Niina Lintu

Physical activity and sedentary behaviour in relation to cardiometabolic risk in children: cross-sectional findings from the Physical Activity and Nutrition in Children (PANIC) Study

BackgroundLower 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.MethodsThe 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.ResultsTotal PA was inversely associated with the cardiometabolic risk score (β = -0.135, p = 0.004), body fat percentage (β = -0.155, p < 0.001), insulin (β = -0.099, p = 0.034), triglycerides (β = -0.166, p < 0.001), VLDL triglycerides (β = -0.230, p < 0.001), VLDL cholesterol (β = -0.168, p = 0.001), LDL cholesterol (β = -0.094, p = 0.046) and HDL triglycerides (β = -0.149, p = 0.004) and directly related to HDL cholesterol (β = 0.144, p = 0.002) adjusted for age and gender. Unstructured PA was inversely associated with the cardiometabolic risk score (β = -0.123, p = 0.010), body fat percentage (β = -0.099, p = 0.027), insulin (β = -0.108, p = 0.021), triglycerides (β = -0.144, p = 0.002), VLDL triglycerides (β = -0.233, p < 0.001) and VLDL cholesterol (β = -0.199, p < 0.001) and directly related to HDL cholesterol (β = 0.126, p = 0.008). Watching TV and videos was directly related to the cardiometabolic risk score (β = 0.135, p = 0.003), body fat percentage (β = 0.090, p = 0.039), waist circumference (β = 0.097, p = 0.033) and systolic blood pressure (β = 0.096, p = 0.039). Resting was directly associated with the cardiometabolic risk score (β = 0.092, p = 0.049), triglycerides (β = 0.131, p = 0.005), VLDL triglycerides (β = 0.134, p = 0.009), VLDL cholesterol (β = 0.147, p = 0.004) and LDL cholesterol (β = 0.105, p = 0.023). Other types of PA and SB had less consistent associations with cardiometabolic risk factors.ConclusionsThe 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 registrationClinicalTrials.gov Identifier: NCT01803776.

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

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

Cardiovascular fitness and haemodynamic responses to maximal cycle ergometer exercise test in children 6–8 years of age

Abstract 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, P < 0.001] and lean mass [mean (2 s) 3.5 (0.9) vs. 3.8 (1.0) W· kg–1, P < 0.001] 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, P < 0.001]. 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.

Measures of cardiorespiratory fitness in relation to measures of body size and composition among children

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.

The Effects of a 2-year Individualized and Family-based Lifestyle Intervention on Physical Activity, Sedentary Behavior and Diet in Children

OBJECTIVE To investigate the effects of a long-term, individualized and family-based lifestyle intervention on physical activity, sedentary behavior and diet quality in children. METHODS We carried out a 2-year intervention study in a population sample of 506 children aged 6-8years in Finland in 2007-2012. We allocated the participants at baseline in the intervention and control group. We assessed physical activity and sedentary behavior by questionnaires and diet by food records. RESULTS Total physical activity (+9min/d in intervention group vs. -5min/d in control group, p=0.001 for time*group interaction), unsupervised physical activity (+7min/d vs. -9min/d, p<0.001) and organized sports (+8min/d vs. +3min/d, p=0.001) increased in the intervention group but not in the control group. Using computer and playing video games increased less in the intervention group than in the control group (+9min/d vs. +19min/d, p=0.003). Consumption of vegetables (+12g/d vs. -12g/d, p=0.001), high-fat vegetable-oil based margarine (+10g/d vs. +3g/d, p<0.001) and low-fat milk (+69g/d vs. +11g/d, p=0.042) and intake of dietary fiber (+1.3g/d vs. +0.2g/d, p=0.023), vitamin C (+4.5mg/d vs. -7.2mg/d, p=0.042) and vitamin E (+1.4mg/d vs. +0.5mg/d, p=0.002) increased in the intervention group but not in the control group. Consumption of butter-based spreads increased in the control group but not in the intervention group (+2g/d vs. -1g/d, p=0.002). CONCLUSIONS Individualized and family-based lifestyle intervention increased physical activity, attenuated increase in sedentary behavior and enhanced diet quality in children. TRIAL REGISTRATION ClinicalTrials.gov: NCT01803776.

Physical activity and sedentary time in relation to academic achievement in children.

Objectives To investigate the independent and combined associations of objectively measured moderate-to-vigorous physical activity (MVPA) and sedentary time (ST) with reading and arithmetic skills. Design Cross-sectional/prospective. Methods Participants were 89 boys and 69 girls aged 6–8 years. MVPA and ST were measured using a combined heart rate and movement sensor and body fat percentage by dual-energy X-ray absorptiometry in Grade 1. Reading fluency, reading comprehension, and arithmetic skills were assessed using standardized tests in Grades 1–3. The data were analyzed using linear regression analyses and analyses of covariance with repeated measures. Results In boys, MVPA was directly and ST inversely associated with reading fluency in Grades 1–3 and arithmetic skills in Grade 1 (P < 0.05). Higher levels of MVPA were also related to better reading comprehension in Grade 1 (P < 0.05). Most of the associations of MVPA and ST with reading and arithmetic skills attenuated after mutual adjustment for MVPA or ST. Furthermore, boys with a combination of lower levels of MVPA and higher levels of ST had consistently poorer reading fluency (P = 0.002) and reading comprehension (P = 0.027) across Grades 1–3 than other boys. In girls, ST was directly associated with arithmetic skills in Grade 2 (P < 0.05). However, this relationship of ST with arithmetic skills was no longer significant after adjustment for body fat percentage. Conclusions Lower levels of MVPA and higher levels of ST and particularly their combination were related to poorer reading skills in boys. In girls, higher levels of ST were related to better arithmetic skills.

Associations of cardiorespiratory fitness, physical activity, and adiposity with arterial stiffness in children

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 < 0.001), lower unstructured PA (β = −0.162, P = 0.042), and higher BF% (β = 0.176, P = 0.044) were related to higher arterial stiffness. When CRF, unstructured PA, and BF% were in the same model, only CRF was associated with arterial stiffness (β = −0.246, P = 0.006). Poorer CRF was also related to lower arterial dilation capacity (β = 0.316, P < 0.001). Children with low CRF (< median) and high BF% (≥ median; P = 0.002), low CRF and low unstructured PA (< median; P = 0.006) or children with low unstructured PA and high BF% (P = 0.005) had higher arterial stiffness than children in the opposite halves of these variables. Poor CRF was independently associated with increased arterial stiffness and impaired arterial dilation capacity among children.

Associations of Physical Performance and Adiposity with Cognition in Children.

OBJECTIVES To investigate the independent and combined associations of cardiorespiratory performance (CP), neuromuscular performance (NP; including motor performance [MP]) and body fat percentage (BF%) with cognition in children. METHODS The participants were 202 boys and 201 girls age 6-8 yr. Cardiorespiratory performance was assessed using maximal cycle ergometer test and was expressed as maximal workload per lean body mass. Neuromuscular performance score included muscle strength, speed, agility, balance, manual dexterity, and flexibility; and MP included speed and agility, balance, and manual dexterity. Body fat percentage was assessed by dual-energy x-ray absorptiometry. Cognition was assessed using Raven Coloured Progressive Matrices (CPM). Linear regression and general linear models were used to analyze the independent and combined associations of CP, NP, MP, and BF% with Raven CPM score. RESULTS Neuromuscular performance and MP were directly associated with the Raven CPM score (β = 0.138-0.190; P < 0.01). Children in the lowest or the highest thirds of BF% and in the lowest third of MP had a lower Raven CPM score than other children (P < 0.05). Children in the lowest or highest third of BF% along with the poorest MP had a lower Raven CPM score than those in the middle third of BF% and higher MP (P < 0.05). These associations and differences were much stronger in boys than in girls. Cardiorespiratory performance was not related to the Raven CPM score. CONCLUSIONS Poorer NP and MP were associated with a worse cognition in children and particularly in boys. Cognition was poorer especially among children with the lowest or highest BF% accompanied with a poorer MP.

Development of cortical motor circuits between childhood and adulthood: A navigated TMS-HdEEG study

Motor functions improve during childhood and adolescence, but little is still known about the development of cortical motor circuits during early life. To elucidate the neurophysiological hallmarks of motor cortex development, we investigated the differences in motor cortical excitability and connectivity between healthy children, adolescents, and adults by means of navigated suprathreshold motor cortex transcranial magnetic stimulation (TMS) combined with high‐density electroencephalography (EEG). We demonstrated that with development, the excitability of the motor system increases, the TMS‐evoked EEG waveform increases in complexity, the magnitude of induced activation decreases, and signal spreading increases. Furthermore, the phase of the oscillatory response to TMS becomes less consistent with age. These changes parallel an improvement in manual dexterity and may reflect developmental changes in functional connectivity. Hum Brain Mapp 38:2599–2615, 2017.

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

Abstract 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.