Higher self-reported physical activity is associated with lower systolic blood pressure: the Dietary Intervention Study in Childhood (DISC)

Associations Between Physical Activity and Hypertension in Chinese Children: A Cross-Sectional Study From Chongqing

Background: Childhood blood pressure is a marker for cardiovascular disease risk later in life. Few studies examined the association between physical activity (PA) and hypertension in Chinese children, and this study aimed to explore this relationship.

Methods: A cross-sectional study among pupils was conducted in Chongqing in 2014. In total, 15,203 children aged 6–12 years in Chongqing were included in this study. The duration of self-reported PA on school days and the weekend in pupils were collected with a standardized questionnaire.

Results: The results showed that, on school days, only 22.3% of boys and 17.8% of girls engaged in more than 60 min of PA per day; while on the weekend, only 38.5% of boys and 32.0% of girls engaged in at least 60 min of PA per day. There was no strong evidence for an association between PA and systolic or diastolic hypertension in boys. However, in girls, a weak negative association between PA on weekdays and hypertension was observed, and there was a significant interactive effect of PA and obesity on hypertension risk (P_{for interaction} = 0.042). In obese children, PA was positively related to the risk of hypertension.

Conclusion: The overall level of PA among pupils in Chongqing was insufficient, and a weak negative relationship between PA and hypertension was found in girls.

Association between pubertal development and elevated blood pressure in children

Blood pressure (BP) increased with age and height development, but little was known about the effect of pubertal development on blood pressure in children. A cross‐sectional study was performed among 4146 children aged 7–12 years old in China. Pubertal development was assessed based on breast stages and testicular volume. The associations of pubertal development with BP levels and the rate of elevated blood pressure (EBP) were quantified using multiple linear and logistic regressions. We found that pubertal developmental level was positively correlated with BP, and children who experienced puberty onset and early pubertal timing had higher BP levels and prevalence of EBP. After adjusting for covariates, children experienced puberty onset had 3.84 and 2.24 mmHg increase in systolic blood pressure and diastolic blood pressure, and 70%, 53%, and 62% increased odds of EBP, ESBP, and EDBP, respectively, compared with those without puberty onset. Similar results were observed for children who had early pubertal timing. The change of BP in puberty is greater and the association between pubertal development and BP is stronger in girls than boys. These findings suggested that pubertal development could be an important independent factor and one critical period for the EBP progress. Monitoring and management of pubertal development are necessary particularly among girls.

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.

Associations of body mass index, physical activity and sedentary time with blood pressure in primary school children from south-west England: A prospective study

Elevated blood pressure in children is a significant risk factor for the development of cardiovascular disease in adulthood. We examined how children’s body mass index (BMI), physical activity and sedentary time at ages 9 and 11 are associated with blood pressure at age 11. Data were from 1283 children from Bristol, UK, who participated in the study aged 11 years, 797 of whom also participated in the study aged 9 years. Child height, weight and blood pressure were measured, and children wore accelerometers for five days, from which moderate-to-vigorous-intensity physical activity and sedentary minutes per day were derived. Multiple imputation of missing data and adjusted linear and logistic regression models were used to examine associations. Child BMI at 11 years was cross-sectionally associated with higher systolic and diastolic blood pressure (mean difference [95% confidence interval]: 0.91 [0.32 to 1.50] mm Hg and 1.08 [0.54 to 1.62] mm Hg, respectively, per standard deviation (SD) of BMI). BMI at age 9 was also positively associated with diastolic blood pressure at age 11 (1.16 mmHg per two years [0.49 to 1.84], per SD of BMI). For girls, sedentary time at age 9 years was associated with increased odds of having high systolic blood pressure at age 11 (odds ratio: 1.08 [1.01 to 1.16], per 10 minutes per day). There was no evidence of associations between sedentary time and blood pressure among boys. Similarly, there was little evidence that physical activity was associated with blood pressure in either cross-sectional or prospective analyses. Effective strategies are needed to prevent excess bodyweight among children in order to reduce cardiovascular disease risk.

Intensity and frequency of physical activity and high blood pressure in adolescents: A longitudinal study

Despite limited evidence on the association between physical activity (PA) and blood pressure (BP) in youth, experts recommend that adolescents engage regularly in moderate-to-vigorous PA. We examined the relationships between PA intensity and frequency and the likelihood of having high BP in a population-based cohort of adolescents from Montréal, Canada. PA was self-reported every 3 months from grade 7 to 11, and BP was measured at ages 12.8, 15.2, and 17.0 years on average. We analyzed data from 993 participants (mean [SD] age = 16.0 [1.0], 51.6% female) with BP data at ages 15.2 and/or 17.0 years, using pooled ordinal logistic regression. BP (normal/elevated/hypertensive range) was the outcome, and past-year PA intensity and frequency were potential predictors. Eight percent of participants had elevated BP (120-129/<80), and 3.2% had BP in the hypertensive range (≥130/≥80). Participants engaged in a median (interquartile range) of 7.0 (4.5, 9.3) and 5.5 (2, 10.8) moderate and vigorous PA sessions/week, respectively. After adjusting for age, sex, mother's education, use of alcohol and cigarette consumption, engaging in PA more intense than light during the previous year was associated with a lower odds of having BP in the hypertensive range (ORs [95% CIs] = 0.93 [0.88, 0.97] to 0.97 [0.94, 0.99]). The relationships were not altered by adjusting for BMI. Our findings support recommendations that adolescents engage in at least moderate PA on a regular basis to prevent development of BP in the hypertensive range.

When should cardiovascular prevention begin? The importance of antenatal, perinatal and primordial prevention

Cardiovascular diseases represent a major health problem, being one of the leading causes of morbidity and mortality worldwide. Therefore, in this scenario, cardiovascular prevention plays an essential role although it is difficult to establish when promoting and implementing preventive strategies. However, there is growing evidence that prevention should start even before birth, during pregnancy, aiming to avoid the onset of cardiovascular risk factors, since events that occur early in life have a great impact on the cardiovascular risk profile of an adult. The two pillars of this early preventive strategy are nutrition and physical exercise, together with prevention of cardio-metabolic diseases during pregnancy. This review attempts to gather the growing evidence of the benefits of antenatal, perinatal and primordial prevention, discussing also the possibility to reverse or to mitigate the cardiovascular profile developed in the initial stages of life. This could pave the way for future research, investigating the optimal time and duration of these preventing measures, their duration and maintenance in adulthood, and the most effective interventions according to the different age and guiding in the next years, the best clinical practice and the political strategies to cope with cardiovascular disease.

Etanercept With IVIg for Acute Kawasaki Disease: A Randomized Controlled Trial

OBJECTIVES

Patients with Kawasaki disease can develop life-altering coronary arterial abnormalities, particularly in those resistant to intravenous immunoglobulin (IVIg) therapy. We tested the tumor necrosis factor α receptor antagonist etanercept for reducing both IVIg resistance and coronary artery (CA) disease progression.

METHODS

In a double-blind multicenter trial, patients with Kawasaki disease received either etanercept (0.8 mg/kg; n = 100) or placebo (n = 101) subcutaneously starting immediately after IVIg infusion. IVIg resistance was the primary outcome with prespecified subgroup analyses according to age, sex, and race. Secondary outcomes included echocardiographic CA measures within subgroups defined by coronary dilation (z score >2.5) at baseline. We used generalized estimating equations to analyze z score change and a prespecified algorithm for change in absolute diameters.

RESULTS

IVIg resistance occurred in 22% (placebo) and 13% (etanercept) of patients (P = .10). Etanercept reduced IVIg resistance in patients >1 year of age (P = .03). In the entire population, 46 (23%) had a coronary z score >2.5 at baseline. Etanercept reduced coronary z score change in those with and without baseline dilation (P = .04 and P = .001); no improvement occurred in the analogous placebo groups. Etanercept (n = 22) reduced dilation progression compared with placebo (n = 24) by algorithm in those with baseline dilation (P = .03). No difference in the safety profile occurred between etanercept and placebo.

CONCLUSIONS

Etanercept showed no significant benefit in IVIg resistance in the entire population. However, preplanned analyses showed benefit in patients >1 year. Importantly, etanercept appeared to ameliorate CA dilation, particularly in patients with baseline abnormalities.

WITHDRAWN: Interventions for treating obesity in children

BACKGROUND

Child and adolescent obesity is increasingly prevalent, and can be associated with significant short- and long-term health consequences.

OBJECTIVES

To assess the efficacy of lifestyle, drug and surgical interventions for treating obesity in childhood.

SEARCH METHODS

We searched CENTRAL on The Cochrane Library Issue 2 2008, MEDLINE, EMBASE, CINAHL, PsycINFO, ISI Web of Science, DARE and NHS EED. Searches were undertaken from 1985 to May 2008. References were checked. No language restrictions were applied.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) of lifestyle (i.e. dietary, physical activity and/or behavioural therapy), drug and surgical interventions for treating obesity in children (mean age under 18 years) with or without the support of family members, with a minimum of six months follow up (three months for actual drug therapy). Interventions that specifically dealt with the treatment of eating disorders or type 2 diabetes, or included participants with a secondary or syndromic cause of obesity were excluded.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data following the Cochrane Handbook. Where necessary authors were contacted for additional information.

MAIN RESULTS

We included 64 RCTs (5230 participants). Lifestyle interventions focused on physical activity and sedentary behaviour in 12 studies, diet in 6 studies, and 36 concentrated on behaviorally orientated treatment programs. Three types of drug interventions (metformin, orlistat and sibutramine) were found in 10 studies. No surgical intervention was eligible for inclusion. The studies included varied greatly in intervention design, outcome measurements and methodological quality.Meta-analyses indicated a reduction in overweight at 6 and 12 months follow up in: i) lifestyle interventions involving children; and ii) lifestyle interventions in adolescents with or without the addition of orlistat or sibutramine. A range of adverse effects was noted in drug RCTs.

AUTHORS' CONCLUSIONS

While there is limited quality data to recommend one treatment program to be favoured over another, this review shows that combined behavioural lifestyle interventions compared to standard care or self-help can produce a significant and clinically meaningful reduction in overweight in children and adolescents. In obese adolescents, consideration should be given to the use of either orlistat or sibutramine, as an adjunct to lifestyle interventions, although this approach needs to be carefully weighed up against the potential for adverse effects. Furthermore, high quality research that considers psychosocial determinants for behaviour change, strategies to improve clinician-family interaction, and cost-effective programs for primary and community care is required.

Physical activity for children with chronic disease; a narrative review and practical applications

BACKGROUND

Physical activity (PA) is associated with a diverse range of health benefits. International guidelines suggest that children should be participating in a minimum of 60 min of moderate to vigorous intensity PA per day to achieve these benefits. However, current guidelines are intended for healthy children, and thus may not be applicable to children with a chronic disease. Specifically, the dose of PA and disease specific exercise considerations are not included in these guidelines, leaving such children with few, if any, evidence-based informed suggestions pertaining to PA. Thus, the purpose of this narrative review was to consider current literature in the area of exercise as medicine and provide practical applications for exercise in five prevalent pediatric chronic diseases: respiratory, congenital heart, metabolic, systemic inflammatory/autoimmune, and cancer.

METHODS

For each disease, we present the pathophysiology of exercise intolerance, summarize the pediatric exercise intervention research, and provide PA suggestions.

RESULTS

Overall, exercise intolerance is prevalent in pediatric chronic disease. PA is important and safe for most children with a chronic disease, however exercise prescription should involve the entire health care team to create an individualized program.

CONCLUSIONS

Future research, including a systematic review to create evidence-based guidelines, is needed to better understand the safety and efficacy of exercise among children with chronic disease.

The Role of Exercise Prescription in Pediatric Preventive Cardiology Programs

Lifestyle changes such as exercise and dietary change are recommended first-line therapy for children with dyslipidemia, hypertension, and obesity. Although most clinicians recommend exercise, specific exercise prescriptions are not usually provided. The optimal type, duration, and intensity of activity to achieve a meaningful outcome is not definitively defined. As the pediatric population becomes more sedentary and morbidity accumulates from this lifestyle, understanding how targeted exercise prescriptions can benefit patients will be critical to effectively manage this group of patients. This review focuses on the role of exercise for the treatment of pediatric patients with dyslipidemia, hypertension, and obesity and describes additional factors that require future research to achieve desired outcomes in this at-risk population. [Pediatr Ann. 2018;47(12):e494-e498.].

Physical Activity, BMI, and Blood Pressure in US Youth: NHANES 2003-2006

PURPOSE

The objective of this study was to examine the independent and combined association of physical activity and body mass index (BMI) with blood pressure in youth.

METHODS

Youth aged 8-18 years from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) with BMI, blood pressure, and physical activity (accelerometer) were included in the analyses. A total of 2585 subjects (1303 males; 47% of all 8- to 18-year-olds) met these criteria.

RESULTS

Obese youth had a systolic blood pressure that was 8 mm Hg higher than normal weight youth. A significant interaction between BMI and physical activity on blood pressure was found (P < .001), and group differences among the BMI/activity groups showed that the 3 obese groups and the overweight/least active group had significantly higher systolic blood pressure than the normal weight/active group across all analyses. The overweight/least active and normal weight/least active groups had significantly higher diastolic blood pressure than the normal weight/active group as well.

CONCLUSIONS

This study showed a significant independent and combined association of BMI and physical activity with blood pressure in youth. Interventions need to focus on the reduction of fatness/BMI as a way to reduce the cardiovascular risk in youth.

Perinatal and childhood exposure to environmental chemicals and blood pressure in children: a review of literature 2007-2017

Exposure to environmental chemicals during periods of renal development from embryogenesis to birth and through childhood can inform critical windows of nephrotoxicity, including changes in childhood blood pressure. This review assessed recent studies that examined the relationship of air pollution, metals, and other organic pollutants with children's blood pressure outcomes. We restricted this review to peer-reviewed studies published in English between January 2007 and July 2017. We identified a total of 36 articles that estimated associations with childhood blood pressure, of which 14 studies examined the effects of air pollution, 10 examined metals, and 12 examined other organic pollutants including phthalates (n = 4), Bisphenol A (n = 3), polychlorinated biphenols (n = 2), organophosphate pesticides (n = 2), or perfluoroalkyl acids (n = 1). Similar to the established relationship between tobacco smoke exposure and childhood blood pressure, the majority of studies that examined air pollutants, particularly exposure to PM10 and PM2.5, reported associations with increased childhood blood pressure. The literature reported conflicting evidence for metals, and putative evidence of the effects of exposure to phthalates, Bisphenol A, polychlorinated biphenols, and pesticides. Overall, our review underscores the need for additional studies that assess the impact of nephrotoxicant exposure during early life, particularly the perinatal period, and blood pressure in childhood.

A longitudinal study of the associations of children's body mass index and physical activity with blood pressure

Childhood blood pressure is a marker of cardiovascular disease risk in later life. We examined how body mass index (BMI) and physical activity, and changes in these, are associated with blood pressure in primary school-aged children. Data are from 1223 children aged 9 years (Year 4) in Bristol, UK, 685 of whom had been assessed at 6 years (Year 1). Child height and weight were measured, and children wore accelerometers for five days, from which average counts per minute, and moderate-to-vigorous-intensity physical activity and sedentary minutes per day were derived. At age 9 years, blood pressure was measured. Multiple imputation of missing data and adjusted linear regression models were used to examine associations. Child BMI at 9 years was cross-sectionally associated with higher systolic (SBP) and diastolic (DBP) blood pressure (mean difference [95% CI]: 1.10 [0.34, 1.87] mmHg and 0.86 [0.13, 1.60] mmHg, respectively, per SD of BMI). Prospective associations of BMI at age 6 with blood pressure at age 9 were consistent with these cross-sectional associations. However, change in BMI between 6 and 9 years was not strongly associated with subsequent SBP or DBP (0.68 [-0.61, 1.98] mmHg and 1.23 [-0.09, 2.54] mmHg, respectively). There was little evidence that physical activity or sedentary time were associated with blood pressure in either cross-sectional or prospective analyses. Greater childhood BMI is associated with higher blood pressure, and this association persists over several years. Prevention of excessive bodyweight from early childhood may be important in stemming the development of cardiovascular risk.

Physical Activity Opportunities Within the Schedule of Early Care and Education Centers

BACKGROUND

Physical activity has many benefits for young children's health and overall development, but few studies have investigated how early care and education centers allot time for physical activity, along with measured individual physical activity levels for indoor/outdoor activities during a typical day.

METHODS

Fifty early care and education centers in central North Carolina participated in 4 full-day observations, and 559 children aged 3-5 years within centers wore accelerometers assessing physical activity during observation days. Observation and physical activity data were linked and analyzed for associations between child activity and type of classroom activity.

RESULTS

Children averaged 51 (13) minutes per day of moderate to vigorous physical activity and 99 (18) minutes per day of light physical activity while in child care. Children averaged 6 (10) and 10 (13) minutes per day of observed outdoor and indoor daily teacher-led physical activity, respectively. Outdoor time averaged 67 (49) minutes per day, and physical activity levels were higher during outdoor time than during common indoor activities (center time, circle time, and TV time).

CONCLUSIONS

Physical activity levels varied between indoor and outdoor class activities. Policy and program-related efforts to increase physical activity in preschoolers should consider these patterns to leverage opportunities to optimize physical activity within early care and education centers.

Trajectories of maternal leisure-time physical activity and sedentary behavior during adolescence to young adulthood and offspring birthweight

PURPOSE

The objectives of the study were to determine the extent to which trajectories of maternal preconception leisure-time physical activity (LTPA) and leisure-time sedentary behavior (LTSB) during adolescence and young adulthood are associated with offspring birth weight (BW) and to test if these associations differ by offspring sex or maternal pre-pregnancy overweight-obese status.

METHODS

Participants with one or more birth (n = 1408) were identified from the National Longitudinal Study of Adolescent to Adult Health. Group-based trajectory modeling was used to characterize trajectories of LTPA (frequency/week) and LTSB (hours/week) which were measured, on average, over 7 years between age 15 and 22 years. Weighted regression and Wald tests were used to estimate and test mean differences and odds ratios for BW, small for gestational age, and large for gestational age (LGA).

RESULTS

Three trajectories were identified for LTPA and five for LTSB. Associations differed by offspring sex for continuous BW and LGA (interaction P = .10 and .008, respectively). Among female offspring, participants with high followed by decreasing LTPA delivered offspring with 90 g greater BW (95% confidence interval [CI]: -4 to 184) and 72% greater risk of LGA (95% CI: 0.94-3.14), compared with participants with low LTPA. Among male offspring, LTPA patterns were not associated with BW. A pattern of high then decreasing LTPA among normal weight, but not overweight-obese women, was associated with 2.03 times greater risk of LGA (95% CI: 1.06-3.88). LTSB trajectories were not associated with BW.

CONCLUSIONS

Associations of preconception trajectories of LTPA with offspring BW may differ by offspring sex and maternal pre-pregnancy overweight-obese status.

Special Article: Physical Activity, Physical Fitness, and Cardiovascular Risk Factors in Childhood

In adults, physical activity and exercise training are associated with reduced cardiovascular morbidity and mortality, a reduced likelihood of developing adverse cardiovascular risk factors, and improved insulin sensitivity. In childhood, participation in appropriate physical activity may prevent the development of cardiovascular risk factors in the future and complement treatment of existing cardiovascular risk factors, including hypertension, dyslipidemia, and overweight. Exercise in children can also significantly improve insulin sensitivity independent of weight loss. These e fects are mediated in overweight children by increases in lean body mass relative to fat mass and associated improvements in inflammatory mediators, endothelial function, and the associated adverse hormonal milieu.

Result of school-based intervention on cardiovascular risk factors

OBJECTIVE

To assess the effectiveness of a two-year school-based intervention, consisting of integrated and replicable physical activity and nutritional education on weight, fat percentage, cardiovascular risk factors, and blood pressure.

DESIGN AND SETTING

Six elementary schools in Reykjavik were randomly assigned to be either intervention (n = 3) or control (n = 3) schools. Seven-year-old children in the second grade in these schools were invited to participate (n = 321); 268 (83%) underwent some or all of the measurements. These 286 children were followed up for two years.

INTERVENTION

Children in intervention schools participated in an integrated and replicable physical activity programme, increasing to approximately 60 minutes of physical activity during school in the second year of intervention. Furthermore, they received special information about nutrition, and parents, teachers, and school food service staff were all involved in the intervention. Subjects. 321seven-year-old schoolchildren.

MAIN OUTCOME MEASURES

Blood pressure, obesity, percentage of body fat, lipid profile, fasting insulin.

RESULTS

Children in the intervention group had a 2.3 mmHg increase in systolic blood pressure (SBP) and a 2.9 mmHg increase in diastolic blood pressure (DBP) over the two-year intervention period, while children in the control group increased SBP by 6.7 mmHg and DPB by 8.4 mmHg. These changes were not statistically significant. Furthermore there were no significant changes in percentage body fat, lipid profile, or fasting insulin between the intervention and control schools.

CONCLUSION

A two-year school-based intervention with increased physical activity and healthy diet did not have a significant effect on common cardiovascular risk factors.

Self-recalled Youth Physical Activity and Postmenopausal Cardiovascular Disease

OBJECTIVES

To evaluate the association between childhood physical activity and incident cardiovascular disease (CVD) during postmenopausal years.

METHODS

Proportional hazards and logistic regression were used describe the association between self-reported childhood physical activity and CVD incidence and mortality in 36,741 postmenopausal women.

RESULTS

Older women, African-Americans, or nondrinkers or past drinkers self-reported the highest levels of youth physical activity and women with a history of diabetes, hypertension, overweight or obesity, or current smoking reported the highest youth physical activity dose. Youth physical activity was not associated with CVD incidence (HR=1.11; 0.93, 1.34) or mortality (HR=1.2; 0.9, 1.73).

CONCLUSIONS

Self-reported youth activity was not associated with postmenopausal CVD incidence or mortality.

Impact of a pilot pharmacy health-care professional out-of-school time physical activity and nutrition education program with exercise on fourth and fifth graders in a rural Texas community

Objectives:

Childhood obesity continues to be a problem. Children in rural populations are more likely to be overweight or obese and a lack of resources in those areas may contribute to this problem. We aimed to assess the impact of a pilot pharmacy health-care professional out-of-school time vigorous physical activity and nutrition education program on fourth and fifth graders in a rural Texas community.

Methods:

We conducted a prospective 12-week cohort study from August to November 2012. Thirty-three children, aged 8–11 years, in Bailey County, Texas, were enrolled in the study. Body mass index, body mass index percentile, blood pressure, waist circumference, and a diet preferences and activities knowledge survey were obtained at 0, 4, 8, and 12 weeks. Study participants completed a twice weekly physical activity and nutrition education program with exercise over weeks 1–4 with no intervention during weeks 5–12.

Results:

Thirty-one (94%) of the 33 children, predominately Hispanic girls, completed the program. Body mass index (−0.30 (95% confidence interval, −0.44 to −0.17); P = <0.0001), body mass index percentile (−2.75 (95% confidence interval, −4.89 to −0.62); P = 0.0026), systolic blood pressure (−1.9 (95% confidence interval, −2.9 to −0.9); P = <0.0001), and waist circumference (−0.47 (95% confidence interval, −0.85 to −0.10); P = <0.0001) mean change decreased between baseline and week 12 with no intervention for 8 weeks. Positive survey results at 3 months indicated a decrease in fried/sweet foods; increase in exercise; decreases in video games and computer use; and a change in knowledge regarding the selection of the most healthy food group servings per day.

Conclusion:

In this pharmacy health-care directed pilot study, participants had a reduction of body mass index, body mass index percentile, systolic blood pressure, waist circumference, and improvement in certain survey results at the end of 12 weeks despite no further intervention after 4 weeks.

Physical Activity and Blood Pressure in Primary School Children

High blood pressure (BP) is becoming increasingly common during childhood. Regular physical activity (PA) reduces BP in adults, but limited studies have reported inconsistent results among children. The aim of this study is to examine, for the first time, the cross-sectional and longitudinal associations between BP and objectively measured PA in young children of predominantly South Asian background. Data from the Birmingham healthy Eating and Active lifestyle for CHildren Study were analyzed. Five hundred seventy-four children, aged 5 to 7 years, underwent a series of measures at baseline and were followed up 2 years later. PA was objectively measured using accelerometry and converted to counts per minute (total PA, cpm), and time spent in moderate-vigorous PA (minutes per day). BP was measured by trained staff using standard protocols. Data were available for 512 children at baseline (mean age 6.5 years, range 5.4–7.8 years), and 427 of these children were followed up. Baseline total PA was inversely associated with diastolic BP at both baseline (adjusted regression coefficient: −0.75 mm Hg [95% CI −1.33 to −0.18] per 20 cpm) and follow-up (−0.74 mm Hg [95% CI −1.40 to −0.08]). All associations remained unchanged after further adjustment for weight status. This study strengthens evidence of a causal association between higher PA and lower BP in children as young as 5, independent of weight status. The results provide support for development of interventions to increase PA in young children.

Increasing blood pressure and its associated factors in Canadian children and adolescents from the Canadian Health Measures Survey

BACKGROUND

Canada is facing a childhood obesity epidemic. Elevated blood pressure (BP) is a major complication of obesity. Reports on the impact of excess adiposity on BP in children and adolescents have varied significantly across studies. We evaluated the independent effects of obesity, physical activity, family history of hypertension, and socioeconomic status on BP in a nationally representative sample of children and adolescents.

METHODS

We analysed cross-sectional data for 1850 children aged 6 to 17 years who participated in the Canadian Health Measures Survey, Cycle 1, 2007-2009. Systolic BP (SBP) and diastolic BP (DBP) were age-, sex-, and height-adjusted to z-scores (SBPZ and DBPZ). Body mass index (BMI) z-scores were calculated based on World Health Organization growth standards. Multivariate linear regression was used to evaluate the independent effects of relevant variables on SBPZ and DBPZ.

RESULTS

For most age/sex groups, obesity was positively associated with SBP. Being obese was associated with higher DBP in adolescent boys only. The BP effect of obesity showed earlier in young girls than boys. Obese adolescents were estimated to have an average 7.6 mmHg higher SBP than normal weight adolescents. BMI had the strongest effect on BP among obese children and adolescents. Moderately active adolescent boys had higher SBP (3.9 mmHg) and DBP (4.9 mmHg) than physically active boys. Family history of hypertension showed effects on SBP and DBP in younger girls and adolescent boys. Both family income and parent education demonstrated independent associations with BP in young children.

CONCLUSIONS

Our findings demonstrate the early impact of excess adiposity, insufficient physical activity, family history of hypertension, and socioeconomic inequalities on BP. Early interventions to reduce childhood obesity can, among other things, reduce exposure to prolonged BP elevation and the future risk of cardiovascular disease.

Physical activity and sedentary behaviour at different life stages and adult blood pressure in the 1958 British cohort

OBJECTIVES

To investigate whether physical activity or sedentary behaviour at different life stages is associated with blood pressure (BP) in mid-adulthood; activity levels have accumulative associations with BP; and adult body mass index (BMI) mediates associations.

METHODS

Information on activity and television-viewing was available at several ages (23, 33, 42, 45 years) and BP at 45 years for the 1958 British birth cohort (n = 9927). Associations were examined with and without adjustment for covariates.

RESULTS

Active adults, generally, had lower mean systolic and diastolic BP and risk of hypertension than nonactive, although varying by age. After adjustment for covariates, systolic and diastolic BP for active men at 23 years or at 45 years were 1-2 mmHg lower; similar associations were seen for women active at 33 years. Some but not all associations attenuated with further adjustment for BMI: odds ratio (OR) for hypertension associated with 23 years activity changed from 0.82 [95% confidence interval (CI) 0.74, 0.91] to 0.79 (0.70, 0.90) after BMI adjustment. Independent associations of activity at more than one age were found, such that prevalence of hypertension was higher in men active at 23 years but not at 45 years, than men sustaining activity (39 vs. 31%). Sitting at work was unrelated to BP, but there was a trend of higher BP with greater television-viewing: for example risk of hypertension was higher by 10-12% per h/day television-viewing at 45 years after adjustment for covariates, attenuating after allowance for BMI.

CONCLUSION

Our study suggests that there are benefits to BP of becoming and sustaining active lifestyles and minimizing television-viewing over many years of adulthood, with a mediating role for BMI.

Physical activity and the achievement gap among urban minority youth

OBJECTIVES

To outline the prevalence and disparities of physical activity among school-aged urban minority youth, causal pathways through which low levels of physical activity and fitness adversely affects academic achievement, and proven or promising approaches for schools to increase physical activity and physical fitness among youth.

METHODS

Literature review.

RESULTS

A large proportion of youth is insufficiently physically active. Estimates of population-wide levels of physical activity indicate that Black and Hispanic youth are less physically active than White youth, with disparities particularly evident for females. The population segments of youth with lowest levels of physical activity and fitness also have least access to school-based physical activity opportunities and resources. Physical activity affects metabolism and all major body systems, exerting powerful positive influences on the brain and spinal cord and, consequently, on emotional stability, physical health, and motivation and ability to learn. The cornerstone of school-based physical activity programs should be a high-quality physical education program based on national standards. Such programs are strongly recommended by the Task Force on Community Preventive Services as a way to increase physical activity and physical fitness among youth.

CONCLUSIONS

Physical inactivity is highly and disproportionately prevalent among school-aged urban minority youth, has a negative impact on academic achievement through its effects on cognition, and effective practices are available for schools to address this problem. Increasing students' physical activity and physical fitness can best be achieved through a comprehensive approach that includes physical education, wise use of recess and after-school times, co-curricular physical activity opportunities, and bicycling or walking to and from school.

Health-related fitness in children and adolescents

PURPOSE

The American Physical Therapy Association Section on Pediatrics developed a task force to summarize fitness guidelines for children and adolescents. The purposes of this article were to review components, measurement methods, and consequences of physical fitness, and to summarize evidence-based activity recommendations for youth.

SUMMARY OF KEY POINTS

Health-related fitness is comprised of body composition, flexibility, cardiorespiratory endurance, and muscular strength and endurance. Each of these components is reviewed in terms of definition, assessment, normative values, and recommendations.

CONCLUSIONS

The task force supports the guidelines of the US Department of Health and Human Services, which state that to promote overall health and wellness, youth should participate in 60 minutes or more of physical activity every day.

RECOMMENDATIONS FOR CLINICAL PRACTICE

Physical therapists should apply research relevant to health-related fitness when treating youth. Promoting fitness, health, and wellness in our communities is a responsibility all therapists should assume.

Long-term follow-up of cardiovascular risk factors after exercise training in obese children

OBJECTIVE

We previously demonstrated beneficial effects of physical activity on cardiovascular disease (CVD) risk factors, body mass index (BMI) and fat mass in pre-pubescent obese children. The aim of this study was to determine whether these changes were maintained 2 years later.

METHODS

Two years after the Randomised Controlled Trial, we performed a follow-up study with 20 of 38 subjects (11.4 ± 1.8 years). Outcomes included blood pressure (BP) by ambulatory monitoring; arterial function and structure using high-resolution ultrasound, BMI, body composition by dual-energy x-ray absorptiometry (DXA), physical activity using accelerometer, and biological markers.

RESULTS

During the 2-year follow-up period, mean 24-hour diastolic BP z-score significantly decreased (1.4 ± 1.2 vs. 0.3 ± 1.4, p = 0.04), while systolic BP z-score was slightly reduced (2.4 ± 1.5 vs. 1.4 ± 1.7, p = 0.067). Blood pressure changes were greater in children who diminished their BMI z-score compared with the ones who did not. Systolic hypertension rates dropped from 50 to 28% and diastolic hypertension from 42 to 6%. In addition, arterial intima-media thickness (0.51 ± 0.03 vs. 0.51 ± 0.06, p = 0.79), BMI z-score (2.9 ± 0.8 vs. 2.9 ± 1.1 kg.cm(-2), p = 0.27), body fat (41.9 ± 6.9 vs. 42.8 ± 6.7%; p = 0.39) and physical activity count (703 ± 209 vs. 574 ± 244 cpm, p = 0.30) were stable.

CONCLUSION

To our knowledge, this is the first study reporting that beneficial effects on adiposity and CVD risk factors of a physical activity centred intervention are sustained 2 years after the cessation of training in obese children. Subjects stabilized BMI z-score and maintained physical activity with further improvement of BP and stabilization of arterial wall remodelling. We conclude that it is important to encourage physical activity in this population. Effects of Aerobic Exercise Training on Arterial Function and Insulin Resistance Syndrome in Obese Children: A Randomised Controlled Trial: NCT00801645.

Prevalence and incidence of hypertension in adolescent girls

OBJECTIVE

To estimate the prevalence and incidence of hypertension and prehypertension and associated factors in adolescent girls.

STUDY DESIGN

A total of 2368 girls (49% Caucasian, 51% African-American) aged 9 or 10 years enrolled in the National Heart, Lung, and Blood Institute Growth and Health Study had blood pressure, height, and weight measured at annual visits through age 18 to 19 years. Prevalence and incidence of hypertension and prehypertension were calculated.

RESULTS

On the basis of 2 visits, hypertension prevalence was approximately 1% to 2% in African-American girls and 0.5% in Caucasian girls. Incidence in 8 years was 5.0% and 2.1%, respectively. Obese girls had higher prevalence (approximately 6-fold higher) and incidence (approximately 2- to 3-fold higher) compared with girls of normal weight. Similar patterns were found for prehypertension, except that prehypertension occurred more in older girls than younger girls. Dietary factors (lower intake of fiber, potassium, magnesium, and calcium, and higher intake of caffeine and calories) were each associated with hypertension incidence (all P<.05). In multivariate analysis, higher body mass index (P<.001) and lower potassium intake (P=.023) were independently associated with incidence of hypertension.

CONCLUSIONS

Hypertension occurred early in childhood and was related to obesity and other modifiable lifestyle factors. Clinicians should monitor blood pressure during childhood and provide focused diet and physical activity guidance to minimize the development of hypertension.

Physical activity, obesity and cardiometabolic risk factors in 9- to 10-year-old UK children of white European, South Asian and black African-Caribbean origin: the Child Heart And health Study in England (CHASE)

AIMS/HYPOTHESIS

Physical inactivity is implicated in unfavourable patterns of obesity and cardiometabolic risk in childhood. However, few studies have quantified these associations using objective physical activity measurements in children from different ethnic groups. We examined these associations in UK children of South Asian, black African-Caribbean and white European origin.

METHODS

This was a cross-sectional study of 2,049 primary school children in three UK cities, who had standardised anthropometric measurements, provided fasting blood samples and wore activity monitors for up to 7 days. Data were analysed using multilevel linear regression and allowing for measurement error.

RESULTS

Overall physical activity levels showed strong inverse graded associations with adiposity markers (particularly sum of skinfold thicknesses), fasting insulin, HOMA insulin resistance, triacylglycerol and C-reactive protein; for an increase of 100 counts of physical activity per min of registered time, levels of these factors were 12.2% (95% CI 10.2-14.1%), 10.2% (95% CI 7.5-12.8%), 10.2% (95% CI 7.5-12.8%), 5.8% (95% CI 4.0-7.5%) and 19.2% (95% CI 13.9-24.2%) lower, respectively. Similar increments in physical activity levels were associated with lower diastolic blood pressure (1.0 mmHg, 95% CI 0.6-1.5 mmHg) and LDL-cholesterol (0.04 mmol/l, 95% CI 0.01-0.07 mmol/l), and higher HDL-cholesterol (0.02 mmol/l, 95% CI 0.01-0.04 mmol/l). Moreover, associations were broadly similar in strength in all ethnic groups. All associations between physical activity and cardiometabolic risk factors were reduced (albeit variably) after adjustment for adiposity.

CONCLUSIONS/INTERPRETATION

Objectively measured physical activity correlates at least as well with obesity and cardiometabolic risk factors in South Asian and African-Caribbean children as in white European children, suggesting that efforts to increase activity levels in such groups would have equally beneficial effects.

Cardiovascular risk factors in children and adolescents living in an urban area of Southeast of Brazil: Ouro Preto Study

This study aims to identify risk factors for cardiovascular disorders in schoolchildren living in Ouro Preto City, Brazil. A cross-sectional study was carried out in a population-based sampling of schoolchildren (6-14 years old), randomly selected and stratified by the proportion of students according to age and gender in each schools of the city. Biochemical, clinical and anthropometric variables as well as physical activity and family history were used in a logistic regression model for obesity or arterial hypertension. Out of 780 schoolchildren sampled, the risk of obesity was greater in subjects presenting high triglyceride and low high density lipoprotein-cholesterol levels, and those whose parents were obese, while the risk of hypertension was high in obese subjects and those who presented low birth weight. It was observed that 44.4% of the schoolchildren were exposed to two or three cardiovascular disease (CVD) risk factors and 8.2% were exposed to four or six factors. These findings should be considered in preventive measures to reduce the future risk for CVD among schoolchildren in Brazil.

Declines in physical activity and higher systolic blood pressure in adolescence

The authors examined the potential association between changes in the number of moderate-to-vigorous physical activity (MVPA) sessions per week, adiposity, and systolic blood pressure (SBP) during adolescence. SBP and anthropometric factors were assessed biannually (1999/2000, 2002, and 2004) in a cohort of 1,293 Canadian adolescents aged 12-13 years in 1999. Self-reported 7-day recall data on MVPA sessions >or=5 minutes in duration were collected every 3 months over the 5-year period. Estimates of initial level and rate of decline in number of MVPA sessions per week from individual growth models were used as predictors of SBP in linear regression models. A decline of 1 MVPA session per week with each year of age was associated with 0.29-mm Hg and 0.19-mm Hg higher SBPs in girls and boys, respectively, in early adolescence (ages 12.8-15.1 years) and 0.40-mm Hg and 0.18-mm Hg higher SBPs, respectively, in late adolescence (ages 15.2-17.0 years). The associations were not attenuated by changes in body mass index, waist circumference, or skinfold thickness in girls during late adolescence. Although weaker, associations were evident in boys during late adolescence, as well as in both girls and boys during early adolescence. These results support prevention of declines in MVPA during adolescence to prevent higher blood pressure in youth.

Concepts guiding therapy for hypertension in children

Increasing attention has been focused on identifying children with prehypertension and hypertension (HTN). Obesity and low birthweight are two risk factors that predispose children to develop HTN during their childhood years or later as adults. Early onset of pre-HTN and HTN increases the lifetime risk for cardiovascular sequelae. Lifestyle modification should be part of the initial recommendations for management of all hypertensive children. In those children requiring pharmacologic therapy, the choice of medication should be guided by the etiology of HTN, the needs of the child and the risk and benefit profiles of the various drug classes. The long-term impact of antihypertensive therapy in children is not known. Concerns regarding the effects of HTN and its treatment on cognitive function are of particular importance in the growing child and warrant further study. Ongoing investigations that offer promise for innovative therapeutic approaches in the future are discussed.

Nutrient intake, physical activity, and CVD risk factors in children: Project HeartBeat!

BACKGROUND

Associations among dietary intake, physical activity, and cardiovascular disease (CVD) risk factors are inconsistent among male and female youth, possibly from lack of adjustment for pubertal status. The purpose of this report is to describe the associations of CVD risk factors among youth, adjusted for sexual maturation.

METHODS

Data analyzed in 2007 from a sumsample of 556 children aged 8, 11, and 14 years in Project HeartBeat!, 1991-1993, provide cross-sectional patterns of CVD risk factors by age and gender, adjusting for sexual maturation, within dietary fat and physical activity categories.

RESULTS

Girls consuming moderate- to high-fat diets were significantly less physically active than those consuming low-fat diets. Boys and girls consuming high-fat diets had higher saturated fat and cholesterol intakes than children in low-fat categories. Boys had no significant differences in physical activity, blood pressure, waist circumference, or plasma cholesterol levels across fat categories. Girls' plasma cholesterol levels showed no significant differences across fat categories. Dietary intake did not differ across moderate-to-vigorous physical activity (MVPA) categories within gender. There were no differences in BMI by fat or MVPA categories for either gender. Girls' waist circumference differed significantly by fat category, and systolic blood pressure differed significantly across fat and MVPA categories. Boys' fifth-phase diastolic blood pressure was significantly different across MVPA categories.

CONCLUSIONS

Girls consuming atherogenic diets were significantly less physically active than those with low fat intakes, whereas boys consuming high-fat diets did not show differences in physical activity measures. With the prevalence of overweight rising among youth, the impact of atherogenic diets and sedentary lifestyles on CVD risk factors is of concern to public health professionals.

Blood pressure screening of school children in a multiracial school district: the Healthy Kids Project

BACKGROUND

There are few studies of the prevalence of elevated blood pressure (BP) that include American Indian school children. Therefore, the intent of this study was to examine the relationships between BP and risk factors in a multiracial, predominantly American Indian, school district.

METHODS

A total of 1,829 American Indian, white, Hispanic, and African American students, 5-17 years old, were included in this study. The mean of two BP measurements, taken at the initial screening with an electronic BP monitor, were categorized as normal, prehypertensive, or hypertensive using the 2004 Fourth Report BP screening recommendations. Prevalence of prehypertensive and hypertensive BP measurements by race, gender, age, and body mass index (BMI) were determined, and their associations analyzed with logistic regression.

RESULTS

The prevalence of prehypertensive measurements was 16.7% and prevalence of hypertensive measurements was 13.8% at first screen. Obesity was a risk factor for elevated BP for females and males (adjusted odds ratio (OR) = 4.01 and 4.33, respectively). Older age was also significantly associated with prehypertensive and hypertensive BP measurements, especially among males (adjusted OR = 6.91). Among females, American Indian race was protective against elevated BP (adjusted OR = 0.61).

CONCLUSIONS

Obesity was consistently associated with an increased risk for elevated BP. American Indian race was associated with decreased risk of elevated BP measurements in females. The high prevalence of obesity-related hypertensive measurements in this population that includes American Indian children was similar to levels found in other multiracial populations of school children when using BP measurements from a single assessment.

Interventions for treating obesity in children

BACKGROUND

Child and adolescent obesity is increasingly prevalent, and can be associated with significant short- and long-term health consequences.

OBJECTIVES

To assess the efficacy of lifestyle, drug and surgical interventions for treating obesity in childhood.

SEARCH STRATEGY

We searched CENTRAL on The Cochrane Library Issue 2 2008, MEDLINE, EMBASE, CINAHL, PsycINFO, ISI Web of Science, DARE and NHS EED. Searches were undertaken from 1985 to May 2008. References were checked. No language restrictions were applied.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) of lifestyle (i.e. dietary, physical activity and/or behavioural therapy), drug and surgical interventions for treating obesity in children (mean age under 18 years) with or without the support of family members, with a minimum of six months follow up (three months for actual drug therapy). Interventions that specifically dealt with the treatment of eating disorders or type 2 diabetes, or included participants with a secondary or syndromic cause of obesity were excluded.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data following the Cochrane Handbook. Where necessary authors were contacted for additional information.

MAIN RESULTS

We included 64 RCTs (5230 participants). Lifestyle interventions focused on physical activity and sedentary behaviour in 12 studies, diet in 6 studies, and 36 concentrated on behaviorally orientated treatment programs. Three types of drug interventions (metformin, orlistat and sibutramine) were found in 10 studies. No surgical intervention was eligible for inclusion. The studies included varied greatly in intervention design, outcome measurements and methodological quality.Meta-analyses indicated a reduction in overweight at 6 and 12 months follow up in: i) lifestyle interventions involving children; and ii) lifestyle interventions in adolescents with or without the addition of orlistat or sibutramine. A range of adverse effects was noted in drug RCTs.

AUTHORS' CONCLUSIONS

While there is limited quality data to recommend one treatment program to be favoured over another, this review shows that combined behavioural lifestyle interventions compared to standard care or self-help can produce a significant and clinically meaningful reduction in overweight in children and adolescents. In obese adolescents, consideration should be given to the use of either orlistat or sibutramine, as an adjunct to lifestyle interventions, although this approach needs to be carefully weighed up against the potential for adverse effects. Furthermore, high quality research that considers psychosocial determinants for behaviour change, strategies to improve clinician-family interaction, and cost-effective programs for primary and community care is required.

Blood pressure variability and classification of prehypertension and hypertension in adolescence

OBJECTIVE

There is little information in pediatrics on the persistence of the prehypertension and hypertension classifications or on the progression of prehypertension to hypertension. This study aimed to examine those issues.

METHODS

An analysis of data from the National Childhood Blood Pressure database was conducted to examine the longitudinal blood pressure outcomes for adolescents classified after a single measurement of blood pressure. Adolescent subjects (N = 8535) for whom serial single blood pressure measurements were obtained at intervals of 2 years were identified. Subjects were stratified according to blood pressure status at the initial measurement, as having normotension, prehypertension, or hypertension.

RESULTS

Among subjects designated as having prehypertension (n = 1470), 14% of boys and 12% of girls had hypertension 2 years later. Among subjects designated as having hypertension, 31% of boys and 26% of girls continued to exhibit hypertension, and 47% of boys and 26% of girls had blood pressure values in the prehypertensive range. Regression models showed no significant effect of race on blood pressure changes but significant effects of initial BMI and changes in BMI.

CONCLUSIONS

These data indicated that the rate of progression of prehypertension to hypertension was approximately 7% per year. Prehypertension can be predictive of future hypertension and may benefit from preventive interventions, especially lifestyle changes.

Rise in childhood obesity with persistently high rates of undernutrition among urban school-aged Indo-Asian children

BACKGROUND

Childhood obesity is an emerging global public health challenge. Evidence for the transition in nutrition in Indo-Asian developing countries is lacking. We conducted these analyses to determine the trends in nutritional status of school-aged children in urban Pakistan.

METHODS

Data on the nutritional status of children aged 5 to 14 years from two independent population-based representative surveys, the urban component of the National Health Survey of Pakistan (NHSP; 1990-1994) and the Karachi survey (2004-2005), were analysed. Using normative data from children in the United States as the reference, trends for age- and gender-standardised prevalence (95% CI) of underweight (more than 2 SD below the weight-for-age reference), stunted (more than 2 SD below the height-for-age reference) and overweight and obese (body mass index (BMI) 85(th) percentile or greater) children were compared for the two surveys. The association between physical activity and being overweight or obese was analysed in the Karachi survey using logistical regression analysis.

RESULTS

2074 children were included in the urban NHSP and 1675 in the Karachi survey. The prevalence of underweight children was 29.7% versus 27.3% (p = 0.12), stunting was 16.7% versus 14.3% (p = 0.05), and prevalence of overweight and obese children was 3.0 versus 5.7 (p<0.001) in the NHSP and Karachi surveys, respectively. Physical activity was inversely correlated with being overweight or obese (odds ratio, 95% CI, 0.51, 0.32-0.80 for those who engaged in more than 30 minutes of physical activity versus those engaged in less than 30 minutes' activity).

CONCLUSIONS

Our study highlights the challenge faced by Pakistani school-aged children. There has been a rapid rise in the number of overweight and obese children despite a persistently high burden of undernutrition. Focus on prevention of obesity in children must include strategies for promoting physical activity.

Physical Activity and Blood Pressure in Childhood

The pathological processes associated with development of cardiovascular disease begin early in life. For example, elevated blood pressure (BP) can be seen in childhood and tracks into adulthood. The relationship between physical activity (PA) and BP in adults is well-established, but findings in children have been inconsistent, with few studies measuring PA mechanically. Children aged 11 to 12 years were recruited from the Avon Longitudinal Study of Parents and Children. 5505 had systolic and diastolic BP measurements, plus valid (at least 10 hours for at least 3 days) accelerometer measures of PA; total PA recorded as average counts per minute (cpm) over the period of valid recording, and minutes per day spent in moderate to vigorous PA (MVPA). Data on a number of possible confounders were also available. Small inverse associations were observed; for systolic BP, β=−0.44 (95% confidence interval −0.59, −0.28) mm Hg per 100 cpm, and β=−0.66 (95% CI −0.92, −0.39) mm Hg per 15 minutes/d MVPA, adjusting for child’s age and gender. After adjustment for potential confounders, associations were weakened but remained. When PA variables were modeled together, associations with total PA were only a little weaker, whereas those with MVPA were substantially reduced; for systolic BP, β=−0.42 (95% CI −0.71, −0.13) mm Hg per 100 cpm, and β=−0.03 (95% CI −0.54, 0.48) mm Hg per 15 minutes/d MVPA. In conclusion, higher levels of PA were associated with lower BP, and results suggested that the volume of activity may be more important than the intensity.