Association between serum adiponectin levels and muscular fitness in Portuguese adolescents: LabMed Physical Activity Study

[Biochemical and cardiovascular indicators associated with handgrip strength in children and adolescents: A scoping review]

Handgrip strength is an indicator of the biological health of children and adolescents. The review's objective is to identify the biochemical and cardiovascular indicators related to handgrip strength. A scoping review was developed, in which the search was conducted in Medline, Web of Science, Science Direct, Scielo, and Sportdiscus from EBSCO. Original research was included if it involved handgrip strength and biochemical or cardiovascular indicators. In the initial search, 15,198 records were identified in databases. 31 studies were selected for this review. These reports identified 36 indicators (29 biochemical and 7 cardiovascular) that had been analyzed for their association with hand grip strength. Blood pressure (n=10; 32.3%) and homeostatic model assessment for insulin resistance (n=7; 22.5%) were the most frequently studied characteristics. In the biochemical indicators, a pattern was found in which handgrip strength had a proportional relationship with HDL levels and an inversely proportional relationship with various cardiometabolic scores. No relationship patterns were found in the cardiovascular indicators.

The Influence of Body Composition, Lifestyle, and Dietary Components on Adiponectin and Resistin Levels and AR Index in Obese Individuals

Adipose tissue of obese people secretes a number of adipokines, including adiponectin and resistin, which have an antagonistic effect on the human metabolism, influencing the pathogenesis of many diseases based on low-grade inflammation. Body composition analysis using bioelectrical impedance analysis (BIA) was performed in 84 adults with obesity, i.e., body mass index (BMI) greater than or equal to 30 kg/m2. Serum was collected to analyze the concentration of adiponectin (ApN) and resistin. The subjects additionally completed a food frequency questionnaire FFQ-6 and a three-day food diary. Adiponectin-resistin index (AR index) was calculated. The results show a positive correlation between resistin levels and BMI and subcutaneous fat content. AR index value was also positively associated with the amount of adipose tissue and body mass. Adiponectin level in the serum of the studied individuals decreased with the content of lean tissue. Adiponectin level also decreased with the amount of carbohydrates, amount of starch, and glycemic load of the diet. Resistin decreased in patients who frequently consumed white pasta and red meat, while AR index was positively associated with the amount of white rice and saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) consumed but negatively associated with the frequent consumption of carbohydrates, including starch. Physical activity was negatively correlated with adiponectin levels and AR index. We concluded that body composition significantly influenced serum resistin and adiponectin concentrations the AR index. Dietary components also had a significant effect.

Lower adiponectin is associated with higher anthropometry and insulin resistance but not with low cardiorespiratory fitness in adolescents

PURPOSE

The aim of this study was to analyze the relationship between adiposity, cardiometabolic risk and cardiorespiratory fitness (CRF) according to different groups of adiponectin concentration.

METHODS

255 adolescents of both sexes, aged 11-17 years old, participated. Anthropometric and biochemical parameters such as body mass, height, abdominal circumference (AC), waist circumference (WC), fat mass, fat-free mass, total cholesterol (TC), high-density lipoprotein (HDL-c), low-density lipoprotein (LDL-c), triglycerides (TG), glucose, insulin, adiponectin, blood pressure, peak oxygen consumption (VO2peak) were measured. Body mass index (BMI), z-score BMI (BMI-z), triponderal mass index (TMI), waist-to-height ratio (WHtR), homeostasis model to assessment insulin resistance (HOMA-IR), and quantitative insulin sensitivity check index (QUICKI) were calculated. Adiponectin was categorized: low adiponectin concentration (LAC  ≤ 5.18 µg/mL-1), intermediate (IAC = 5.18 and 7.63 µg/mL-1) and high (HAC ≥ 7.63 µg/ml-1).

RESULTS

LAC showed higher BMI, BMI-z and TMI than the other groups (p < 0.05) and higher AC, WC and WHtR that the HAC (p < 0.05). IAC showed lower values of TC, LDL-c and TG, and the LAC presented the highest values of insulin, HOMA-IR and QUICKI (p < 0.05) to the IAC and HAC. HAC presented the lower VO2peak than the other groups (p < 0.01). BMI, TMI, glucose, insulin, HOMA-IR showed inverse, and QUICKI a direct and weak correlation with adiponectin (p < 0.05). No significant association was found between adiponectin and VO2peak (p > 0.05).

CONCLUSION

The LAC group had higher means in the anthropometric variables and the worst results related to insulin resistance and sensitivity. Thus, adiponectin may play an important role in obesity and reduced concentration may be a factor in the development of obesity-associated morbidities.

Sleep duration and cardiorespiratory fitness in adolescents: Longitudinal analysis from the LabMed study

PURPOSE

We aimed to investigate longitudinal associations between sleep duration and cardiorespiratory fitness, in adolescents.

METHODS

Sleep duration was self-reported and cardiorespiratory fitness was assessed by the 20 m shuttle run test, both at baseline and follow-up (2-year follow-up). Participants were 734 Northern Portuguese adolescents (349 girls), aged 14.6 ± 1.8 years, from the LabMed study.

RESULTS

Significant decreases were found between baseline and follow-up for sleep duration, whereas for cardiorespiratory fitness there was an increase. Adolescents with short sleep duration at baseline had lower cardiorespiratory fitness at follow-up, comparing to those meeting the sleep guidelines (odds ratio [OR] = 0.506, 95% confidence interval [CI]: 0.326-0.785; p = .002 for whole week; OR = 0.597, 95% CI: 0.407-0.875; p = .008 for weekdays). Girls who were short sleepers at baseline had lower odds of having a healthy cardiorespiratory fitness at follow-up, comparing to those meeting the sleep guidelines (OR = 0.311, 95% CI: 0.158-0.613; p < .001 for whole week; OR = 0.469, 95% CI: 0.262-0.838; p = .011 for weekdays). No significant associations between sleep duration and cardiorespiratory fitness were found for boys.

DISCUSSION

There was a significant longitudinal association between short sleep duration and lower cardiorespiratory fitness levels, particularly in girls. Future interventions targeting adolescents' sleep duration should acknowledge behavioral differences between genders, as well as different behaviors adopted by boys ang girls, specifically on weekends.

Moderating role of 1-minute abdominal test in the relationship between cardiometabolic risk factors and adiponectin concentration in adolescents

BACKGROUND

Adiponectin is an anti-inflammatory cytokine secreted by adipose tissue, has been associated with adiposity and cardiometabolic risk, and has controversial results with muscular fitness. The aim of this study was to analyze the interaction of 1-minute abdominal test in the relationship between adiposity, body composition, cardiometabolic risk and adiponectin concentration in adolescents.

METHODS

This is a cross-sectional study conducted with 62 adolescents of both sexes, aged 11 to 16 years, approved by the Ethics Committee of Research in Humans (CAEE: 62963916.0.0000.5223). Body mass, height, abdominal circumference (AC), waist circumference (WC), fat mass (FM), fat-free mass (FFM), high density lipoprotein (HDL-c), low density lipoprotein (LDL-c), triglycerides (TG), adiponectin, systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean blood pressure (MBP), 1-minute abdominal test (ABD) were measured. Body mass index (BMI), z-score BMI (BMI-z), triponderal mass index (TMI), and waist-to-height ratio (WHtR) were calculated. The macro PROCESS for SPSS v.24.0 was used for moderation analyses, with linear regression models.

RESULTS

Inverse interactions were found for adiposity (BMI, BMI-z, TMI, AC, WC, WHtR), body composition (FM, FFM) and CMRF (SBP, DBP, MBP, TG) versus 1-minute abdominal test with adiponectin concentration, demonstrating that abdominal test is a moderator in these relationships.

CONCLUSION

We conclude that 1-minute abdominal test may play an important role in the relationship between obesity and cardiometabolic risk. We found that muscular fitness can confer a protective effect on adolescents with high levels of abdominal test.

Preliminary results indicate that regular training induces high protection against oxidative stress in basketball players compared to soccer

In elite athlete several metabolic changes occur during regular training. These modifications are associated with changes in blood metabolic profile and can lead to adaptive mechanisms aimed at establish a new dynamic equilibrium, which guarantees better performance. The goal of this study was to characterize the plasma metabolic profile and redox homeostasis, in athletes practicing two different team sports such as soccer and basketball in order to identify potential metabolic pathways underlying the differences in training programs. A cohort of 30 male, 20 professional players (10 soccer and 10 basketballs) and 10 sedentary males as control were enrolled in the study. Plasma redox balance, metabolites and adiponectin were determined. The results show low levels of oxidative species (25.5%), with both high antioxidant capacity (17.6%) and adiponectin level (64.4%) in plasma from basketball players, in comparison to soccer players. Metabolic analysis indicates in basketball players a significant high plasma level of amino acids Valine and Ornithine both involved in redox homeostasis and anti-inflammatory metabolism.

Is the Leptin/Adiponectin Ratio a Better Diagnostic Biomarker for Insulin Resistance than Leptin or Adiponectin Alone in Adolescents?

Background: Recently, the leptin/adiponectin (L/A) ratio has been suggested as a novel predictor of cardio-metabolic and other chronic diseases. Aim: To evaluate the ability of leptin (L), adiponectin (A), and the L/A ratio in identifying high risk of insulin resistance IR in adolescents, adjusted by cardiorespiratory fitness, adherence to the Mediterranean diet, and body fat percentage. Subjects and methods: This is a cross-sectional analysis with 529 adolescents aged 12−18 years-old. Blood samples were taken to analyze glucose, insulin, leptin, and adiponectin levels. IR (homeostasis model assessment of insulin resistance (HOMA-IR) was estimated from fasting serum insulin and glucose). Results: Adiponectin, leptin, and L/A ratio were accurate to predict IR among adolescents. The optimal L/A cut-off value to indicate risk of IR development was >0.35 in boys and >0.97 in girls. Logistic analyses showed that the suggested cut-off points for adiponectin (girls: OR: 2.87 (1.26−6.53); p = 0.012); leptin (boys: OR: 5.23 (1.16−7.14) p = 0.006; girls: OR: 2.99 (1.10−8.09) p = 0.031), and the L/A ratio (boys: OR: 8.38 (2.6−26.8) p < 0.001; girls: OR: 6.1 (2.1−17.0) p < 0.001), were significant predictors of IR, after adjustments for age, pubertal stage, adherence to the Mediterranean diet, cardiorespiratory fitness, and body fat percentage. Conclusion: Leptin and L/A ratio were associated with IR risk, after adjustments for confounders in both sexes and adiponectin in girls. The L/A ratio seems to have a higher diagnostic accuracy to identify IR risk than adiponectin or leptin, in both sexes.

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.

Relationships between Sex and Adaptation to Physical Exercise in Young Athletes: A Pilot Study

The purpose of this study was to compare the redox, hormonal, metabolic, and lipid profiles of female and male basketball players during the seasonal training period, compared to their relative sedentary controls. 20 basketball players (10 female and 10 male) and 20 sedentary controls (10 female and 10 male) were enrolled in the study. Oxidative stress, adiponectin level, and metabolic profile were determined. Male and female athletes showed an increased antioxidant capacity (27% for males; 21% for females) and lactate level (389% for males; 460% for females) and reduced salivary cortisol (25% for males; 51% for females) compared to the sedentary controls. Moreover, a peculiar metabolite (in particular, amino acids and urea), hormonal, and lipidic profile were highlighted in the two groups of athletes. Female and male adaptations to training have several common traits, such as antioxidant potential enhancement, lactate increase, and activation of detoxifying processes, such as the urea cycle and arachidonic pathways as a response to inflammation. Moreover, we found different lipid and amino acid utilization related to sex. Deeper investigation could help coaches in developing training programs based on the athletes’ sex in order to reduce the drop-out rate of sporting activity by girls and fight the gender stereotypes in sport that also have repercussions in social fields.

Muscular Fitness and Cardiometabolic Variables in Children and Adolescents: A Systematic Review

BACKGROUND

The importance of muscular fitness (MF) in the performance of activities of daily living is unequivocal. Additionally, emerging evidence has shown MF can reduce cardiometabolic risk in children and adolescents.

OBJECTIVES

The purpose of this study was to examine and summarize the evidence regarding the relationship between MF phenotypes (i.e., maximum muscular strength/power, muscular endurance, and maximum muscular strength/power/endurance) and cardiometabolic variables (obesity, blood pressure, lipids, glucose homeostasis, inflammatory markers, and clustered cardiometabolic variables) in children and adolescents.

DESIGN

This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and was registered with PROSPERO, number CRD42020179273.

DATA SOURCES

A systematic review was performed on five databases (PubMed, EMBASE, SciELO, Scopus, and Web of Knowledge) from database inception to May 2020, with complementary searches in reference lists.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Eligibility criteria included (1) a study sample of youth aged ≤ 19 years, (2) an assessment of MF with individual or clustered cardiometabolic variables derived from adjusted models (regardless of test/measurement adopted or direction of reported association), and (3) a report of the association between both, using observational studies. Only original articles published in peer-reviewed journals in English, Portuguese, and Spanish languages were considered. The quality of the included studies was assessed by using the National Heart, Lung, and Blood Institute checklist. The percentage of results reporting a statistically significant inverse association between each MF phenotype and cardiometabolic variables was calculated.

RESULTS

Of the 23,686 articles initially identified, 96 were included (77 cross-sectional and 19 longitudinal), with data from children and adolescents from 35 countries. The score for the quality of evidence ranged from 0.33 to 0.92 (1.00 maximum). MF assessed by maximum muscular strength/power was inversely associated with lower obesity (64/113 total results (56.6%)) and reduction in clustered cardiometabolic risk (28/48 total results (58.3%)). When assessed by muscular endurance, an inverse association with obesity (30/44 total results (68.1%)) and cardiometabolic risk (5/8 total results (62.5%)) was identified. Most of the results for the relationship between MF phenotypes with blood pressure, lipids, glucose homeostasis, and inflammatory markers indicated a paucity of evidence for these interrelationships (percentage of results below 50.0%).

CONCLUSION

MF assessed by maximum muscular strength/power or muscular endurance is potentially associated with lower obesity and lower risk related to clustered cardiometabolic variables in children and adolescents. There is limited support for an inverse association between MF with blood pressure, lipids, glucose homeostasis biomarkers, and inflammatory markers in children and adolescents.

Prevalence, patterns and socio-demographic correlates of sleep duration in adolescents: results from the LabMed study

OBJECTIVE

The aim of this study was to report the prevalence of adequate sleep and the correlates of sleep duration in Portuguese adolescents aged 12-18 years.

METHODS

Cross-sectional analysis with 1017 adolescents (471 girls) aged 14.6 ± 1.8 years. Adolescents self-reported their sleep duration.

RESULTS

The percentage of adolescents meeting the guidelines was 72.7%, 60.7% and 51.3%, during a whole week, on weekdays and on weekends, respectively. Boys were always more compliant with the guidelines than girls, for all week categories. A significant difference was found on sleep duration on weekends, between boys and girls (p < 0.001). During weekdays, more adolescents were classified as short sleepers when compared to long sleepers. Younger adolescents were more likely to meet the guidelines over the whole week and on weekdays (OR = 2.23, OR = 2.13, respectively; p < 0.05) and being long sleepers on weekends (OR = 1.49, p < 0.05). Those of medium and low SES were less likely to meet the sleep guidelines for all week categories (p_trend<0.001). Girls were more likely than boys to meet the guidelines or being long sleepers on weekends (OR = 1.78, OR = 2.85, respectively; p < 0.05).

CONCLUSIONS

During weekends, the percentage of girls sleeping more than recommended is high, indicating a clear compensation of low sleep duration during weekdays. Those of low SES and older adolescents were less likely to meet the sleep guidelines. Policy makers and researchers should consider the potential effects that SES, gender and age might have on sleep duration, when designing targeted interventions to promote adequate sleep duration.

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, physical activity, or sedentary patterns? Integrated analysis with obesity surrogates in a large youth sample

OBJECTIVE

Physical fitness (PF) and physical activity (PA) are inversely associated with body mass index and waist circumference (WC), whereas sedentary time (ST) seems to boost obesity in youth. The aim was to examine the associations of each selected PF test, PA-related exposures, and specific ST patterns with obesity and determine the most relevant ones, in a large sample of a school-aged adolescent.

METHODS

The sample consisted of 2696 Portuguese youth aged 10 to 18 years. Height, weight, and WC were measured. PA and ST components were measured using accelerometry. PF was evaluated using a battery of tests.

RESULTS

The Progressive Aerobic Cardiovascular Endurance Run (PACER) and push-up tests seemed to be the exposures that presented the strongest and more consistent associations with obesity, independent of PA/ST profiles (P < .05). The second exposure of relevance for adolescent obesity level was the breaks in ST with a negative relationship regardless of PA/PF profiles (P < .05). Finally, ST accumulated in periods of <30 minutes, and moderate-to-vigorous PA were favorably associated with obesity, independent of ST/PF.

CONCLUSIONS

Independent of PA and ST, cardiorespiratory fitness (CRF), measured by PACER, was associated with obesity markers. This may be in part due to the dependence of PACER performance on adiposity. Also, limiting prolonged ST and promoting interruptions in this behavior were associated with obesity. These associations suggest that future research should examine other strategies beyond PA promotion for tackling obesity that consider CRF and breaking ST.

IDEAL CARDIOVASCULAR HEALTH STATUS AND HEALTH-RELATED QUALITY OF LIFE IN ADOLESCENTS: THE LABMED PHYSICAL ACTIVITY STUDY

Objective:

Adolescent’s ideal cardiovascular health index (ICVH) seems to be an important indicator of youth’s lifestyles and cardiometabolic health with potential positive consequences for their Health-Related Quality of Life (HRQoL). The purpose of this study was to examine the associations between the ICVH index and HRQoL in adolescents.

Methods:

This was a cross-sectional study based on secondary analyses from the LabMed Physical Activity Study (n=407 adolescents, 53% girls). ICVH, as defined by the American Heart Association, was determined as meeting ideal behaviors (physical activity, body mass index, smoking status, and diet intake) and health factors (blood pressure, total glucose, and cholesterol). HRQoL was measured with the Kidscreen-10 self-report questionnaire.

Results:

Analysis of covariance (ANCOVA) showed a significant association between the accumulation of ideal cardiovascular health metrics and HRQoL (F_(4,403)=4.160; p=0.003). In addition, the higher the number of ideal health behaviors accumulated, the higher the mean values of HRQoL (p-value for trend=0.001), after adjustments for age, sex, socioeconomic status and pubertal stage.

Conclusions:

ICVH index was positively associated with HRQoL in adolescents. Ideal health behaviors metrics seem to have a stronger association with HRQoL than the ideal health factors metrics in adolescents.

Higher Cardiorespiratory Fitness Levels May Attenuate the Detrimental Association between Weight Status, Metabolic Phenotype and C-Reactive Protein in Adolescents-A Multi-Cohort Study

Results from several studies show that only obese, unfit subjects, but not obese, fit subjects, are at higher mortality risk than are normal-weight fit subjects. The aim of the study was two-fold: (1) to examine the differences in C-reactive protein levels across different metabolic phenotypes (healthy and unhealthy) of weight status and (2) ascertain whether high levels of cardiorespiratory fitness (CRF) attenuate the association of C-reactive protein and metabolic phenotypes of weight status. This was a pooled study, which included data from three cross-sectional projects (1706 youth (921 girls) aged 12-18 years). We used a Shuttle run test to assess CRF. Adolescents were classified into six metabolic phenotypes (healthy and unhealthy) of weight status (non-overweight, overweight and obese), based on age- and sex-specific cutoff points for triglycerides, systolic blood pressure, HDL-cholesterol, glucose and body mass index. High-sensitivity assays were used to obtain the C-reactive protein as inflammatory biomarker. After adjustment for potential confounders (age, sex, pubertal stage and country), the analysis of covariance (ANCOVA) shows that C-reactive protein is directly associated with metabolic phenotypes of weight status. Subjects with obesity, regardless of their metabolic profile, had higher levels of C-reactive protein Z-score. In addition, (after adjustments for potential confounders) a two-way ANCOVA showed that high levels of CRF attenuated the associations of C-reactive protein levels in metabolic healthy non-overweight and in adolescents with obesity. In conclusion, higher CRF levels may attenuate the detrimental association between obesity and C-reactive protein independently of metabolic phenotype. Findings from this study are important for prevention, clinical practice on issues associated with adiposity and metabolic disorders.

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.

Relationship between insulin resistance and adipocytokines: the mediator role of adiposity in children

Background: Leptin and adiponectin interact with each other in the modulation of obesity and insulin resistance (IR) and it is also important to consider the role of cardiorespiratory and muscular fitness in these relationships.Aim: To analyse the relationship between IR with adipocytokines in children, and to test the mediation effect of %BF (percentage of body fat) in the association of IR with leptin, adiponectin, and L/A ratio.Subjects and methods: This cross-sectional study comprised a sample of 150 schoolchildren, aged 6-11 years, from school in Porto Alegre, Brazil. The following variables were evaluated: cardiorespiratory fitness (CRF), muscular fitness (MF), percentage of body fat (%BF), and biochemical variables (leptin, adiponectin, glucose, and insulin).Results: IR was associated with leptin and L/A ratio, after adjustments for age, sex, sexual maturation, and CRF. When adjusted for age, sex, sexual maturation, and MF, an association was found between IR with leptin and L/A ratio. Moreover, %BF was a mediator in the association between IR and leptin, as well as IR and L/A ratio, explaining 54% and 57% of these associations, respectively.Conclusion: Leptin and L/A ratio are positively associated with IR after adjustments. Also, %BF is a mediator in the associations between IR and leptin and L/A ratio.

Ability of 2 estimation methods of body fat percentage in identifying unfavorable levels of cardiometabolic biomarkers in adolescents: Results from the LabMed study

Background:

To assess and compare the ability of body fat percentage (BF%) estimated by 2 methods, bioelectrical impedance analysis (BIA) and by the Slaughter et al equations for triceps and subscapular skinfold thickness (SKF), in identifying unfavorable levels of several biomarkers of cardiometabolic risk.

Methods:

Cross-sectional school-based study with 529 apparently healthy adolescents (267 girls), aged 14.3 ± 1.7 years.

Results:

BF% estimated by both methods always showed higher areas under the curve (AUC) for each biomarker in girls than in boys (with the exception of BIA for leptin). BF% estimated by BIA and by SKF presented a discriminatory ability in identifying unfavorable levels in all biomarkers of cardiometabolic risk in girls; however, BF% estimated by BIA displayed the highest AUC (except for C-reactive protein). In boys, BF% estimated by SKF presented higher AUC for C-reactive protein, fibrinogen and erythrocyte sedimentation rate; and BF% estimated by BIA for complement C3 and leptin. Positive and significant associations between BIA and SKF with all biomarkers (P < .05) were found (except for SKF and complement C4 in girls, and SKF and fibrinogen and erythrocyte sedimentation rate in boys), after adjustments for pubertal stage, cardiorespiratory fitness, adherence to the Mediterranean diet and socioeconomic status.

Conclusions:

Overall, diagnostic performance was more accurate in girls. BF% estimated by BIA presented a slightly better overall discriminatory ability for each biomarker than BF% estimated by SKF in girls, while in boys no method clearly prevailed over the other.

Adiposity and attained height in adolescents: a longitudinal analysis from the LabMed Physical Activity Study

Background To investigate the associations between adiposity and attained height over a 2-year period in healthy adolescents. Methods One thousand and seventeen adolescents aged 12-18 years participated in this cohort study; 893 (87.8%) were reevaluated 1 year later (T2) and 734 (72.2%) subjects 2 years later (T3). Body fat and anthropometry were measured according to standardized procedures. Socioeconomic status, pubertal stage and lifestyles determinants were gathered and used as confounders. Prospective associations between adiposity and height were examined using generalized linear models. Results Greater adiposity at T1 was significantly associated with a lower attained height over time, when adjusting for confounders, which varied between 0.03 and 1 cm in T2 and 0.1 and 1 cm in T3. Conclusions Excess of adiposity in early adolescence may exert an effect on attained height in late adolescence. This study supports future lifestyles intervention studies aiming at preventing overweight and obesity and improving attained height.

Association of Dairy Product Consumption with Metabolic and Inflammatory Biomarkers in Adolescents: A Cross-Sectional Analysis from the LabMed Study

This study aimed to investigate the association between dairy product consumption and metabolic and inflammatory biomarkers in Portuguese adolescents, and whether the association differed by weight status. A cross-sectional study was conducted during the school year 2011/2012 with 412 Portuguese adolescents (52.4% girls) in 7th and 10th grade (aged 12 to 18 years old). The World Health Organization cutoffs were used to categorize adolescents as non-overweight (NW) or overweight (OW). Blood samples were collected to analyze C-reactive protein (CRP), interleukin-6 (IL-6), leptin, and adiponectin. Dairy product intake was evaluated using a food frequency questionnaire. Participants were divided by tertiles according to the amount of dairy product consumed. The associations between dairy product consumption with metabolic and inflammatory biomarkers were evaluated using generalized linear regression models with logarithmic link and gamma distribution and adjusted for potential confounders. The majority of adolescents were NW (67.2%). NW adolescents had lower IL-6, CRP, and leptin concentration than their counterparts (p < 0.05, for all comparisons). Higher levels of total dairy product and milk intake were inversely associated with IL-6 (P for trend <0.05, for all) in NW adolescents, but not in OW adolescents. NW adolescents in the second tertile of yogurt consumption had lower level of IL-6 compared to those in the first tertile (p = 0.004). Our results suggest an inverse association between total dairy product and milk intake and serum concentrations of IL-6 only among NW adolescents.

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.

Dietary habits of adolescents living in North America, Europe or Oceania: A review on fruit, vegetable and legume consumption, sodium intake, and adherence to the Mediterranean Diet

AIMS

This review aimed at investigating fruit, vegetable and legume consumption, salt/sodium intake, and the adherence to the Mediterranean dietary pattern in adolescents, three key aspects towards the adoption of a healthy diet.

DATA SYNTHESIS

Three separate searches were carried out on PubMed and Scopus, using the same procedure, searching for studies published in the previous decade with data on fruit and/or vegetable or legume consumption, salt or sodium intake, and adherence to the Mediterranean Diet assessed using the KIDMED questionnaire. The review included a total of 58 papers, which describe original investigations on healthy adolescents (10-19 years old) living in North America, Europe or Oceania, with a sample size >150 participants. The average fruit and vegetable consumption has been found strongly below the recommended values of 400 grams or 5 portions per day in almost all the examined populations. Very little is known about adolescents' legume consumption. Few available data have been found also for sodium intake and, for the majority of the screened populations, levels were far above the recommended 5 grams per day. Lastly, a medium-low adherence to the Mediterranean Diet has been found for adolescents living in Mediterranean Countries.

CONCLUSIONS

Adolescents living in North America, Europe or Oceania are far from being compliant with the nutritional recommendations for fruit, vegetables, legumes, and sodium, and they do not follow the principles of the Mediterranean Diet. Educational and behavioural interventions are required to improve adolescents' dietary patterns.

Associations between physical fitness and adherence to the Mediterranean diet with health-related quality of life in adolescents: results from the LabMed Physical Activity Study

Background

Physical fitness (PF) and adherence to the Mediterranean diet are important indicators of healthy lifestyles. The purpose of this study is to analyze the independent and combined associations between PF and adherence to Mediterranean diet with health-related quality of life (HRQoL) in adolescents.

Methods

This is a cross-sectional analysis with 956 Portuguese adolescents aged 12-18 years. HRQoL was measured with the Kidscreen-10 questionnaire. PF was assessed with the ALPHA health-related fitness battery. The 20-m shuttle run test was used for the estimation of cardiorespiratory fitness; handgrip strength and standing long jump tests were applied for the assessment of muscular fitness and the 4 × 10 m shuttle run test for the assessment of motor fitness (speed and agility). The results of the PF tests (cardiorespiratory fitness, muscular fitness and motor fitness) were transformed into standardized values (Z-scores) by age and sex. Adherence to the Mediterranean diet was assessed with the KIDMED index. Regression analysis and analysis of covariance were performed.

Results

PF (B = 0.228; P < 0.05) and adherence to the Mediterranean diet (B = 0.259; P < 0.05) were positively associated with HRQoL, after controlling for several variables. Participants classified as high PF and high adherence to Mediterranean diet had on average the highest HRQoL score compared with those with low PF and low adherence to Mediterranean diet (F(3, 939) = 4.270; P = 0.005), after adjustments for potential confounders.

Conclusions

The combination of high PF levels and optimal adherence to Mediterranean diet is positively associated with HRQoL.

Adiposity and adipocytokines: the moderator role of cardiorespiratory fitness and pubertal stage in girls

Background Cardiorespiratory fitness (CRF) and pubertal stages have been related to many health outcomes, including obesity and adipocytokines. Thus, the present study aimed to analyze the moderator role of CRF and pubertal stage in the relationship between adiposity and adipocytokines in girls. Method This cross-sectional study was performed with 42 pre-pubertal girls aged from 7 to 11 years and 54 post-pubertal girls aged from 13 to 17 years. Blood samples were collected to determine the serum levels of leptin and adiponectin, and then the leptin/adiponectin ratio (L/A ratio) was calculated. CRF, anthropometric and body composition indicators were assessed. For statistical analysis, descriptive statistics and several linear regression models were used. The moderation analysis was tested using the PROCESS macro. Results An interaction between body mass index (BMI) and CRF (β: -0.70; confidence interval [CI]: -1.29, -0.12), as well as between BMI and pubertal stage (β: 0.79; CI: 0.28, 1.30) with leptin, was found. Regarding the L/A ratio, an interaction was found only in BMI × CRF (β: -0.56; CI: -1.06, -0.06). Using a combined interaction (CRF and pubertal stage), the results showed a positive association between BMI with leptin and L/A ratio only in low CRF, pre-pubertal and post-pubertal stages. Conclusion This study suggests a protective role of high levels of CRF in the relationship between BMI and adipocytokines. Despite the effect of pubertal stage, the results suggest that youth should be engaged in physical activity in order to improve CRF levels and consequently improve cardiometabolic health.

Muscular fitness and cardiorespiratory fitness are associated with health-related quality of life: Results from labmed physical activity study

BACKGROUND

Adolescents' physical fitness levels are an important indicator of their lifestyle and seem to have positive consequences in health-related quality of life (HRQoL).

OBJECTIVE

The purpose of this study is to analyse the combined associations of cardiorespiratory fitness and muscular fitness with HRQoL and to assess the differences between HRQoL scores across groups of cardiorespiratory fitness and muscular fitness in Portuguese adolescents.

DESIGN

This is a cross-sectional analysis with 567 Portuguese adolescents aged 12-18 years-old.

METHODS

HRQoL was measured using the Kidscreen-10 questionnaire. Cardiorespiratory fitness was estimated with the 20-m shuttle-run test. Muscular fitness was evaluated using the handgrip and the standing long jump tests and a muscular fitness index was computed by means of standardized measures of both tests. Socioeconomic status was assessed using the Family Affluence Scale. Body composition (body mass and height) was measured according to standard protocols. Accelerometers were used to obtain objective physical activity time. Pubertal stage was assessed using Tanner stages. Adherence to the Mediterranean diet was assessed using the KIDMED index. Participants were divided into four groups based on low or high values of both cardiorespiratory and muscular fitness. Regression analysis, mediation analysis and ANCOVA were performed.

RESULTS

HRQoL was positively associated with cardiorespiratory fitness (B = 0.112; p < 0.05) and muscular fitness score (B = 0.328 p < 0.05), after controlling for potential confounders. However, when both fitness variables were entered in the same model only cardiorespiratory fitness remained significantly associated with HRQoL (B = 0.093 p < 0.05). Cardiorespiratory fitness acted as a full mediator variable on the relationship between muscular fitness and HRQoL in adolescents (p < 0.05). ANCOVA showed that adolescents with high cardiorespiratory fitness/high muscular fitness exhibit better HRQoL scores when compared to those with low muscular fitness/low cardiorespiratory fitness and with those with low muscular fitness/high cardiorespiratory fitness (p < 0.05).

CONCLUSIONS

In adolescents, the combination of high cardiorespiratory fitness and high muscular fitness was positively associated with a better HRQoL.

Independent and combined associations of physical fitness components with inflammatory biomarkers in children and adolescents

BACKGROUND

We aimed to examine the independent and combined associations of cardiorespiratory fitness, muscular fitness, and motor ability with single and clustered inflammatory biomarkers in children and adolescents.

METHODS

This study included 503 children and adolescents. Cardiorespiratory fitness, upper- and lower-muscular fitness, and motor ability were assessed using field-based tests. Fasting blood samples were obtained to determine the levels of a set of inflammatory biomarkers. Global physical fitness and clustered inflammatory biomarker scores were computed. Associations between physical fitness and inflammatory biomarkers were analyzed through linear regression. Differences in inflammatory biomarker levels between physical fitness tertiles were tested.

RESULTS

Global physical fitness was inversely associated with single and clustered inflammatory biomarkers in children (p < 0.05); and with C-reactive protein, complement factor C4, leptin, and clustered inflammatory biomarkers in adolescents (p < 0.025). Cardiorespiratory fitness and upper-muscular fitness were negatively and independently associated with several single and clustered inflammatory biomarkers in children and adolescents (p < 0.05). Differences were found between the lowest and the highest tertiles of global physical fitness in clustered inflammatory biomarker levels (p < 0.010).

CONCLUSION

Physical fitness was negatively associated with single and clustered inflammatory biomarkers, independently of body mass index. Increasing physical fitness levels in youth might contribute to reduce the cardiovascular risk.

Fruit, vegetable consumption and blood pressure in healthy adolescents: A longitudinal analysis from the LabMed study

BACKGROUND AND AIMS

The associations between fruit and vegetable consumption and high blood pressure among adults are well studied. Nonetheless, data on the influence of a low consumption of fruit and vegetables on cardiovascular disease risk, particularly blood pressure, among healthy adolescents are scarce. Therefore, we aim to analyse the associations between fruit and/or vegetable intake and blood pressure over a two-year period in healthy adolescents.

METHODS AND RESULTS

As part of a cohort, 606 adolescents from the LabMed Physical Activity study were evaluated in 2011 (baseline) and 2013 (follow-up). Blood pressure was measured according to standardized procedures and fruit and vegetable consumption was assessed with a food frequency questionnaire. Anthropometric variables, socioeconomic status, pubertal stage and lifestyle determinants were gathered and used as confounders. Prospective associations between fruit and/or vegetable intake and blood pressure were examined using generalized linear models. Girls who consumed more fruit at baseline had a significant decrease in diastolic blood pressure at follow-up [unstandardized beta: -0.005 mmHg (95%CI: -0.01; -0.0002) (p = 0.038)].

CONCLUSION

In apparently healthy adolescents, fruit intake may already start to have an effect in blood pressure. Girls who consumed more fruit exhibited lower levels of diastolic blood pressure.

The combined association of adherence to Mediterranean diet, muscular and cardiorespiratory fitness on low-grade inflammation in adolescents: a pooled analysis

PURPOSE

Low-grade inflammation leads to several metabolic disorders, and adherence to a Mediterranean diet (MedDiet), cardiorespiratory fitness (CRF), and muscular fitness (MF) has been considered important markers of metabolic healthy in youth. We investigated the combined association of adherence to Mediterranean diet, and muscular and cardiorespiratory fitness on high-sensitivity C-reactive protein (hs-CRP) in adolescents.

METHODS

This is a cross-sectional analysis with 1462 adolescents (625 girls) aged 9-18 years from Colombia and Portugal. MedDiet was assessed by Kidmed questionnaire. Shuttle run test was used to assess CRF. MF was assessed by the standing long-jump and handgrip tests. High-sensitivity assays were used to obtain the hs-CRP level.

RESULTS

Logistic regression shows that subjects with a low adherence to MedDiet and LowMF/LowCRF had a similar odds (OR = 2.3; 95% CI 1.2-4.0) as those with an optimal adherence to MedDiet and LowMF/LowCRF (OR = 2.3; 95% CI 1.2-5.0) of expressing high inflammatory profile when compared to those with an optimal adherence to MedDiet and HighMF/HighCRF. In addition, ANCOVA showed that subjects classified as high adherence to MedDiet and HighMF/HighCRF had, on average, the lowest levels of hs-CRP (F_(7,1454) = 2.051 p = 0.04).

CONCLUSION

The combination of optimal levels of CRF and MF and adherence to MedDiet is associated with lower hs-CRP. However, high MF and CRF seems to counteract the deleterious effect of having a low adherence to the MedDiet on hs-CRP levels.

Longitudinal association between ideal cardiovascular health status and muscular fitness in adolescents: The LabMed Physical Activity Study

BACKGROUND AND AIMS

Muscular fitness is an emerging predictor for cardiovascular disease mortality. The ideal cardiovascular health metrics has been inversely related to a subsequent cardiometabolic health in adulthood. However, evidence regarding muscular fitness and ideal cardiovascular health in adolescents is scarce. This study aimed to examine the longitudinal association between ideal cardiovascular health index and muscular fitness.

METHODS AND RESULTS

This study cohort consisted of 331 adolescents (183 girls) from the LabMed Physical Activity Study who were followed from 2011 to 2013. Ideal cardiovascular health, as defined by the American Heart Association, was determined as meeting ideal health factors (total cholesterol, blood pressure, and glucose) and behaviors (smoking status, body mass index, physical activity, and diet). Handgrip strength and standing long jump tests assessed muscular fitness and were transformed into standardized values according to age and sex. ANCOVA showed a significant association between the accumulation of ideal cardiovascular health metrics at baseline and muscular fitness indices at follow-up (F_{(4, 322)} = 2.280, p = 0.04). In addition, the higher the number of ideal cardiovascular health metrics accumulated, the higher the likelihood of having a high muscular fitness over a two-year period (p for trend = 0.01), after adjustments for age, sex, pubertal stage and socioeconomic status and muscular fitness at baseline.

CONCLUSION

The ideal cardiovascular health status during adolescence was associated with high muscular fitness levels over a two-year period.

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.

Low-grade inflammation and muscular fitness on insulin resistance in adolescents: Results from LabMed Physical Activity Study

BACKGROUND

Low muscular fitness (MF) and low-grade inflammation has been linked to insulin resistance (IR).

OBJECTIVE

To evaluate the associations between MF and a clustered score of inflammatory biomarkers on IR and to investigate the combined impact of MF and inflammation on IR in adolescents.

METHODS

This is a cross-sectional analysis with 529 adolescents (267 girls) aged 12 to 18 years. Pubertal stage, socioeconomic status, adherence to the Mediterranean diet, cardiorespiratory fitness, and waist circumference were assessed. Standing long-jump and isometric handgrip dynamometry were used as indicators of MF. Continuous score of clustered inflammatory biomarkers (InflaScore) (sum of Z-scores of C-reactive protein, C3, C4, fibrinogen, and leptin) and IR (homeostasis model assessment of insulin resistance [HOMA-IR] estimated from fasting serum insulin and glucose) were assessed.

RESULTS

HOMA-IR and fasting insulin were positively associated with InflaScore and negatively associated with MF, independently of age, sex, pubertal stage, socioeconomic status, adherence to the Mediterranean diet, cardiorespiratory fitness, and waist circumference. Adolescents classified as High InflaScore/Unfit showed significantly higher HOMA-IR when compared than those with High InflaScore/Fit and those with Low InflaScore/Fit (F_(3,519)  = 4.761, P < .003), after adjustments for potential confounders. Unfit adolescents with high InflaScore had the highest odds of expressing high HOMA-IR (odds ratio, OR = 2.40, 95% confidence interval [CI]: 1.2-5.6) and insulin risk (2.53 95% CI, 1.5-5.9) when compared to those of the Low InflaScore/Fit group, after adjustments for potential confounders.

CONCLUSION

Higher levels of MF seem to minimize the deleterious effect of inflammation on IR.

Handgrip strength is positively related to blood pressure and hypertension risk: results from the National Health and nutrition examination survey

Background

Isometric handgrip resistance exercise, a nonpharmacological lifestyle modification, has been recommended as a first-line treatment for hypertension. This study aimed to examine the relationship of handgrip strength to blood pressure and the risk of hypertension.

Methods

The responses and examination of 4597 participants in the National Health and Nutrition Examination Survey (NHANES) were analyzed in this study. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were transformed to age- and sex-specific z-scores. Handgrip strength was adjusted by weight (kg) and converted to an age- and sex-specific z-score. The relationships of SBP and DBP to handgrip strength were analyzed by Pearson correlation test and multivariable linear regression. Binary logistic regression was used to analyze the association between handgrip strength and prevalence of hypertension.

Results

Handgrip strength was positively related to higher DBP in men and women. In men, logistic regression models revealed that increased handgrip strength was associated with higher risk of hypertension after adjusting for age, BMI, smoking and drinking status; OR was 1.24 (95%CI: 1.04–1.48). After stratifying on BMI, handgrip strength was significantly associated with higher risk of hypertensions after adjusting for age, BMI, smoking and drinking status in overweight and obese men; OR was 1.31 (95%CI: 1.05–1.63). No significant associations were observed in women.

Conclusions

Increased handgrip strength is associated with higher DBP in men and women. In men, especially overweight and obese men, strong handgrip strength may be associated with higher risk of hypertension.

Electronic supplementary material

The online version of this article (10.1186/s12944-018-0734-4) contains supplementary material, which is available to authorized users.

Environmental perceptions and its associations with physical fitness and body composition in adolescents: longitudinal results from the LabMed Physical Activity Study

Background The environmental correlates have been extensively studied in the last years, but most associations with physical fitness (PF) and body composition have been cross-sectional in nature. Objective This study aimed to determine if adolescents' environmental perceptions associated with PF and body composition in a 2-year follow-up. Subjects Participants were 583 adolescents aged 12-18 years (299 girls) from the LabMed Physical Activity Study. Methods PF and body composition were assessed with the protocols of the ALPHA health-related fitness battery and environmental perceptions with the ALPHA environmental questionnaire. Linear regression models were used to determine the associations between environmental perceptions at baseline and PF and anthropometric measures at follow-up. Results Results showed that perceptions of distant facilities at baseline were associated with lower fitness at follow-up in boys. Also, boys' lower study environment perceptions at baseline were associated with higher body composition at follow-up. Positive perceptions of a pleasant environment at baseline were associated with better fitness at follow-up in boys. Additionally, girls' positive bike lanes availability and esthetics perceptions at baseline were associated with better body composition at follow-up. Conclusion Positive environmental perceptions at baseline are associated with better PF and body composition at follow-up.

Ability of Nontraditional Risk Factors and Inflammatory Biomarkers for Cardiovascular Disease to Identify High Cardiometabolic Risk in Adolescents: Results From the LabMed Physical Activity Study

PURPOSE

Then objective of this study was to evaluate the ability of several nontraditional cardiometabolic and inflammatory biomarkers in identifying high cardiometabolic risk in adolescents.

METHODS

A cross-sectional study was conducted with 529 Portuguese adolescents (267 girls) aged 14.3 ± 1.7 years. A clustered cardiometabolic risk score (body fat percentage, systolic blood pressure, ratio of total cholesterol to high-density lipoprotein cholesterol, triglycerides, homeostatic model assessment of insulin resistance, and negative values of cardiorespiratory fitness) was computed. The nontraditional cardiometabolic biomarkers assessed were complement factors (C3 and C4), C-reactive protein (CRP), fibrinogen, leptin, white blood cells (WBCs), albumin, interleukin-6, and a clustered score of inflammatory biomarkers (InflaScore) (C3, C4, CRP, fibrinogen, and leptin).

RESULTS

Receiver operating characteristic curves analyses showed that C3, C4, CRP, fibrinogen, leptin, and the InflaScore were able to present discriminatory ability in identifying an unfavorable cardiometabolic profile in both girls and boys (p <.01 for all). Logistic regression analyses showed that C3, C4, CRP, fibrinogen, leptin, the InflaScore (in both sexes), and WBC (boys) were associated with high cardiometabolic risk, independent of age, pubertal stage, socioeconomic status, or adherence to a Mediterranean diet (p <.05 for all).

CONCLUSIONS

C3, C4, CRP, fibrinogen, and leptin were associated with high cardiometabolic risk in both sexes and WBC in boys. In addition, the clustered inflammatory biomarkers seem to have a better diagnostic accuracy in identifying an unfavorable cardiometabolic profile than single biomarkers. Such biomarkers may have utility in motivating health professionals, public health workers, and adolescents' families toward lifestyle changes, improving prevention efforts early in life.

Cardiorespiratory Fitness and Blood Pressure: A Longitudinal Analysis

OBJECTIVES

To examine the association between cardiorespiratory fitness and cardiovascular indices 2 years later, and to determine whether changes in cardiorespiratory fitness are associated with cardiovascular indices at a 2-year follow-up in adolescents.

STUDY DESIGN

The sample comprised 734 adolescents (349 girls) aged 12-18 years followed for 3 years from the LabMed Physical Activity Study. Cardiorespiratory fitness was assessed by the 20-meter shuttle run test. Height, weight, waist circumference, and resting blood pressure (BP) were measured according to standard procedures.

RESULTS

Regression analyses showed a significant inverse association between cardiorespiratory fitness at baseline and systolic BP (B = -0.126; P = .047) and rate pressure product (B = -29.94; P = .016), at follow-up after adjustments for age, sex, height, pubertal stage, socioeconomic status, and waist circumference. Significant differences were found between cardiorespiratory fitness groups (fit vs unfit) at baseline and systolic BP and rate pressure product at follow-up (P < .05 for all). Analysis of covariance showed a significant association between cardiorespiratory fitness changes and systolic BP (P = .024) and rate pressure product (P = .014), after adjustment for age, sex, height, pubertal status, socioeconomic status, and waist circumference.

CONCLUSIONS

Changes in cardiorespiratory fitness during adolescence were associated with cardiovascular indices over a 2-year period. Adolescents with persistently low levels of cardiorespiratory fitness exhibited the highest levels of systolic BP and rate pressure product.

Muscular fitness, Southern European Atlantic Diet and inflammation in adolescents. Azorean Physical Activity and Health Study II

High muscular fitness (MF) and high adherence to the Southern European Atlantic Diet (the SEADiet) have been associated with several positive metabolic outcomes. The purpose of the present study was two-fold: (i) to explore the independent associations between MF and C-reactive protein (CRP) levels; and (ii) to investigate the combined impact of MF and SEADiet on the CRP levels in a sample of adolescents. A cross-sectional school-based study was conducted on 463 adolescents (272 girls) aged 15-18 years, from the Portuguese Azorean Archipelago. Anthropometric indicators (stature, body mass, waist circumference (WC)) were measured by standardized protocols and pubertal stages were assessed by Tanner criteria. Blood samples were taken after an overnight fast. MF was assessed by the curl-up and push-up tests (from the Fitnessgram test battery). Adherence to the SEADiet was assessed with a semi-quantitative food frequency questionnaire. Linear regression models showed that MF was inversely associated with hs-CRP (unstandardized B = -0.127; p < .009), after adjustments for age, sex, and pubertal stage, adherence of SEADiet, total energy intake and low-energy reporter and WC. Analysis of covariance (ANCOVA) showed a significant difference between the low adherence of SEADiet with low MF group and those with a high adherence of SEADiet and high MF (p < .05) (F_{(5, 453)} = 2.238, p = .040). Our results showed that MF is inversely associated with hs-CRP. In addition, the adolescents with Low adherence of SEADiet/Low MF group had high levels of hs-CRP compared those who with high adherence of SEADiet/high MF group.

Muscular fitness, adherence to the Southern European Atlantic Diet and cardiometabolic risk factors in adolescents

BACKGROUND AND AIM

Muscular fitness and an adherence to the Southern European Atlantic Diet (SEADiet) have been inversely associated with cardiometabolic risk. Our aim was to assess the independent and combined associations of muscular fitness and adherence to the SEADiet on cardiometabolic risk in adolescents.

METHODS AND RESULTS

A total of 467 Portuguese adolescents (275 girls) participated in this cross-sectional study. Sum of the Z-Scores of Curl-Up and Push-Up tests was used to create a muscular fitness score. Adherence to SEADiet was obtained using a food frequency questionnaire. A cardiometabolic risk score was computed from sum of Z-score of triglycerides, systolic blood pressure, total cholesterol/HDL ratio, HOMA-IR and waist circumference. Adolescents with low muscular fitness and low adherence to the SEADiet had the poorest cardiovascular profile F_(5, 452) = 5.074 (p < 0.001) and the highest odds of having a high cardiometabolic risk score (OR = 4.5; 95% CI: 2.1-14) when compared to those with High muscular fitness/High adherence to the SEADiet after adjustments for age, sex, pubertal stage, socioeconomic status, total energy intake, low-energy reporter and cardiorespiratory fitness.

CONCLUSIONS

Our findings seem suggest that improving muscular fitness as well as an adherence to the SEADiet could be an important strategy to reduce clustered cardiometabolic risk in youth.

Association between Leptin, Adiponectin, and Leptin/Adiponectin Ratio with Clustered Metabolic Risk Factors in Portuguese Adolescents: The LabMed Physical Activity Study

Introduction: Circulating leptin and adiponectin levels have been associated with impaired vascular function, insulin resistance, and acute cardiovascular evens. This study aimed to evaluate the associations of leptin, adiponectin, and the leptin/adiponectin (L/A) ratio with a clustering of metabolic risk factors (MRF) in adolescents aged 12-18 years. Methods: This is a cross-sectional analysis with 529 Portuguese adolescents aged 12-18 years. Blood samples were taken to analyze total cholesterol (TC) and high-density lipoprotein (HDL) cholesterol (HDL-c), triglycerides glucose, insulin, leptin, and adiponectin levels. A continuous variable of clustered MRF score (sum of Z-scores of body fat percentage, systolic blood pressure, ratio TC/HDL, triglycerides, homeostatic model assessment insulin resistance, and cardiorespiratory fitness*[-1]) was computed. Results: Regression analyses showed that adiponectin was a significant and negative predictor of MRF score (boys: β = -0.199; p < 0.001; girls: β = -0.200; p < 0.001); whereas leptin was a significant positive predictor of MRF score (boys: β = 0.553; p < 0.001; girls: β = 0.399; p < 0.001). The L/A ratio was also a significant positive predictor of MRF score in both sexes (boys: β = 0.593; p < 0.001; girls: β = 0.461; p < 0.001), after adjustments for age, pubertal stage, adherence to the Mediterranean diet, and socioeconomic status. In addition, adiponectin, leptin, and L/A ratio were accurate to predict MRF among adolescents, but L/A ratio showed the highest area under receiver operating characteristic curve. Conclusion: Leptin, adiponectin, and L/A ratio are associated with the clustering of MRF in adolescents after adjustments for age, sex, pubertal stage, adherence to the Mediterranean diet, and socioeconomic status. L/A ratio was more strongly associated with MRF score than adiponectin or leptin.

Changes in the Composition of Adiponectin Fractions over a 3-Year Period in Children: A Population-Based Cohort Study

BACKGROUND

Little information is available regarding changes in adiponectin fractions. The objective of this study was to examine changes in the composition of differing adiponectin fractions using a population-based, prospective pediatric cohort.

METHODS

A total of 358 fourth graders (9-10 years old) from Ina town in Saitama, Japan, were followed up for 3 years. BMI and total adiponectin (TAD), high-molecular weight adiponectin (HAD), medium-molecular weight adiponectin, and low-molecular weight adiponectin levels were measured in these subjects at baseline and at the end of the follow-up.

RESULTS

Of the fourth graders participating in the study, 326 (172 boys and 154 girls; follow-up rate, 91.1%) became available for follow-up. No significant changes were observed in TAD values after 3 years. HAD values were significantly decreased in both the boys (2.4 to 2.2 μg/mL: p < 0.001) and girls (3.1 to 2.7 μg/mL: p = 0.005). All values in the parameters examined at baseline and after 3 years were significantly correlated. A negative correlation was found between the ratios of follow-up compared to baseline values for BMI and those for TAD (boys, r = -0.322, p < 0.001; girls, r = -0.433, p < 0.001) as well as those for HAD (boys, r = -0.353, p < 0.001; girls, r = -0.351, p < 0.001).

CONCLUSIONS

HAD had the most robust correlation between its values at baseline and those after 3 years in both boys and girls. The changes in HAD also had the most robust correlation between the changes in BMI in 3 years.