Prevalence of elevated mean arterial pressure and how fitness moderates its association with BMI in youth

Effectiveness of high intensity and sprint interval training on metabolic biomarkers, body composition, and physical fitness in adolescents: randomized controlled trial

Objective

The aim of this study was to evaluate the effect of HIIT and SIT programmes on body composition, blood pressure, lipid profile, glucose, cardiorespiratory fitness, and strength of adolescents and to compare the effect between those different protocols.

Methods

Sixty adolescents were recruited from a high school and were randomly placed into three groups. SIT and HIIT undertook a training for 8 weeks, twice a week, for 12 min per session, during their Physical Education lessons. SIT group performed 6 sets of 60 s of work (90-95%HRmax) / 60 s of rest (50-55%HRmax), and HIIT group performed 3 sets of 2 min of work (80-85%HRmax) / 2 min of rest (50-55%HRmax).

Results

After adjustment by sex, both experimental groups exhibited a significant reduction in fat mass (p < 0.01), and trunk fat mass (p < 0.01), as well as a significant increase in lean mass (p = 0.01; <0.01), hand-grip strength (p < 0.01) and standing long jump (p = 0.05-0.04, respectively). In addition, HIIT showed a significant (p < 0.05) improvement in blood pressure, diastolic blood pressure, heart rate and VO2max, and a tendency toward a significant reduction in low density lipoprotein.

Conclusion

The implementation of a HIIT protocol within high school Physical Education sessions, maintained for 8 weeks, at a rate of 3 sets of 2 min of work (80-85% RHR)/2 min of rest (50-55% RHR) generated adaptations such as improved fitness condition, changes in body composition, and improvements in blood parameters and blood pressure. However, the group of adolescents who performed SIT, shorter but more intense sets, did not experience as many benefits.

Early maternal sensitivity and markers of physical health: Enduring or transient associations from childhood to adulthood?

Individual differences in the quality of early experiences with primary caregivers have been reliably implicated in the development of socioemotional adjustment and, more recently, physical health. However, few studies have examined the development of such associations with physical health into the adult years. To that end, the current study used prospective, longitudinal data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development (N = 1,306, 52% male, 77% White/non-Hispanic) to investigate whether associations between direct observations of maternal sensitivity in the first 3 years of life and repeated assessments of two commonly used, objective indicators of physical health (i.e., body mass and mean arterial blood pressure) remained stable or diminished in magnitude over time. Associations between early maternal sensitivity and lower body mass remained relatively stable from age 54 months to 26 years and were robust to the modeling of autoregressive and second-order stability processes as well as the inclusion of potential demographic confounders. In contrast, although associations between early caregiving and lower mean arterial pressure remained relatively stable from Grade 4 to age 15 years (the oldest age for which mean arterial pressure was assessed thus far), these associations were not robust to the inclusion of covariates and the modeling of second-order stability processes. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Validity of equations for estimating aerobic fitness in Mexican youth

The purpose of this study was to evaluate the validity of prediction equations for estimating maximal oxygen uptake (VO_2peak) based on the PACER test and different adiposity indicators in Mexican youth. A convenience sample of youth aged 9-18 years from schools in Mexico City was recruited. VO_2peak was evaluated with a laboratory exercise test on a treadmill and using a gas analyser and with the 20-m PACER test guidelines. The sample was randomly divided to develop new equations (n = 220) and to evaluate their validity (n = 106). Prediction equations of VO_2peak were developed using multiple linear regression models. The adiposity indicators were BMI, waist circumference and body fat. The validity of the new and previously published equations was evaluated based on linear regression models, intra-class coefficient, Akaike's information criterion, mean absolute percentage error and Bland-Altman graphs. Equations with waist circumference and body fat performed better than those with BMI and without any anthropometric indicator. The accuracy of the developed equations (R² = 57.0%-59.50%) was higher than that of previously published equations (R² = 24.1%-56.0%). The new equations had lower bias in estimating VO_2peak. In Mexican youth, the estimation of VO_2peak from the 20-m PACER test is more accurate after including waist circumference or body fat than with BMI.

Obesity as a Mediator between Cardiorespiratory Fitness and Blood Pressure in Preschoolers

OBJECTIVES

To analyze the relationships between body mass index (BMI), cardiorespiratory fitness (CRF), and blood pressure (BP), and to examine whether obesity acts as a mediator between fitness and BP in children.

STUDY DESIGN

A cross-sectional analysis using a population-based sample of 1604 school children aged 4-7 years attending 21 schools from the provinces of Ciudad Real and Cuenca, Spain, was undertaken. Data on anthropometric variables, BP measurements, and CRF were collected. The relationships between body composition (BMI, percent body fat, and waist circumference), CRF, and mean arterial pressure was estimated using Pearson correlation coefficients. ANCOVA tested the differences in BP measurements by categories of BMI and CRF, controlling for different sets of confounders. The PROCESS macro developed by Preacher and Hayes was used for mediation analysis.

RESULTS

BP values were significantly higher in school children with excess weight and poorer CRF. In addition, BMI acts as a full mediator in the association between CRF and mean arterial pressure in boys at 62.28% (z = -5.433; P ≤ .001) and a partial mediator in girls at 35.24% (z = -5.246; P ≤ .001).

CONCLUSIONS

BMI mediates the relationship between CRF and mean arterial pressure. These findings highlight the importance of maintaining a healthy weight for the prevention of high BP levels in childhood.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01971840.

Associations among cardiorespiratory endurance, body mass index and blood pressure in Han Chinese children: results from the 2010 Chinese National Survey On Students' Constitution and Health

The associations among cardiorespiratory endurance (CRE), body mass index (BMI) and blood pressure (BP) in children are still unclear. This study aimed to examine the relationships among CRE, BMI and BP in Chinese children. Data were derived from the 2010 Chinese National Survey on Students' Constitution and Health. An endurance run test was used to determine CRE and children were stratified into low and high/moderate CRE groups. BMI was dichotomized into non-overweight and overweight. Among overweight children aged 7-12 years, the risk of high BP (HBP) was significantly higher in the low CRE group than in the high/moderate CRE group (in boys, odds ratio=1.13, 95% confidence interval: 1.03-1.24, P=0.010; in girls, odds ratio=1.18, 95% confidence interval: 1.04-1.33, P=0.010) after adjusting for age, BMI, socioeconomic status and area of residence. However, among all children aged 13-18 years and non-overweight children aged 7-12 years, we did not observe similar results. Higher CRE is associated with lower BP. Overweight children have a significantly higher risk of HBP and low CRE may increase the risk of HBP, independently of BMI, among 7- to 12-year-old overweight children.

Risk Factors in Adolescent Hypertension

Hypertension is a complex and multifaceted disease, with many contributing factors. While diet and nutrition are important influences, the confounding effects of overweight and obesity, metabolic and genetic factors, racial and ethnic predispositions, socioeconomic status, cultural influences, growth rate, and pubertal stage have even more influence and make diagnosis quite challenging. The prevalence of hypertension in adolescents far exceeds the numbers who have been diagnosed; studies have found that 75% or more go undiagnosed. This literature review summarizes the challenges of blood pressure classification in adolescents, discusses the impact of these confounding influences, and identifies actions that will improve diagnosis and treatment outcomes.

Overweight predicts poorer exercise capacity in congenital heart disease patients

Background

Overweight (OW) and obesity (OB) are endemic in the United States and affect adolescents and adults with congenital heart disease (ACHD). Defining the burden of excess weight on the cardiovascular system in ACHD is the goal of this study. Limitation of exercise capacity due to overweight or obesity might be reversible with weight loss and improve quality of life for ACHD adults.

Methods

Exercise tests performed using a Bruce protocol and measurement of maximum oxygen consumption were retrospectively reviewed on 418 CHD patients. OW and OB were defined as the 85–95 or > 95 percentile respectively for age and gender or by adult criteria. Severity of CHD was assigned based on criteria published in standard guidelines.

Results

63 patients had mild, 198 moderate, and 157 severe heart disease. Each ACHD group was 32 to 34% OW or OB. Measured exercise time (ET) of CHD patients with moderate or severe heart disease was less than that of controls in each weight categories. However, OB or OW people have shorter ET than their normal weight peers with CHD. Multiple regression using ET as the dependent variable finds that female sex, relative BMI, and VE/VCO2 at peak exercise are all associated with lesser ET with high significance. Peak heart rate is associated with greater ET, with borderline significance. Severity of heart disease is not independently associated with ET.

Conclusions

OW and OB are strongly associated with reduced ET in persons with congenital heart disease. Losing weight may improve exercise capacity in ACHD.

Modeling longitudinal changes in hypertensive and waist phenotype: The oporto growth, health, and performance study

OBJECTIVES

This study aimed to: (1) model changes in the hypertensive and waist phenotype (HWP) in youth, and (2) investigate the effects of sex, biological maturation, total physical activity (TPA), and physical fitness (PF) in HWP trajectories.

METHODS

Data were obtained annually for 3 years from the Oporto Growth, Health, and Performance Study, and comprised 5,549 adolescents (2,732 girls) divided into four age cohorts (10, 12, 14, and 16 years). The HWP was computed as the sum of the standardized score of waist circumference and mean arterial pressure. Biological maturation was indirectly assessed by the maturity offset procedure; TPA was estimated with the Baecke questionnaire; PF measures included 1-mile run/walk, 50-yard dash (50YD), standing long jump (SLJ), handgrip strength (HGr), and agility shuttle run. Longitudinal changes in HWP were analyzed using multilevel modelling.

RESULTS

HWP increased across time with a nonlinear trend in girls and boys. However, when adjusted for a set of predictors, the trend was reversed: girls and boys had a significant annual decrease on HWP of -0.202 ± 0.032 and -0.147 ± 0.032, respectively. Maturity offset was positively associated with HWP changes (β = 0.913 ± 0.023); TPA had a negative association (β = -0.027 ± 0.011); and improved PF tests were associated with a significant reduction in HWP across time (β1mile  = -0.081 ± 0.009; βSLJ  = -0.003 ± 0.00; β50YD =0.106 ± 0.020; and βHGr  = -3.335 ± 0.196).

CONCLUSIONS

Boys showed higher HWP values compared to girls from 10 to 18 years of age. Adolescents who were more biologically mature had a more adverse HWP. Longitudinal increases in TPA and PF predicted annual decreases in HWP across the adolescence years.Am. J. Hum. Biol. 28:387-393, 2016. © 2015 Wiley Periodicals, Inc.

Physical fitness and hypertension in a population at risk for cardiovascular disease: the Henry Ford ExercIse Testing (FIT) Project

BACKGROUND

Increased physical fitness is protective against cardiovascular disease. We hypothesized that increased fitness would be inversely associated with hypertension.

METHODS AND RESULTS

We examined the association of fitness with prevalent and incident hypertension in 57 284 participants from The Henry Ford ExercIse Testing (FIT) Project (1991–2009). Fitness was measured during a clinician‐referred treadmill stress test. Incident hypertension was defined as a new diagnosis of hypertension on 3 separate consecutive encounters derived from electronic medical records or administrative claims files. Analyses were performed with logistic regression or Cox proportional hazards models and were adjusted for hypertension risk factors. The mean age overall was 53 years, with 49% women and 29% black. Mean peak metabolic equivalents (METs) achieved was 9.2 (SD, 3.0). Fitness was inversely associated with prevalent hypertension even after adjustment (≥12 METs versus <6 METs; OR: 0.73; 95% CI: 0.67, 0.80). During a median follow‐up period of 4.4 years (interquartile range: 2.2 to 7.7 years), there were 8053 new cases of hypertension (36.4% of 22 109 participants without baseline hypertension). The unadjusted 5‐year cumulative incidences across categories of METs (<6, 6 to 9, 10 to 11, and ≥12) were 49%, 41%, 30%, and 21%. After adjustment, participants achieving ≥12 METs had a 20% lower risk of incident hypertension compared to participants achieving <6 METs (HR: 0.80; 95% CI: 0.72, 0.89). This relationship was preserved across strata of age, sex, race, obesity, resting blood pressure, and diabetes.

CONCLUSIONS

Higher fitness is associated with a lower probability of prevalent and incident hypertension independent of baseline risk factors.

A cross-cultural comparison of body composition, physical fitness and physical activity between regional samples of Canadian and English children and adolescents

OBJECTIVES

Cross-cultural comparisons in children's body composition, health-related fitness and physical activity (PA) are rare due to a shortage of comparable data, but such comparisons may help avert worrying global prevalence in childhood obesity, and declining fitness and PA.

METHODS

We drew samples of Canadian and English children (10 years, n=1630, 50% boys) and adolescents (15 years, n=1406, 56% boys) from three separate, regional studies that conducted comparable school-based assessments (2006-2011). For each age-sex group, we assessed between-country differences for body composition (mass, height, BMI, waist circumference), cardiorespiratory fitness (CRF; 20 m shuttle run test), strength (handgrip) and self-reported PA. We used multiple regression to investigate whether between-country differences in fitness were explained by body composition and PA.

RESULTS

At any age, Canadian boys and girls were taller, heavier, and had greater BMIs and waist circumferences. English children had higher CRF than Canadians, which was explained by differences in body composition and PA. Canadian children were significantly stronger, partly due to greater body size. There were no between-country differences in adolescent boys. Canadian adolescent girls reported more PA than their English counterparts, but neither PA nor body size explained why Canadian adolescent girls had greater CRF or strength.

CONCLUSION

Future cross-cultural studies of PA should include indices of growth and fitness to better understand the relationship between intricate differences in PA and health outcomes.