Cardiorespiratory Fitness and Blood Pressure: A Longitudinal Analysis

Cardiovascular and cardiorespiratory effects of high-intensity interval training in body fat responders and non-responders

This study aimed to investigate cardiovascular and cardiorespiratory adaptations to exercise intervention among participants who showed higher (responders-RSBFP) and lower (non-responders-NRSBFP) levels of body fat percentage (BFP) responsiveness. Adolescents (42.5% males) participated in a ten-week school-based high-intensity interval training (HIIT), followed by a comparison of BFP, blood pressure (BP), and cardiorespiratory fitness (CRF). RSBFP age of 16.15 ± 0.36 years, body height 170.82 ± 8.16 cm, weight 61.23 ± 12.80 kg, and BMI 20.86 ± 3.29 kg/m2. Meanwhile, NRSBFP age of 16.04 ± 0.36 years, body height 168.17 ± 8.64 cm, weight 57.94 ± 8.62 kg, and BMI 20.47 ± 2.24 kg/m2. HIIT intervention impacted BFP, with a higher decrease in the RSBFP than the NRSBFP (ΔBFPRs = - 2.30 ± 3.51(10.34%) vs. ΔBFPNRs = 1.51 ± 1.54(6.96%) p < 0.001). The primary comparison showed a statistically significant interaction effect in relation to CRF (F(1,71) = 14.12; p < 0.001). Detailed comparisons showed large and significant CRF changes in RSBFP (7.52%; d = 0.86; p < 0.001) but not in NRSBFP (2.01%; d = 0.11; p = 0.576). In addition, RSBFP and NRSBFP benefited equally in SBP (5.49%, d = 0.75; p < 0.001; 4.95%, d = 0.74; p < 0.001, respectively). These findings highlight that exercise benefits on body fat may be mainly related to gains in CRF. Due to substantial intra-individual variability in adaptation, there is a need for personalized intervention tailored for those with different reaction thresholds in body mass components.

Cardiorespiratory fitness attenuates the association between fatness and cardiometabolic risk in Chinese children

Background

Childhood obesity tends to persist into adulthood, predisposing individuals to cardiometabolic risk (CMR). This study aims to investigate the mediating role of cardiorespiratory fitness (CRF) in the associations between multiple fatness indicators and individual CMR markers and clustered CMR-score, and explore sex differences.

Methods

We recruited 1,557 children (age: 8 to 10, male/female: 52.7%/47.3%) in September 2022 in Ningbo, China. Physical examinations, overnight fasting blood test, and CRF was evaluated. The CMR-score was calculated by summing age- and sex-specific z scores of four CMR markers, including mean arterial blood pressure, triglycerides, the total cholesterol to high-density lipoprotein cholesterol ratio, and homeostatic model assessment for insulin resistance. Generalized linear mixed models were used to identify the associations, mediation analyses were performed to dissect the function of CRF.

Results

Partial correlation analyses revealed positive associations between high fatness indicators (including body mass index [BMI], BMI z score, body fat mass index [BFMI] and waist-to-height ratio [WHtR]) and increased CMR markers, whereas high CRF was associated with decreased CMR markers (all P < 0.05). In the mediation analyses, CRF emerged as a partial mediator, attenuating the relationship between four fatness indicators and CMR-score. Specifically, CRF mediated 6.5%, 7.7%, 5.3%, and 12.5% of the association between BMI, BMI z score, BFMI, WHtR and CMR-score (all P < 0.001). And the mediating effects of CRF between WHtR and four individual CMR markers was particularly robust, ranging from 10.4% to 21.1% (all P < 0.05). What's more, CRF mediates the associations between WHtR and CMR-score more pronounced in girls than boys with a mediation effect size of 17.3% (P < 0.001).

Conclusion

In Chinese children, CRF partially mitigates the adverse effects of fatness on CMR, underscoring the significance of enhancing CRF in children.

Cardiorespiratory and Muscular Fitness in Children and Adolescents with Obesity

PURPOSE OF REVIEW

Examine the current state of literature related to the impact of obesity in children and adolescents on health-related physical fitness and the resultant cardiometabolic disease risk.

RECENT FINDINGS

Cardiorespiratory fitness of children and adolescents has declined over the past few decades which corresponds with an increase in obesity rates. Children with obesity are more likely to have low cardiorespiratory fitness which is associated with higher cardiometabolic disease risk and poorer mental health. The impact of obesity on muscular fitness in children and adolescents is more difficult to ascertain, but in general measures of physical function are lower in children with obesity which has also been associated with higher cardiometabolic disease risk. Components of health-related physical fitness are trending negatively in children and adolescents and appear to be related to the increase in prevalence of obesity. The resultant cardiometabolic disease risk has also risen which suggests a greater disease burden in the future. These disparaging findings highlight the need for aggressive interventions to improve physical fitness in children and adolescents.

Four-year longitudinal associations of physical activity, waist circumference, and blood pressure in UK adolescents

BACKGROUND

This study assessed the specific influence of physical activity (PA) and waist circumference (WC) on the 4-year growth trajectory of blood pressure in UK high-school students.

METHODS

Four-year longitudinal monitoring of 1501 adolescents was conducted as part of the EoEHHS. Measurements were taken in Grades (G)7, 9, and 11.

RESULTS

Systolic (SBP) and diastolic blood pressure (DBP) increased over the 4-year period (SBP G7 114.6 ± 8.9 mmHg, G9 118.1 ± 9.7 mmHg, G11 122.8 ± 7.8 mmHg; DBP G7 66.7 ± 6.6 mmHg, G9 68.0 ± 6.4 mmHg, G11 70.0 ± 5.2 mmHg). Baseline WC predicted baseline and growth in SBP, but the strongest contribution to SBP came from changes in WC (β = 0.084, p = 0.002). Baseline PAQ-A score (β = -0.822, p = 0.020) and changes in PAQ-A score (β = -0.650, p = 0.019) were associated with smaller increases in DBP over the 4-year measurement period.

CONCLUSIONS

Baseline and change in WC predicted the growth trajectory of SBP, while baseline and change in PA predicted the growth trajectory of DBP. PA and WC have a prognostic value in predicting changes in blood pressure in adolescents. Increasing PA during adolescence could slow the rise in DBP over time. This is meaningful for future hypertension and CVD risk reduction into adulthood.

IMPACT

Hypertension in adolescents is a growing health problem that is often overlooked. Baseline and changes in waist circumference over a 4-year period predicted development of systolic blood pressure, while baseline and changes in physical activity predicted development of diastolic blood pressure. Physical activity and waist circumference have a prognostic value in predicting changes in blood pressure in adolescents and could be valuable in planning programmes to prevent hypertension in similar communities and reduce the risk of future adult hypertension.

Cardiorespiratory fitness and development of childhood cardiovascular risk: The EXAMIN YOUTH follow-up study

Background: Obesity- and hypertension-related cardiovascular (CV) risk has been shown to originate in childhood. Higher body mass index (BMI) and blood pressure (BP) have been associated with increased large artery stiffness and a lower microvascular arteriolar-to-venular diameter ratio (AVR) in children. This study aimed to investigate the association of cardiorespiratory fitness (CRF) with development of BMI, BP and vascular health during childhood. Methods: In our prospective cohort study, 1,171 children aged 6-8 years were screened for CRF, BMI, BP, retinal vessel diameters and pulse wave velocity using standardized protocols. Endurance capacity was assessed by 20 m shuttle run test. After 4 years, all parameters were assessed in 664 children using the same protocols. Results: Children with a higher CRF at baseline developed a significantly lower BMI (β [95% CI] -0.09 [-0.11 to -0.06] kg/m2, p < 0.001), a lower systolic BP (β [95% CI] -0.09 [-0.15 to -0.03] mmHg, p = 0.004) and a higher AVR (β [95% CI] 0.0004 [0.00004 to 0.0007] units, p = 0.027) after 4 years. The indirect association of CRF with development of retinal arteriolar diameters was mediated by changes in BMI. Conclusion: Our results identify CRF as a key modulator for the risk trajectories of BMI, BP and microvascular health in children. Obesity-related CV risk has been shown to track into adulthood, and achieving higher CRF levels in children may help counteract the development of CV risk and disease not only in pediatric populations, but may also help reduce the burden of CVD in adulthood. Registration: http://www.clinicaltrials.gov/ (NCT02853747).

Training, detraining and retraining effects of moderate vs. high intensity exercise training programme on cardiovascular risk factors

BACKGROUND

The aim of the present study was to analyse the effect of 12 weeks of training, 7 weeks of detraining and 16 weeks of retraining using a moderate or high intensity training programme on cardiovascular risk factors in hypertensive patients.

METHOD

Thirty-four patients took part in the study. The intensity training was 80-90% of maximum heart rate for the high-intensity training (HIT) group ( n  = 15) and at 50-70% of maximum heart rate for the moderate training (MT) group ( n  = 19). Blood pressure, body composition, lipid profile, fasting glucose, strength and cardiovascular fitness were analysed.

RESULTS

The first training period did not decrease blood pressure, but the second training period saw significant decreases in blood pressures in HIT group. Moreover, 12 weeks of MT or HIT did not decrease body mass, body mass index or fat mass. However, after 7 weeks of detraining, the inclusion of a second training period using HIT saw decreases in these body composition variables. Both training periods and intensities improved high-density lipoprotein and low-density lipoprotein, but only HIT decreased total cholesterol. In addition, after 7 weeks of detraining, the lipid profile variables returned to baseline values. Additionally, 16 weeks of retraining with HIT or MT decreased blood glucose significantly. Moreover, MT and HIT training programmes in both periods improved cardiorespiratory fitness, but with 7 weeks of detraining, it returned to baseline values.

CONCLUSION

Our data demonstrated the effectiveness of the inclusion of a MT or HIT programme as adjuvant therapy in hypertensive patients.

An Investigation of the Utility of Waist Circumference Predicting Cardiorespiratory Fitness in School Children: A Cross-Sectional Study

The early identification of modifiable risk factors and their monitoring, also within school physical education (PE) classes, are becoming indispensable in the context of public health. The aim of this study was to test whether making use of waist circumference (WC) measurements increases the possibility of predicting the results of cardiorespiratory fitness (CRF) in school-age children, as compared with body mass index (BMI) and other somatic indicators related to body fat. The cross-sectional study covered 190 children aged 10 to 15 years, participating in school PE classes. Body height (BH), body weight (BW), WC, hip circumference (HC) and percentage of body fat (BF%) were measured. BMI, waist to hip ratio (WHR) and waist to height ratio (WHtR) were calculated, and a CRF test was performed by means of a 20 m shuttle run test (20mSRT). The peak heart rate (HR_peak) of the children was also measured. The regression model that was developed showed that WC (R² = 47.1%), beyond BF% (R² = 50.3%) and WHtR (R² = 50.0%), was a useful measure of CRF, and stronger than BMI (R² = 45.8%) or WHR (R² = 39.2%). The risk of obtaining the CRF result classified below a good level (below the percentile range of P60-P80) was significantly higher in children with a larger WC (odds ratio (OR) for the WC change of 1 cm equals 1.14 (95% CI: 1.09-1.20; p < 0.001)). The simplicity of measuring WC and the possibility of using this measurement in the calculation of WHtR with reference to CRF indicate its usefulness in the prophylactic exams of school children.

Physical fitness mediates and predicts for high blood pressure among children in relation to weight status

Background

Pediatric hypertension contributes to adulthood hypertension and target organ damage. Obesity is a well-known predictor for pediatric hypertension; however, the relationship between physical fitness and blood pressure (BP) is unclear among children. This study aimed to compare the differences in demographics, anthropometrics, and physical fitness across BP subgroups and investigate whether physical fitness was related to pediatric hypertension independent of weight status.

Methods

This quantitative, cross-sectional study investigated demographic, anthropometric, physical fitness, and BP measures among 360 healthy school-aged children. Continuous variables were compared across BP subgroups with the one-way analysis of variance. Mediation and moderation analyses were used to explore the mechanism. Multivariable regression models were used to assess independent associations for hypertension.

Results

There were 177 (49.2%), 37 (10.3%), and 146 (40.6%) children in the normotensive, elevated BP, and hypertensive subgroups, respectively. The hypertensive subgroup had higher body mass index (BMI) and waist/height ratio percentiles and performed worse in 800-m run, standing long jump (SLJ), and 1-min sit-ups than the normotensive subgroup. Furthermore, the 800-m run percentile (total effect: β = 0.308, standard error = 0.044, p < 0.001) and sit and reach percentile (total effect: β = 0.308, standard error = 0.044, p < 0.001) mediated the relationship between the BMI percentile and systolic BP percentile; the SLJ percentile was directly associated with the diastolic BP percentile (β,-0.197, 95% confidence interval,-0.298-0.097; p < 0.001). The parsimonious model of multivariable regression models revealed that the SLJ percentile (adjusted exp (β), 0.992, 95% confidence interval, 0.985-0.999; p = 0.042) and BMI percentile (adjusted exp (β), 1.024, 95% confidence interval, 1.016-1.032; p < 0.001) were two independent predictors for pediatric hypertension.

Conclusion

Physical fitness mediates the relationship between anthropometric and BP measures. The SLJ percentile is associated with pediatric hypertension independent of the BMI percentile. Proactive screening and health promotion for not only healthy weight status but also good physical fitness may be beneficial for BP control among school-aged students.

Sex-Related Differences in the Relationship between Sugar-Sweetened Beverage Consumption and Cardiorespiratory Fitness: Results from Chinese Cross-Sectional Study on Children

Sugar-sweetened beverage (SSB) consumption continues to increase among children, with adverse health effects, and China is no exception. Our study investigates the association between SSB consumption and cardiopulmonary fitness. We used stratified whole group sampling to investigate and test SSB consumption and cardiopulmonary fitness in 21,055 children aged 13−15 years in China. A chi-square test and one-way ANOVA were used to compare different categories of SSB consumption. General linear regression analysis and logistic regression analysis were used to analyze the relationship between different SSB consumption and cardiopulmonary fitness in Chinese children. Our research results show the proportions of Chinese children with SSB consumption ≤ 1 time/week, 2−4 times/week, and ≥5 times/week were 33.3%, 52.8%, and 13.9%, respectively. VO2max in children consuming ≥ 5 times/week was lower than those consuming 2−4 times/week and ≤2 times/week of SSB by 0.15 and 0.301 mL·kg−1·min−1, with statistically significant differences (F-value 18.807, p < 0.001). After relevant confounders were adjusted, children in the SSB consumption ≥ 5 times/week group had a higher risk of developing poorer cardiopulmonary fitness than those in the SSB consumption ≤ 1 time/week group (OR: 1.336, 95% CI: 1.181, 1.511) (p < 0.001). In conclusion, the consumption of SSBs among children aged 13−15 in China is higher than the recommended intake by the World Health Organization, and boys are higher than girls. In addition, after adjusting for relevant confounders, the association between SSB consumption and an increased risk of poor cardiorespiratory fitness remained. The relationship between SSB consumption and cardiopulmonary fitness was higher in girls compared with boys.

Cardiovascular health behavior and blood pressure in adolescents: A longitudinal analysis

BACKGROUND

The ideal cardiovascular health behaviors (ICHB) have been associated with a subsequent positive health status in adults. However, evidence regarding blood pressure (BP) and ICHB in adolescents is scarce. The aim of this prospective cohort was to evaluate the impact of accumulation of ICHB on BP values in adolescents over two years.

METHODS

This is a longitudinal analysis with 445 adolescents (232 girls) aged 12-18 years old. Resting blood pressure was measured at baseline and 2 years later, and ICHBs at baseline according to standard procedures. Based on the American Heart Association definition, the ICHB index was defined as a sum of meeting the ICHBs (from 0 to 4, where 4 would be the healthiest profile of all ICHBs) for a healthy diet, physical activity, smoking status and body mass index.

RESULTS

Adjusted means values (ANCOVA) of BP parameters through achievement of a greater number of (between 1-4) the ICHBs (adjusting for potential confounders, age, sex, pubertal stage and socioeconomic status) showed that, as increase the number of ICHB accumulated as a lower the BP levels [ICHB and SBP (F_3.435) = 4.501, p = 0.004), DBP (F_(3.435) = 2.725, p = 0.044), pulse pressure (F_(3.435) = 4.004, p = 0.008), and rate pressure product (F_(3.435) = 2.866, p = 0.036)] over two years.

CONCLUSION

A lower number of ICHB (smoking status, body mass index, physical activity, and diet) during adolescence play a key role on blood pressure over two years. A higher number of ICHB is seen to be associated with a lower risk of short-term, hypertension.

Body fat percentage, cardiorespiratory fitness and arterial blood pressure in children and adolescents: a longitudinal analysis

Background

A better understanding of how cardiorespiratory fitness (CRF) and adiposity interact to associate with arterial blood pressure over time remains inconclusive. Thus, the aim of the present study was to examine whether changes in CRF moderates the association between body fat percentage (BF%) and arterial blood pressure in children and adolescents.

Methods

This is an observational longitudinal study with 407 children and adolescents aged 8–17 years followed-up for three years from a city in Southern Brazil. Participants were evaluated in 2011 and 2014. CRF was measured by validated field-based tests following the Projeto Esporte Brazil protocols and peak oxygen uptake (VO_2peak) was estimated. BF% was determined by the measures of tricipital and subscapular skinfolds using equations according to sex. Systolic and diastolic blood pressure (SBP, DBP) were measured with a sphygmomanometer according to standard procedures. Moderation analyses included multiple linear regression models adjusted for sex, age, pubertal status, height, socioeconomic level, skin color, and the arterial blood pressure variable itself at baseline.

Results

It was observed a significant inverse association between VO_2peak at baseline with SBP (β = − 0.646 CI95% = − 0.976  − 0.316) and DBP (β = − 0.649 CI95% = − 0.923  − 0.375) at follow-up and a positive association between BF% at baseline with SBP (β = 0.274; CI95% = 0.094 0.455) and DBP (β = 0.301; CI95% = 0.150 0.453) at follow-up. In addition, results indicated a significant interaction term between changes in VO_2peak and BF% at baseline with both SBP (p = 0.034) and DBP at follow-up (p = 0.011), indicating that an increase of at least 0.35 mL/kg/min and 1.78 mL/kg/min in VO_2peak attenuated the positive relationship between BF% with SBP and DBP.

Conclusion

CRF moderates the relationship between BF% and SBP and DBP in children and adolescents.

Identification of Lifestyle Risk Factors in Adolescence Influencing Cardiovascular Health in Young Adults: The BELINDA Study

Cardiovascular diseases are the leading cause of mortality worldwide. These diseases originate in childhood, and a better understanding of their early determinants and risk factors would allow better prevention. The BELINDA (BEtter LIfe by Nutrition During Adulthood) study is a 10−14-year follow-up of the HEalthy Lifestyle in Europe by Nutrition in Adolescence study (the HELENA study, a European cross-sectional study in adolescents). The study aims to evaluate cardiovascular risk using the PDAY (Pathobiological Determinants of Atherosclerosis in Youth) risk score during young adulthood (21−32 years), and to examine the impact of risk factors identified during adolescence (12.5−17.5 years). Our secondary objective is to compare the characteristics of the BELINDA study population with the HELENA population not participating in the follow-up study. The HELENA study recruited 3528 adolescents during 2006−2007 and reassessed 232 of them 10−14 years later as young adults. We assessed clinical status, anthropometry, nutrition, physical activity (including sedentary behavior), physical fitness, and mental health parameters, and collected biological samples (blood, stool, and hair). Dietary intake, and physical activity and fitness data were also collected. A multivariable linear regression model will be used for the analysis of the primary outcome. A Chi-square and T-test were conducted for the comparison of the descriptive data (gender, age, weight, height, body mass index (BMI), and maternal school level) between participating and non-participating BELINDA adolescents. When comparing the 1327 eligible subjects with the 232 included in the BELINDA study, no significant differences regarding gender (p = 0.72), age (p = 0.60), height (p = 0.11), and weight (p = 0.083) at adolescence were found. However, the participating population had a lower BMI (20.4 ± 3.1 kg/m2 versus 21.2 ± 3.6 kg/m2; p < 0.001) and a higher maternal educational level (46.8% high school or university level versus 38.6%; p = 0.027) than the HELENA population who did not participate in the BELINDA study. The complete phenotyping obtained at adolescence through the HELENA study is a unique opportunity to identify adolescent risk factors for cardiovascular diseases. This paper will serve as a methodological basis for future analysis of this study.

Percentage of Age-Predicted Cardiorespiratory Fitness and Risk of Incident Hypertension: A PROSPECTIVE COHORT STUDY

PURPOSE

There are inverse and independent associations between cardiorespiratory fitness (CRF) and several adverse cardiometabolic outcomes including hypertension (HTN). The prospective relationship between percentage of age-predicted CRF and risk of HTN has not been previously investigated. We aimed to assess the association of percentage of age-predicted CRF with incident HTN in a long-term prospective cohort study.

METHODS

Cardiorespiratory fitness, as measured by peak oxygen uptake, was assessed using the gold standard respiratory gas exchange analyzer in 1602 men who underwent cardiopulmonary exercise testing. The age-predicted CRF estimated from a regression equation for age was converted to percentage of age-predicted CRF ([achieved CRF/age-predicted CRF] × 100). The HR with 95% CI were estimated for HTN.

RESULTS

During a median follow-up of 26.8 yr, 308 HTN cases were recorded. There was a linear relationship between age-predicted CRF and incident HTN (P value for nonlinearity = .68). A 1-SD increase in percentage of age-predicted CRF was associated with a decreased risk of HTN in analysis adjusted for established risk factors (HR = 0.79: 95% CI, 0.69-0.90), which remained consistent on further adjustment for several other potential confounders including alcohol consumption, physical activity, socioeconomic status, and inflammation (HR = 0.83: 95% CI, 0.72-0.95). The corresponding adjusted HRs were 0.55 (95% CI, 0.38-0.80) and 0.63 (95% CI, 0.43-0.91), respectively, when comparing extreme quartiles of percentage of age-predicted CRF levels.

CONCLUSIONS

Percentage of age-predicted CRF is linearly, inversely, and independently associated with risk of incident HTN, and it is comparable to absolute CRF as a risk indicator for HTN in a general population of middle-aged men.

Associations between cardiorespiratory fitness, fatness, hemodynamic characteristics, and sedentary behaviour in primary school-aged children

BACKGROUND

Low cardiorespiratory fitness (CRF) is associated with the development of cardiovascular diseases during childhood, adolescence and older ages. The purpose of the study was to investigate associations between fatness, hemodynamic characteristics and secondary time with CRF in primary school-aged children.

METHODS

Height, weight, body mass index (BMI), blood pressure (BP), heart rate (HR), CRF (20 m shuttle-run) and sedentary time were measured for 105 children (categorized as normal, overweight, obese). The independent sample t-test checked for differences and one-way ANOVA-Post Hoc Test and stepwise linear regression analysis assessed the 20 m shuttle-run performance predictors.

RESULTS

There was a statistically significant difference in CRF between boys and girls. There was a statistically significant difference between (p < 0.05) CRF for Normal weight (M = 47.58 ± 3.26 kg m^-2) and Obese (M = 44.78 ± 3.23 kg m^-2). CRF correlated with age, BMI and sedentary time (r > 0.3; p < 0.05). BMI is the best independent predictor of CRF.

CONCLUSIONS

Children with normal BMI tend to present better CRF performance than obese and overweight children. Sedentary behaviour is associated with lower CRF in primary school-aged children.

The Mediation Role of Fatness in Associations between Cardiorespiratory Fitness and Blood Pressure after High-Intensity Interval Training in Adolescents

BACKGROUND

Low cardiorespiratory fitness (CRF), elevated blood pressure (BP), and high fatness are cardiovascular disease risk factors. It remains unknown how fatness affects the influence of CRF on BP. Therefore, the aim was to examine whether the associations between baseline CRF and HIIT-postintervention resting BP were mediated through fatness in adolescents.

MATERIAL AND METHODS

The sample (n = 64) comprised 28 boys 36 girls aged 16 years. The analysed factors were fitness index- reflecting CRF, body fat mass (BFM), fat mass index (FMI), and body mass index (BMI). Bootstrapped mediation procedures were performed. The mediation analysis was conducted concerning the sex moderation effect.

RESULTS

The mediation effect of sex was confirmed; therefore, mediations models were designed separately for boys and girls. The results showed a statistically significant inverse relationship between baseline CRF and post-intervention systolic blood pressure (SBP) in both sexes (boys: B = -0.603, p = 0.010; girls: B = -0.394, p = 0.037). The relations between CRF and SBP revealed the mediation effect of the BFM and the FMI only in boys.

CONCLUSIONS

Fatness mediated associations between CRF and SBP in boys. Therefore, both CRF and fatness are necessary to maintain positive results of the BP revealed in normal SBP ranges after HIIT.

Adding Estimated Cardiorespiratory Fitness to the Framingham Risk Score and Mortality Risk in a Korean Population-Based Cohort Study

BACKGROUND

The added value of non-exercise-based estimation of cardiorespiratory fitness (eCRF) to cardiovascular disease (CVD) risk factors for mortality risk has not been examined in Korean populations.

METHODS

This population-based prospective cohort study examined the relationship of the 10-year Framingham risk score (FRS) for CVD risk and eCRF with all-cause and CVD mortality in a representative sample of Korean adults aged 30 years and older. Data regarding a total of 38,350 participants (16,505 men/21,845 women) were obtained from the 2007-2015 Korea National Health and Nutrition Examination Survey (KNHANES). All-cause and CVD mortality were the main outcomes. The 10-year FRS point sum and eCRF level were the main exposures.

RESULTS

All-cause and CVD mortality was positively correlated with the 10-year FRS point summation and inversely correlated with eCRF level in this study population. The protective of high eCRF against all-cause and CVD mortality was more prominent in the middle and high FRS category than in the low FRS category. Notably, the FRS plus eCRF model has better predictor power for estimating mortality risk compared to the FRS only model.

CONCLUSIONS

The current findings indicate that eCRF can be used as an alternative to objectively measured CRF for mortality risk prediction.

Cardiovascular health behavior and cardiorespiratory fitness in adolescents: a longitudinal study

Cardiorespiratory fitness has been substantially associated with health status. However, longitudinal studies on cardiorespiratory fitness and ideal cardiovascular health behavior (ICHB) in adolescents are scarce. The aim of this study was to evaluate the longitudinal association between ICHB (at baseline) and cardiorespiratory fitness (at follow-up). This is a 2-year prospective analysis of 445 adolescents (232 girls) aged 12-18 years. The ICHB was developed by the American Heart Association as meeting the ideal health behaviors for a healthy diet, physical activity, smoking status, and body mass index. ANCOVAS adjusted by age, sex, pubertal stage, socioeconomic status, and cardiorespiratory fitness showed that the higher the number of ICHB metrics accumulated at baseline (from 1 to 4), the higher the cardiorespiratory fitness levels over a 2-year period (p = 0.038). In logistic regressions, after adjusting for potential confounders, the odds ratios for having high cardiorespiratory fitness at follow-up was 4.9 (95% CI, 1.2-20.1, p = 0.02) for those who accumulated all four metrics of ICHB, when compared to those with 1 or less metrics of ICHB. In addition, the higher the number of ICHB metrics accumulated, the higher the likelihood of having a high cardiorespiratory fitness level over a 2-year period (p for trend = 0.01).

CONCLUSION

 We identified a significant association between ICBH and cardiorespiratory fitness in adolescents. Therefore, improving ICBH in adolescence is likely to benefit the cardiorespiratory fitness.

WHAT IS KNOWN

• Smoking status, body mass index, physical activity, and diet are associated to cardiorespiratory fitness in adulthood. • Lifestyle behaviors such as physical activity, smoking, body weight, and healthy diet are individually linked with cardiorespiratory fitness and, however, have not been examined jointly, as combined health behaviors.

WHAT IS NEW

• Accumulation of cardiovascular health behavior metrics was positively associated with cardiorespiratory fitness at a 2-year follow-up, in adolescents. • Meeting all the four metrics of ideal cardiovascular health behavior seems important for healthy cardiorespiratory fitness during adolescence.

Factors affecting systolic blood pressure trajectory in low and high activity conditions

Background: Typically, blood pressure dips during sleep and increases during daytime. The blood pressure trend is affected by the autonomic nervous system. The activity of this system is observable in the low and high activity conditions. The aim of this study was to assess the effect of individual characteristics on systolic blood pressure (SBP) across day-night under low and high activity conditions.

Methods: The samples were 34 outpatients who were candidates for evaluation of 24 hours of blood pressure with an ambulatory. They were admitted to the heart clinic of Farshchian hospital, located in Hamadan province in the west of Iran. The hourly SBP during 24 hours was considered as a response variable. To determine the factors effecting SBP in each condition, the hidden semi-Markov model (HSMM), with 2 hidden states of low and high activity, was fitted to the data.

Results: Males had lower SBP than females in both states. The effect of age was positive in the low activity state (β=0.30; p<0.001) and negative in high activity state (β= -0.21; p=0.001). The positive effect of cigarette smoking on SBP was seen in low activity state (β=5.02; p=0.029). The overweight and obese patients had higher SBP compared to others in high activity state (β=11.60; p<0.001 and β=5.87; p=0.032, respectively).

Conclusion: The SBP variability can be displayed by hidden states of low and high activity. Moreover, the effects of studied variables on SBP were different in low and high activity states.

Mediterranean diet quality index is associated with better cardiorespiratory fitness and reduced systolic blood pressure in adults: A cross-sectional study

BACKGROUND

Literature suggests higher cardiorespiratory fitness (CRF) is inversely related to chronic diseases such as metabolic syndrome and cardiovascular disease and hypertension. The aim of this study was to assess the association of Mediterranean dietary quality index (Med-DQI) with CRF and hypertension in a sample of Iranian adults.

METHODS

This was a cross-sectional study on 270 healthy men and women, aged 18-45 years. Dietary intake and physical activity level were assessed through a validated food frequency questionnaire (FFQ); and the International Physical Activity Questionnaires (IPAQ), respectively. Cardiorespiratory fitness was assessed by using a graded exercise treadmill test. The association between Med-DQI and CRF was investigated using multiple regression models.

RESULTS

Participants in the top tertiles of Med-DQI, had higher VO2 max (mL/kg/min) (p = 0.02) and lower SBP (p = 0.01). When we controlled for age, sex, weight, smoking, physical activity and energy intake, the significant results were remained. Results of unadjusted linear regression shows that CRF was positively associated with cholesterol (p < 0.001) and fish (p < 0.001). Also, CRF was positively associated with vegetables and fruits (p < 0.001) and olive oil (p = 0.05). After adjustments for confounders, the significant associations of olive oil and cholesterol with CRF were disappeared while vegetables and fruits and total score of Med-DQI remained significant. There were no significant relations between saturated fatty acids meat, and cereals with Med-DQI.

CONCLUSIONS

Our results demonstrated that Med-DQI was associated with better CRF in Iranian adults and SBP. Further studies with interventional approaches are needed to better clarify the causal inference of these associations.

Decreased ventricular size and mass mediate the reduced exercise capacity in adolescents and adults born premature

BACKGROUND

Premature birth is associated with lower levels of cardiorespiratory fitness (CRF) but the underlying mechanisms responsible remain unclear. This study assessed whether differences in cardiac morphology or function mediate differences in CRF among adolescents and young adults born preterm.

METHODS

Adolescents and young adults born moderately to extremely premature (gestational age ≤ 32 weeks or birth weight < 1500 g) and age-matched term born participants underwent resting cardiac MRI and maximal exercise testing. Mediation analysis assessed whether individual cardiovascular variables accounted for a significant proportion of the difference in maximal aerobic capacity between groups.

RESULTS

Individuals born preterm had lower VO2max than those born term (41.7 ± 8.6 v 47.5 ± 8.7, p < 0.01). Several variables differed between term and preterm born subjects, including systolic and diastolic blood pressure, mean pulmonary artery pressure, indexed left ventricular end-diastolic volume (LVEDVi), right ventricular end-diastolic volume (RVEDVi), LV mass (LVMi), LV stroke volume index (LVSVi), and LV strain (p < 0.05 for all). Of these variables, LVEDVi, RVEDVi, LVSVi, LVMi, and LV longitudinal strain were significantly related to VO2max (p < 0.05 for all). Significant portions of the difference in VO2max between term and preterm born subjects were mediated by LVEDVi (74.3%, p = 0.010), RVEDVi (50.6%, p = 0.016), and LVMi (43.0%, p = 0.036).

CONCLUSIONS

Lower levels of CRF in adolescents and young adults born preterm are mediated by differences in LVEDVi, RVEDVi, and LVMi. This may represent greater risk for long-term cardiac morbidity and mortality in preterm born individuals.

Fitness, fatness, body movement, and diet in adolescents: clustering and associations with elevated blood pressure

BACKGROUND

The study of clusters of risk factors for elevated blood pressure (EBP) among adolescents from low- middle-income countries has received little research attention. The objective of the study was to identify clusters of EBP precursors (i.e., overweight, physical fitness, risk diet, and body movement) and to analyze its associations with EBP.

METHODS

This a cross-sectional study conducted in a sample of 965 secondary schools' students aged between 12 and 17 years-old from Colombia. Measurements included blood pressure, sociodemographic information, and four EBP precursors: Overweight, body movement, risk diet, and physical fitness. Cluster analysis was applied with the two-step method to identify the patterns of EBP precursors, and logistic regression models were used to analyze the association between clusters and EBP.

RESULTS

Findings indicate that EBP was present in 28.9% of the students, approximately 20% of adolescents had desirable profile (normal weight, normal-high physical fitness, low-risk diet, and middle-high body movement), and 16% of them had the four EBP precursors. The cluster solution revealed five clusters, formed according to the accumulation of EBP precursors, this is, characterized by having zero, one (low body movement), two (low body movement and high-risk diet), three (low body movement, high risk diet, and low fitness), or four (low body movement, high risk diet, low fitness, and overweight) EBP precursors. The cluster with four EBP precursors had a higher risk of having EBP.

CONCLUSIONS

According to these findings, it is necessary to implement programs that simultaneously address multiple health-related behaviors to promote health in adolescents.

Blood Pressure in Children: Association with Anthropometric Indicators, Body Composition, Cardiorespiratory Fitness and Physical Activity

Fundamento:

Evidências apontam variáveis antropométricas e de condicionamento físico como fatores associados à pressão arterial infantil. Analisá-los em apenas um contexto é um meio relevante de identificar o peso que cada um deles pode apresentar no desenvolvimento da hipertensão arterial.

Objetivo:

Identificar as possíveis associações de medidas antropométricas, da composição corporal, da atividade física moderada-vigorosa (AFMV) e da aptidão cardiorrespiratória (ApC) com a pressão arterial em crianças.

Métodos:

Estudo correlacional com abordagem quantitativa. Duzentos e quinze (215) estudantes com idades de 6 a 12 anos de uma escola pública de Porto Alegre, selecionados por critério de conveniência. A pressão arterial foi aferida através de um esfigmomanômetro digital. Para o tratamento dos dados, os valores de pressão arterial sistólica e diastólica foram padronizados (escore Z) e somados. As variáveis testadas como preditoras foram: AFMV; Percentual de gordura (%G); Índice de massa corporal (IMC); Razão cintura/estatura (RCE); Maturação somática; ApC. Após a verificação dos parâmetros de normalidade, as associações brutas e ajustadas (para sexo, idade e maturação somática) foram testadas através de equações de regressão linear. Para as análises, foi considerado p < 0,05.

Resultados:

Três diferentes modelos indicaram os melhores conjuntos de fatores associados à pressão arterial padronizada: O Modelo 1 (R² = 0,21) se constituiu das variáveis RCE (β = 9,702) e AFMV (β = – 0,021); O Modelo 2 (R² = 0,19) foi composto pelas variáveis IMC (β = 0,156) e AFMV (β = – 0,021); O Modelo 3 (R² = 0,18) incluiu as variáveis %G (β = 0,063) e ApC (β = – 0,004).

Conclusões:

A pressão arterial de crianças é predita pelas variáveis corporais %G, IMC e RCE. Além disso, está associada negativamente à AFMV e a ApC.

Improvements in Physical Fitness are Associated with Favorable Changes in Blood Lipid Concentrations in Children

Although accumulating evidence suggests the benefits of cardiorespiratory fitness and muscular fitness, little knowledge exists on how other physical fitness (PF) components are associated with cardiovascular disease (CVD) risk markers in children. Additionally, much of the relevant evidence is from longitudinal studies with CVD risk markers at a single time point (i.e., baseline) rather than changes in PF. The purpose of the present study was to examine whether initial 1-year changes in different performance measures of PF (i.e., endurance performance, muscular strength/endurance, flexibility, agility, and speed) can predict the subsequent changes (2-year change) in blood lipid concentrations in children. This 2-year longitudinal study included a total of 251 Japanese children (mean age 9.2 ± 0.4). PF tests were performed to comprehensively evaluate the participant's fitness levels (handgrip strength [upper body muscular strength], bent-leg sit-ups [muscular endurance], sit-and-reach [flexibility], side-step [agility], 20-meter shuttle run [endurance performance], 50-meter sprint [speed], standing long jump [lower body muscular strength], and softball throw [explosive arm strength and throwing ability]). Fasting lipid profile was assayed for triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and non-HDL-C concentration. Multilevel linear regressions were used to examine the associations between the preceding changes (over 1-year) in PF and subsequent changes (over 2-years) in blood lipid concentrations. We also examined the simultaneous associations between 2-year changes in PF and 2-year changes in blood lipid concentrations. For boys, preceding improvement in handgrip strength was negatively associated with TG concentration (β = -0.260, p = 0.030); improvements in bent-leg sit-ups were negatively associated with clustered lipid scores (β = -0.301, p = 0.038) and non-HDL-C (β = -0.310, p = 0.044); and improvements in 50m sprinting were associated with subsequent changes in non-HDL-C (β = 0.348, p = 0.006) and LDL-C (β = 0.408, p = 0.001). For girls, improvements in handgrip strength was negatively associated with TG concentration (β = -0.306, p = 0.017); and improvements in standing long jump were negatively associated with non-HDL-C (β = -0.269, p = 0.021) and LDL-C (β = -0.275, p = 0.019). For boys and girls, there were no significant simultaneous associations between 2-year changes in PF and 2-year changes in blood lipid concentrations. In conclusion, preceding change in physical fitness in relation to change in blood lipid concentration likely reflect a physiological adaptation to growth and maturation since these associations diminished in the subsequent year.

The mediating role of adiposity in the longitudinal association between cardiorespiratory fitness and blood pressure in adolescents: LabMed cohort study

BACKGROUND

The aim of this prospective cohort study was to examine whether the association between the cardiorespiratory fitness (CRF) at baseline and blood pressure (BP) at follow-up is mediated by adiposity in adolescents.

MATERIALS AND METHODS

The sample comprised 734 adolescents (349 girls) aged 12-18 years from the LabMed Physical Activity Cohort Study. The variables of interest were measured in 2011 (baseline) and in 2013 (2-year follow-up). CRF was assessed by the 20-m shuttle run test. Body mass index, waist circumference, body fat percentage, pubertal status and resting BP were assessed according to standard procedures. Boot-strapped mediation procedures were performed, and indirect effects (IE) with confidence intervals (CI) not including zero were considered statistically significant.

RESULTS

After adjusting for potential confounders, body mass index acted as a mediator of the relationship between CRF and systolic BP (IE = -0. 023; CI = -0.039; -0.009), pulse pressure (IE = -0.023; CI = -0.034; -0.012) and rate product pressure (IE = -2.839; CI = -5.329; -0.340). Similar results were obtained for waist circumference as mediator for systolic BP (IE = -0.019; CI = -0.033; -0.005), pulse pressure (IE = -0.017; CI = -0.028; -0.007) and rate product pressure (IE = -3.793; CI = -6.097; -1.689). Likewise, body fat percentage mediated the association for: systolic BP (IE = -0.029; CI = -0.048; -0.010), pulse pressure (IE = -0.027; CI = -0.041; -0.013) and rate product pressure (IE = -4.280; CI = -7.488; -1.264).

CONCLUSIONS

Adiposity mediated the association between CRF and BP in adolescents. Therefore, both optimal CRF and adiposity levels are important to maintain normal BP ranges throughout adolescence.

Fitness, waist circumference and their association with future blood pressure in youth: The UP&DOWN Longitudinal Study

OBJECTIVES

The aim was to determine the independent associations of muscular fitness (MF), cardiorespiratory fitness (CRF) and waist circumference (WC) with blood pressure (BP) levels over 2 years in children and adolescents.

METHODS

1089 children (517 females) and 787 adolescents (378 females) with complete data on fitness, WC and BP (systolic [SBP] and diastolic [DBP]) were included. Upper MF was assessed through the handgrip strength test, and lower MF using the standing long jump test. The 20-m shuttle run test was used to assess CRF. WC was obtained following standardized methods. Different regression models were fitted by introducing fitness and WC at baseline and their changes as exposures and BP at follow-up and their changes as outcomes.

RESULTS

WC at baseline was positively and independently associated with each BP variable at follow-up in children and adolescents (β=0.094-0.260; p≤0.05), and CRF was negatively associated with DBP in adolescents (β=-0.096; p=0.034). WC changes were associated with BP variables 2 years later in children (β=0.121-0.142; p<0.01). In adolescents, changes in upper MF (β=-0.116; p=0.001) and WC (β=0.080-0.098; p<0.05) were associated with SBP at follow-up. WC changes were independently associated with changes in each BP variable in children (β=0.111-0.145; all p<0.05) and SBP changes in adolescents (β=0.103 to 0.117; all p<0.01).

CONCLUSIONS

WC, but neither MF nor CRF, is independently associated with BP and its changes over 2 years. The attainment or maintenance of optimal fatness levels in the pediatric population should be highly encouraged for the prevention of future hypertension.

Association of Adipocytokines and Inflammatory Biomarkers with Blood Pressure in Adolescents: A Longitudinal Analysis

BACKGROUND AND AIMS

Several cross-sectional, but few prospective, studies suggest that inflammation may be involved in the development of high blood pressure. We examined markers of inflammation for their associations with blood pressure levels over a two-year period in healthy adolescents.

METHODS AND RESULTS

The sample comprised 406 adolescents (209 girls) aged 12-18 years in the LabMed Physical Activity Study were followed-up for 2 years. Anthropometric (weigh, height, BMI), markers of inflammation (high sensitivity C-reactive protein, complement factors C3 and C4, fibrinogen, leptin and adiponectin) and ambulatory blood pressure (BP) were collected. Socioeconomic status, pubertal development, adherence to Mediterranean diet and cardiorespiratory fitness were measured for adjustment for potential confounders. Adjusted linear regression models revealed a significant association of Leptin/Adiponectin (L/A) Ratio (baseline) with systolic BP (β = 0.120; p < 0.034) and with diastolic BP (β = 0.125; p < 0.036) at follow-up (full adjusted model). Leptin was associated with systolic BP at follow-up (β = 0.102; p < 0.038) after adjustment for systolic BP at baseline, height, pubertal stage, socioeconomic status, adherence to Mediterranean diet, cardiorespiratory fitness, however, not independently of BMI.

CONCLUSION

L/A ratio was positively associated with systolic BP and diastolic BP even after adjusting confounding variables. Therefore, a higher misbalance between leptin and adiponectin (higher L/A ratio) early adolescence may exert a negative effect BP levels in late adolescence regardless of several confounders factors.

Association of Cardiorespiratory Fitness Levels During Youth With Health Risk Later in Life: A Systematic Review and Meta-analysis

IMPORTANCE

Although the associations between cardiorespiratory fitness (CRF) and health in adults are well understood, to date, no systematic review has quantitatively examined the association between CRF during youth and health parameters later in life.

OBJECTIVES

To examine the prospective association between CRF in childhood and adolescence and future health status and to assess whether changes in CRF are associated with future health status at least 1 year later.

DATA SOURCES

For this systematic review and meta-analysis, MEDLINE, Embase, and SPORTDiscus electronic databases were searched for relevant articles published from database inception to January 30, 2020.

STUDY SELECTION

The following inclusion criteria were used: CRF measured using a validated test and assessed at baseline and/or its change from baseline to the end of follow-up, healthy population with a mean age of 3 to 18 years at baseline, and prospective cohort design with a follow-up period of at least 1 year.

DATA EXTRACTION AND SYNTHESIS

Data were processed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Random-effects models were used to estimate the pooled effect size.

MAIN OUTCOMES AND MEASURES

Anthropometric and adiposity measurements and cardiometabolic health parameters.

RESULTS

Fifty-five studies were included with a total of 37 563 youths (46% female). Weak-moderate associations were found between CRF at baseline and body mass index (r = -0.11; 95% CI, -0.18 to -0.04; I2 = 59.03), waist circumference (r = -0.29; 95% CI, -0.42 to -0.14; I2 = 69.42), skinfold thickness (r = -0.34; 95% CI, -0.41 to -0.26; I2 = 83.87), obesity (r = -0.15; 95% CI, -0.23 to -0.06; I2 = 86.75), total cholesterol level (r = -0.12; 95% CI, -0.19 to -0.05; I2 = 75.81), high-density lipoprotein cholesterol (HDL-C) level (r = 0.11; 95% CI, 0.05-0.18; I2 = 69.06), total cholesterol to HDL-C ratio (r = -0.19; 95% CI, -0.26 to -0.13; I2 = 67.07), triglyceride levels (r = -0.10; 95% CI, -0.18 to -0.02; I2 = 73.43), homeostasis model assessment for insulin resistance (r = -0.12; 95% CI, -0.18 to -0.06; I2 = 68.26), fasting insulin level (r = -0.07; 95% CI, -0.11 to -0.03; I2 = 0), and cardiometabolic risk (r = -0.18; 95% CI, -0.29 to -0.07; I2 = 90.61) at follow-up. Meta-regression analyses found that early associations in waist circumference (β = 0.014; 95% CI, 0.002-0.026), skinfold thickness (β = 0.006; 95% CI, 0.002-0.011), HDL-C level (β = -0.006; 95% CI, -0.011 to -0.001), triglyceride levels (β = 0.009; 95% CI, 0.004-0.014), and cardiometabolic risk (β = 0.007; 95% CI, 0.003-0.011) from baseline to follow-up dissipated over time. Weak-moderate associations were found between change in CRF and body mass index (r = -0.17; 95% CI, -0.24 to -0.11; I2 = 39.65), skinfold thickness (r = -0.36; 95% CI, -0.58 to -0.09; I2 = 96.84), obesity (r = -0.21; 95% CI, -0.35 to -0.06; I2 = 91.08), HDL-C level (r = 0.05; 95% CI, 0.02-0.08; I2 = 0), low-density lipoprotein cholesterol level (r = -0.06; 95% CI, -0.11 to -0.01; I2 = 58.94), and cardiometabolic risk (r = -0.08; 95% CI, -0.15 to -0.02; I2 = 69.53) later in life.

CONCLUSIONS AND RELEVANCE

This study suggests that early intervention and prevention strategies that target youth CRF may be associated with maintaining health parameters in later life.

Association between cardiorespiratory fitness and handgrip strength with age-related macular degeneration: a population-based study

AIM

To assess whether cardiorespiratory fitness (CRF) and handgrip strength, two objective markers of physical fitness, are associated with age-related macular degeneration (AMD).

METHODS

We analysed cross-sectional data from the population-based Study of Health in Pomerania (2008-2012) including 1173 adult men and women aged 20-79 years. Fundus photography of the central retina was recorded with a non-mydriatic camera, and images were graded according to an established clinical AMD classification scale by an experienced reader. CRF was measured using peak oxygen uptake (peakVO₂), oxygen uptake at the anaerobic threshold (VO₂@AT), and maximum power output (W_max) from standardised cardiopulmonary exercise testing on a bicycle ergometer according to a modified Jones protocol. Handgrip strength was assessed using a handheld dynamometer. Adjusted prevalence ratios (PR) for the associations of peakVO₂, VO₂@AT, W_max and handgrip strength with AMD were derived from multivariable Poisson regression models.

RESULTS

PeakVO₂, VO₂@AT, W_max and handgrip strength were not associated with AMD. Adjusted PR for AMD associated with a 1-SD increment in peakVO₂, VO₂@AT, W_max and handgrip strength were 1.05 (95% CI 0.82 to 1.34), 0.96 (95% CI 0.78 to 1.18), 1.10 (95% CI 0.86 to 1.41) and 1.01 (95% CI 0.79 to 1.30), respectively. These associations were not modified by age, sex, smoking, body mass index and diabetes. Estimates in sensitivity analysis for confounding, selection bias and missing data were similar.

CONCLUSION

In our study, CRF and handgrip strength were not associated with AMD. Nevertheless, longitudinal studies with bigger sample sizes are needed to furtherly examine these associations.

Cardiorespiratory Fitness in Youth: An Important Marker of Health: A Scientific Statement From the American Heart Association

Cardiorespiratory fitness (CRF) refers to the capacity of the circulatory and respiratory systems to supply oxygen to skeletal muscle mitochondria for energy production needed during physical activity. CRF is an important marker of physical and mental health and academic achievement in youth. However, only 40% of US youth are currently believed to have healthy CRF. In this statement, we review the physiological principles that determine CRF, the tools that are available to assess CRF, the modifiable and nonmodifiable factors influencing CRF, the association of CRF with markers of health in otherwise healthy youth, and the temporal trends in CRF both in the United States and internationally. Development of a cost-effective CRF measurement process that could readily be incorporated into office visits and in field settings to screen all youth periodically could help identify those at increased risk.

High levels of adiponectin attenuate the detrimental association of adiposity with insulin resistance in adolescents

BACKGROUND AND AIM

This study aimed to: i) examine the differences in insulin resistance (IR) across adiposity levels; and ii) ascertain whether high levels of adiponectin attenuate the detrimental association of adiposity with IR in adolescents.

METHODS AND RESULTS

A total of 529 adolescents aged 12-18 years participated in this cross-sectional study (267 girls). Anthropometry and body adiposity parameters [body mass index (BMI), sum of skinfolds, body fat percentage (BF %) by bio-impedance analysis and waist circumference (WC)], were measured according to standardized procedures and categorized into age- and sex-specific quartiles. Socioeconomic status, pubertal stage and lifestyle determinants (Mediterranean diet adherence and cardiorespiratory fitness) were gathered and used as confounders. Serum adiponectin and IR (homeostasis model assessment of insulin resistance [HOMA-IR] estimated from fasting serum insulin and glucose were assessed. Analysis of covariance (ANCOVA) showed that HOMA-IR increased in a linear fashion throughout the quartiles of all adiposity measures (p < 0.001 for all), independently of age, sex, pubertal stage, socioeconomic status, adherence to the Mediterranean diet and cardiorespiratory fitness. Two-way ANCOVA showed that adolescents in the higher quartile of adiposity for BF%, BMI, WC and skinfolds sum (Q4) presented the highest adiponectin levels, and had 0.77 Standard Deviation (SD), 0.8 SD, 0.85 SD and 0.8 SD lower HOMA-IR, respectively (p < 0.01) than their low adiponectin group counterparts, after adjustments for potential confounders.

CONCLUSION

Higher adiponectin levels may attenuate the detrimental association between adiposity and IR, particularly in subjects with higher adiposity.

Changes in cardiorespiratory fitness through adolescence predict metabolic syndrome in young adults

BACKGROUND AND AIMS

Higher cardiorespiratory fitness (CRF) has been suggested to reduce the risk of metabolic syndrome (MetS). We aimed to longitudinally examine the changes of CRF on MetS and its risk factors from adolescence to adulthood.

METHODS AND RESULTS

At the age of 15 years, 1076 subjects were recruited from 2 cohorts. CRF was measured on a cycle ergometer. MetS was classified as having at least 3 of the following parameters above the threshold of risk factors: waist circumference, triglycerides, high-density lipoprotein cholesterol (HDL), high blood pressure (BP) and fasting glucose. In addition, insulin, total cholesterol and low-density lipoprotein cholesterol were measured and homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. Persistently high, increasing, decreasing and persistently low CRF groups were formed according to change in CRF from adolescence to adulthood. Longitudinal increase in CRF was positively associated with change in HDL and negatively associated with change in insulin, HOMA-IR, triglycerides, BP and prevalence of MetS after adjustment for potential confounders. Subjects with persistently low CRF had 11.5- to 34.4-times higher risk of MetS at the age of 25 and 33 years compared to subjects with persistently high CRF and 14.6- to 15.9-times higher risk compared to the increasing CRF group.

CONCLUSION

Higher CRF is strongly related to lower values of MetS risk factors. Increasing CRF from adolescence to adulthood reduces the risk to have MetS later in adulthood. High CRF in adolescence that decreases during adulthood has similar risks to MetS compared to individuals with persistently low CRF.

Cardiorespiratory fitness, adiposity, and ambulatory blood pressure in adolescents

BACKGROUND

This study examined the association of cardiorespiratory fitness (fitness) and adiposity (Body Mass Index [BMI] and waist circumference [WC]) with ambulatory blood pressure (ABP) and tested the moderating effect of adiposity on the association between fitness and ABP.

METHODS

A cross-sectional study was conducted with 370 adolescents aged 11-16 years. Fitness was assessed by a height-adjusted step test and estimated by heart rate recovery, defined as the difference between peak heart rate during exercise and heart rate two minutes postexercise. Adiposity was measured using dichotomized values for percentiles of BMI (≥85th) and WC (≥50th). ABP was measured every 30-60 minutes over 24 hours on a school day. Mixed-effects regression analysis was used.

RESULTS

Each unit increase in fitness was associated with a decrease of systolic blood pressure (SBP) [-0.058 mmHg, P=0.001] and diastolic blood pressure (DBP) [-0.043 mmHg, P<0.001] after adjustment for WC and covariates. Each unit increase in fitness was associated with a decrease in SBP [-0.058 mmHg, P=0.001] and DBP [-0.045 mmHg, P<0.001] after adjustment for BMI and covariates. Fitness and BMI≥85th percentile (or WC ≥ 50th percentile) interactions were not associated with ABP after adjustment for covariates.

CONCLUSIONS

Our findings indicate a small but statistically significant inverse effect of fitness on ABP in adolescents. No evidence of a modifying effect of adiposity on this association suggesting that fitness and weight management have essential roles for maintaining lower ABP in adolescents.

Influence of Mediterranean diet adherence, physical activity patterns, and weight status on cardiovascular response to cardiorespiratory fitness test in Chilean school children

OBJECTIVE

The aim of this study was to determine the association between Mediterranean diet adherence, physical activity (PA) patterns (i.e., screen time and PA after school), and weight status with the cardiovascular response following a cardiorespiratory fitness test.

METHODS

Participants were 605 school children: 272 girls (11.79 ± 0.93 y old) and 333 boys (12.06 ± 1.03 y old). Body mass index, waist circumference (WC), food habits, and PA patterns were evaluated. Heart rate (HR), and systolic (SBP) and diastolic (DBP) blood pressures were assessed before and immediately after the 20-m shuttle run test and the changes induced were calculated (Δ = post/pretest).

RESULTS

The cardiovascular response was higher in obese than normal weight and overweight children in terms of HR (P = 0.007) and SBP (P < 0.001). The ΔSBP presented inverse association with WC (β = -0.09; 95% confidence interval [CI], -0.17 to -0.01; P = 0.026), food habits (β = -0.65; 95% CI, -0.81 to -0.49; P < 0.001), PA after school (β = -7.03; 95% CI, -7.84 to -6.22; P < 0.001) and PA patterns (β = -5.96; 95% CI, -6.40 to -5.52, P < 0.001). ΔDBP was not associated with food habits or PA patterns (P > 0.005). Finally, ΔHR reported inverse association with PA patterns (β = -1.67; 95% CI, -3.18 to -0.17; P = 0.029).

CONCLUSION

School children with obesity showed a higher cardiovascular response in HR and SBP than normal weight and overweight peers. Moreover, the increment of the SBP presented inverse association with food habits and PA patterns.

Cardiorespiratory Fitness Normative Values in Latin-American Adolescents: Role of Fatness Parameters

The aim of this study was to provide percentile values for a cardiorespiratory fitness (CRF) field test for Latin-American adolescents (34,461 girls and 38,044 boys) aged 13 to 15 years. The role of fatness parameters on the CRF level across age groups was also examined, with a focus on non-obese (healthy) and obese groups. CRF was assessed using the 20-meter shuttle run test protocol. Anthropometric parameters were measured using body mass index z-score (body mass index (BMI) z-score), BMI, waist circumference (WC), and waist-to-height ratio (WHtR). Participants were categorized according to the BMI z-score, WC, and WHtR international cut-off points as healthy and obese. Age- and sex-specific reference tables for the 3rd, 10th, 25th, 50th, 75th, 90th, and 97th centile scores were calculated using Cole’s lambda, mu, and sigma method. The prevalence of obesity according to the BMI z-score, WC, and WHtR was 9.6%, 11.2%, and 15.0%, respectively. Across all age and sex groups, a negative association was found between relative peak oxygen uptake (V˙O₂peak) and BMI, WC, and WHtR. In boys and girls there were higher levels of performance across all age groups, with most apparent gains between the ages of 13 and 14 years old. Overall, participants categorized in the healthy group had shown to have significantly higher V˙O₂peak than their obese counterparts (p < 0.001; Cohen’s d > 1.0). In conclusion, our study provides age- and sex-specific reference values for CRF (V˙O₂peak, mL·kg⁻¹·min⁻¹). The anthropometric parameters were inversely associated with CRF in all ages in both sexes. The obese group had worse CRF than their healthy counterparts independent of anthropometric parameters used to determine obesity.

Cardiorespiratory fitness and health-related quality of life in adolescents: A longitudinal analysis from the LabMed Physical Activity Study

OBJECTIVE

The purpose of this study was to examine the longitudinal associations between cardiorespiratory fitness and health-related quality of life (HRQoL) in a sample of adolescents, and to determine whether changes in cardiorespiratory fitness were associated with HRQoL over a 2-year follow-up.

METHODS

This is a longitudinal analysis with 571 Portuguese adolescents (274 boys and 297 girls) aged 12-18 years. HRQoL was measured with the Kidscreen-10 questionnaire; the 20 m shuttle-run was used to estimate cardiorespiratory fitness; socioeconomic status was assessed with the Family Affluence Scale; and pubertal stage was assessed with Tanner stages. Linear regression and analysis of covariance (ancovas) were used to examine the associations between cardiorespiratory fitness and HRQoL.

RESULTS

HRQoL decreased over a 2-year period both in boys and girls (P < .05). Moreover, girls at baseline and at follow-up reported significantly lower HRQoL values than boys (between subjects P < .001). After adjustments for potential confounders, regression analyses showed significant cross-sectional associations between cardiorespiratory fitness and HRQoL both at baseline (B = 0.095; P = .023) and at follow-up (B = 0.090; P = .012). ancova showed that adolescents whose cardiorespiratory fitness decreased over time exhibited lower scores of HRQoL at follow-up, compared to those with persistent high cardiorespiratory fitness; this held after adjustments for age, sex, socioeconomic status, and pubertal stage.

CONCLUSIONS

Changes in cardiorespiratory fitness during adolescence were associated with HRQoL over a 2-year period. This study suggests that improving cardiorespiratory fitness could be an important strategy in improving the HRQoL of adolescents.

Physical activity in adolescents and children and relationship to metabolic health

PURPOSE OF REVIEW

To summarize the recent developments relating to the role of physical activity in improving insulin resistance and metabolic syndrome in children and adolescents.

RECENT FINDINGS

The current literature strengthens previous findings on the relationship between physical activity and metabolic health in children; suggests a protective role for physical activity in the setting of obesity; examines population-specific findings; addresses specific effects of different modalities of physical activity in improving health; reveals potential mediators in the relationship between physical activity and metabolic health; and suggests new markers of metabolic health that could potentially be used as outcomes in future physical activity studies.

SUMMARY

Recent research generally confirms the role of physical activity in decreasing insulin resistance and metabolic syndrome in children and adolescents. However, the current literature is limited by unstandardized research methods and definitions, and also aggregation of different age groups, genders, and weight status. Future research should address these issues to offer targeted physical activity interventions.

Cardiorespiratory Fitness Attenuates the Obesity Risk in Chinese Children Who Have Parents with Overweight/Obesity

OBJECTIVE

To evaluate the impact of parental weight status and offspring cardiorespiratory fitness on the risk of obesity among Chinese children.

STUDY DESIGN

This cross-sectional study was conducted in Wuhan, China from May to June 2010. Children's height, weight, and waist circumference were measured for assessing their total and central obesity. Their cardiorespiratory fitness was determined by the 20-m shuttle-run test. We calculated parental body mass index according to self-reported height and weight, and divided it into normal weight or overweight/obesity. Multivariable logistic regression model was applied to estimate the combined relationships of cardiorespiratory fitness and parental weight status with the risk of obesity of children.

RESULTS

A total of 587 Chinese children (343 boys and 244 girls) aged 9.6 (0.7) years participated in this study. Compared with those who had low cardiorespiratory fitness and at least 1 parent with overweight/obesity, children who had high cardiorespiratory fitness and at least 1 parent with overweight/obesity reported lower risks of total obesity (OR 0.12, 95% CI .05-0.30) and central obesity (OR .09, 95% CI .04-0.20), and children who had high cardiorespiratory fitness and no parent with overweight/obesity were 89% (OR 0.11, 95% CI .05-0.24) less likely to have total obesity and 92% (OR .08, 95% CI .04-0.16) less likely to have central obesity (all P < .001).

CONCLUSIONS

High level of cardiorespiratory fitness among children could attenuate the influence of parental obesity on their offspring's weight status.

Changes in muscular fitness and its association with blood pressure in adolescents

The aims of this study were to examine the longitudinal association between muscular fitness (MF) and blood pressure (BP) 2 years later, and to determine whether changes in MF over a 2-year period were associated with BP at follow-up, in adolescents. The sample comprised 734 youths (349 girls) aged from 12 to 18 years. MF was assessed with the standing long jump and handgrip tests. Socioeconomic status, pubertal stage, waist circumference, resting BP, and cardiorespiratory fitness were measured according to standard procedures. Regression analyses showed a significant inverse association between MF at baseline and systolic BP (β = - 0.072; p = 0.032) and rate pressure product (β = - 0.124; p < 0.001) at follow-up, after adjustments for age, sex, height, pubertal stage, and socioeconomic status. However, when analyses were further adjusted for waist circumference and cardiorespiratory fitness, these associations did not remain significant. Adolescents with persistently high and increasing MF exhibited the lowest levels of diastolic BP (F_{(3, 721)} = 3.814, p = 0.018) and systolic BP (F_{(3, 721)} = 3.908, p = 0.014) when compared to those with persistent low MF after adjustment for age, sex, height, socioeconomic status, cardiorespiratory fitness, and waist circumference.Conclusion: This study suggests that persistent greater and increasing MF in youth are associated with lower levels of BP across the adolescence. What is Known: • Currently, there is a growing interest on the health benefits of muscular fitness. • Cross-sectional studies have identified an association between muscular fitness and blood pressure in adolescents. What is New: • Changes in muscular fitness during adolescence were associated with systolic and diastolic BP over a 2-year period. • Adolescents with persistently low muscular fitness exhibited the highest levels of diastolic and systolic BP.

Optimal Adherence to a Mediterranean Diet May Not Overcome the Deleterious Effects of Low Physical Fitness on Cardiovascular Disease Risk in Adolescents: A Cross-Sectional Pooled Analysis

To examine the combined association of cardiorespiratory fitness (CRF), muscular fitness (MF), and adherence to a Mediterranean diet (MeDiet) on cardiovascular risk in adolescents, a pooled study, including cross-sectional data from two projects [2477 adolescents (1320 girls) aged 12–18 years], was completed. A shuttle run test was used to assess CRF. MF was assessed by the standing-long jump and handgrip tests. Adherence to a MeDiet was assessed by the Kidmed questionnaire. A cardiovascular risk score was computed from the following components: Age and sex, waist circumference, triglycerides, systolic blood pressure, high-density lipoprotein cholesterol (HDL), and glucose. Analysis of covariance showed that participants classified as having optimal (High) adherence to a MeDiet/HighMF/HighCRF, as well those classified as low adherence to a MeDiet/HighMF/HighCRF, had, on average, the lowest cardiovascular risk score (F = 15.6; p < 0.001). In addition, the high adherence to a MeDiet/LowMF/LowCRF group had the highest odds of having a high cardiovascular risk (OR = 7.1; 95% CI: 3.4–15.1; p < 0.001), followed by the low adherence to a MeDiet/LowMF/LowCRF group (OR = 3.7; 95% CI: 2.2–6.3; p < 0.001), high adherence to a MeDiet/HighMF/LowCRF group (OR = 3.1; 95% CI: 1.4–7.0; p = 0.006), and low adherence to a MeDiet/LowMF/HighCRF group (OR = 2.5; 95% CI: 1.5–4.4; p = 0.002) when compared to those with high adherence to a MeDiet/HighMF/HighCRF, after adjustments for potential confounders. In conclusion, our findings showed that, regardless of the MeDiet status, adolescents with low MF and low CRF cumulatively, presented the highest cardiovascular disease risk. Therefore, these findings suggest that the combination of these two fitness components may be beneficial to adolescents’ cardiometabolic profile, independent of MeDiet behaviour.