Independent and combined effects of physical activity and sedentary behavior on blood pressure in adolescents: gender differences in two cross-sectional studies

Serum Vitamin D Levels Mediate the Association Between Physical Activity and Blood Pressure in Adolescents

Individuals with low levels of vitamin D are associated with cardiovascular risks, such as elevated blood pressure (BP), and are; therefore, more likely to develop hypertension. Patients with vitamin D deficiency may face an increased risk of cardiovascular events. In this study, a multicenter, cross-sectional, and school-based investigation was conducted as part of the ERICA project. The sample comprised 1152 adolescents aged 12-17 years from 4 Brazilian cities. Anthropometric variables, BP measurements, and hydroxyvitamin D concentrations were assessed. A 2-level linear regression was fitted to examine the relationship between each level of BP and independent variables. Our findings indicate that movement behaviors were not associated with BP levels, with the exception of sleep time, which demonstrated a positive association. However, after adjustment, this association was found to be nonsignificant. Our study's mediation analysis revealed that vitamin D mediates up to 12.9% of the association between physical activity and systolic BP. Vitamin D is inversely associated with BP in adolescents. In addition to mediating the physical activity and systolic BP association, engaging in physical activity, particularly outdoors, can provide a dual benefit for adolescents by increasing serum vitamin D levels and assisting in the control of BP levels.

Prolonged screen watching behavior is associated with high blood pressure among children and adolescents: a systematic review and dose-response meta-analysis

BACKGROUND

Numerous cardio-metabolic risk factors influence screen-related behaviors in children and adolescents. Numerous studies with inconsistent results revealed a relationship between blood pressure and screen time in the children and adolescents. This systematic review and meta-analysis summarized the data regarding the relationship between screen time and hypertension (HTN) in children and adolescents.

METHODS

We examined three electronic databases, including Scopus, PubMed, and Embase to find the recent research on the relationship between screen time and HTN up to 19 July 2022. Twenty papers were included in the final two-class and dose-response meta-analysis. We conducted subgrouping to identify the source of heterogeneity.

RESULTS

The highest category of screen time increased the odds of HTN by 8% [odds ratio (OR): 1.15; 95% confidence interval (CI): 1.08, 1.23; P < 0.001; I2 = 83.20%] and 1.9 mmHg increase in systolic blood pressure [weighted mean difference (WMD): 1.89; 95% CI: 0.18-3.62; P = 0.030; I2 = 83.4]. However, there was no significant difference in diastolic blood pressure. Moreover, screen time in hypertensive children and adolescents was 0.79 h (47.4 min) higher than normotensive subjects (WMD: 0.79; 95% CI: 0.02, 1.56; P = 0.046; I2 = 92.8). A departure from linearity was observed between increased screen time [digital video discs, personal computers, and video games and HTN (Pnonlinearity = 0.049).

CONCLUSION

This systematic meta-analysis review is the first to demonstrate a positive correlation between screen time and HTN in children and adolescents.

Safety and adherence of pressure garment therapy in children with upper limb unilateral cerebral palsy. Results from a randomized clinical trial ancillary analysis

Background

This study was conducted to assess the safety and adherence of the use of a PGT (Pressure Garment Therapy) Lycra® sleeve to treat upper limb unilateral cerebral palsy (UCP) in children.

Methods

This study was conducted as a prospective, placebo-controlled, double-blinded, randomized monocenter study. Included in the study were 58 UCP children, 49 of whom were analyzed. 25 children (mean age 6.6 ± 1.6 years; 12 girls) were allocated to the active group vs. 24 (mean age 6.7 ± 1.6 years; 10 girls) in the placebo group. The intervention consisted of an active PGT Lycra® arm sleeve manufactured to generate a homogeneous pressure ranging from 15 to 25 mmHg. The placebo PGT Lycra® sleeve was manufactured to generate a homogeneous pressure under 7 mmHg. The time of wearing period was set at 3 h/day at minimum and 6 h/day at maximum, over the course of 6 months. The main outcome measures were safety outcomes including the number and intensity of Adverse Events of Special Interest (AESIs). AESIs were defined as adverse events imputable to compressive therapy and Lycra® wearing. Level of adherence was expressed in percentage of number of days when the sleeve was worn for at least 3 h per day compared to length of duration in days (start and end date of wearing period).

Results

Frequency of AESIs were very low and no different between groups (4.12 ± 11.32% vs. 1.83 ± 3.38%; p = 0.504). There were no differences in adherence (91.86 ± 13.86% vs. 94.30 ± 9.95%; p = 0.425).

Conclusion

The use of PGT Lycra® arm sleeve in children with UCP is safe and well-tolerated with a very good adherence. The low rate of AESIs is promising for further randomized clinical trials on efficacy.

Can Food and Beverage Advertising Questionnaire Predict Overweight and Obesity in Children and Adolescents from Low- and Middle-Income Countries?

Background: Information about the reliability and validity of questionnaires in low- and middle-income countries remains scarce. Objective: To test the reliability and predictive validity of a food and beverage marketing/advertising questionnaire for South American children and adolescents. Methods: A sample of 330 children (3-10 years old) and 215 adolescents (11-18 years old) was included from seven South American cities: Buenos Aires, Lima, Medellín, Montevideo, Santiago, Sao Paulo, and Teresina. The questionnaire consisted of seven questions about food and beverage marketing/advertising and decision influence. We assessed the reliability using temporal stability (2-week interval) and internal consistency. We assessed the predictive validity based on the risk of excess weight. Results: In children, reliability agreement from κ coefficients ranged from 63.7% to 86.3%, and Cronbach's α (internal consistency estimate) ranged from 0.14 to 0.75. In adolescents, the reliability agreement ranged from 78.9% to 85.7%, and Cronbach's α ranged from 0.14 to 0.76. Exploratory factor analysis revealed two factors for both age groups. The predictive probabilities for excess weight ranged from 22.3% to 61.1% in children and from 24.9% to 64.1% in adolescents. Conclusions: The screen/marketing media questionnaire is a reliable and valid measure for the pediatric population from low- and middle-income countries. This subjective tool provides a feasible screening measure for the influence of advertising on children and adolescents at risk of overweight and obesity.

The Role of Adiposity in the Association Between Physical Activity and Blood Pressure in Children

Purpose: To analyze whether body adiposity mediates and/or moderates the association between time in moderate-to-vigorous physical activities (MVPA) and blood pressure in children. Methods: This was a cross-sectional study of 577 children aged 5 to 7 years old. MVPA was measured by accelerometry. Body mass index (BMI), waist circumference (WC), and the sum of tricipital and subscapular skinfolds (skinfolds) assessed children's body adiposity. Systolic (SBP) and diastolic blood pressure (DBP) were used as the dependent variables. Results: In the primary analysis adjusting for BMI or skinfolds measures, additional time in MVPA was associated with higher SBP. On the other hand, further analyses showed that children in the largest BMI tertile (β_SBP:0.18; 95%CI: 0.12-0.24; β_DBP:0.11; 95%CI: 0.05-0.17), waist circumference (β_SBP:0.16; CI: 0.09-0.22; β_DBP:0.08; CI:0.02-0.14), or sum of skinfolds (β_SBP:0.18; CI: 0.11-0.24; β_DBP:0.09; CI: 0.03-0.16) presented a positive relationship between MVPA and blood pressure whereas no positive association was observed for children in the first and second adiposity tertiles. Adiposity also mediated the association between MVPA and blood pressure. A decrease of 0.03 mmHg in the systolic blood pressure was observed by decreasing the sum of skinfolds for each additional minute per day in MVPA. A decrease in diastolic blood pressure of 0.02 mmHg was observed for each additional minute per day in MVPA, which was related to a negative association between time in MVPA and waist circumference and sum of skinfolds. Conclusion: Not accounting for the potential moderation and mediation role of adiposity may lead to misinterpretations in the MVPA and blood pressure relationship.

High Fructose Intake Contributes to Elevated Diastolic Blood Pressure in Adolescent Girls: Results from The HELENA Study

BACKGROUND

The association between high fructose consumption and elevated blood pressure continues to be controversial, especially in adolescence. The aim of this study was to assess the association between fructose consumption and elevated blood pressure in an European adolescent population.

METHODS

A total of 1733 adolescents (mean ± SD age: 14.7 ± 1.2; percentage of girls: 52.8%) were analysed from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study in eight European countries. Blood pressure was measured using validated devices and methods for measuring systolic blood pressure (SBP) and diastolic blood pressure (DBP). Dietary data were recorded via repeated 24 h recalls (using specifically developed HELENA-DIAT software) and converted into pure fructose (monosaccharide form) and total fructose exposure (pure fructose + fructose from sucrose) intake using a specific fructose composition database. Food categories were separated at posteriori in natural vs. were non-natural foods. Elevated BP was defined according to the 90th percentile cut-off values and was compared according to tertiles of fructose intake using univariable and multivariable mixed logistic regression models taking into account confounding factors: centre, sex, age and z-score-BMI, MVPA (Moderate to Vigorous Physical Activity) duration, tobacco consumption, salt intake and energy intake.

RESULTS

Pure fructose from non-natural foods was only associated with elevated DBP (DBP above the 10th percentile in the highest consuming girls (OR = 2.27 (1.17-4.40); p = 0.015) after adjustment for cofounding factors.

CONCLUSIONS

Consuming high quantities of non-natural foods was associated with elevated DBP in adolescent girls, which was in part due to high fructose levels in these foods categories. The consumption of natural foods containing fructose, such as whole fruits, does not impact blood pressure and should continue to remain a healthy dietary habit.

Factors Associated with Primary Hypertension in Pediatric Patients: An Up-to-Date

BACKGROUND

Arterial hypertension in children is considered a common alteration nowadays, mainly because obesity is a growing worldwide problem closely related to increased blood pressure. Childhood hypertension can be classified as primary or secondary, depending on the etiology. Primary or essential hypertension still has its pathophysiology not fully elucidated, and there is no consensus in the literature on most underlying mechanisms. In this review, genetic and environmental factors, including sodium and potassium intake, socioeconomic status, ethnicity, family structure, obesity, sedentary lifestyle, prematurity and low birth weight, prenatal and postnatal exposures are highlighted.

OBJECTIVE

The present study aimed to perform an update on primary hypertension in childhood, providing clinicians and researchers an overview of the current state of the literature regarding the influence of genetic and environmental factors.

METHODS

This integrative review searched for articles on genetic and environmental factors related to primary hypertension in pediatric patients. The databases evaluated were PubMed and Scopus.

RESULTS

The studies have provided insights regarding many genetic and environmental factors, in addition to their association with the pathophysiology of primary hypertension in childhood. Findings corroborated the idea that primary hypertension is a multifactorial disease. Further studies in the pediatric population are needed to elucidate the underlying mechanisms.

CONCLUSION

The study of primary hypertension in pediatrics has utmost importance for the adoption of preventive measures and the development of more efficient treatments, therefore reducing childhood morbidity and the incidence of cardiovascular diseases and other health consequences later in life.

Sedentary behavior is more related with cardiovascular parameters in normal weight than overweight adolescents

This study analyzed the relationship between sedentary behavior and cardiovascular parameters in normal weight and overweight adolescents. The sample included 449 boys and 555 girls with mean age of 13 years from public schools, which were divided into five geographical regions, with data collections performed in one selected school from each region. Sedentary behavior was assessed by screen time on TV, computer, videogame and cell phone/tablet, with good reliability in adolescents. Physical activity was assessed by Baecke's questionnaire, validated for adolescents. Measures of body weight, height and waist circumference were collected. Adolescents were classified as overweight or normal weight by cut-off points of body mass index for age and sex. Cardiovascular parameters were evaluated by oscillometric device and heart rate by specific monitor. Computer use was positively related to systolic blood pressure (SBP) (β = 0.35; 95%CI = 0.07-0.62) and diastolic blood pressure (DBP) (β = 0.25; 95%CI = 0.05-0.44) in normal weight but not in overweight adolescents. Similar results were observed for cell phone/tablet in SBP (β = 0.46; 95%CI = 0.20-0.72) and DBP (β = 0.36; 95%CI = 0.18-0.54), only for normal weight. The cluster of screen time was related to SBP in normal weight (β = 0.44; 95%CI = 0.03-0.84) and overweight (β = 0.60; 95%CI = 0.01-1.19). Screen time in computer and cell phone/tablet was more related to cardiovascular parameters in normal weight than overweight adolescents.

Combined effects of the rs9810888 polymorphism in calcium voltage-gated channel subunit alpha1 D (CACNA1D) and lifestyle behaviors on blood pressure level among Chinese children

Backgrounds

A recent GWAS Study found a new locus (rs9810888 in CACNA1D) was associated with blood pressure (BP) in Chinese adults. But whether the association exists in children is unknown. Whether lifestyle behaviors could interact with rs9810888 on BP is not clear. This study aimed to identify the association between rs9810888 and BP in children, and also explore the gene-lifestyle interaction.

Methods

A case-control study was conducted among 2030 Chinese children aged 7 to 18 years. Genotyping was conducted by using the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Lifestyle behaviors were investigated with questionnaire.

Results

With adjustment for age, age square, sex, study group and body mass index (BMI), rs9810888 was significantly associated with diastolic BP (DBP) (b = 1.69, p = 0.021) and mean arterial BP (MAP) (b = 1.56, p = 0.010). Stratified analysis showed that the rs9810888 GG genotype carriers had higher DBP than GT/TT carriers (b = 3.78, p = 0.023) in the subgroup having protein intake (meat/fish/soybeans/egg) <twice/day, but not in the subgroup ≥twice/day. In addition, in the subgroup with screen time≥2h/day, the rs9810888 GG genotype carriers had higher DBP than GT/TT carriers (b = 5.49, p = 0.012), but not in the subgroup with screen time<2h/day. For MAP, in the subgroup having either fruits or vegetables < twice/day, the rs9810888 GG genotype carriers had higher MAP than GT/TT carriers (b = 2.64, p = 0.037), but not in the subgroup with both fruits and vegetables intake ≥twice/day. Additionally, in the subgroup with screen time≥2h/day, the rs9810888 GG genotype carriers had higher MAP than GT/TT carriers (b = 4.80, p = 0.017), but not in those with screen time<2h/day.

Conclusions

The CACNA1D rs9810888 polymorphism was significantly associated with DBP and MAP. In addition, unhealthy lifestyle behaviors and rs9810888 GG genotype had combined effects on BP level among Chinese children.

Association between leisure-time physical activity and sedentary behavior with cardiometabolic health in the ELSA-Brasil participants

Objectives:

To assess associations, both individually and in combination, between leisure-time physical activity and sedentary behavior, and cardiometabolic health.

Methods:

This cross-sectional study included 13,931 civil servants participating in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Leisure-time physical activity was analyzed using the leisure-time domain of the long-form International Physical Activity Questionnaire, while questions related to cumulative sitting time and leisure-based screen time on a weekday and on one day on the weekend were used to establish sedentary behavior. Data analysis was performed using multivariate logistic regression.

Results:

Following adjustment for confounding variables, high levels of leisure-time physical activity and low levels of sedentary behavior were both associated with favorable cardiometabolic health markers in both genders. When these two factors were analyzed in conjunction, taking the combination of low levels of leisure-time physical activity and high levels of sedentary behavior as the reference, the inverse associations with cardiometabolic variables became even more significant.

Conclusion:

High levels of leisure-time physical activity and low levels of sedentary behavior were both inversely associated with the cardiometabolic variables analyzed; however, the two variables when evaluated in conjunction appear to produce more consistent associations, particularly when sedentary behavior is evaluated according to leisure-based screen time.

Interaction between physical activity and television time on blood pressure level: cross-sectional data from 45 000 individuals

OBJECTIVES

The aim was to investigate if there is an interaction between sitting time and leisure time physical activity on blood pressure and if there are age differences and sex differences in this respect.

METHODS

Linear regression analysis on cross-sectional data was performed in more than 45 000 men and women from two Swedish cohort studies, EpiHealth (45-75 years) and LifeGene (18-45 years). Self-reported leisure time physical activity was given in five levels from low (level 1) to vigorous physical activity (level 5) and television time was used as a proxy measure of sitting time.

RESULTS

High physical activity was associated with lower DBP (P = 0.001), but not SBP. Active middle-aged men had lower DBP (-1.1 mmHg; 95% CI -1.7 to -0.4) compared with inactive participants. Prolonged television time was associated with higher SBP (P < 0.001) and DBP (P = 0.011) in both sexes and in most age groups. Watching 3 h instead of 1 h television per day was associated with higher SBP in middle-aged women (SBP: 1.1 mmHg; 95% CI 0.7-1.4) and men (SBP: 1.2 mmHg; 95% CI 0.8-1.6). Only in young men, a high physical activity (level 4 instead of level 1) could compensate for a prolonged television time (3 h per day) in terms of DBP.

CONCLUSION

Prolonged television time was associated with higher SBP and DBP in both sexes and at most ages, whereas an increased physical activity was mainly associated with a lower DBP. Only in young men, a high physical activity could compensate for prolonged television time regarding DBP.

Comparing measures of general and abdominal adiposity as predictors of blood pressure in college students

OBJECTIVE

To compare anthropometric measures of body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), and sagittal abdominal diameter (SAD) as predictors of blood pressure in college students.

PARTICIPANTS

Students (N = 116) were recruited from November 2012 to May 2014 at an urban university and rural community colleges.

METHODS

Students underwent a brief physical examination during which anthropometric measures were obtained and blood pressure was measured. Covariates were measured using self-reported questionnaires. Hierarchical multiple linear regressions were used for the data analysis.

RESULTS

All anthropometric measures were predictive of systolic (SBP) and diastolic blood pressure (DBP). WC was the strongest predictor of SBP (β = .582, p < .01) explaining an additional 3-4% of the variance than BMI, WHtR, or SAD. The measures were similar in predicting DBP. WC predicted SBP independent of BMI.

CONCLUSIONS

Clinicians should consider using WC to assess the risk for hypertension in college students.

Cross-sectional, school-based study of 14-19 year olds showed that raised blood pressure was associated with obesity and abdominal obesity

AIM

Gaining weight has been directly associated with an increased probability of developing high blood pressure (HBP) and metabolic abnormalities. We examined the independent and combined effects of overweight, obesity and abdominal obesity on blood pressure in adolescents.

METHODS

This cross-sectional school-based study evaluated 869 adolescents (53.4% girls) from 14 to 19 years of age, and the data were collected in 2013 in the city of Imperatriz, Maranhão, Brazil. The outcome was HBP. The independent variables were overweight and obesity classified by body mass index, abdominal obesity classified by the waist-to-height ratio and the combination of obesity and overweight and abdominal obesity. The potential confounding variables were age, the socio-economic status of the family, parental education, type of school and physical activity levels.

RESULTS

The prevalence ratios of HBP were higher when male and female adolescents were overweight (1.61-3.11), generally obese (3.20-4.70), had abdominal obesity (2.18-3.02) and were both generally obese and had abdominal obesity (3.28-5.16) compared with normal weight adolescents.

CONCLUSION

Obesity or abdominal obesity increased the risk of HBP in adolescents aged 14-19. However, adolescents who were both generally obese and had abdominal obesity showed an even higher risk of having HBP.

Combinations of physical activity, sedentary behaviour and sleep: relationships with health indicators in school-aged children and youth

The purpose of this systematic review was to determine how combinations of physical activity (PA), sedentary behaviour (SB), and sleep were associated with important health indicators in children and youth aged 5-17 years. Online databases (MEDLINE, EMBASE, SPORTdiscus, CINAHL, and PsycINFO) were searched for relevant studies examining the relationship between time spent engaging in different combinations of PA, SB, and sleep with the following health indicators: adiposity, cardiometabolic biomarkers, physical fitness, emotional regulation/psychological distress, behavioural conduct/pro-social behaviour, cognition, quality of life/well-being, injuries, bone density, motor skill development, and self-esteem. PA had to be objectively measured, while sleep and SB could be objectively or subjectively measured. The quality of research evidence and risk of bias for each health indicator and for each individual study was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. A total of 13 cross-sectional studies and a single prospective cohort study reporting data from 36 560 individual participants met the inclusion criteria. Children and youth with a combination of high PA/high sleep/low SB had more desirable measures of adiposity and cardiometabolic health compared with those with a combination of low PA/low sleep/high SB. Health benefits were also observed for those with a combination of high PA/high sleep (cardiometabolic health and adiposity) or high PA/low SB (cardiometabolic health, adiposity and fitness), compared with low PA/low sleep or low PA/high SB. Of the 3 movement behaviours, PA (especially moderate- to vigorous-intensity PA) was most consistently associated with desirable health indicators. Given the lack of randomized trials, the overall quality of the available evidence was low.

Objectively measured sedentary behaviour and health and development in children and adolescents: systematic review and meta-analysis

Sedentary behaviour has emerged as a unique determinant of health in adults. Studies in children and adolescents have been less consistent. We reviewed the evidence to determine if the total volume and patterns (i.e. breaks and bouts) of objectively measured sedentary behaviour were associated with adverse health outcomes in young people, independent of moderate-intensity to vigorous-intensity physical activity. Four electronic databases (EMBASE MEDLINE, Ovid EMBASE, PubMed and Scopus) were searched (up to 12 November 2015) to retrieve studies among 2- to 18-year-olds, which used cross-sectional, longitudinal or experimental designs, and examined associations with health outcomes (adiposity, cardio-metabolic, fitness, respiratory, bone/musculoskeletal, psychosocial, cognition/academic achievement, gross motor development and other outcomes). Based on 88 eligible observational studies, level of evidence grading and quantitative meta-analyses indicated that there is limited available evidence that the total volume or patterns of sedentary behaviour are associated with health in children and adolescents when accounting for moderate-intensity to vigorous-intensity physical activity or focusing on studies with low risk of bias. Quality evidence from studies with robust designs and methods, objective measures of sitting, examining associations for various health outcomes, is needed to better understand if the overall volume or patterns of sedentary behaviour are independent determinants of health in children and adolescents.

Sedentary behavior in Brazilian children and adolescents: a systematic review

OBJECTIVE

To describe the methodological characteristics of the studies selected and assess variables associated with sedentary behavior in Brazilian children and adolescents.

METHODS

For this systematic review, we searched four electronic databases: PubMed, Web of Knowledge, LILACS, SciELO. Also, electronic searches were applied in Google Scholar. A supplementary search was conducted in the references lists of the included articles and in non-indexed journals. We included observational studies with children and adolescents aged from three to 19 years developed in Brazil, presenting analyses of associations based on regression methods and published until September 30, 2014.

RESULTS

Of the 255 potential references retrieved by the searches, 49 met the inclusion criteria and composed the descriptive synthesis. In this set, we identified a great number of cross-sectional studies (n = 43; 88.0%) and high methodological variability on the types of sedentary behavior assessed, measurement tools and cut-off points used. The variables most often associated with sedentary behavior were "high levels of body weight" (in 15 out of 27 studies; 55.0%) and "lower level of physical activity" (in eight out of 16 studies; 50.0%).

CONCLUSIONS

The findings of this review raise the following demands to the Brazilian agenda of sedentary behavior research geared to children and adolescents: development of longitudinal studies, validation of measuring tools, establishment of risk cut-offs, measurement of sedentary behavior beyond screen time and use of objective measures in addition to questionnaires. In the articles available, the associations between sedentary behavior with "high levels of body weight" and "low levels of physical activity" were observed in different regions of Brazil.

The association between time spent in sedentary behaviors and blood pressure: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Sedentary behaviors, defined as waking behaviors with low energy expenditure while sitting, are positively associated with several adverse health outcomes. However, the association between sedentary behaviors and blood pressure (BP) is inconclusive. This study aimed to conduct a systematic review and meta-analysis on the association between time spent in sedentary behaviors and BP.

METHODS

We searched PubMed, MEDLINE, and Web of Science for papers published before August 2014 that assessed the association between time spent in sedentary behaviors and BP. Studies on both adults and children were included. Only good quality studies were included. The pooled estimates of systolic BP (SBP) and diastolic BP (DBP) increase per hour of time spent in sedentary behaviors a day were computed using a fixed-effects model and a random-effects model, respectively. Another pooled estimate of odds ratio per hour of time spent in sedentary behaviors a day on having high BP was computed using a fixed-effects model. A sub-group analysis was conducted for studies using self-reported and objectively assessed time spent in sedentary behaviors separately.

RESULTS

A total of 31 papers of good quality were included in the systematic review, 18 of which found no association between time spent in sedentary behaviors and BP (58.1%). A total of 28 papers were included in the meta-analysis. Pooled effects showed that an additional hour of time spent in sedentary behaviors per day was associated with an increase of 0.06 mmHg (108,228 participants, 95% CI 0.01-0.11, p = 0.01) of SBP and 0.20 mmHg (107,791 participants, 95% CI 0.10-0.29, p < 0.001) of DBP. Accelerometer-assessed time spent in sedentary behaviors was not associated with either SBP (p = 0.06) or DBP (p = 0.33). The odds ratio (OR) of having high BP with an additional hour of time spent in sedentary behaviors per day was 1.02 (98,798 participants, 95% CI 1.003-1.03, p = 0.02).

CONCLUSIONS

Self-reported but not accelerometer-assessed time spent in sedentary behaviors was associated with BP. Further studies are warranted to determine the preventive effect of reducing sedentary behaviors on high BP.

Prediction of bone mineral density and content from measures of physical activity and sedentary behavior in younger and older females

BACKGROUND

Little is known regarding the extent to which physical activity (PA) and sedentary behavior (SB) influence bone mineral content (BMC) and bone mineral density (BMD) in females across the lifespan.

METHODS

Data from 2232 females aged 12 years and older collected as part of the 2007-2008 National Health and Nutrition Examination Survey were analyzed. Categories of PA and SB were used to predict femoral and spinal BMD and BMC in four age groups (G1: 12-17; G2: 18-39; G3: 40-64; G4: ≥ 65 years). Self-reported PA categories included sufficient moderate-to-vigorous recreational PA (S-MVRPA) and insufficient MVRPA (I-MVRPA).

RESULTS

G1 females who accumulated S-MVRPA displayed greater femoral and spinal BMC and BMD compared to G1 females who displayed I-MVRPA. For G4 females, higher levels of SB were associated with lower femoral BMC and BMD.

CONCLUSIONS

These findings highlight the importance of engaging in sufficient moderate-to-vigorous physical activity during adolescence and reducing sedentary behavior in older adults to improve bone health in females.

The combined effect of physical activity and sedentary behaviors on a clustered cardio-metabolic risk score: The Helena study

BACKGROUND/OBJECTIVE

Increased physical activity (PA) and decreased sedentary behaviors (SBs) may have beneficial effects on cardio-metabolic risk in adolescents. The aim of this study was to examine the associations between independent/combined effects of PA and SB with individual/clustered cardio-metabolic risk factors.

METHODS

A sample of 769 adolescents (12.5-17.5 years) from the HELENA cross-sectional study (Healthy Lifestyle in Europe by Nutrition in Adolescence) and with valid data on metabolic risk factors were included.

RESULTS

Concerning moderate-to-vigorous-PA (MVPA) and vigorous-PA (VPA), measured with accelerometers, girls tended to do more MVPA (36%) and VPA (114%) than boys. Unadjusted analyses show a positive association between "PA ≥ 60 min/d; SB ≥ 2 h" and the ratio TC/HDL-c (β = 0.27; 95%CI 0.01 to 0.52; p < 0.05), and a negative association between "MVPA ≥ 60 min/d; SB < 2h" with the ∑ 4Skinfolds (β = -0.32; 95%CI -0.61 to -0.02; p<0.05). Moreover, "SB ≥ 2 h/d" was associated with increased cardio-metabolic risk (PR 1.59; 95%CI 1.05 to 2.39; p < 0.05), while "PA ≥ 60 min/d; SB < 2h" had a protective effect against cardio-metabolic risk (PR 0.48; 95%CI 0.25 to 0.91; p < 0.05). After adjustment for potential confounders, a positive association between SB and ∑ 4Skinfolds was shown (β = 0.28; 95%CI 0.04 to 0.53; p < 0.05). Furthermore, VO2max (mL/kg/min) tends to increase in those participants who do higher VPA and less SB (p = 0.042), and there was a protective effect of "VPA ≥ 30 min/d; SB < 2h" against cardio-metabolic risk (PR 0.24; 95%CI 0.07 to 0.85; p < 0.05).

CONCLUSION

The current study suggests that adolescents should be encouraged to decrease sedentary lifestyle and increase physical activity, especially vigorous physical activity, in order to reduce cardio-metabolic risk.

Physical activity modifies the associations between genetic variants and blood pressure in European adolescents

We hypothesized that physical activity and sedentary behavior could modify the associations between known genetic variants blood pressure-associated genes in European adolescents. Meeting current physical activity recommendations (≥ 60 minutes/day) was able attenuate the deleterious effect of the NOS3 rs3918227 polymorphism on systolic blood pressure in European adolescents.

Nutrition and lifestyle in european adolescents: the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study

Adolescence is a critical period, because major physical and psychologic changes occur during a very short period of time. Changes in dietary habits may induce different types of nutritional disorders and are likely to track into adulthood. The aim of this review is to describe the key findings related to nutritional status in European adolescents participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. We performed a cross-sectional study in 3528 (1845 females) adolescents aged 12.5–17.5 y. Birth weight was negatively associated with abdominal fat mass in adolescents and serum leptin concentrations (in female adolescents), providing additional evidence for a programming effect of birth weight on energy homeostasis control. Breakfast consumption was associated with lower body fat content and healthier cardiovascular profile. Adolescents eat half of the recommended amount of fruit and vegetables and less than two-thirds of the recommended amount of milk and milk products but consume more meat and meat products, fats, and sweets than recommended. For beverage consumption, sugar-sweetened beverages, sweetened milk, low-fat milk, and fruit juice provided the highest amount of energy. Although the intakes of saturated fatty acids (FAs) and salt were high, the intake of polyunsaturated FAs was low. Adolescents spent, on average, 9 h/d of their waking time (66–71% and 70–73% of the registered time in boys and girls, respectively) in sedentary activities. Factors associated with adolescents’ sedentary behavior included the following: 1) age; 2) media availability in the bedroom; 3) sleeping time; 4) breakfast consumption; and 5) season. Sedentary time was also associated with cardiovascular risk factors and bone mineral content. In European adolescents, deficient concentrations were identified for plasma folate (15%), vitamin D (15%), pyridoxal 5′-phosphate (5%), β-carotene (25%), and vitamin E (5%). Scientists and public health authorities should raise awareness of the importance of a healthy and sustainable lifestyle as a foundation of the health of the European population, now and in the future.

Objectively measured sedentary behaviour and cardio-metabolic risk in youth: a review of evidence

The aim of this paper was to review studies that examine the association between volume and pattern of objectively measured sedentary behaviour and markers of cardio-metabolic risk in youth. A search for relevant articles was conducted in PubMed and SportDiscus, and the following inclusion criteria were applied: (i) youth participants (age range 6-19); (ii) accelerometer-measured volume and/or pattern of sedentary behaviour and its association with ≥1 cardio-metabolic outcome; and (iii) published, in press or accepted in an English language peer-reviewed journal between January 2000 and October 2013. A total of 45 articles met the a priori criteria and, thus, were considered eligible for inclusion. Although youth accumulate approximately 6 to 8 h of daily sedentary behaviour, little evidence supports an association with individual and clustered cardio-metabolic risk when adjusted for moderate-to-vigorous physical activity (MVPA).

CONCLUSION

We suggest that youth should be encouraged to engage in recommended levels of MVPA and reduce excessive time spent in screen-based sedentary behaviour. Future studies should examine the association between volume and pattern of objectively measured sedentary behaviour and cardio-metabolic risk independent of time spent in MVPA.