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.

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.

Moderation of Physical Activity between Cardiometabolic Risk and Adiponectin in Adolescents

The aims of the study were to examine the moderating role of physical activity in the relationship between cardiometabolic risk factors and adiponectin concentration in adolescents. This is a cross-sectional study conducted with 96 adolescents of both sexes, between 11 and 17 years old. Body mass, height, fat mass (FM), fat-free mass, systolic blood pressure, diastolic blood pressure, high density lipoprotein, low density lipoprotein (LDL-c), triglycerides, insulin, adiponectin, C-reactive protein, and level of physical activity (energy expenditure questionnaire) were measured. Body mass index (BMI), triponderal mass index (TMI), homeostasis model to assessment insulin resistance (HOMA-IR), and quantitative insulin sensitivity check index (QUICKI) were calculated. Macro-PROCESS for SPSS was used for moderation analyses. Direct interactions were found for BMI, TMI, FM, insulin, and HOMA-IR and inverse for LDL-c, and QUICKI. Protection against cardiometabolic risk was found when the PA-coeff was completed above 1.57 coeff (BMI), 1.62 coeff (TMI), 1.55 coeff (FM), 1.41 coeff (LDL-c)1.60 coeff (insulin), 1.59 coeff (HOMA-IR) and 1.35 coeff (QUICKI). We conclude that physical activity was a moderator in the relationship with adiposity, insulin resistance and sensitivity, LDL-c, and adiponectin. In this context, we evidenced a relevant clinical impact on the health of adolescents, demonstrating the interaction between anthropometrics variables and physical activity.

Adolescents who practice physical activity have adequate food choices, regardless of the level of somatic maturation and adiposity

OBJECTIVES

Regular physical activity and adequate food are part of a healthy lifestyle for the maintenance of physical and metabolic health. To verify the moderating role of physical activity (PA) in the relationship between dietary patterns and body adiposity in adolescents, according to somatic maturation.

METHODS

Study with cross-sectional design, sample of 336 adolescents of both sexes, aged between 11 and 17 years. Body mass, height, and waist circumference (WC) were evaluated. Body mass index (BMI), BMI z-score (BMI-z), waist-to-height ratio (WHtR), and somatic maturation by peak height velocity (PHV) were calculated. The level of PA was measured by the International Physical Activity Questionnaire and dietary pattern by the Food Frequency Questionnaire ELSA - Brazil (short version). Moderation analyzes were tested using multiple linear regression models, by PROCESS macro for SPSS.

RESULTS

An inverse interaction of PA was observed in the relationship between food consumption factor 5 (ultra-processed foods category) and WC in boys categorized as pre-pubertal and pubertal PHV (β=-5.344; CI95 % -10.108 -0.580; p=0.028). For girls, no interaction was observed in any of the models analyzed.

CONCLUSIONS

It was observed that the level of PA can influence food choices in prepubertal and pubertal boys, since the active boys showed better dietary pattern and lower central adiposity. Therefore, the findings reinforce the need to encourage the regular practice of physical activities from an early age, mainly aimed at preventing obesity in children and adolescents.

Effects and individual response of continuous and interval training on adiponectin concentration, cardiometabolic risk factors, and physical fitness in overweight adolescents

This study aimed to evaluate the effect and individual responsiveness after 12 weeks of high-intensity interval training (HIIT) and moderate-intensity of continuous training (MICT) on adiponectin, cardiometabolic risk factors and physical fitness in overweight adolescents. This study was participated by 52 adolescents, both sexes, 11 and 16 years old, separated into HIIT (n = 13), MICT (n = 15), and control group (CG, n = 24). Body mass, height, waist circumference (WC), fat mass (FM), fat-free mass (FFM), blood pressure, high-density lipoprotein (HDL-c), low-density lipoprotein (LDL-c), triglycerides, glucose, insulin, adiponectin, and C-reactive protein (CRP) were evaluated. Body mass index z-score (BMI-z), waist-to-height ratio (WHtR), insulin resistance, and insulin sensitivity were calculated. Resting heart rate (HR_rest), peak oxygen consumption (VO_2peak), right handgrip strength (HGS-right), left handgrip strength (HGS-left), and abdominal resistance (ABD) was evaluated. HIIT session lasted around 35 min and MICT of 60 min of exercises on stationary bicycle, three times a weekday for 12 weeks. ANOVA, effect size, and prevalence of responders were used for statistical analysis. HIIT reduced BMI-z, WHtR, LDL-c, and CRP, while increased of physical fitness. MICT reduced HDL-c, while increased of physical fitness. CG reduced FM, HDL-c, and CRP, while increased FFM and HR_rest. Frequencies of respondents in HIIT were observed for CRP, VO_2peak, HGS-right, and HGS-left. Frequencies of respondents in MICT were observed for CRP and HGS-right. Frequencies of no-respondents in CG were observed for WC, WHtR, CRP, HR_rest, and ABD.  Conclusion: Interventions with exercises were effective to adiposity, metabolic health, and physical fitness improvements. Individual responses were observed in inflammatory process and physical fitness, important changes in overweight adolescent's therapy.  Trial registration number and date of registration: This study was registered with the Brazilian Registry of Clinical Trials (REBEC), the number RBR-6343y7, date of registration May 3, 2017. What is Known: • Effect of regular physical exercise positively affects overweight, comorbidities, and metabolic diseases, recommended mainly for children and adolescents. What is New: • Due to the great inter-individual variability, the same stimulus can provide different responses; adolescents who benefit from the stimulus are considered responsive. • Intervention of HIIT and MICT did not alter the concentrations of adiponectin; however, the adolescents presented responsiveness to the inflammatory process and physical fitness.

Sedentary time play a moderator role in the relationship between physical fitness and brain-derived neurotrophic factor in children. A pilot study

Aim

Despite some advances, there are many controversies concerning brain-derived neurotrophic factor (BDNF) and its relationships with variables related to physical fitness and sedentary time, especially in children. The aim of the study was to explore the moderating role of sedentary time on the association between physical fitness and BDNF. Therefore, this study will add to the perspective of understanding how much time children may spend being sedentary with no deleterious influence on the positive association between physical fitness and BDNF.

Methods

This cross-sectional study included 44 children aged between 6 and 11 years (9.02 ± 1.43) from a public school in Porto Alegre, Brazil. Cardiorespiratory fitness (CRF) was determined by the 6-min walk/run test, and muscular strength was determined through the lower limb strength test (LLS). Sedentary time was assessed through accelerometers, and blood samples were collected to determine serum BDNF levels (z score). Moderation analysis was performed using the PROCESS macro adjusted for sex, age, somatic maturation, waist circumference, and socioeconomic level.

Results

Sedentary time moderates the relationship between CRF and BDNF, such that children should spend less than 511 minutes per day sedentary to achieve the benefits of CRF in BDNF concentrations.

Conclusion

Sedentary time plays a significant moderating role in the relationship between CRF and BDNF. Therefore, to promote brain health in children, both increasing physical fitness and reducing sedentary time might be encouraged.

Prediction equations for maximal heart rate in obese and nonobese children and adolescents: a systematic review and meta-analysis

OBJECTIVE

The aim of this study was to analyze which equation best estimates maximal heart rate (HRmax) for the pediatric population according to body mass.

DATA SOURCE

We performed a meta-analysis (PROSPERO No. CRD42020190196) of cross-sectional studies that aimed to validate or develop HRmax equations and that had children and adolescents as samples. The search was conducted in Scopus, Science Direct, Web of Science, PubMed, and Biblioteca Virtual em Saúde with the descriptors "prediction or equation," "maximal heart rate," "maximum heart rate," "determination of heart rate," children, and adolescent. The TRIPOD Statement tool was used to assess the methodological quality and the relevant data were extracted for analysis. The meta-analysis was conducted in the Comprehensive Meta-Analysis, adopting p<0.05 and a 95% confidence interval (CI).

DATA SYNTHESIS

In total, 11 studies were selected, of which 3 developed predictive equations, 10 performed external validity of the preexisting models, and 1 incremented values related to equations already developed. The results of the methodological quality analysis showed a moderate rating in most studies. The 164 + (0.270 × HRres) - (0.155 × body mass) + (1.1 × METs) + (0.258 × body fat percent) (r=0.500, 95%CI 0.426-0.567, p<0.001) and 166.7+ (0.46 × HRres) + (1.16 × maturation) (r=0.540, 95%CI 0.313-0.708, p<0.001) equations presented stronger correlations with measured HRmax in nonobese adolescents. The predictive model developed by 208 - (0.7 × age) showed a greater accuracy among the possible models for analysis (SDM=-0.183, 95%CI -0.787 to -0.422, p=0.554). No specific predictive equation was found for obese adolescents.

CONCLUSIONS

Future research should explore new possibilities for developing predictive equations for this population as a tool to control exercise intensity in the therapeutic management of childhood and adolescent obesity.

Estimation of fat mass in Southern Brazilian female adolescents: development and validation of mathematical models

abstract This study aimed to develop and validate the first mathematical models, based on anthropometric properties, to estimate fat mass (FM) in a heterogeneous sample of female adolescents. A cross-sectional and quantitative study conducted with 196 individuals aged 12 to 17 years from the metropolitan region of Curitiba, Paraná, Brazil. The participants were randomly divided into two groups: regression sample (n = 169) and validation sample (n = 27). Dual-energy X-ray absorptiometry (DXA) was used as the reference method to determine body fat in relative and absolute values. Stature, body mass, waist girth and triceps, subscapular, biceps, iliac crest, abdominal, front thigh and medial calf skinfold thickness were defined as independent variables and measured according to an international technical protocol. Statistical analyzes used the Ordinary Least Square (OLS) regression model, paired t test and Pearson correlation. Four multivariate mathematical models with high determination coefficients (R2 ≥90%) and low estimated standard errors (SEE = ≤2.02 kg) were developed. Model 4 stands out for its low number of independent variables and significant statistical performance (R2 = 90%; SEE = 1.92 kg). It is concluded that the four mathematical models developed are valid for estimating FM in female adolescents in southern Brazil.

Family history of arterial hypertension and central adiposity: impact on blood pressure in schoolchildren

BACKGROUND

A family history of arterial hypertension is an important risk factor for arterial hypertension. This study aimed to verify the mediating role of high central adiposity in the relationship between family history of arterial hypertension and blood pressure in schoolchildren.

METHODS

Cross-sectional study with 118 schoolchildren of both sexes aged between 11 and 17 years. Weight, height, waist circumference and body mass index z score were verified. Somatic maturation was predicted by age for peak growth velocity. The family history of arterial hypertension was verified and defined as hypertensive schoolchildren with systolic blood pressure or diastolic blood pressure. Mediation analysis was used with linear regression models applied by PROCESS macro for SPSS (version 22.0), with significance p < 0.05.

RESULTS

It was observed that 34.7% of the students have family history of arterial hypertension, 36% of the girls and 44.2% of the boys have arterial hypertension. In girls, the relationship between waist circumference and systolic blood pressure was direct (β = 0.535 p = 0.005), and those with a family history of arterial hypertension and who had a waist circumference greater than those without a family history of arterial hypertension was significant (β = -5,437 p = 0.009). Likewise, the relationship between family history of arterial hypertension and systolic blood pressure was attenuated when waist circumference was included in the model (β = -5.544; p = 0.103), indicating waist circumference as a mediator with an influence percentage of 19%. For boys, waist circumference is not a mediator of the relationship between family history of arterial hypertension and blood pressure.

CONCLUSIONS

Elevated central adiposity was a mediator of the relationship between family history of arterial hypertension and high blood pressure in girls, indicating the importance of family health strategies in the prevention and management of arterial hypertension in children and adolescents.

EFFECT OF MICT AND HIIT ON CARDIOMETABOLIC RISK AND BODY COMPOSITION IN OBESE BOYS

ABSTRACT Introduction: The prevalence of childhood obesity has increased and is associated with the development of several chronic diseases. Moderate-intensity continuous training is recommended as the main exercise method for treating obesity. However, in overweight and obese individuals, high-intensity interval training models have similar or greater fat reduction potential than moderate-intensity continuous training. Objective: This study aimed to compare the effects of 12 weeks of moderate-intensity continuous training and high-intensity interval training on cardiometabolic parameters, body composition, and cardiorespiratory fitness in obese adolescent boys. Methods: Fifty-six obese boys, aged 10-16 years old, were included. Anthropometric measurements, blood pressure, body composition, oxygen consumption, glucose, insulin, and the lipid profile were assessed. Participants were assigned to moderate-intensity continuous training (n=20), high-intensity interval training (n=20), and control (n=16) groups. The moderate-intensity continuous training sessions consisted of 90 minutes of cycling/walking exercises and the high-intensity interval training sessions consisted of 15 minutes of warm-up, 15-18 minutes of interval exercises, and 15 minutes of cool-down. Both were performed three times a week. A two-way mixed-model factorial analysis of variance (ANOVA) with repeated measures was used. Results: In the high-intensity interval training group, there was an increase in relative and absolute oxygen consumption and a reduction in diastolic blood pressure. However, in the moderate-intensity continuous training group, there were increases in relative oxygen consumption and high-density lipoproteins, as well as reductions in anthropometric measurements, fat mass, and triglycerides. Conclusion: Moderate-intensity continuous training may be a better protocol for the reduction of fat mass, anthropometric measurements, and improvement of the lipid profile, while high-intensity interval training may be more effective in improving blood pressure among obese boys. Both exercises improve cardiorespiratory fitness. Level of evidence II; Therapeutic studies - investigation of treatment results.

Effects of resistance training on the glycemic control of people with type 1 diabetes: a systematic review and meta-analysis

Resistance training has shown the potential to contribute to better glycemic control in people with Type 1 Diabetes (T1D), however, there are contradictory results in this regard and a need to clarify the effects of isolated resistance training on glycemic control in T1D. The aim was to verify the effects of resistance training on the glycemic control of people with T1D. Original articles were selected, randomized and non-randomized clinical trials that aimed to verify chronic responses, through the concentrations of glycated hemoglobin (HbA1c), to a structured program of resistance exercise in the glycemia of patients with T1D. The following databases were searched; MEDLINE, PubMed, Web of Science, Scopus, ScienceDirect, LILACS, and SciELO. Five studies were included in the review. A reduction in HbA1c was observed (SMD = -0.568 ± 0.165 [95% CI = -0.891 to -0.246]; p = 0.001; I2 = 82%) in patients undergoing resistance training, when compared to the control group (SMD = 1.006 ± 0.181 [95% CI = 0.653 to 1.360]; p <0.001). Two studies, with children and adolescents and longer interventions, demonstrated a significant reduction in HbA1c, increased strength, and an improved lipid profile. Resistance training was efficient for assisting in glycemic control in people with T1D and should be incorporated in treatment plans.

Growth, body composition and bone mineral density among pubertal male athletes: intra-individual 12-month changes and comparisons between soccer players and swimmers

Background

Puberty is a period of intense changes in human body and, additionally, participation in sports is viewed as prominent form of physical activity among male adolescent athletes. The current study was aimed to examine the intra-individual changes in body composition and bone tissue during years of maximal growth and the effect of 12-month participation in sports contrasting in mechanical impact.

Methods

The sample included 40 male adolescent athletes (soccer: n = 20; swimming: n = 20) aged 12.57 ± 0.37 years who were followed for 12 months. Stature and body mass were measured, bone mineral content (BMC), areal bone mineral density (aBMD), lean soft and fat tissues assessed using DXA. Food intake was estimated using a questionnaires and training sessions individually monitored. Repeated measures ANOVA tested the differences between sports and 12-month intra-individual variation (time moments: TM1, TM2). The analyses on aBMD for total body and total body less head were repeated controlling for variation in stature at baseline.

Results

Soccer players completed 63 ± 31 sessions (95 ± 47 h). Respective values for swimmers were 248 ± 28 sessions and 390 ± 56 h. In general, the analysis of aBMD as dependent variable evidenced significant effect of sport-associated variation (F = 5.254, p < 0.01; η² = 0.35) and 12-month increments, particularly at lower limbs (F = 97.238, p < 0.01; η² = 0.85). Respective mean values for aBMD were SCC_TM1 = 0.885 g.cm⁻², SWM_TM1 = 0.847 g.cm⁻², SCC_TM2 = 0.939 g.cm⁻², SWM_TM2 = 0.880. Regarding the lean soft tissue, the magnitude of effects was very large for intra-individual variation (F = 223.043, p < 0.01; η² = 0.92) and moderate between sports (F = 7.850, p < 0.01; η² = 0.41): SCC_TM1 = 30.6 kg, SWM_TM1 = 34.9 kg, SCC_TM2 = 35.8 kg, SWM_TM2 = 40.5 kg). Finally, d-cohen values reporting percentage of intra-individual changes in aBMD between soccer players ad swimmers were large for the trochanter (d = 1.2; annual increments: SCC = 8.1%, SWM = 3.6%).

Conclusion

Puberty appeared as a period of significant intra-individual changes in lean soft tissue and bone mineral density. With increasing accumulated training experience, mean difference between sports contrasting in mechanical impact tended to me more pronounced in particular at the lower limbs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03321-2.

ADRB2 gene influences responsiveness to physical exercise programs: A longitudinal study applied to overweight or obese Brazilian children and adolescents

We aimed to investigate whether the expression levels and polymorphisms in the ADRB2 gene have influenced the anthropometric and cardiometabolic outcomes changes in obese/overweight children submitted to physical exercise programs. This longitudinal study included 197 overweight or obese children aged 10-16 years, submitted to physical exercise programs - three sessions per week for 12 weeks. Anthropometric and cardiometabolic profile was collected before and after interventions. The ADRB2 gene expression levels were also measured in these two moments in a small intervention group (n = 17) and a control group (n = 18). Arg16Gly and Gln27Glu polymorphisms were genotyped. A positive correlation between ADRB2 expression and loss of body fat (%) (p = 0.038) was observed, which remained after sex and BMI change corrections. Carriers of the Glu27Glu genotype presented a better response to physical exercise programs regarding their triglycerides levels and triglyceride-glucose index (p = 0.001 for both). The participants' responsiveness to physical exercise programs showed variation due to the ADRB2 gene expression and the Gln27Glu polymorphism. A more significant loss of body fat was associated with higher levels of ADRB2 expression, and the Glu27Glu genotype was associated with a better cardiometabolic response. The Arg16Gly polymorphism did not show interaction with the responsiveness to physical exercise.

Acute changes in glucose induced by continuous or intermittent exercise in children and adolescents with type 1 diabetes

Objective

To estimate the rate of change during exercise and during recovery in moderate-continuous exercise (MCE) and high-intensity intermittent exercise (HIIE) in children and adolescents with type 1 diabetes (T1D).

Methods

Participants performed 2 sessions of exercise: thirty minutes of continuous activity on a cycle ergometer (60% of VO_2max) and thirty minutes (60% VO_2max) interspersed with five bouts of maximum intensity lasting ten seconds every five minutes. Capillary blood glucose was measured before and after each test. The glucose rate of change in exercise (RoC_E) was calculated (final blood glucose - onset blood glucose/exercise time), and the glucose rate of change in recovery (RoC_R) (blood glucose 30 minutes after exercise - end of exercise blood glucose/recovery time).

Results

The study included thirty-one participants (aged 13 ± 1.88 years). A lower blood glucose reduction was observed in the HIIE group, as well as better recovery values before, after, and thirty minutes after the test, respectively (333.14 ± 69.53, 226.19 ± 68.05 and 201.77 ± 66.84 versus 211.36 ± 91.03, 155.98 ± 82,68 and 165.76 ± 72.94). Covariance analyses showed a significant difference in glycemic variation between continuous and intermittent protocols immediately after exercise (-2.90 versus -2.08) and during the recovery period (-0.677 versus -0.389).

Conclusion

HIIE led to a lower glucose reduction rate per minute during exercise and better recovery in the first 30 minutes after exercise compared to MCE in children and adolescents with T1D.

Responsiveness on metabolic syndrome criteria and hepatic parameters after 12 weeks and 24 weeks of multidisciplinary intervention in overweight adolescents

PURPOSE

This study aimed to evaluate the effect and individual responsiveness after 12 (12wk) and 24 weeks (24wk) of physical exercise (PE) and nutritional guidance (NG) on metabolic syndrome (MetS) criteria and hepatic parameters in overweight adolescents.

METHODS

The study comprised 94 overweight adolescents, aged between 10 and 16 years old, from both sexes, allocated into groups: PE and NG (PENGG, n = 64) and control with NG (NGCG, n = 30). Variables were collected at baseline, 12wk, and 24wk. Weight, height, abdominal circumference (AC), blood pressure, and peak oxygen consumption (VO_2peak), as well as insulin, triglycerides (TAG), high-density lipoprotein (HDL-c), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were evaluated. HOMA-IR and QUICKI were calculated. PE session consisted of 45 min of indoor cycling, 45 min of walking, and 20 min of stretching, three times a week. The NG consisted of three collective sessions in the first 12wk. Anova, effect size, and prevalence of responders were used for statistical analysis.

RESULTS

The PENGG12wk reduced anthropometric and metabolic measurements, while increased VO_2peak and HDL-c. The PEG24wk promoted anthropometric, blood pressure, metabolic, and VO_2peak improvements, but participants without PE returned to pre-exercise status and presented worsening AST and ALT concentrations. Frequencies of respondents in PENGG12wk versus (vs) NGCG12wk were, respectively, AC (69.1% vs 17.6%, p < 0.01), HDL-c (87.2% vs 23.5%, p < 0.01), TAG (67.3% vs 41.7%, p = 0.05) and ALT (45.5% vs 5,9%; p = 0.003).

CONCLUSION

Interventions with PE were effective to reduce MetS components in 12wk and maintenance in 24wk, showing anthropometric, metabolic, and VO_2peak improvements. Higher individual responses were observed in 12wk and in 24wk, important changes in overweight adolescent's therapy.

LEVEL OF EVIDENCE

Level I, evidence obtained from well-designed controlled trials randomization.

TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION

Brazilian Registry of Clinical Trials (RBR-4v6h7b) and date of registration April 4th, 2020.

Life-history data of a key amphipod species from three NE Atlantic estuaries under different levels of anthropogenic pressure

Knowledge on population dynamics of ecosystem's key-species is invaluable to understand how populations will respond to natural and human-induced perturbations. The amphipod Echinogammarus marinus is a key-species from European estuarine habitats with a distribution ranging from Norway to Portugal [1]. The present article contains supportive data related to a research article entitled ‘Comparing production and life-history traits of a key amphipod species within and between estuaries under different levels of anthropogenic pressure’ [2]. The present dataset presents the density, biomass, fecundity, and production of E. marinus in three estuaries under different anthropogenic pressure and, within each estuary, at three sampling sites, which differed in terms of the distance to the estuary mouth, vegetation cover, and organic matter content. Monthly environmental abiotic data and seasonal concentration of PAH and other contaminants are also provided. Sampling took place monthly for 13 months at low tide on intertidal mudflats. At each site, Fucus fronds containing E. marinus individuals were randomly collected. All E. marinus individuals were counted, sexed, and measured under a binocular stereo microscope to estimate the density and the biomass of E. marinus in Fucus fronds. Finally, the annual production of E. marinus at each sampling site was estimated through the size-frequency method. This dataset may be used to compare population traits of E. marinus populations across different estuaries and it may overall assist designing studies regarding population dynamics and designing management strategies in coastal systems, namely targeting at habitat conservation and restoration.

Instruments For Assessment Of Excessive Daytime Sleepiness In Brazilian Children And Adolescents: Systematic Review

Objective:

To systematically review the literature on the instruments used to assess excessive daytime sleepiness (EDS) in Brazilian children and adolescents.

Data source:

A systematic review of the literature was performed in the databases MEDLINE PubMed, Scopus, Web of Science, LILACS, Scielo and SPORTDiscus, with no time limit for searches. The eligibility criteria were studies published in English and Portuguese, original articles that used questionnaires to assess EDS and whose sample consisted of Brazilian children and/or adolescents. As search strategy, the following terms were combined with Boolean operators “OR” and/or “AND”: drowsiness, disorders of excessive somnolence, excessive daytime sleepiness, day sleepiness, midday sleepiness, daytime sleepiness, adolescents, Brazil, Brazilian adolescents, and children.

Data synthesis:

Sixteen articles were selected, in which nine different instruments were applied to 8.240 children and adolescents from the South, Southeast, Midwest and Northeast regions of Brazil. The mean of methodological quality of studies was 16.1±1.9 points. The instruments most frequently used were the Pediatric Daytime Sleepiness Scale (PDSS) and Karolinska Sleepiness Scale (KSS), but only PDSS was shown reliable to assess EDS in Brazilian children and adolescents.

Conclusions:

The PDSS was the only instrument considered reliable to assess EDS in Brazilian children and adolescents. Further research on EDS in children and adolescents are suggested to perform the validation of other instruments for Brazil and present internal consistency values.

Comparing production and life-history traits of a key amphipod species within and between estuaries under different levels of anthropogenic pressure

Inter-population variability may arise as a response to adverse natural and anthropogenic stressors. The dynamics of a key amphipod species (Echinogammarus marinus) was followed during ≈ 1-year at its southerly range (NW Portugal), in three estuaries with different levels of anthropogenic pressure (High - Ave estuary; Moderate - Mondego estuary; Low - Minho estuary). We hypothesised that E. marinus populations would present lower production and fitness, and higher intersexuality incidence with increasing anthropogenic pressure. According to a GAM model explaining ≈70% of the observed variability, E. marinus biomass depends on temperature, organic matter, Fucus area and time of the year. Significant differences were found between the gammarid biomass in Minho and Mondego estuaries and within sites from the same estuary. As expected, Ave estuary exhibited the lowest average annual production, abundance and fecundity rates. However, the highest average production was found in Mondego and not in Minho estuary, although the turnover ratio (P/B) of both estuaries was very similar. Besides the system's global ecological status, E. marinus also seems to respond to microhabitat conditions, which may explain the spatial heterogeneity observed in the amphipod production within the same estuary. Intersexuality prevalence was negligible in the three populations, which does not support the idea of a link between anthropogenic pressure and intersexuality in E. marinus. We argue that the dependence of E. marinus on Fucus sp. should be further investigated to fully understand the role of both fucoids and the gammarid in coastal foodwebs.

Serum metabolites associated with increased insulin resistance and low cardiorespiratory fitness in overweight adolescents

BACKGROUND AND AIMS

Obesity affects metabolism, increasing the risk of developing non-communicable diseases in adolescence, due to excess adipose tissue and low cardiorespiratory fitness (CRF). The metabolomics approach allows the elucidation of metabolites, which may have the concentrations altered by several factors, such as body composition (BC). We aimed to analyze the metabolomic profile of normal-weight and overweight adolescents and associate the metabolites with clinical markers related to BC, insulin resistance (IR), and CRF.

METHODS AND RESULTS

The sample was composed of 57 adolescents and divided into two groups: the normal-weight group (NWG, n = 24) and the overweight group (OWG, n = 33). They underwent blood collection and anthropometric, BC, and CRF assessment. Blood serum samples were analyzed by ¹H-NMR spectroscopy (600 MHz). The OWG presented higher values of body weight (BW), body mass index (BMI), waist circumference (WC), fasting glucose, insulin, IR, cholesterol, and percentage of fat mass (%FM) and lower levels of peak oxygen consumption (VO₂ peak) compared with the NWG. The OWG presented lower concentrations of 3-hydroxyisovalerate, glutamate, and methionine as well as higher concentrations of aspartate, asparagine, creatine, glycerol, myo-inositol, proline, pyruvate, tyrosine, and valerate compared with the NWG. The concentrations of glutamate, myo-inositol, creatine, methionine, and valerate correlated with %FM; pyruvate and valerate positively correlated with IR; and glutamate, tyrosine, and valerate negatively correlated with CRF.

CONCLUSION

Changes in the BC lead to changes in the metabolomic profile of adolescents, and the altered metabolites are associated with increased IR and low CRF. These results indicate new targets for health monitoring and prevention of cardiovascular and metabolic diseases in adolescents.

Excess adiposity and low physical fitness hamper Supine-to-Stand test performance among sedentary adolescents

OBJECTIVE

The aim of this study was to analyze the relationship between body adiposity and physical fitness with performance in the Supine-to-Stand test (STS-test) in sedentary adolescents.

METHODS

Sixty-two adolescents, of both sexes, between 10 and 16 years old, participated in the study. Body mass (BM), height, waist circumference (WC), fat mass (FM), fat-free mass (FFM), right and left handgrip strength (HGS-right, HGS-left), abdominal resistance (ABDO), flexibility (FLEX), and cardiorespiratory fitness (VO_2peak) were measured. Body mass index (BMI), z-score BMI (BMI-z), tri-ponderal mass index (TMI) and waist-to-height ratio (WHtR) were calculated. The STS-test was applied to evaluate the STS-MC by the movement patterns in the execution of the test. The STS-time in seconds (s) was categorized into terciles: fast (FG < 2.0 s), intermediate (IG = 2.0-2.6 s) and slow (SG > 2.6 s). One-way ANOVA, Chi-square, Spearman's correlation coefficient as well as non-parametric tests were used, with significance p ≤ 0.05.

RESULTS

The SG presented higher BMI, BMI-z, TMI, WHtR, FM, %FM, as well as lower averages for %FFM, HGS-right, HGS-left, FLEX, ABDO, VO_2peak, VO_2peak relative to BM (VO_2peakBM) in relation to GF. The BMI, BMI-z, TMI, WC, WHtR and FM showed moderate and direct correlations with STS-time and inverse with STS-MC (p < 0.01). HGS-right, HGS-left, ABDO, and VO_2peakBM showed moderate and an inverse correlation with STS-time (p < 0.05). The VO_2peakBM was moderate and with direct correlations to STS-MC (p < 0.01).

CONCLUSION

It is concluded that excess fat and low physical fitness hamper STS-test performance. Therefore, the STS-test can be used for screening students to assess MC.

Novel approaches to reduce the risk of falling in community dwellings: effects of two multimodal programs in lower-body strength—a pilot study

Background

Muscle weakness is a key risk factor for falls and strength exercises should be included in fall prevention programs. A psychomotor intervention promoting motor stimulation and the whole-body vibration (WBV) providing muscle contractions may reduce the incidence of falls. Our hypothesis relies on the greater benefits of a combined program. This study aimed to evaluate the effectiveness and the feasibility of two 12-week multimodal programs in lower-body strength in community dwellings fallers or with balance impairment.

Methods

Thirty-seven participants (34 women; mean age 74.3 ± 5.2 years) were allocated into: experimental group 1 [EG1] (psychomotor intervention), or experimental group 2 [EG2] (combined program: psychomotor intervention plus WBV), 3x/week. Maximal strength of knee extensors and flexors was assessed by an isokinetic dynamometer at 60°/s. Wilcoxon and Mann-Whitney tests were performed.

Results

The overall adherence rate was high (86.3%), with a level intensity in the rating of perceived exertion of 12.1 ± 0.3 points, in EG1, and 12.5 ± 0.4 points, in EG2. Significant changes between the pre-post intervention were observed exclusively in EG2, in the variables ‘Peak torque extension’ (71.7 ± 28.6 Nm vs. 79.2 ± 23.5 Nm, P = 0.042) and ‘Agonist/Antagonist ratio’ (60.2 ± 13.0 vs. 53.5 ± 8.6, P = 0.013). The effect size (r) in both variables was medium. No significant changes between groups were detected.

Conclusions

This pilot results indicate that both programs were feasible and well-tolerated. The combined program demonstrates larger effectiveness, since the WBV may positively influence the lower-body strength, reducing the risk of falls. Trial Registration: ClinicalTrials.gov Identifier: NCT03446352. Funding: This pilot was granted by the ESACA Project (Grant ALT20-03-0145-FEDER-000007) and by FCT (SFRH/BD/147398/2019).

Predicting Cardiorespiratory Fitness Using the 20-m Shuttle Run Test: New Insights Using Nonlinear Allometry

PURPOSE

Recently, doubts have been raised concerning the validity of the 20-m shuttle run test (20mSRT) to predict cardiorespiratory fitness (CRF) in youth. Despite these doubts, authors continue to provide powerful evidence that CRF can be predicted reliably using the 20mSRT albeit using contrasting models. Therefore, we aimed to compare a new linear model with an alternative allometric model to predict CRF (peak oxygen uptake, V˙O2peak) using the 20mSRT.

METHODS

The study included 148 adolescents (43% girls) age 13.37 ± 1.84 yr. Adolescents were randomly assigned to validation (n = 91) and cross-validation (n = 57) groups. V˙O2peak was measured using a gas analyzer in both maximal exercise tests in the laboratory and the 20mSRT. Multiple linear regression methods were applied to develop the linear models using the 20mSRT (laps), body mass index, and body fat percentage. Alternative allometric models were also proposed/fitted using the 20mSRT (laps), height, and body mass.

RESULTS

The criterion validity values of both the linear and the allomeric models were found to be acceptable, with R2 = 82.5% and 82.7% respectively, providing reassuring evidence that the 20mSRT can be used with confidence to predict CRF. However, the allometric model identified a height-to-mass ratio, not dissimilar to the inverse body mass index (known to be a measure of leanness), to be associated with CRF. The allometric model also revealed that the rise in energy cost (V˙O2peak) with increasing laps was exponential. This will more accurately reflect the nonlinear rise in energy demand of shuttle running as the test progresses to exhaustion.

CONCLUSIONS

These observations provided powerful evidence that allometric models are more than satisfactory in terms of both criterion and construct validity when predicting CRF (V˙O2peak) using the 20mSRT.

Effects and Responsiveness of a Multicomponent Intervention on Body Composition, Physical Fitness, and Leptin in Overweight/Obese Adolescents

Physical exercise reduces the biochemical markers of obesity, but the effects of multicomponent interventions on these markers should be explored. The present study aimed to elucidate how overweight/obese adolescents respond to a multicomponent program approach on body composition, physical fitness, and inflammatory markers, using a quasi-experimental study with 33 overweight/obesity adolescents (control group (CG) = 16; intervention group (IG) = 17). The intervention consisted of 24 weeks with physical exercises and nutritional and psychological guidance. Both groups were evaluated at the pre/post-intervention moments on body mass index (BMI); body fat (%Fat); waist circumference (WC); waist/hip ratio (WHR); waist-to-height ratio (WHtR), cardiorespiratory fitness (CRF); abdominal strength, flexibility; leptin; interleukin 6; interleukin 10; and tumor necrosis factor-alpha. Mixed-analysis of variance and generalized estimation equations were used for statistical analysis. There was an interaction effect between groups and time on %Fat (p = 0.002), WC (p = 0.023), WHR (p < 0.001), WHtR (p = 0.035), CRF (p = 0.050), and leptin (p = 0.026). Adolescents were classified as 82.4% responders for %Fat, 70.6% for WC, 88.2% for WHR, and 70.6% for CRF. Further, there was an association between changes in %Fat (p = 0.033), WC (p = 0.032), and WHR (p = 0.033) between responders and non-responders with CRF in the IG. There was a positive effect on body composition, physical fitness, and leptin. In addition, reductions in body composition parameters were explained by CRF improvements.

Validity and accuracy of body fat prediction equations using anthropometrics measurements in adolescents

BACKGROUND

The pediatric relative fat mass (RFM) has been recently presented and validated as an index for estimating percentage body fat (%BF) in North American children and adolescents. Similar to body mass index (BMI) and tri-ponderal mass index (TMI), RFM uses anthropometric measures (i.e., weight, height and waist circumference) to estimate body composition. The primary purpose of this study was to validate the newly developed RFM equation for %BF prediction in Southern Brazilian adolescents; as secondary objective, we compared %BF estimation from BMI- and TMI-derived equations.

METHODS

A total of 631 individuals (434 boys) aged 11 to 18 were analyzed. Bland-Altman analyses were used to determine concordance between predicted equations and %BF measured by DXA; results are presented using mean difference (i.e., bias) and standard deviation. Sensitivity and specificity were calculated for %BF percentile classifications.

RESULTS

RFM underestimated %BF in 65.2% of boys (- 4.3 ± 2.8%) and 84.8% of girls (- 5.3 ± 2.7%). In contrast, TMI overestimated %BF in 62.9% of boys (4.0 ± 2.9%) and 56.3% (3.5 ± 3.0%) of girls. The performance of BMI showed mixed results; %BF was overestimated in 68.4% of boys (5.0 ± 4.0%) and underestimated in 67.5% of girls (- 3.9 ± 2.6%), all p < 0.001. Although, RFM had the highest specificity for %BF percentile classifications, sensitivity was low and inferior to BMI and TMI.

CONCLUSION

TMI was superior to RFM and BMI in predicting %BF in Southern Brazilian adolescents. Using RFM, BMI or TMI equations for %BF prediction without a population-specific correction factor may lead to incorrect interpretations. We suggest that correction factors should be investigated to improve the accuracy of these surrogate indices for body composition assessment.

LEVEL OF EVIDENCE

Level V, cross sectional descriptive study.

PHYSICAL ACTIVITY, EATING HABITS AND SLEEP DURING SOCIAL ISOLATION: FROM YOUNG ADULT TO ELDERLY

ABSTRACT Introduction Social isolation is one of the strategies used to prevent the contagion and transmission of the coronavirus (COVID-19), but it impacts on the daily routines and lifestyle of the population. Objective Therefore, the aim of this study was to analyze the physical activity, sleep and eating habits of adults and the elderly during the COVID-19 pandemic. Method A cross-sectional study with a sample comprising 135 participants, divided by age group. First, the whole group was divided into age groups with a 10-year cut-off. They were then characterized by sex, type of home, eating habits, sleep, and physical activity. For the second analysis, the participants were organized into three groups: young adults (18-40 years), middle-aged adults (41-60 years) and elderly (>60 years). An online questionnaire was sent to all the participants, with 26 questions focusing on eating habits, sleep, protective behaviors against COVID-19, and physical activity. Results The participants were mainly women (85.9%), external community (71.1%), students’ families (17.1%), teachers and staff (11.8%). Of the total participants, 40% were dedicated to home care activities and 21.1% had started working from home. The remainder (38.9%) were engaged in activities such as studying or caring for dependents. The younger age group (18-40 years old) reported spending more time in sedentary activities during the day, and 34.2% did not perform physical activity and ate lower quality food during social isolation (p<0.01). All groups, with the exception of the 30-40 age group (p <0.01) highlighted the importance of having the presence of a teacher responsible for guiding physical activities during isolation. Conclusion We conclude that, social isolation has more negative impact on the habits of the younger group. Cross-sectional study.

Altered metabolomic profiling of overweight and obese adolescents after combined training is associated with reduced insulin resistance

Exercise training and a healthy diet are the main non-pharmacological strategies for treating chronic conditions, such as obesity and insulin resistance (IR), in adolescents. However, the isolated metabolic changes caused by exercise training without dietary intervention have not yet been established. We investigated how combined training (CT) without dietary intervention altered the concentrations of serum metabolites, biochemical, anthropometric and functional parameters in overweight and obese adolescents. Thirty-seven adolescents (14.6 ± 1.05 years), of both sexes, were randomly assigned to the control group (CG, n = 19) or the training group (TG, n = 18). The CT was composed by resistance training and aerobic training performed in the same session (~ 60 min), three times a week, for 12 weeks. All assessments were performed pre and post-intervention. Metabolomics analyses were conducted using nuclear magnetic resonance spectroscopy (1H NMR) in a 600 MHz spectrometer. There was a decrease in body weight (BW), body mass index (BMI), waist circumference (WC), % body fat (%BF), fasting glucose, insulin levels, and insulin resistance (IR), by HOMA-IR, in the TG. An increase in fat-free mass (FFM) was also observed in the CG. The metabolic changes were given mainly by changes in the levels of metabolites 2-oxoisocaproate (↓TG), 3-hydroxyisobutyrate (↑CG and ↓TG), glucose (↓TG), glutamine (↓CG and ↑TG) and pyruvate (↓TG). These findings demonstrate the positive effects of CT program without dietary intervention on metabolomic profile, body composition, biochemical markers, and glucose metabolism in overweight and obese adolescents.

Validation of equations to estimate the peak oxygen uptake in adolescents from 20 metres shuttle run test

This study aimed to develop new prediction models from directly determined peak of oxygen uptake (VO_2peak) in adolescents using 20-metre shuttle run test (20 m-SR) and to compare the new models with previously published equations. This study included 148 adolescents (43% girls), aged 13.37 ± 1.84 years old. Adolescents were randomly assigned to validation (n = 91) and cross-validation (n = 57) groups. VO_2peak was measured using a gas analyser in both maximal exercise tests in the laboratory as well as by 20 m-SR. The multiple linear regression method was applied to develop the models using BMI, BMI-z score and body fat percentage (%FM). The proposed models presented better predictive performance (R2 = 75.6% to 78.9%) and a lower absolute percentage error (%error = 10.51 to 11.78%) than the previously published equations (R2 = 38.8% to 69.1%; %error = 13.13% to 21.54%). The Model with BMI-z was the best fit equation in girls, and the model with BMI-z and %FM in boys. Therefore, it is recommended that the equations developed in the present study be used in future research and projects in the school environment to estimate VO_2peak in adolescents by the 20 m-SR test.

Hypertensive Measures In Schoolchildren: Risk Of Central Obesity And Protective Effect Of Moderate-To-Vigorous Physical Activity

Background The proportion of arterial hypertension (AH) has increased in children and adolescents and is associated with several comorbidities. Objective To verify the association of arterial hypertension with central and general obesity as well as according to the level of physical activity in schoolchildren. Methods 336 children and adolescents aged 11 to 17 participated in the study. Height, body weight, waist circumference (WC) and blood pressure (BP) were measured. The body mass index z-score (BMI-z) was calculated. The level of physical activity was assessed by the short form of the International Physical Activity Questionnaire (IPAQ) according to the practice of moderate-to-vigorous physical activities (AF-mv). Students with systolic (SBP) and/or diastolic blood pressure (DBP) higher than the 95thpercentile according to sex, age and height or ≥120/80 were considered hypertensive. Statistical tests of t-Student, Chi-square, Mann-Whitney and binary logistic regression model were used, considering the significance level of p<0.05. Results It was found that 40.5% of the students had AH, 35.11% were overweight (12.5% obese), 13.39% had high WC and 40.2% were considered insufficiently active in AF-mv. The chances of AH were related to high WC (OR = 6.11; 95% CI: 2.59¬-14.42) and overweight (OR = 2.91; 95% CI: 1.76-4.79). In addition, adolescents who practiced AF-mv had a lower risk of high DBP (OR = 0.33; 95% CI: 0.15-0.72). Conclusion Central obesity was the best predictor of AH in children and adolescents, as well as general obesity and males. The practice of AF-mv demonstrated a protective effect on high DBP in schoolchildren. (Arq Bras Cardiol. 2020; 115(1):42-49).

Different amounts of moderate to vigorous physical activity and change in glycemic variability in adolescents with type 1 diabetes: is there dose-response relationship?

OBJECTIVE

To identify the level of physical activity and glycemic variability of adolescents with type 1 diabetes mellitus and to compare glycemic variability on days with different amounts of moderate to vigorous physical activity (MVPA).

SUBJECTS AND METHODS

A sample of 34 subjects aged 10 to 15 years, 18 (52.94%) female; age: 13.04 ± 1.94; HbA1c: 9.76 ± 1.51. Physical activity was measured by wGT3X accelerometer. The glucose data were obtained using continuous glucose monitoring, and the following glycemic variability measures were calculated: standard deviation (SD), low blood glucose index (LBGI), high blood glucose index (HBGI), mean amplitude of glycemic excursions (MAGE), glycemic risk assessment in diabetes equation (GRADE) and coefficient of variation (CV). The most and least active days (the days with greater and lesser time dedicated to physical activities of moderate to vigorous intensity, respectively) were identified. In addition, based on the whole period of accelerometer use, daily means of time spent in MVPA were identified among participants, who were then divided into three groups: up to 100 minutes; from 101 to 200 minutes and above 201 minutes. Then, the measures of glycemic variability were compared among the most and least active days and among the groups too.

RESULTS

The amount of MVPA was significantly different between the days evaluated (237.49 ± 93.29 vs. 125.21 ± 58.10 minutes), but glycemic variability measures did not present a significant difference.

CONCLUSION

Despite the significant differences in the amount of MVPA between the two days evaluated, the glycemic variability did not change significantly. Arch Endocrinol Metab. 2020;64(3):312-8.

Scaling left ventricular mass in adolescent female soccer players

BACKGROUND

The aim of the study was to examine the contribution of chronological age (CA), skeletal maturation, training experience and concurrent body size descriptors, to inter-individual variance in left ventricular mass (LVM) among female adolescent soccer players.

METHODS

The sample included 228 female soccer players 11.8-17.1 years. Training experience defined as years of participation in competitive soccer (range 2-9 years), was obtained by interview. Stature, body mass and skinfolds (triceps, medial calf) were measured. Fat mass was estimated; Fat-free mass was derived. LVM was assessed by echocardiography. Skeletal maturity status was as the difference of skeletal age (SA, Fels method) minus CA.

RESULTS

Fat-free mass was the most prominent single predictor of LVM (R2 = 36.6%). It was associated with an allometric coefficient close to linearity (k = 0.924, 95%CI: 0.737 to 1.112). A significant multiplicative allometric model including body mass, fat-free mass, CA, training experience and skeletal maturity status was also obtained (R = 0.684; R2 = 46.2%).

CONCLUSION

Stature has limitations as a valid size descriptor of LVM. Body mass, fat-free mass, training experience, CA, body mass and skeletal maturity status were relevant factors contributing to inter-individual variability in LVM.

EFFECT OF PHYSICAL TRAINING ON EXERCISE-INDUCED BRONCHOSPASM IN YOUNG ASTHMATICS

ABSTRACT Introduction: Asthma is the most common chronic disease in childhood and its prevalence has increased in recent years. Although regular physical activity (PA) is considered to be beneficial for the health of asthmatics, especially children and adolescents, it can also be one of the elements that triggers asthma. This is known as exercise-induced bronchospasm (EIB), and is considered one of the factors that limits asthmatics’ participation in PA. Objective: This study aims to review the effects of physical conditioning on EIB in asthmatic children and adolescents. Methods: A systematic review was carried out on the Pubmed, Bireme and Web of Science databases, considering publications from 1998 to April 2019. Results: Eight articles were retrieved; five of the articles presented no significant difference in EIB parameters after physical training, and three demonstrated significant benefits in EIB. Conclusion: There is insufficient evidence that physical training helps reduce the frequency and severity of EIB in young asthmatics. There are still few studies that seek to show the effect of a physical training program on the improvement of EIB in children and adolescents. It is suggested that further randomized clinical trials be conducted, to investigate the effects of physical training on EIB parameters in children and adolescents. Level of Evidence II; Systematic review.

Effect of combined interval training on the cardiorespiratory fitness in heart failure patients: a systematic review and meta-analysis

BACKGROUND

The combination of interval training and resistance training has showed interesting results in chronic heart failure patients, corroborating the benefits of physiological adaptations of both protocols.

OBJECTIVE

To evaluate the effect of the combination of interval training and resistance training program when compared to interval training alone and/or without intervention group on cardiorespiratory fitness in patients with chronic heart failure.

METHODS

We search MEDLINE via PubMed, ScienceDirect, Sportdiscus, BIREME and Scielo, from their inception to December 2018. Were included both randomized and non-randomized controlled trials comparing the effect of combined training, interval training alone and/or WI group on VO2peak (expressed in ml/kg/min), in people with chronic heart failure patients. The meta-analysis was conducted via Review Manager v 5.3 software, using random effect model.

RESULTS

Ten articles were selected (nine randomized controlled trial), involving 401 participants. Six studies compared combined training with interval training and six studies compared combined training with the without intervention group. Eighty percent of the trials presented moderate risk of bias and twenty percent low risk of bias. Data showed significant difference and major increase in VO2peak in favor to combined training group compared to interval training group (SMD=0.25; CI=0.04-0.46) and without intervention group (SMD=0.46; CI=0.29-0.64), respectively.

CONCLUSION

The combination of interval training and resistance training showed more effective in increasing cardiorespiratory fitness in patients with heart failure than interval training alone and non-exercise therapy. However, further studies should be conducted to increase the understanding of this combined training method.

MAXIMAL FAT OXIDATION DURING AEROBIC EXERCISE IN ADOLESCENTS WITH TYPE 1 DIABETES

ABSTRACT Objective: To compare maximal fat oxidation rates (FATMAX) and analyze their association with cardiorespiratory fitness in adolescents with type 1 diabetes mellitus (T1DM). Methods: Twenty-two male and female adolescents aged between 11 to 17 years, following clinical and anthropometric evaluations, were assigned to the diabetic group (DG; n = 10) or control group (CG; n = 12). Cardiorespiratory fitness was determined by maximal oxygen uptake (VO2max) during a maximal aerobic test on a cycle ergometer using the Balke protocol. Maximal fat oxidation (FATMAX) was determined by the respiratory exchange ratio proposed in the Lusk table. Results: Adolescents in the DG had lower mean FATMAX (p<0.01) and %VO2FATMAX (p=0.001) values when compared with those in the CG. FATMAX values were inversely correlated with serum glycosylated hemoglobin (HbA1c) levels (r= −0.77) and directly correlated with BMI z-scores (r=0.76), while %VO2FATMAX results were correlated with age (r=0.81), BMI z-scores (r=0.65), and VO2max values (r=0.81). On multiple linear regression, HbA1c values explained 54% (adjusted r²=0.54, p=0.009) and BMI z-scores explained 3.1% (adjusted r²=-0.031, p=0.009) of the variation in FATMAX in the DG. Adolescents with T1DM had similar cardiorespiratory fitness and lower FATMAX rates (35±11 VO2max) when compared with controls (60±12 VO2max). Conclusion: These results suggest lower fat oxidation rates and greater use of glucose as an energy substrate during exercise and worse control in T1DM. Therefore, results may contribute to appropriate exercise prescription in T1DM, after verifying exercise intensity to reduce hypoglycemia risk. Level of evidence III; Case-control study.

ADRB2 GLN27GLU POLYMORPHISM ASSOCIATED WITH ADIPOSITY INDICATORS AND IL-10 IN ADOLESCENTS

ABSTRACT Introduction: Studies of association between obesity and genetic factors have demonstrated a significant contribution of polymorphisms related to body fat distribution and subclinical inflammatory process. Objective: To investigate the association between genotypes of the Gln27Glu polymorphism of the ADRB2 gene and indicators of adiposity, inflammatory markers, metabolic parameters and parameters of physical fitness in overweight adolescents. Methods: A total of 44 male and female adolescents, aged between 13 and 17 years, with positive clinical diagnosis of overweight, were divided into two groups according to the Gln27Glu polymorphism genotypes of the ADRB2 gene: a) Group of carriers of the 27Glu allele (Gln27Glu/Glu27Glu) (n = 22); b) Group of non-carriers of the 27Glu allele (Gln27Gln) (n = 22). Both groups were evaluated for body composition, sexual maturation, cardiorespiratory fitness variables and indicators of muscle strength. Basal glycemia and insulin, lipid profile and inflammatory profile were measured. Abdominal subcutaneous and visceral adiposities were evaluated by ultrasonography. Genotyping of the Gln27Glu polymorphism of the ADRB2 gene was performed by the Taqman allelic discrimination assay. Results: The genotype frequency found was: Gln/Gln (n = 22) (50.0%), Gln/Glu (n = 18) (41.0%) and Glu/Glu (n = 4) %). The frequency of the 27Glu allele was 29.5%. The group of adolescent carriers of the 27Glu allele of the ADRB2 gene presented higher mean adiposity indicators (abdominal circumference, trunk fat mass and visceral fat), as well as lower IL-10 concentrations when compared to non-carriers. Conclusions: The 27Glu allele was associated with adiposity indicators in overweight adolescents, while subcutaneous abdominal fat exhibited an inverse relationship with inflammatory variables and maximum oxygen uptake, which may result in more damage to health. Level of evidence III; Case-control study.

PREDICTIVE EQUATIONS OF MAXIMUM OXYGEN CONSUMPTION BY SHUTTLE RUN TEST IN CHILDREN AND ADOLESCENTS: A SYSTEMATIC REVIEW

ABSTRACT Objective: To systematically review the literature as for the level of evidence of predictive equations of VO2peak through the 20-meter shuttle run test (20m-SRT) in children and adolescents. Data sources: Searches were conducted independently by two researchers, according to the procedures adopted by PRISMA, in the electronic databases MEDLINE via PubMed, ScienceDirect, Web of Science, LILACS and SciELO, for articles published until September 2017 in English and Portuguese. The inclusion criteria were: original studies, abstract available, using predictive equations of VO2peak through 20m-SRT, conducted with adolescents and/or children, non-athletes, and mentioning correlation analysis between predicted and measured VO2peak. The level of evidence of equations was based on the risk of bias of the studies using the following criteria: sample number, sample characteristics, and statistical analysis. Data synthesis: Eighteen studies were selected, in which fifteen equations were found and analyzed. The studies had been conducted with samples composed of subjects of both sexes, aged 8 to 19 years. Equations of Léger and Matsuzaka had their level of evidence classified as high, and estimation ranged between r=0.54-0.90 and r=0.65-0.90. Equations by Ruiz, Barnett and Matsuzaka had their level of evidence classified as moderate, and estimation ranged between r=0.75-0.96, r=0.66-0.84 and r=0.66-0.89, respectively. Conclusions: Matsuzaka’s equation presented satisfactory parameters for estimates of VO2peak in children and adolescents. Although not explored in equations, body adiposity and pubertal stage are significantly associated with cardiorespiratory fitness in children and adolescents.

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.

Association between Toll-like receptors (TLR) and NOD-like receptor (NLR) polymorphisms and lipid and glucose metabolism

Recent evidences had shown activation of TLR (toll-like receptors) and NLR (nod-like receptors) in response to imbalance in nutrients intake, such as lipid and glucose. The main aim of this study was to investigate possible associations between 11 SNPs in TLR2, TLR4, NLRC4, CARD8 and NEK7 genes and lipid and glucose metabolism. Sample was composed by healthy children and adolescents (n = 158) and adults (n = 115). DNA extraction was obtained by salting-out and sample genotyping by matrix-assisted laser desorption ionization time-of-flight mass spectrometry based system. LDL-cholesterol, HDL-cholesterol, triglycerides, total cholesterol, glucose and insulin were measured by standard automated methods. Means were compared by t-test or Mann-Whitney test. Univariate and multivariate logistic regression were used to verify association between polymorphisms and lipid and glucose markers. Seven polymorphisms in 5 genes were associated with lipid and glucose parameters. For lipid parameters, the following associations were found: higher LDL-C levels and C allele of rs1554973 (TLR4) and G allele of rs6671879 (NEK7); higher HDL-cholesterol levels and A allele of rs13105517 (TLR2); higher total cholesterol and TT genotype of rs3804099 (TLR2) and G allele of rs6671879 (NEK7); higher triglycerides levels and G allele of rs455060 (NLRC4). For glucose parameters associations were found between C allele of rs7258674 (CARD8) and higher glucose levels, and between C allele of rs212704 (NLRC4) and G allele of rs455060 (NLRC4) and insulin levels. These findings indicate a relationship between polymorphisms of TLRs and NLRs genes and markers of lipid and glucose metabolism.

Effects of polymorphisms in APOB, APOE, HSD11β1, PLIN4, and ADIPOQ genes on lipid profile and anthropometric variables related to obesity in children and adolescents

Genes can influence lipid profile and anthropometric variables related to obesity. The present study aimed to verify if variants of the APOE, APOB, ADIPOQ, HSD11β1, and PLIN4 genes are associated with lipid levels or anthropometric variables in a sample comprised of 393 Euro-Brazilian children and adolescents. DNA was genotyped by TaqMan allelic discrimination assay. The ε4 and ε2 alleles of the APOE gene were associated respectively with lower high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels (p=0.015 and p=0.012, respectively), while the ε3 allele was associated with higher abdominal circumference (p=0.0416) and excess weight (p=0.0001). The G allele (rs846910) of the HSD11β1 gene was also associated with excess weight (p=0.039). No other association was found. Our results indicate that the ε4 and ε2 alleles could contribute to lower HDL-C and LDL-C levels, respectively, furthermore, the ε3 allele and the G allele (rs846910) of HSD11β1 gene may be risk factors for excess of weight.These findings are very important because we observed that some genetic variants influence the lipid profile and anthropometric variables early in life.

12-Week aerobic exercise and nutritional program minimized the presence of the 64Arg allele on insulin resistance

BACKGROUND

The objective of the study was to investigate the response of 64Arg allele carriers of the ADRB3 gene (Trp64Arg polymorphism) in the anthropometric, cardiorespiratory and metabolic variables in overweight adolescents after a 12-week aerobic exercise and nutritional program.

METHODS

A total of 92 overweight adolescents, 10-16 years old and of both genders, participated. Body composition, waist circumference (WC), pubertal stage status, blood pressure, glucose, insulin and lipid profile and direct maximal oxygen uptake were assessed at baseline and after 12 weeks of a training program. The homeostasis metabolic assessments [homeostasis model assessment of insulin resistance (HOMA-IR)] and quantitative insulin sensitivity check index (QUICKI) were determined and the Trp64Arg polymorphism of the ADRB3 gene was investigated by Taqman single nucleotide polymorphism (SNP) genotyping assays. Exercise sessions consisted of 100-min aerobic exercise and 20-min stretching, 3 times a week, totalizing 36 sessions. Multivariate analysis of variance (MANOVA), analysis of covariance (ANCOVA) and effect size were used for variables, with p<0.05 considered significant.

RESULTS

In baseline, HOMA-IR was higher in carriers of the 64Arg allele and decreased more after 12 weeks than in non-carriers (p=0.01). The anthropometric, physical fitness and metabolic profiles had similar responses after training in carriers and non-carriers.

CONCLUSIONS

Overweight adolescents present changes in body composition and physical fitness, independent of Trp64Arg genotypes. However, a 12-week aerobic exercise and nutritional program promoted greater reductions in insulin resistance in carriers of the 64Arg allele.

LOCALIZED FAT-FREE MASS DOES NOT INFLUENCE MUSCLE STRENGTH IN OBESE AND NON-OBESE BOYS

ABSTRACT Introduction: Obesity in adolescents has increased worldwide, and is generally associated with poor eating habits and physical inactivity. Objective: To compare absolute and relative muscle strength with body mass (BM), fat-free mass (FFM) and localized FFM of upper and lower limbs among obese and non-obese adolescents. Methods: BM, height and body mass index (BMI) were verified in 39 male adolescents (aged 13-17 years). Body composition was measured by dual-energy X-ray absorptiometry (DXA) and maximal strength of upper and lower limbs was estimated by a one-repetition maximum (1RM) test. Participants were divided into three groups: eutrophic (normal weight) (n=11), overweight (n=14), and obese (n=14). One-way ANOVA was used to compare the variables, followed by a Bonferroni post-hoc test for multiple comparisons. Pearson's correlation coefficient was used for relevant correlations and multiple linear regression to verify the influence of anthropometric variables, body composition and muscle strength of upper and lower limbs. Results: Obese and overweight adolescents had absolute muscle strength values similar to those of the eutrophic adolescents, which were lower when corrected by BM (p<0.001). However, muscle strength related to FFM and localized FFM were similar between groups in both upper and lower limbs. Linear regression showed that BMI explained 59% of the variation in absolute muscle strength of the lower limbs (β=0.59, p<0.05), FFM explained 84% of the variation in absolute muscle strength of the upper limbs (β=0.84, p<0.01) and 68% of the lower limbs (β=0.68; p<0.01), while localized FM was inversely associated in the lower limbs (β=−0.53, p<0.05). Conclusion: Muscle strength of lower and upper limbs, when corrected by localized FFM, does not distinguish between overweight and normal weight adolescents, indicating that obesity does not have a negative effect on generation of muscle strength in obese boys. Level of Evidence III; Case-control study.

Trp64Arg polymorphism of the ADRB3 gene associated with maximal fat oxidation and LDL-C levels in non-obese adolescents

OBJECTIVE

To analyze the association between the Trp64Arg polymorphism of the ADRB3 gene, maximal fat oxidation rates and the lipid profile levels in non-obese adolescents.

METHODS

72 schoolchildren, of both genders, aged between 11 and 17 years, participated in the study. The anthropometric and body composition variables, in addition to total cholesterol, HDL-c, LDL-c, triglycerides, insulin, and basal glycemia, were evaluated. The sample was divided into two groups according to the presence or absence of the polymorphism: non-carriers of the Arg64 allele, i.e., homozygous (Trp64Trp: n=54), and carriers of the Arg64 allele (Trp64Arg+Arg64Arg: n=18), in which the frequency of the Arg64 allele was 15.2%. The maximal oxygen uptake and peak of oxygen uptake during exercise were obtained through the symptom-limited, submaximal treadmill test. Maximal fat oxidation was determined according to the ventilatory ratio proposed in Lusk's table.

RESULTS

Adolescents carrying the less frequent allele (Trp64Arg and Arg64Arg) had higher LDL-c levels (p=0.031) and lower maximal fat oxidation rates (p=0.038) when compared with non-carriers (Trp64Trp).

CONCLUSIONS

Although the physiological processes related to lipolysis and lipid metabolism are complex, the presence of the Arg 64 allele was associated with lower rates of FATMAX during aerobic exercise, as well as with higher levels of LDL-c in adolescents.

ATIVIDADE FÍSICA E ALTERAÇÕES NA HEMOGLOBINA GLICADA EM ADOLESCENTES COM DIABETES MELITTUS TIPO 1: QUANTO É NECESSÁRIO?

O presente estudo objetivou verificar o nível de atividade física de adolescentes com diabetes melittus tipo 1 (DM1) e a correlação com a hemoglobina glicada (HbA1c), e  identificar qual a quantidade mínima de atividade física moderada a vigorosa (AFMV) é necessária para promover benefícios no controle glicêmico através da HbA1c. Sendo assim, encontrou-se correlação inversa entre  HbA1c e AFMV (r=-0,34; p=0,04) e correlação direta entre o IMC escore z e Hba1c (r=0,43; p=0,01), a curva ROC identificou a área sob a curva (AUC) de 70% para 45 minutos de AFMV por dia. Dessa forma, adolescentes diabéticos devem realizar no mínimo 45 minutos por dia de AFMV para promover benefícios no controle glicêmico avaliado por meio da HbA1c.  

Sleep deprivation and drowsiness of medical residents and medical students

OBJECTIVE

to evaluate sleep quality and daytime sleepiness of residents and medical students.

METHODS

we applied a socio-demographic questionnaire, the Pittsburgh Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale (ESS) to a population of residents and medical students.

RESULTS

hundred five residents and 101 undergraduate medical students participated. Residents presented higher mean PSQI (6.76±2.81) with poorer sleep quality when compared with undergraduates (5.90±2.39); Both had similar measures of sleepiness by ESS (p=0.280), but residents showed lower duration and lower subjective sleep quality.

CONCLUSION

medical students and residents presented sleep deprivation, indicating the need for preventive actions in the medical area.

FTO rs9939609 Does Not Interact with Physical Exercise but Influences Basal Insulin Metabolism in Brazilian Overweight and Obese Adolescents

PURPOSE

The rs9939609 SNP (T > A) in FTO gene is associated with obesity and type 2 diabetes. The present study aimed at verifying whether this SNP influenced biochemical outcomes of children and adolescents who are overweight/obese submitted to a program of physical exercise and also if there was influence on basal levels of these biochemical variables.

METHODS

The sample was composed by 432 children and adolescents grouped in three ways (obese, overweight, and normal weight); of these, 135 children and adoloescents who are obese and overweight were submitted to a physical exercise program for 12 weeks. All were genotyped by TaqMan SNP genotyping assay.

RESULTS

The children and adolescents who are overweight/obese and carriers of AA genotype had higher levels of insulin (p=0.03) and HOMA (p=0.007) and lower levels of glucose (p=0.003), but the SNP did not modulate the response to physical exercise.

CONCLUSIONS

In our study, the rs9939609 AA genotype was associated with parameters related to insulin metabolism but did not interact with physical exercise.

Será a combinação dos treinamentos intervalado e resistido mais efetiva sobre a aptidão física em adultos? Uma revisão sistemática e metanálise

Interval training (HIIT / SIT) combined with resistance training (RT) has been highlighted as a strategy for the improvement of health-related physical fitness markers (HRPF) in adults. Thus, the aim of this meta-analysis was to compare the efficacy of combined training (HIIT / SIT + RT) with other exercise protocols on HRPF markers in adults. A systematic search was performed in MEDLINE via PebMed, Cochrane-CENTRAL, SPORTDiscus, LILACS, SCIELO and Scopus databases between January and March 2017, using the following keywords in English and Portuguese: physical fitness, high-intensity interval training, sprint interval training, resistance training and adults. The quality of studies was evaluated using the PEDro scale. After applying both inclusion and exclusion criteria, nine articles were selected (n = 231). The extraction of means and standard deviations from studies was performed independently by two authors and the RevMan software was used to perform the meta-analysis. Combined training interventions lasted from 6 to 12 weeks and generated greater increase in maximal oxygen uptake than other forms of exercise. The combination of interval training and strength training may be considered more effective to improve aerobic capacity levels in adults. 

Association between adiposity indicators, metabolic parameters and inflammatory markers in a sample of female adolescents

OBJECTIVE

The aim of this study was to investigate the association between total and abdominal adiposity with metabolic parameters and inflammatory markers, in female adolescents.

SUBJECTS AND METHODS

The sample consisted of 53 adolescents aged 13 to 17 years from a public school in Curitiba, Brazil. The adiposity indicators studied were body mass index (BMI), waist circumference (WC), trunk fat mass (TKFM), total fat mass (TFM) and body fat percentage (BF%) measured by dual-energy X-ray absorptiometry. The metabolic and inflammatory parameters studied were systolic blood pressure (SBP), diastolic blood pressure (DBP), glucose, insulin, homeostasis model assessment index for insulin resistance (HOMA-IR), lipids, C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), leptin, adiponectin and resistin.

RESULTS

Eighty percent of WC variation, 87% of TKFM and TFM, and 73% of BF% were predicted by BMI variation. There was a significant positive correlation between all indicators of adiposity with SBP, DBP, insulin, HOMA-IR, CRP and leptin. Triglycerides were positively correlated with BMI and WC, and adiponectin correlated negatively with BMI. TNF-α, IL-6, glucose, total cholesterol, and high- and low-density lipoprotein cholesterol did not correlate to the studied variables.

CONCLUSION

BMI showed a significant association with most of the parameters studied, and WC was slightly better than BMI to predict insulin resistance in this specific population.