016 in Finland (N = 688). Parents completed a questionnaire reporting their children's sedentary behaviour, their parental congruency regarding ST rules, and their educational level. Associations were examined using linear regression. RESULTS: Children of parents with higher congruence regarding ST rules engaged in less ST, this was moderated by parental education levels. Children whose parents had a high level of education and parents' who strongly agree or somewhat agree on ST rules was negatively associated with ST. Furthermore, children whose parents had a medium level of education and parents' who strongly agree on ST rules was negatively associated with ST. CONCLUSION: Children of parents who agree on ST rules engaged in less ST compared with children of parents who do not agree on ST rules. Providing advice to parents regarding parental congruency could be the focus of future interventions.

Comparing estimates of physical activity in children across different cut-points and the associations with weight status.

This study aimed to compare sedentary time (SED) and intensity-specific physical activity (PA) estimates and the associations of SED and PA with body mass index (BMI) and waist circumference (WC) using three different sets of cut-points in preschool-aged children. A total of 751 children (4.7 ± 0.9 years, boys 52.7%) wore an ActiGraph GT3X+BT accelerometer on their hip for 7 days (24 h). Euclidean norm -1 G with negative values rounded to zero (ENMO) and activity counts from vertical axis (VACounts) and vector magnitude (VMCounts) were derived. Estimates of SED and light, moderate, vigorous, and moderate-to-vigorous PA (MVPA) were calculated for commonly used cut-points by Hildebrand et al., Butte et al., and Evenson et al. Furthermore, the prevalence of meeting the PA recommendation, 180 min/day of which at least 60 min/day being MVPA, were assessed for the cut-points. Multilevel mixed analysis was used to examine associations of SED and PA with BMI and WC. In accordance with the results, SED and PA intensity estimates differed largely across cut-points (i.e., SED = 22-341 min/day; light PA = 52-257 min/day; moderate PA = 5-18 min/day; vigorous PA = 7-17 min/day; MVPA = 13-35 min/day), and the prevalence of children meeting the PA recommendation varied from 4% to 70%. Associations of SED and PA with BMI or WC varied between the cut-points. Our results indicate that SED and PA estimates in preschool-aged children between studies using these cut-points are poorly comparable. Methods facilitating accelerometer-derived PA estimate comparison between studies are highly warranted.

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.

Effects of the DAGIS randomized controlled trial on home environment and children's food consumption according to the degree of implementation.

BACKGROUND: Combining process evaluation data with effectiveness data and examining the possible mediators of intervention effects elicits valuable knowledge about how and for whom these interventions are effective. The aim of this study was to examine whether the parental degree of implementation (DOI) of a home-involving preschool intervention affected children's food consumption via home mediators. METHODS: The five-month Increased Health and Wellbeing in Preschools (DAGIS) intervention involved 476 participating children aged 3-6 years and was conducted in 2017-2018. Parents reported children's food consumption (g/day) outside childcare hours, the availability of foods at home, role modelling of food consumption, and the norms related to food consumption. In addition, parents reported the extent to which they had implemented the intervention program at home. Mediation analyses were conducted to examine the effect of low and high DOI compared to control group on the change in children's consumption of fruit and vegetables (FV), sugary everyday foods, sugary treats, and sugar-sweetened beverages (SSB) via food availability in the home, parental role modelling and parental norms. RESULTS: Compared to the control group, there was a direct effect of a high DOI on diminishing consumption of SSB (B -27.71, 95% CI -49.05, -4.80). No indirect effects were detected. In the high DOI group, a change in parental norm was associated with increased FV consumption showing an indirect effect (B 4.31, 95% CI 0.23, 10.59). In the low DOI group, there was an indirect effect via decreased food availability leading to decreased sugary everyday food consumption (B -2.17, 95% CI -5.09,  -0.09). CONCLUSIONS: Combining process evaluation and effectiveness data revealed a decrease in children's SSB consumption only in the high DOI group, as well as indirect effects on children's consumption of FV and sugary everyday foods. In order to gain more intervention effects, further studies are required in order to examine parental facilitators and barriers to the implementation of interventions and how to impact effectively the determinants of the targeted behavior. TRIAL REGISTRATION: ISRCTN57165350 (8 January, 2015).

Associations between hair and salivary cortisol, salivary alpha-amylase, and temperament dimensions among 3-6-year-olds.

Associations between hair cortisol concentration (HCC), diurnal salivary cortisol (sCort) and alpha-amylase (sAA), and temperament dimensions were examined among 3-6-year-old Finnish children (n = 833). Children's hair samples were collected at preschool, while parents collected five saliva samples from children during one weekend day and completed a questionnaire assessing child's temperament dimensions i.e. surgency, negative affectivity, and effortful control (HCC, n = 677; AUCg of sAA, n = 380; AUCg of sCort, n = 302; temperament dimensions, n = 751). In linear regression analysis, diurnal sCort associated positively with HCC, the association persisting after adjustments (ß 0.31, 95% CI 0.20-0.42). In logistic regression analysis, increasing scores in effortful control associated with higher likelihood of having high HCC (OR 1.47, 95% CI 1.07-2.03), the association slightly attenuating to non-significant after adjustments. Otherwise, no clear indication for associations between temperament and stress-related biomarkers were found.

Temperament, physical activity and sedentary time in preschoolers - the DAGIS study.

BACKGROUND: Identifying individual characteristics linked with physical activity (PA) and sedentary time (SED) can assist in designing health-enhancing interventions for children. We examined cross-sectional associations of temperament characteristics with 1) PA and SED and 2) meeting the PA recommendation in Finnish children. METHODS: Altogether, 697 children (age: 4.7 ± 0.9 years, 51.6% boys) within the Increased Health and Wellbeing in Preschools (DAGIS) study were included. Parents responded to the Very Short Form of the Children's Behavior Questionnaire consisting of three temperament dimensions: surgency, negative affectivity, and effortful control. PA and SED were assessed for 7 days (24 h per day) using a hip-worn ActiGraph accelerometer, and the daily minutes spent in light PA (LPA), moderate PA (MPA), vigorous PA (VPA), and SED were calculated. The PA recommendation was defined as having PA at least 180 min/day, of which at least 60 min/day was in moderate-to-vigorous PA. Adjusted linear and logistic regression analyses were applied. RESULTS: Surgency was associated with LPA (B = 3.80, p = 0.004), MPA (B = 4.87, p < 0.001), VPA (B = 2.91, p < 0.001), SED (B = - 11.45, p < 0.001), and higher odds of meeting the PA recommendation (OR = 1.56, p < 0.001). Effortful control was associated with MPA (B = - 3.63, p < 0.001), VPA (B = - 2.50, p < 0.001), SED (B = 8.66, p < 0.001), and lower odds of meeting the PA recommendation (OR = 0.61, p = 0.004). Negative affectivity was not associated with PA, SED, or meeting the PA recommendation. CONCLUSION: Children's temperament should be considered when promoting PA in preschoolers. Special attention should be paid to children scoring high in the temperament dimension effortful control.

Do stressed children have a lot on their plates? A cross-sectional study of long-term stress and diet among Finnish preschoolers.

We examined the association between hair cortisol concentration (HCC) - an indicator of long-term stress - and diet among preschoolers in a cross-sectional design. The participants were 597 Finnish 3-6-year-olds, and the data were collected in 2015-16. We used 4-cm hair samples to analyze HCC during the past four months. Food consumption was assessed using a food frequency questionnaire, and we used consumption frequencies of selected food groups as well as data-driven dietary pattern scores in the analyses. The parents of the participating children reported their educational level and family income. The researchers measured the children's weight and height. We examined the associations between HCC and diet using multilevel linear mixed models adjusted for age, gender, the highest education in the family, household relative income, and child BMI. Higher HCCs were associated with less frequent consumption of fruit and berries (B estimate -1.17, 95% CI -2.29, -0.05) and lower scores in a health-conscious dietary pattern (B estimate -0.38, 95% CI -0.61, -0,14). Higher HCCs were also associated with more frequent consumption of sugary beverages (B estimate 1.30, 95% CI 0.06, 2.54) in a model adjusted for age, gender and highest education in the family, but the association attenuated after further adjustments. Our results are parallel with previous studies that show a link between stress and unhealthy diet. In the future, longitudinal studies are needed to establish a causal relationship between stress and diet among children.

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.

Associations of cardiometabolic risk factors with heart rate variability in 6- to 8-year-old children: The PANIC Study.

BACKGROUND: Associations of cardiometabolic risk factors with heart rate variability (HRV) in children are unclear. We examined associations of cardiometabolic risk score (CRS) and individual cardiometabolic risk factors with HRV variables in 6- to 8-year-olds. METHODS: The participants were a population-based sample of 443 children participating in baseline measurements of the Physical Activity and Nutrition in Children trial. Cardiometabolic risk factors included waist circumference (WC), insulin, glucose, triglycerides, HDL cholesterol, systolic blood pressure (SBP), and diastolic blood pressure (DBP). CRS was calculated as WC + insulin + glucose + triglycerides - HDL cholesterol + the mean of SBP and DBP. HRV variables (SDNN, RMSSD, HF, LF, LF/HF, Mean RR) were measured using 5-minute electrocardiography at rest and analyzed using the Kubios HRV software. In this cross-sectional study, associations of CRS and individual cardiometabolic risk factors with HRV were investigated using linear regression analyses adjusted for sex and peak height velocity. RESULTS: CRS was negatively associated with RMSSD, HF, Mean RR (P value < .05) and positively with LF/HF (P value = .005). Insulin was negatively associated with SDNN, RMSSD, HF, LF, and Mean RR (P value < .05) and positively with LF/HF (P value = .008). SBP was negatively associated with SDNN, RMSSD, HF, LF, and Mean RR (P value < .05). DBP was negatively associated with SDNN, RMSSD, and Mean RR (P value < .05). WC, glucose, triglycerides, or HDL cholesterol were not associated with HRV variables. CONCLUSIONS: Higher CRS, insulin, and blood pressure were associated with smaller HRV, mainly indicating lower parasympathetic activity, in young children. This knowledge may help improving the clinical management of metabolic syndrome and cardiovascular diseases since childhood.

Association of screen time with long-term stress and temperament in preschoolers: results from the DAGIS study.

Screen time is increasing rapidly in young children. The aim of this study was to examine associations of long-term stress and temperament with screen time in Finnish preschool children and the moderating role of socioeconomic status. Cross-sectional DAGIS data were utilized. Long-term stress was assessed using hair cortisol concentration, indicating values of the past 2 months. Temperament was reported by the parents using the Children's Behavior Questionnaire (the Very Short Form), and three broad temperament dimensions were constructed: surgency, negative affectivity, and effortful control. Screen time was reported by the parents over 7 days. The highest education level in the household was used as an indicator of socioeconomic status. In total, 779 children (mean age, 4.7 ± 0.9 years, 52% boys) were included in the study. Of the temperament dimensions, a higher effortful control was associated with less screen time (B = - 6.70, p = 0.002). There was no evidence for an association between hair cortisol concentration and screen time nor a moderating role of socioeconomic status in the associations (p > 0.05).Conclusion: Our findings indicate that preschool children with a higher score in effortful control had less screen time. Because effortful control reflects general self-regulatory abilities, promoting these skills may be effective in reducing screen time in young children. What is Known: • Screen time has increased rapidly during the last decades, and higher screen time has been linked with numerous adverse health consequences in children. • There are no previous studies investigating associations of long-term stress and temperament with screen time in young children. What is New: • Of the temperament dimensions, effortful control was associated with higher screen time in preschool children, but there was no association found between long-term stress and screen time. • Since effortful control reflects general self-regulatory abilities, promoting these skills may be effective in reducing screen time in young children.

Hip and wrist accelerometers showed consistent associations with fitness and fatness in children aged 8-12 years.

AIM: Physical activity (PA) has traditionally been measured wearing accelerometers on the hip, but they are increasingly being worn on the wrist. We compared hip and wrist accelerometers with regard to their acceptability and any associations between PA and fatness and fitness. METHODS: This cross-sectional study comprised 103 children aged 8-12 years (62% boys) who participated in the ActiveBrains trial by the University of Granada, Spain, in 2014-2016. The children wore both ActiGraph GT3X+ hip and wrist accelerometers round the clock for 7 days. The acceptability of both placements was evaluated by a questionnaire, while the children's fat mass index, waist circumference and cardiorespiratory fitness (CRF) were assessed. RESULTS: Wearing wrist accelerometers caused less disturbance, mainly because hip accelerometers caused more issues during the night. The measurements from both placements showed that lower PA levels were associated with fatness and that higher PA levels were associated with better CRF. CONCLUSION: Both placements showed consistent results with regard to measuring associations between PA levels and fatness and fitness. However, wearing them on the wrist caused less discomfort at night. Future studies are needed to confirm the best placement for accelerometers during PA studies.

Compliance with the 24-h movement guidelines and the relationship with anthropometry in Finnish preschoolers: the DAGIS study.

BACKGROUND: Recent 24-h movement guidelines for the early years established recommendations for physical activity (PA), screen time (ST), and sleep. To date, few studies have focused on compliance with meeting the guidelines and their associations with health outcomes. Thus, we aimed to investigate: 1) compliance with the 24-h movement guidelines, and 2) associations between compliance and anthropometry in Finnish preschoolers. METHODS: We utilized DAGIS survey data that were collected in 2015-2016 (N = 864). PA was assessed 24 h/day over 7 days using a waist-worn ActiGraph wGT3X-BT accelerometer. ST and sleep were reported by the parents during the same 7 days. Anthropometry was assessed using body mass index (BMI, kg/m2) and waist circumference (WC, cm). Children were classified as meeting the guidelines if they averaged ≥180 min/day of PA, which consisted of ≥60 min of moderate-to-vigorous intensity; ≤60 min/day of ST; and 10-13 h/day of sleep. In total, 778 children (51% boys, mean age: 4.7 ± 0.9 years) were included in the study. The compliance with meeting the 24-h movement guidelines was calculated for each behavior separately and in combinations. Adjusted linear regression analyses were applied to examine associations of compliance with BMI and WC. RESULTS: Children were physically active on average 390 (±46.2) min/day and spent 86 (±25.5) min/day in moderate-to-vigorous PA. They spent 76 (±37.4) min/day on ST and had on average 10:21 (±0:33) h:min/day of sleep. The compliance rate in meeting all three movement guidelines overall was 24%. The highest compliance rate was found for PA (85%), followed by sleep (76%) and ST (35%). Meeting guidelines separately for PA or sleep, or for both, were associated with lower WC (PA: B = -1.37, p < 0.001; Sleep: B = -0.72, p = 0.009; PA + Sleep: B = -1.03, p < 0.001). In addition, meeting guidelines for sleep or for both PA and sleep were associated with lower BMI (Sleep: B = -0.26, p = 0.027; PA + Sleep: B = -0.30, p = 0.007). There were no significant associations found regarding ST. CONCLUSIONS: Meeting recommendations for PA and sleep may have an important role in supporting a healthy weight status in young children. However, there is still a need to improve compliance with the 24-h movement guidelines, especially for ST.

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.

Physical Activity and Body Composition in Children and Their Mothers According to Mother's Gestational Diabetes Risk: A Seven-Year Follow-Up Study.

Background and Objectives: There is lack of knowledge on whether mothers' gestational diabetes (GDM) risk is related to their physical activity (PA) or their children's PA and body composition. We aimed to examine the difference in (1) change in self-reported PA from pre-pregnancy to seven-year follow-up and (2) accelerometer-based PA at seven years after delivery between the mothers having GDM risk (GDMRyes-mothers) and not having GDM risk (GDMRno-mothers). Furthermore, we examined the difference in children's PA and/or body composition at six years of age according to their mothers' GDM risk. Materials and Methods: The study included 199 Finnish women. GDM risk factors were screened at the beginning of pregnancy, and the women were classified as GDMRyes-mothers if they had at least one GDM risk factor (body mass index ≥25 kg/m2; age ≥40 years; family history of diabetes; GDM, signs of glucose intolerance, or newborn's macrosomia (≥4500 g) in earlier pregnancy) or as GDMRno-mothers if they had no risk factors. Mothers' PA was assessed by self-reporting at 8-12 gestational weeks concerning pre-pregnancy PA and at a follow-up seven years after the delivery. Moreover, mothers' and their children's PA was measured using a triaxial Hookie AM20-accelerometer at seven years after delivery. Children's body composition was assessed using a TANITA bioelectrical impedance device. Adjusted linear regression analyses were applied. Results: GDMRno-mothers increased their self-reported PA more than GDMRyes-mothers from pre-pregnancy to the seven-year follow-up. Concerning women's measured PA as well as children's PA and body composition at seven years after delivery, the differences were non-significant between GDMRyes-mothers and GDMRno-mothers. However, of the GDM risk factors, mothers' pre-pregnancy body mass index was positively related to unhealthier body composition in boys at six years of age. Conclusion: Health promotion should be targeted at women with GDM risk factors, in particular overweight women, in enhancing women's PA in the long term and their children's healthy body composition.

Physical Activity Level Using Doubly-Labeled Water in Relation to Body Composition and Physical Fitness in Preschoolers.

Background and objectives: There is a lack of studies investigating associations of physical activity level (PAL) and activity energy expenditure (AEE) using the doubly-labeled water (DLW) method with body composition and physical fitness in young children. Thus, we aimed to examine cross-sectional associations of PAL and AEE with body composition indices and physical fitness components in Swedish preschool children. Materials and methods: PAL was calculated as total energy expenditure measured using DLW divided by the predicted basal metabolic rate in 40 children aged 5.5 (standard deviation 0.2) years. AEE was calculated as total energy expenditure minus basal metabolic rate and the thermic effect of food, and divided by fat-free mass. Body composition was assessed using the 3-component model by combining measurements based on isotope dilution and air-displacement plethysmography. Physical fitness (muscular strength, motor fitness, and cardiorespiratory fitness) was evaluated using the PREFIT test battery. Multiple linear regression models were conducted. Results: PAL and AEE were negatively associated with body mass index, percent body fat, and fat mass index (PAL: standardized ß -0.35, -0.41, and -0.45, all p < 0.036; AEE: standardized ß -0.44, -0.44, and -0.47, all p < 0.006, respectively). Furthermore, PAL and AEE were positively associated with the standing long jump test (PAL: standardized ß 0.37, p = 0.017; AEE: standardized ß 0.38, p = 0.014). There were no statistically significant associations found regarding PAL or AEE with fat-free mass index or any other physical fitness test. Conclusions: Greater PAL and AEE at the age 5.5 were significantly associated with body fatness and improved lower-body muscular strength. Therefore, increasing physical activity, and thus energy expenditure, at young ages may be beneficial for preventing overweight/obesity. However, further studies with larger sample sizes are needed to confirm the results.

Physical activity during pregnancy: predictors of change, perceived support and barriers among women at increased risk of gestational diabetes.

The aim of this study was to examine the predictors of change in intensity-specific leisure-time physical activity (LTPA) during pregnancy, and the perceived support and barriers of LTPA in Finnish pregnant women at increased risk of gestational diabetes. The study population consisted of 399 pregnant women who participated in a randomized controlled trial aiming to prevent gestational diabetes. Evaluation of LTPA was based on a self-report at baseline, 26-28, and 36-37 weeks' gestation. Data on predictors of change, perceived support and barriers were collected with questionnaires and from the maternity cards. Multinomial logistic regression was used to assess associations between the variables. The average weekly minutes of light-intensity LTPA were 179 at baseline, 161 at 26-28 weeks' gestation, and 179 at 36-37 weeks' gestation. The corresponding minutes of moderate-to-vigorous-intensity LTPA were 187, 133 and 99. At 26-28 weeks' gestation, the strongest predictors for light-intensity LTPA were meeting the PA recommendations prior to pregnancy, having polytechnic education and working part-time, while having a physically active spouse prior to pregnancy was the strongest predictor for moderate-to-vigorous-intensity LTPA. The people and/or factors that encouraged women to LTPA the most were the spouse, a child, other family members and weather, whereas tiredness, nausea, perceived health, work and lack of time restricted their LTPA the most. The strongest predictors for maintaining LTPA during pregnancy were pre-pregnancy LTPA, education, working part-time and a spouse's LTPA. Most common barriers were perceived health, work and lack of time.