Association between resting heart rate and cardiovascular risk factors in adolescents

Using explainable machine learning and fitbit data to investigate predictors of adolescent obesity

Sociodemographic and lifestyle factors (sleep, physical activity, and sedentary behavior) may predict obesity risk in early adolescence; a critical period during the life course. Analyzing data from 2971 participants (M = 11.94, SD = 0.64 years) wearing Fitbit Charge HR 2 devices in the Adolescent Brain Cognitive Development (ABCD) Study, glass box machine learning models identified obesity predictors from Fitbit-derived measures of sleep, cardiovascular fitness, and sociodemographic status. Key predictors of obesity include identifying as Non-White race, low household income, later bedtime, short sleep duration, variable sleep timing, low daily step counts, and high heart rates (AUCMean = 0.726). Findings highlight the importance of inadequate sleep, physical inactivity, and socioeconomic disparities, for obesity risk. Results also show the clinical applicability of wearables for continuous monitoring of sleep and cardiovascular fitness in adolescents. Identifying the tipping points in the predictors of obesity risk can inform interventions and treatment strategies to reduce obesity rates in adolescents.

Urbanisation negatively impacts sleep health and mood in adolescents: a comparative study of female students from city and rural schools of North India

This study investigated the impact of social settings on sleep, physical and mental health in female adolescents of North India (latitude 29.5 oN; longitude 77.5 oE). Using a battery of questionnaires, we compared the chronotype, sleep-wake pattern, sleep health (e.g. sleep quality, daytime sleepiness and fatigue) and mood (via depression, anxiety and stress symptoms) in female students (age 14-18 years) from rural (N = 719) and urban (N = 1033) schools separated by about 35 km, but families had almost similar socio-demographic details. The morning type was prevalent amongst rural, whilst the evening type was prevalent amongst urban students who also had access to smart phones, suggesting a possible greater use of the internet. There were greater negative sleep effects, daytime sleepiness, overall poor sleep quality, higher fatigue and anxiety levels in urban than the rural cohort. Interestingly, these measures also differed between school days and free days, suggesting an impact of the conflict between internal biological and social timings (= social jet lag). We also found a significant relationship between chronotype, internet addiction, mood-related parameters and measures of sleep health. Overall, these results suggest a possible impact of social settings on sleep health and mood-related behaviours in female adolescents.

Resting heart rate associations with violence exposure and posttraumatic stress symptoms: sex differences in children

BACKGROUND

Traumatic events experienced in childhood can lead to increased risk of cardiovascular disorders in adulthood. Black Americans are disproportionately affected, as they are at increased risk for experiencing childhood trauma and cardiovascular diseases in adulthood. One of the hypothesized mechanisms of this association is through long-lasting dysregulation of the autonomic nervous system, a hallmark physiological biomarker of posttraumatic stress disorder (PTSD), which is twice as prevalent in women compared to men.

METHODS

Ninety-one, majority Black American children, aged 9 were recruited to be a part of our longitudinal study of child development at research centers in Atlanta, GA and Detroit, MI. Resting HR was measured through a electrocardiogram (ECG) recording using the Biopac MP150. Self-report measures of violence exposure and PTSD symptoms were administered by research staff.

RESULTS

Children with more violence exposure reported increased PTSS as well as lower resting HR. Regression analysis showed evidence of sex modifying this relationship, (B = -0.64, p < 0.05), such that the association between resting HR and PTSS was stronger in girls than in boys. In our exploratory analysis with standard clinical cutoffs of resting HR, the normative HR group was found to significantly moderate the relationship between violence exposure and PTSS in boys, (B = -2.14, p < 0.01), but not girls (B = -0.94, p = 0.27).

CONCLUSION

In our sample of primarily Black urban children, we found that violence exposure was associated with slower, more adult-like HR, that girls showed greater PTSS associated with slower HR while boys did not, and that girls with lower than normative HR showed significantly higher PTSS compared to girls with normative HR. Our sample's demonstration of psychological consequences in addition to the physiological implications could provide new information about a psychobiological sequelae of violence exposure.

Evaluation of physical fitness and health of young children aged between 3 and 6 based on cluster and factor analyses

BACKGROUND

As life improves and sedentary time increases, young children's physical fitness gradually declines.

METHODS

Multi-stage stratified whole cluster sampling was utilized to sample 5584 preschoolers. Young infants' morphology, function, and quality were revealed using cluster and factor analysis.

RESULTS

The cluster analysis separated 3-6-year-olds into two genders: 1,551 men in group A "high physical fitness" 1,499 men in group B "low physical fitness"; 1,213 women in group A and 1,321 women in group B. Young children's fitness was measured by standing long jump(1.00), weight(1.00), and height(1.00). A cluster analysis of 3-4-year-olds classified them into three groups: 272 "muscular strength," 75 "average physical fitness," and 250 "low agility." Young children's health depends on weight (1.00), height (0.57), and chest circumference (0.54). A cluster analysis of the 4-5-year-olds classified them into two groups: 1070 "balance" and 806 "muscular strength." Young children's health depends on weight (1.00), height (0.74), and chest circumference (0.71). A cluster analysis of the 5-6-year-olds divided them into three groups: 1762 "high physical fitness," 384 "obese," and 105 "low physical fitness." Young children's physical health depends on BMI (1.00), weight (1.00), and chest circumference (1.00). Factor analysis demonstrated that muscle strength, body shape, cardiovascular variables, and physical fitness composite components affected young children's health.

CONCLUSION

Women should focus on motor function and strength, while men on flexibility. Male group B "low physical fitness" should focus on strength, motor function, and balance, whereas male group A "high physical fitness" should focus on flexibility. Then, female group A "high physical fitness" should emphasize variety.2) For 3-4-year-olds, group A "muscular strength" should focus on flexibility, and group C "low agility" on motor function. 3) For 4-5-year-olds, group A "balanced" should focus on strength and motor function; 4) For 5-6-year-olds, group B "obese" should emphasize weight loss, and group C "low fitness" should emphasize strength, motor function, and flexibility; 5) Young children's physical fitness depends on muscle strength, body shape, cardiovascular factors, and physical fitness composite.

The cardiorespiratory response and physiological determinants of the 6-min handbike cycle test in healthy children: A cross-sectional study

INTRODUCTION

The submaximal tests are used to measure aerobic capacity and correlate with activities of daily living in chronic patients. The 6-min handbike cycle test (6mhct) was created for nonambulatory subjects, but there are no reference values to quantify and classify the cardiorespiratory fitness of children in this condition.

OBJECTIVE(S)

Generate 6mhct reference values and determine predictive variables in a population of Chilean children between 8 and 13 years old.

MATERIALS AND METHODS

Cross-sectional study. Sampling for convenience, stratified by age. Evaluation of anthropometric variables, handgrip strength, heart rate (HR), effort perception, and blood pressure were performed, then the 6mhct was applied. Descriptive statistics, Student's t test and Mann-Whitney U test, correlation coefficient, and regression equation were used to estimate the total revolutions by age, being significant p < 0.05.

RESULTS

Were evaluated 120 children homogeneously distributed by age. The total revolutions performed by boys and girls were 861.4 ± 102.9 and 771.8 ± 90.2, respectively (p < 0.001). There was a significant correlation between total revolutions and age (r = .52), weight (r = .29), height (r = .46), average  UULL (length of the upper limb) length (r = .44), average handgrip strength (r = .53), peak HR (r = .67), recovery HR (r = .44), and HR reserve (r = .72). The regression equation was established.

CONCLUSIONS

These results can be used as preliminary reference values for the 6mhct in Chilean children from 8 to 13 years old. Handgrip strength, age, peak HR, and HR reserve influenced the performance of the 6mhct.

Effects of a Physical Exercise Program and Health Advice on Sedentary Behavior of Adolescents

Sedentary behavior (SB) is a risk factor for chronic non-communicable diseases. This study aimed to assess the effects of an extracurricular physical exercise program and health advice on SB in adolescents. This was a non-randomized experimental study involving 19 adolescents divided into an intervention group (IG) and a control group (CG), aged 13-16 years from a public school in a Brazilian municipality. SB was measured using self-reports and accelerometers. The intervention included physical exercise and health advice. Repeated measures analysis of variance with a significance level of α = 5% was used. There was a time*group interaction for the subscapular fold ((pre IG = 16.30 mm vs. CG = 13.44 mm, post IG = 14.00 mm vs. CG = 15.89 mm) p = 0.001), and VO2MAX ((pre IG = 32.75 mL/kg/min vs. CG = 30.66 mL/kg/min, post IG = 35.76 mL/kg/min vs. CG = 29.28 mL/kg/min) p = 0.008). The accelerometer showed significant differences between groups in the total SB ((pre IG = 647.49 min/day vs. CG = 535.24 min/day, post IG = 614.02 min/day vs. CG = 586.97 min/day) p = 0.045), with a significant decrease in the IG. In conclusion, an extracurricular physical exercise program and health advice was effective in reducing SB in adolescents.

Association between clustering of cardiovascular risk factors and resting heart rate in Chinese population: a cross-sectional study

BACKGROUND

Epidemiologic studies have explored the association between a single cardiovascular risk factor (CVRF) and resting heart rate (RHR), but the research on the relation of multiple risk factors with RHR remains scarce. This study aimed to explore the associations between CVRFs clustering and the risk of elevated RHR.

METHODS

In this cross-sectional study, adults aged 35-75 years from 31 provinces were recruited by the China PEACE Million Persons Projects from September 2015 to August 2020. We focused on seven risk factors: hypertension, diabetes mellitus, dyslipidemia, obesity, smoking, alcohol use, and low physical activity. Multivariate logistic regression was used to calculate odds ratios (OR) for elevated RHR (> 80 beats/min).

RESULTS

Among 1,045,405 participants, the mean age was 55.67 ± 9.86 years, and 60.4% of participants were women. The OR (95% CI) for elevated RHR for the groups with 1, 2, 3, 4 and ≥ 5 risk factor were 1.11 (1.08-1.13), 1.36 (1.33-1.39), 1.68 (1.64-1.72), 2.01 (1.96-2.07) and 2.58 (2.50-2.67), respectively (P _trend < 0.001). The association between the CVRFs clustering number and elevated RHR was much more pronounced in young males than in other age-sex subgroups. Clusters comprising more metabolic risk factors were associated with a higher risk of elevated RHR than those comprising more behavioral risk factors.

CONCLUSIONS

There was a significant positive association between the CVRFs clustering number and the risk of elevated RHR, particularly in young males. Compared clusters comprising more behavioral risk factors, clusters comprising more metabolic risk factors were associated with a higher risk of elevated RHR. RHR may serve as an indicator of the cumulative effect of multiple risk factors.

Physical activity is associated with lower pulsatile stress but not carotid stiffness in children

The cardiovascular disease (CVD) process may begin early in life when accompanied by atherosclerotic risk factors. CVD risk factors in children are associated with stiffening of the large elastic arteries, a reflection of subclinical atherosclerosis. Physical activity is a preventative lifestyle strategy that may benefit arterial stiffness by attenuating the hemodynamic stress on the artery wall. This study examined the relations between physical activity, carotid pulsatile stress, and carotid stiffness in children. One hundred and forty children (9-11 yrs; 50.0% male, 57.9% African-American, 42.10% Caucasian, body mass index (BMI) 20.1 ± 4.7 kg/m2) participated in this study. Physical activity counts were measured using a wrist-worn accelerometer and averaged over 7 days. Carotid artery β-stiffness and pulse pressure (calibrated to brachial mean and diastolic pressure) were assessed as via ultrasound and tonometry, respectively. Pulsatile stress was calculated as the product of carotid pulse pressure and heart rate. Physical activity counts were correlated with pulsatile stress (r = -0.27), and BMI (r = -0.23), but were unrelated to carotid stiffness. In multivariate models, associations between physical activity counts and pulsatile stress remained (B = -1.3 [95%CI, -2.4, -0.2], β = -0.20, p < 0.05) after covariate adjustment for age, race, sex, pubertal stage, and BMI. Carotid pulsatile stress was related to regional carotid stiffness (r = 0.45, p < 0.05). These data suggest that higher levels of physical activity at young age are associated with lower hemodynamic stress in the carotid artery. Findings are discussed in the context of an inverse relationship between hemodynamic pulsatile stress and carotid stiffness in children.

Association of Chinese Visceral Adiposity Index and Its Dynamic Change With Risk of Carotid Plaque in a Large Cohort in China

Background

We aimed to evaluate the association between the Chinese visceral adiposity index (CVAI) and its dynamic change and risk of carotid plaque based on a large Chinese cohort.

Methods and Results

This cohort included 23 522 participants aged 20 to 80 years without elevated carotid intima‐media thickness and carotid plaque at baseline and who received at least 2 health checkups. CVAI was calculated at baseline and at every checkup. The dynamic change in CVAI was calculated by subtracting CVAI at baseline from that at the last follow‐up. Cox proportional hazard regression model was used to estimate hazard ratios (HRs) and 95% CIs. The restricted cubic spline was applied to model the dose‐response association between CVAI and carotid plaque risk. During the 82 621 person‐years of follow‐up, 5987 cases of carotid plaque developed (7.25/100 person‐years). We observed a significant positive correlation between CVAI and carotid plaque risk (HR, 1.53; 95% CI, 1.48–1.59 [P<0.001]) in a nonlinear dose‐response pattern (P_nonlinearity<0.001). The sensitivity analyses further confirmed the robustness of the results. The association was significant in all subgroup analyses stratified by sex, hypertension, and fatty liver disease except for the diabetes subgroup. The association between CVAI and carotid plaque risk was much higher in men than in women. No significant association was identified between change in CVAI and carotid plaque risk.

Conclusions

CVAI was positively associated with carotid plaque risk in a nonlinear dose‐response pattern in this study. Individuals should keep their CVAI within a normal level to prevent the development of carotid plaque.

Effects of L-Citrulline Supplementation and Aerobic Training on Vascular Function in Individuals with Obesity across the Lifespan

Children with obesity are at higher risk for developing cardiometabolic diseases that once were considered health conditions of adults. Obesity is commonly associated with cardiometabolic risk factors such as dyslipidemia, hyperglycemia, hyperinsulinemia and hypertension that contribute to the development of endothelial dysfunction. Endothelial dysfunction, characterized by reduced nitric oxide (NO) production, precedes vascular abnormalities including atherosclerosis and arterial stiffness. Thus, early detection and treatment of cardiometabolic risk factors are necessary to prevent deleterious vascular consequences of obesity at an early age. Non-pharmacological interventions including L-Citrulline (L-Cit) supplementation and aerobic training stimulate endothelial NO mediated vasodilation, leading to improvements in organ perfusion, blood pressure, arterial stiffness, atherosclerosis and metabolic health (glucose control and lipid profile). Few studies suggest that the combination of L-Cit supplementation and exercise training can be an effective strategy to counteract the adverse effects of obesity on vascular function in older adults. Therefore, this review examined the efficacy of L-Cit supplementation and aerobic training interventions on vascular and metabolic parameters in obese individuals.

Sensitivity and Specificity of Cutoff Points of Resting Heart Rate from 6,794 Brazilian Adolescents: A Cross-Sectional Study

Fundamento

A frequência cardíaca em repouso (FCR) pode ser uma ferramenta útil de triagem para o risco cardiovascular. Porém, os pontos de corte para FCR nunca foram descritos em populações jovens.

Objetivo

Estabelecer os pontos de corte para FCR em adolescentes brasileiros e analisar se há associação entre pontos de corte e fatores de risco cardiovascular.

Métodos

A amostra foi composta por 6.794 adolescentes (de 10 a 19 anos). A pressão arterial e a FCR foram avaliadas por dispositivo oscilométrico. Também foram avaliados o índice de massa corporal e a circunferência da cintura. Foi adotada a curva ROC para analisar a sensibilidade e especificidade, e as associações de FCR elevada com os fatores de risco cardiovascular foram analisadas por regressão logística binária. Foi considerado estatisticamente significante um valor de p < 0,05 para todas as análises.

Resultados

Os valores médios da FCR eram mais altos entre os participantes de 10 a 14 anos do naqueles de 15 a 19 anos, em meninos (p < 0,001) e meninas (< 0,001). Os pontos de corte de FCR propostos para detecção de fatores de risco cardiovascular foram significativos para meninos de 10 a 14 (> 92 bpm) e de 15 a 19 anos (> 82 bpm) e para meninas de 15 a 19 anos (> 82 bpm) (p < 0,05 para todos), enquanto nenhum ponto de corte foi identificado para as meninas de 10 a 14 anos (p > 0,05). Os pontos de corte propostos para a FCR foram associados com obesidade abdominal, sobrepeso e pressão arterial elevada em meninos e meninas. Os pontos de corte da FCR foram associados ao conjunto de fatores de risco cardiovascular em adolescentes de 15 a 19 anos.

Conclusões

Os pontes de corte propostos para a FCR foram associados com os fatores de risco cardiovascular em adolescentes.

Continuity of physical activity practice from childhood to adolescence is associated with lower neck pain in both sexes and lower back pain in girls

BACKGROUND

The literature on physical activity practice through sports as a protective factor for back pain in adolescents is conflicting. However, few studies have aimed to verify if continuity of the practice of physical activity from childhood to adolescence may be related to lower chances of back pain in adolescents.

OBJECTIVES

The objective of this study was to analyze the association between physical activity practice from childhood to adolescence and back pain in adolescents.

METHODS

The random sample was composed of 870 adolescents with a mean age of 13.7 ± 2.0 years. The continuity of physical activity practice was assessed through the continuity of sports practice from childhood to adolescence. Pain in the neck and low back were evaluated through a questionnaire.

RESULTS

The prevalence of neck pain and low back pain in boys was 17.5% and in girls was 20.9% for neck pain and 21.9% for low back pain. Physical activity practice during childhood to adolescence was a protective factor for neck pain (OR = 0.57 [CI = 0.35-0.94]) and low back pain (OR = 0.53 [CI = 0.33-0.86]) in girls and neck pain in boys (OR = 0.52 [CI = 0.30-0.90]), even after adjusting for confounding factors.

CONCLUSION

Girls with physical activity practice during childhood to adolescence were less likely to develop neck pain and back pain when compared to girls who did not maintain practice of physical activity. Similar results were observed in boys considering neck pain.

Participation in Non-professional Sports and Cardiovascular Outcomes Among Adolescents: ABCD Growth Study

OBJECTIVES

Sports are an important way to improve health during adolescence. However, it is still unclear whether the association between sports, blood pressure, and metabolic profile could be affected by sex, biological maturation, and trunk fatness. The aim of this study was to analyze the association between sports participation and the cluster of cardiovascular markers among adolescents of both sexes.

METHODS

A cross-sectional study involving 285 adolescents aged from 11 to 17 years of age (202 boys and 83 girls). Cardiovascular variables were composed of systolic blood pressure (SBP), diastolic blood pressure (DBP), resting heart rate (RHR), and carotid (CIMT) and femoral (FIMT) intima-media thickness, which were used to calculate the Cardiovascular_{Z score}. Sports participation was assessed through a face-to-face interview. Age of peak height velocity (APHV) was used as a covariate.

RESULTS

Among girls, the group engaged in sports presented lower values of RHR (sport: - 0.344 [95% CI - 0.650 to - 0.037] versus non-sport: 0.540 [95% CI 0.125 to 0.954]) and Cardiovascular_{Z score} (sport: - 0.585 [95% CI - 1.329 to 0.159] versus non-sport: 0.879 [95% CI - 0.127 to 1.884]), explaining 12.2% and 6.1% of all variance, respectively. Among boys, the group engaged in sports presented lower values of DBP (sport: - 0.158 [95% CI - 0.335 to 0.018] versus non-sport: 0.160 [95% CI - 0.091 to 0.412]) and FIMT (sport: - 0.128 [95% CI - 0.300 to - 0.044] versus non-sport: 0.211 [95% CI - 0.032 to 0.454]), explaining 2.2% and 2.6% of all variance, respectively.

CONCLUSIONS FOR PRACTICE

Adolescents engaged in sports presented healthier cardiovascular parameters, and sports participation seems to affect cardiovascular health differently in boys and girls.

Is physical activity associated with resting heart rate in boys and girls? A representative study controlled for confounders

OBJECTIVE

Investigate the relationship between different domains of physical activity and resting heart rate (RHR) in boys and girls.

METHOD

The sample included 1011 adolescents, aged between 10 and 17 years. RHR was measured by a heart rate monitor and physical activity was assessed in total and in three different domains (school, occupational, and sports practice) by a questionnaire. Anthropometry was directly obtained for body mass index and central fat. Ethnicity, sedentary behavior, and smoking habits were self-reported and used to adjust the analysis, through hierarchical linear regression.

RESULTS

Total physical activity was associated with low RHR in boys (β=-0.52; 95% CI: -0.92, -0.12) and girls (β=-0.67; 95% CI: -1.07, -0.28). Although sporting physical activities were associated with low RHR in both boys (β=-0.58; 95% CI: -1.05, -0.11) and girls (β=-0.87; 95% CI: -1.34, -0.39), occupational physical activity was related to low RHR only in boys (β=-1.56; 95% CI: -2.99, -0.14).

CONCLUSION

The practice of physical activity in the sport practice domain and total physical activity were related to low RHR in both sexes, while occupational physical activities were associated with RHR only in boys.

Effects of high-intensity interval training on endothelial function, lipid profile, body composition and physical fitness in normal-weight and overweight-obese adolescents: A clinical trial

Endothelium-aggressive factors are associated with the development of atherosclerosis. Exercise training can either prevent or attenuate this process, but little is known about the effects of high-intensity interval training (HIIT) in adolescents. Thus, we assessed the effects of HIIT on endothelial function, lipid profile, body composition and physical fitness in normal-weight and overweight-obese adolescents. Thirty-eight participants aged 14-17 years who were physically inactive (IPAq) were divided in two groups: normal weight (NW, n = 13) and overweight-obese (OW, n = 25). Body composition, lipid profile, physical fitness and endothelial function (flow-mediated dilation, FMD) were assessed before and after undergoing the study protocol consisting of 12-week HIIT (∼15 min) + sport activities (30 min, 3×/week) + no diet. The differences were tested by GEE, Bonferroni post-hoc, p < 0.05. There were no changes in body composition after training period, but the OW group showed a reduction in waist (4.8 cm; p = 0.044) and abdominal circumference (3.7 cm; p = 0.049). We found improved physical fitness (cardiorespiratory endurance, explosive strength, abdominal muscle endurance and flexibility) in both groups. Lower endothelial function was found in the OW compared to NW (p = 0.042) at baseline. FMD increased (p < 0.001) in both groups from baseline (NW Δ4.1%; Cohen's effect size 0.64; OW Δ4.5%; Cohen's effect size 0.73) with no significant difference between the groups. In conclusion, a HIIT program even without any dietary changes can improve physical fitness and endothelial function among adolescents. These findings are clinically relevant because they support a reduction in endothelial damage that precedes the development of atherosclerosis.

Cutoffs of Short-Term Heart Rate Variability Parameters in Brazilian Adolescents Male

A low heart rate variability (HRV) has been associated with cardiovascular risk factors in adolescents. However, no cut-off points are known for HRV parameters in this age group, making it difficult to use in clinical practice. Thus, the aims of the current study were to establish cutoffs of HRV parameters and to examine their association with cardiovascular risk in Brazilian adolescents male. For this reason, this cross-sectional study included 1152 adolescent boys (16.6 ± 1.2 years old). HRV measures of time (SD of all RR intervals, root mean square of the squared differences between adjacent normal RR intervals, and the percentage of adjacent intervals over 50 ms), frequency domains [low (LF) and high (HF) frequency], and Poincaré plot (SD1, SD2 and SD1/SD2 ratio) were assessed. Cardiovascular risk was assessed by sum of abdominal obesity, high blood pressure, overweight, and low physical activity level. The proposed cutoffs showed moderate to high sensitivity, specificity, and area under curve values (p < 0.05). HRV frequency parameters were statistically superior when compared to time-domain and Poincaré plot parameters. The binary logistic regression analysis indicated that all proposed HRV cutoffs were independently associated with a clustering of cardiovascular risk factors, with greater magnitude of HF and SD1/SD2 ratio (two or more risk factors: OR = 3.59 and 95% CI 1.76-7.34). In conclusion, proposed HRV cutoffs have moderate to high sensitivity in detecting of the cardiovascular risk factor and HRV frequency-domain were better discriminants of cardiovascular risk than time-domain and Poincaré plot parameters.

Childhood dietary trajectories and adolescent cardiovascular phenotypes: Australian community-based longitudinal study

OBJECTIVE

With the intention to inform future public health initiatives, we aimed to determine the extent to which typical childhood dietary trajectories predict adolescent cardiovascular phenotypes.

DESIGN

Longitudinal study. Exposure was determined by a 4 d food diary repeated over eight waves (ages 4-15 years), coded by Australian Dietary Guidelines and summed into a continuous diet score (0-14). Outcomes were adolescent (Wave 8, age 15 years) blood pressure, resting heart rate, pulse wave velocity, carotid intima-media thickness, retinal arteriole-to-venule ratio. Latent class analysis identified 'typical' dietary trajectories from childhood to adolescence. Adjusted linear regression models assessed relationships between trajectories and cardiovascular outcomes, adjusted for a priori potential confounders.

SETTING

Community sample, Melbourne, Australia.

SUBJECTS

Children (n 188) followed from age 4 to 15 years.

RESULTS

Four dietary trajectories were identified: unhealthy (8 %); moderately unhealthy (25 %); moderately healthy (46 %); healthy (21 %). There was little evidence that vascular phenotypes associated with the trajectories. However, resting heart rate (beats/min) increased (β; 95 % CI) across the healthy (reference), moderately healthy (4·1; -0·6, 8·9; P=0·08), moderately unhealthy (4·5; -0·7, 9·7; P=0·09) and unhealthy (10·5; 2·9, 18·0; P=0·01) trajectories.

CONCLUSIONS

Decade-long dietary trajectories did not appear to influence macro- or microvascular structure or stiffness by mid-adolescence, but were associated with resting heart rate, suggesting an early-life window for prevention. Larger studies are needed to confirm these findings, the threshold of diet quality associated with these physiological changes and whether functional changes in heart rate are followed by phenotypic change.

Effects of resting heart rate on blood pressure and hypertension in Chinese children: findings from blood pressure surveillance program

The purpose of this study was to analyze the association between resting heart rate (RHR) and prevalence of hypertension in Chinese children and to identify if this association was mediated by body mass index (BMI). The data of 5445 children who participated in the Blood Pressure Surveillance Program (2011-2017) were analyzed in this study. Children were divided into four groups according to quartiles of RHR in boys and girls, respectively. Compared to those in the first quartile, boys and girls in the fourth quartile were 3.06 (95% CI 2.12, 4.41) and 4.94 (95% CI 3.21, 7.61) times more likely to have hypertension, respectively. Meanwhile, every 10 beats per minute (bpm) increase in RHR was associated with a 41% (95% CI 1.27, 1.56) and 66% (95% CI 1.49, 1.85) greater risk of hypertension in boys and girls, respectively. There were no significant interactions between RHR and BMI on the prevalence of hypertension. This study confirms the existence of a relationship between elevated RHR and increased risk of hypertension in children, independent of BMI. An elevated RHR could be considered as a risk factor for the risk assessment of hypertension, no matter from a clinical setting or a public health perspective.

Physical Activity and Heart Rate Variability in Adolescents with Abdominal Obesity

Physical activity is a protective factor for autonomic dysfunction. However, whether this occurs in adolescents with abdominal obesity is still unclear. Thus, the aim of this study was to analyze the association between physical activity and heart rate variability (HRV) in adolescents with and without abdominal obesity. This cross-sectional study included 1152 boys (age: 17 ± 1 years). HRV measures of time (root mean square of the squared differences between adjacent normal RR intervals-RMSSD and the percentage of adjacent intervals over 50 ms-PNN50) and frequency domains (balance sympathetic-vagal-LF/HF) were evaluated, as well as total physical activity, commuting physical activity, leisure-time physical activity, and abdominal obesity. All physical activity domains were associated with better RMSSD, PNN50, and LF/HF in normal weight adolescents (p < 0.05), whereas in adolescents with abdominal obesity only leisure-time physical activity was associated with better PNN50 (b = 0.174, p = 0.035) independent of age, period of the day, body mass index, and blood pressure. In conclusion, higher leisure-time physical activity, but not total and commuting physical activity levels, was associated with improved HRV in adolescents with abdominal obesity.

Analysis of different anthropometric indicators in the detection of high blood pressure in school adolescents: a cross-sectional study with 8295 adolescents

•

Overweight adolescents classified in any of three anthropometric indices have more HBP.

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The sensitivity of the indicators was low and the specificity was high in detecting HBP.

•

Parents must be aware that high BMI, WC or WTHR are highly associated with HBP.

Background

High blood pressure is strongly associated with obesity in different populations. However, it is unclear whether different anthropometric indicators of obesity can satisfactorily predict high blood pressure in the school setting.

Objectives

This study evaluated the sensitivity and specificity of body mass index, waist circumference, and waist to height ratio in the detection of high blood pressure in adolescents.

Methods

The sample consisted of 8295 adolescents aged 10–17 years. Weight was measured using a digital scale, height with a stadiometer, and waist circumference using a tape measure. Blood pressure was measured by an automatic blood pressure measuring device. ROC curves were used for the analysis of sensitivity and specificity of the three anthropometric indices in identifying high blood pressure. Binary Logistic Regression was used to assess the association of body mass index, waist circumference, and waist to height ratio with high blood pressure.

Results

Low values of sensitivity were observed for body mass index (0.35), waist circumference (0.37), and waist to height ratio (0.31) and high values of specificity for body mass index (0.86), waist circumference (0.82), and waist to height ratio (0.83) in the detection of high blood pressure. An association was observed between adolescents classified with high body mass index (OR = 3.57 [95% CI = 3.10–4.10]), waist cirumference (OR = 3.24 [95% CI = 2.83–3.72]), and waist to height ratio (OR = 2.94 [95% CI = 2.54–3.40]) with high blood pressure.

Conclusions

Body mass index, waist circumference, and waist to height ratio presented low sensitivity to identify adolescents with high blood pressure. However, adolescents classified with high body mass index, waist circumference, and waist to height ratio demonstrated a high association of presenting high blood pressure.

Relationship between Cardiometabolic Parameters and Elevated Resting and Effort Heart Rate in Schoolchildren

Background

Little has been studied on heart rate and its relationship with metabolic disorders.

Objective

To identify possible association between heart rate (HR) and metabolic disorders in children and adolescents.

Methods

This cross-sectional study evaluated 2.098 subjects, aged between 7 and 17 years. The variables evaluated were: HR, systolic (SBP) and diastolic blood pressure (DBP), pulse pressure (PP), double-product (DP), myocardial oxygen consumption (mVO2), lipids, glucose and uric acid levels, body mass index (BMI) and waist circumference (WC). The values of HR at rest and effort were divided into quartiles. The association between continuous values of HR and cardiometabolic indicators was tested by linear regression.

Results

LDL cholesterol presented a significantly higher mean (p = 0.003) in schoolchildren with resting HR greater or equal to 91 bpm, compared to students with less than 75 bpm. Compared with the quartiles of effort HR, SBP, DBP, glucose and uric acid presented high values when HR was greater or equal than 185 bpm. SBP, glucose and HDL cholesterol demonstrated a significant association with resting HR. Uric acid was observed as a predictor of increased effort HR.

Conclusion

Schoolchildren with a higher resting HR have higher mean of LDL cholesterol. For effort HR, there was an increase in blood pressure, glucose and uric acid levels. Uric acid has been shown to be a predictor of elevated effort HR.

Resting Heart Rate Percentiles and Associated Factors in Children and Adolescents

OBJECTIVES

To present population-based resting heart rate (RHR) percentiles and associated factors in children and adolescents.

STUDY DESIGN

Standardized RHR measurements with an oscillometric device were obtained from 3- to 17-year-olds who participated in the German Health Interview and Examination Survey for Children and Adolescents (n = 11 986). Age- and sex-specific RHR percentiles were derived using flexible age-dependent modeling. Linear regression was used to test associations of RHR and associated factors.

RESULTS

RHR decreased with age and mean RHR was on average 3.0 beats per minute (bpm) higher in girls than in boys (P < .01). The 95th RHR-KiGGS-percentile (P95) in boys and girls are up to 10 bpm lower than P95 based on pooled heterogeneous international studies and more similar to percentiles based on population data from NHANES (higher or lower by ≤5 bpm, depending on age). Factors independently associated with RHR in both sexes were age, SBP and height in children aged 3-10 years; and age, systolic blood pressure, and high aerobic fitness in adolescents aged 11-17 years. In girls, we further found an association between RHR and underweight (OR 3.3 and 4.7 for underweight girls aged 3-10 and 11-17, respectively, compared with normal weight girls). Associations between RHR and aerobic fitness, physical activity, and media use were stronger in boys than in girls.

CONCLUSION

This study provides population-based RHR percentiles and evidence for sex-dependent associations of cardiovascular risk factors with RHR in children and adolescents, many of which are lifestyle related.

Association of elevated resting pulse rate with increased risk of hypertension development in children: A prospective study in Suzhou, China

BACKGROUND

Elevated resting heart rate (RHR) or resting pulse rate (RPR) is associated with increased risk of hypertension development. However, information is limited to adults. The purpose of this study is to analyze this association among Chinese children in a prospective design.

METHODS

A total of 4861 children who participated in the Blood Pressure Surveillance Program (2011-2017) were selected in this research. To investigate the association between RPR and hypertension development, children were divided into 4 groups according to the quartiles of RPR at baseline. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using logistic regression model.

RESULTS

Over a mean follow-up of 3.0 ± 0.1 years, there were 384 cases of incident hypertension. Compared to boys and girls in the 1st quartile, those in the 4th quartile were 1.73 (95% CI 1.13, 2.65), 2.22 (95% CI 1.43, 3.45) times more likely to have hypertension, respectively. Every 10 bpm increase in RPR was associated with a 26% greater risk of hypertension development in boys (OR: 1.26; 95% CI 1.10, 1.44), while this risk was 1.28 (95% CI 1.13, 1.44) in girls. Baseline blood pressure (BP) and body mass index (BMI) did not have significant interactions with RPR on risk of hypertension development.

CONCLUSION

This study confirms the relationship between elevated RPR and increased risk of hypertension development in children, independent of confounders including baseline BP and BMI. An elevated RPR could be considered as a risk factor for the assessment of hypertension, no matter from a clinical setting or a public health perspective.

Cardiovascular Risk Factors in Adolescents With Celiac Disease: A Cross-sectional Population-Based Study

BACKGROUND

Recent data have shown that adults with celiac disease (CD) may have a higher prevalence of risk factors for cardiovascular disease (CVD) compared with the general population. Thus, we aimed to investigate the association of CD with CVD risk factors at late adolescence in a cross-sectional population-based study.

METHODS

A total of 2,001,353 Jewish Israeli adolescents who underwent a general health examination at median age of 17.1 years from 1988 to 2015 were included. Covariate data included demographic measures, blood pressure (BP), resting heart rate, and risk factors associated with CVD.

RESULTS

Overall, 10,566 cases of CD were identified (0.53%). Multivariate analysis showed that mean diastolic BP was significantly lower in subjects with CD (men: 72.0±8.7 vs 70.4 ± 8.5, P < 0.0001; women: 70.0 ± 8.3 vs 69.0 ± 8.2, P < 0.0001), whereas systolic BP did not differ between groups. Resting heart rate was higher in CD cases (an absolute difference of 0.4 beats per minute, P < 0.0001). The proportions of overweight and obese subjects were significantly lower in CD cases. Noninsulin-dependent diabetes mellitus (relative risk [RR], 4.1; 95% confidence interval [CI] 2.8-5.7), hypercoagulability (RR, 2.6; 95% CI 1.5-4.5), and hyperlipidemia (RR, 1.9; 95% CI 1.2-3) were significantly more common in subjects with CD.

CONCLUSIONS

At the age of 17 years, the prevalence of risk factors for CVD is higher in subjects with CD compared with the general population. There is, however, neither increase in BP nor increase in overweight and obesity rates.

Urban versus rural lifestyle in adolescents: associations between environment, physical activity levels and sedentary behavior

Objective

To analyze the levels of physical activity and sedentary behavior in adolescents living in urban and rural areas.

Methods

An epidemiological, cross-section study with quantitative design, carried out at the regional level. The sample comprised 6,234 students aged 14 to 19 years, selected using random cluster sampling. The χ2 test and binary logistic regression were used in the analysis.

Results

A total of 74.5% of adolescents lived in urban areas. After adjustment, rural residents spent less time watching television (odds ratio - OR: 0.45; 95% confidence interval - 95%CI: 0.39-0.52), using a computer and/or playing video games (OR: 0.30; 95%CI: 0.22-0.42), or sitting down (OR: 0.66; 95%CI: 0.54-0.80); chose passive leisure less often (OR: 0.83; 95%IC: 0.72-0.95) and were less likely to be classified as insufficiently active (OR: 0.88; 95%IC: 0.78-0.99) when compared to urban residents, regardless of sex or age. The fact that adolescents living in rural areas who did not work were more likely to be classified as insufficiently active (OR: 2.59; 95%CI: 2.07-3.24) emphasized the significant role of occupation in physical activity levels in this group.

Conclusion

Adolescents living in rural areas were less exposed to the sedentary behaviors, chose more active leisure, and had higher levels of physical activity. Place of residence and occupation may play a major role in youth lifestyle.

Objetivo

Analisar os níveis de atividade física e o comportamento sedentário em adolescentes das áreas urbanas e rurais.

Métodos

Estudo epidemiológico, transversal, com abordagem quantitativa e abrangência estadual, cuja amostra foi constituída por 6.234 estudantes (14 a 19 anos), selecionados por meio de uma estratégia de amostragem aleatória de conglomerados. As análises foram realizadas por meio do teste χ2 e da regressão logística binária.

Resultados

Na amostra, 74,5% dos adolescentes eram residentes em área urbana. Após o ajuste, constatou-se que os adolescentes oriundos da área rural usavam menos televisão (odds ratio - OR: 0,45; intervalo de confiança de 95% - IC95%: 0,39-0,52), computador e/ou videogame (OR: 0,30; IC95%: 0,22-0,42), passavam menos tempo sentados (OR: 0,66; IC95%: 0,54-0,80), optaram menos pelo lazer passivo (OR: 0,83; IC95%: 0,72-0,95) e tinham menos chances de serem classificados como insuficientes ativos (OR: 0,88; IC95%: 0,78-0,99), quando comparados àqueles que residiam na área urbana, independentemente do sexo e da idade. Os adolescentes da área rural que não trabalhavam apresentaram mais chances de serem classificados como insuficientemente ativos (OR: 2,59; IC95%: 2,07-3,24), mostrando que a ocupação tinha um papel importante no nível de atividade física deste grupo.

Conclusão

Os adolescentes residentes na área rural estiveram menos expostos aos comportamentos sedentários, optaram mais por um lazer ativo e apresentaram um melhor nível de atividade física, podendo a zona de domicílio e a ocupação influenciar no estilo de vida deles.

The number of visits and blood pressure measurements influence the prevalence of high blood pressure in adolescents

The aim of this study was to analyze the influence of the number of visits and the number of blood pressure (BP) measurements on the prevalence of high blood pressure (HBP) in adolescents. A cross-sectional epidemiologic study with 481 adolescents (14-19 years old) selected using a random cluster sampling strategy. We measured the BP three times in a first visit. Adolescents with HBP performed subsequent visits. The final calculation of BP followed four strategies: the 1st measure, mean of 1st and 2nd measurements, mean of all three measurements, and averaging the 2nd and 3rd measurements. The prevalence of HBP in the first and second visits was 6.4% and 1.9%, and the prevalence of hypertension (after three visits) was 1.7%. The prevalence of HBP varied from 8.6%-18.6% for boys and 4.6%-9.2% for girls, using the average 2nd and 3rd measurements and the 1st measurement, respectively. In all strategies, HBP and hypertension were more prevalent in boys and students attending the nocturnal shift. The number of visits and number of measurements affect the prevalence of HBP and hypertension in adolescents. Thus, clinicians and researchers should consider these aspects when assessing BP in adolescents aged 14-19 years old.

Overweight effect on spirometric parameters in adolescents undergoing exercise

Objective

To evaluate effects of overweight on spirometric parameters in adolescents who underwent bronchial provocation test for exercise.

Methods

We included 71 male adolescents. The diagnosis of asthma was done based on participants’ clinical history and on the International Study Questionnaire Asthma and Allergies in Childhood, and the diagnosis of obesity was based on body mass index above 95th percentile. The bronchospasm induced by exercise was assessed using the run-walk test on a treadmill for eight minutes. The decrease in forced expiratory volume in one second > or equal to 10% before exercise was considered positive, and to calculate the intensity in exercise-induced bronchospasm we measured the maximum percentage of forced expiratory volume in one second and above the curve area. Data analysis was carried out using the Mann-Whitney U test and Friedman test (ANOVA), followed by Wilcoxon test (p<0.05). In addition, we used Fisher’s exact test to analyze the exercise-induced bronchospasm frequency.

Results

Significant differences were observed among obese adolescents in exercise-induced bronchospasm frequency (p=0,013) and in relation to time required for recovery after exercise (p=0,007).

Conclusion

Overweight can influence the increase in the exercise-induced bronchospasm frequency in non-asthmatic adolescents compared with eutrophic adolescents.

Regional differences in the prevalence of underweight, overweight and obesity among 13-year-old adolescents in Greece

Background and objectives

To assess regional differences in the weight status and abdominal obesity among 13-year-old Greek adolescents.

Design and setting

Cross-sectional, nationwide study in Greece.

Patients and methods

A representative sample of 4833 13-year-old adolescents (50.7% boys) was recruited throughout the nine regional districts of Greece from 2010 to 2012. Basic anthropometry measurements (weight, height, and waist circumference) were obtained. Abdominal obesity and weight status were assessed according to the International Obesity Task Force criteria.

Results

The majority of the sample had a healthy body weight (60.3%), 4.1% were underweight, 27.2% were overweight, and 8.5% were obese. For boys, the highest prevalence of underweight was recorded in Epirus, normal body weight on the Ionian Islands, overweight in Central Greece and Macedonia, and obesity on the Ionian Islands. Among girls, the highest underweight prevalence was on the Ionian Islands, normal body weight in Macedonia, overweight in Central Greece and Macedonia, and obesity in Crete. Abdominal obesity affected 12.9% of the sample, with the greatest prevalence among Cretan boys and Thracian girls. Additionally, residing on the Greek islands was associated with a higher prevalence of central adiposity.

Conclusion

Greek 13-year-old adolescents who are subjected to geographical changes exhibit high obesity and abdominal obesity rates. This study provides evidence to design regionally tailored interventions that aim to tackle and prevent the disease among the nine regional districts in Greece.

Circadian and ultradian cardiovascular rhythmicity in obese children

Altered circadian and ultradian blood pressure (BP) and heart rate (HR) rhythmicity have been described in diseases with increased cardiovascular risk. We analyzed cardiovascular rhythmicity in obese children. BP and HR rhythmicity was assessed with Fourier analysis from 24-h ambulatory BP measurements in 75 obese children and compared with an age- and gender-matched, lean healthy reference group of 150 subjects. Multivariate regression analysis was applied to identify significant independent factors explaining variability of rhythmicity. Prevalence of 24- and 6-h BP rhythmicity in the obese group was lower (p = 0.03 and p = 0.02), whereas the prevalence of HR rhythmicity was comparable in both groups. Excluding hypertensive participants, the results remained similar. Twenty-four-hour BP and HR acrophase were delayed in obese children (p = 0.004, p < 0.0001), 24-h BP amplitude did not differ (p = 0.07), and 24-h HR amplitude was blunted (p = < 0.0001). BP Mesor in the obese group was higher (p = 0.02); HR Mesor did not differ (p = 0.1). Multivariate regression analysis failed to identify a single anthropometric or blood pressure parameter explaining the variability of BP and HR rhythmicity.

CONCLUSION

Prevalence and parameters of circadian and ultradian BP and HR rhythmicity in obese children are altered compared to a healthy reference group, independent of preexisting hypertension.

WHAT IS KNOWN

• Altered cardiovascular rhythmicity has been described in children with different diseases such as primary hypertension or chronic renal failure. What is New: • This study reveals altered cardiovascular rhythmicity in obese children compared to an age and gender-matched healthy reference group independent from preexisting hypertension.