A biophysical analysis on the arm stroke efficiency in front crawl swimming : comparing methods and determining the main performance predictors

Purpose: to compare different methods to assess the arm stroke efficiency ( ηF ), when swimming front crawl using the arms only on the Measurement of Active Drag System (MAD System) and in a free-swimming condition, and to identify biophysical adaptations to swimming on the MAD System and the main biophysical predictors of maximal swimming speed in the 200 m front crawl using the arms only ( v200m ). Methods: fourteen swimmers performed twice a 5 × 200 m incremental trial swimming the front crawl stroke using the arms only, once swimming freely, and once swimming on the MAD System. The total metabolic power was assessed in both conditions. The biomechanical parameters were obtained from video analysis and force data recorded on the MAD System. The ηF was calculated using: (i) direct measures of mechanical and metabolic power (power-based method); (ii) forward speed/hand speed ratio (speed-based method), and (iii) the simplified paddle-wheel model. Results: both methods to assess ηF on the MAD System differed (p < 0.001) from the expected values for this condition ( ηF = 1), with the speed-based method providing the closest values ( ηF ~0.96). In the free-swimming condition, the power-based ( ηF ~0.75), speed-based ( ηF ~0.62), and paddle-wheel ( ηF ~0.39) efficiencies were significantly different (p < 0.001). Although all methods provided values within the limits of agreement, the speed-based method provided the closest values to the “actual efficiency”. The main biophysical predictors of v200m were included in two models: biomechanical (R2 = 0.98) and physiological (R2 = 0.98). Conclusions: our results suggest that the speed-based method provides the closest values to the “actual ηF ” and confirm that swimming performance depends on the balance of biomechanical and bioenergetic parameter

What is the role of cardiorespiratory fitness and sedentary behavior in relationship between the genetic predisposition to obesity and cardiometabolic risk score?

Background: Genetic factors along with inadequate lifestyle habits are associated with the development of cardiometabolic alterations. Thus, the present study aimed to examine the role of sedentary behavior on the relationship between rs9939609 polymorphism (fat mass and obesity-associated gene-FTO) and cardiometabolic risk score according to cardiorespiratory ftness (CRF) levels in children and adolescents. Methods: A cross-sectional study with 1215 children and adolescents (692 girls), aged between 6 and 17 years. Screen time as a marker of sedentary behavior was evaluated through a self-reported questionnaire and CRF was estimated using the 6-min walking and running test. The genotyping of the FTO rs9939609 polymorphism was performed using a real-time polymerase chain reaction. Clustered cardiometabolic risk score (cMetS) was calculated by summing z-scores of total cholesterol/high-density lipoprotein cholesterol ratio, triglycerides, glucose, systolic blood pressure, and waist circumference, and dividing it by fve. Moderation analyses were tested using multiple linear regression models. Results: The coefcient of the interaction term of FTO (rs9939609) and screen time indicated that screen time was a signifcant moderator on the relationship between FTO rs9939609 polymorphism and cMetS (p=0.047) in children and adolescents classifed with low CRF (β=0.001; 95% CI=0.001; 0.002). It was observed a signifcant association between genotype risk (AA) of FTO polymorphism and cMetS, in participants that spent more than 378 min a day in front of screen-based devices (β=0.203; 95% CI=0.000; 0.405). No interaction term was found for those with high CRF. Conclusions: High sedentary behavior seems to infuence the relationship between genetic predisposition to obesity and cardiometabolic risk factors in children and adolescents with low CRF

Associação entre aptidão cardiorrespiratória e hábitos sedentários em escolares do Sul do Brasil

Este estudo transversal teve como objetivo verificar associação entre aptidão cardiorrespiratória (APCR) e hábitos sedentários em escolares de Santa Cruz do Sul – RS. A amostra foi constituída por 1.407 escolares, de 10 a 16 anos, de ambos os sexos, escolares da rede pública. Foi utilizado para avaliar os hábitos sedentários um questionário adaptado. Os níveis de APCR foram avaliados por meio do teste de corrida/caminhada de seis minutos, preconizado pelo Projeto Esporte Brasil. A regressão de Poisson foi aplicada para testar a associação entre a variável desfecho (APCR) com as variáveis independentes (hábitos sedentários). Os dados foram expressos em razão de prevalência (RP) e intervalo de confiança (IC) para 95%. Os adolescentes apresentaram prevalência elevada de baixos níveis de APCR (60,1%), deslocamento sedentário para a escola (66,5%) e alta frequência de tempo de tela igual ou superior de duas horas diárias (61,1%). Meninas que não praticam atividade física apresentam maior prevalência de baixos níveis de APCR (RP: 1,25; IC: 1,03-1,53; p=0,026). Pode-se concluir que baixos níveis de APCR estão associados a hábitos sedentários em escolares, o que pode resultar em complicações futuras em sua qualidade de vida

Physical fitness attenuates the genetic predisposition to obesity in children and adolescents

Obesity is an important risk factor associated with non-communicable cardiometabolic diseases. Previous studies have indicated that children and adolescents with a predisposed genetic risk for obesity could benefit from an active lifestyle, but there are no studies investigating whether physical fitness moderates the association of genetics and obesity. The aim of this study was to verify the moderating role of physical fitness in the relationship between genetic risk score (GRS) and body mass index (BMI) in children and adolescents. This cross-sectional study was carried out with 1471 children and adolescents, aged between 6 and 17 years from Santa Cruz do Sul, Brazil. Weight and height were assessed to determine BMI. Physical fitness components (cardiorespiratory fitness [CRF], lower limb strength [LLS], upper limb strength, and abdominal strength) were evaluated. The GRS was based on previously associated obesity single-nucleotide polymorphism rs9939609 (FTO), rs6548238 (TMEM18), and rs16835198 (FNDC5). Moderation analyses were tested using linear regression models, and the interactions were represented by physical fitness components X GRS (categorical variable). All analyses were adjusted for skin color/ethnicity, sex, and sexual maturation. Significant interactions for CRF (P = 0.041), LLS (P = 0.041), and abdominal strength (P = 0.046) X 5 and 6 risk alleles with BMI were found only in adolescents. In addition, there was evidence that fitness components attenuated the high genetic predisposition to high BMI. Physical fitness components are moderators in the relationship between GRS and BMI in adolescents. These findings highlight the need for interventions targeting to improve this aspect, which is an important health indicator in all ages

Metabolic risk is associated with sociodemographic characteristics in adolescents from both rural and urban regions from southern Brazil

Background: The prevalence of several cardiovascular metabolic disorders are increasingly cause for concern in adolescents worldwide. Given the complex interrelations between metabolic risk (MR) and sociodemographic variables, the present study aims to examine the association between the presence of MR with sociodemographic characteristics (sex, skin color, residential area, and parental socioeconomic status) in adolescents from Southern Brazil. Methods: Cross-sectional study conducted with 1,152 adolescents (507 males) aged between 12 and 17 years. MR was assessed using a continuous score (cMetS; sum of Z-scores of the following variables: waist circumference, systolic blood pressure (SBP), glucose, high-density lipoprotein cholesterol [HDL-C, inverse], triglycerides [TG], and estimated cardiorespiratory fitness [CRF, inverse]). Poisson regression was used to examine associations between sociodemographic variables with the dichotomized cMetS and separate metabolic variables. The results were expressed with prevalence ratios (PR) and 95% confidence intervals (CI). Results: The presence of MR (evaluated by the cMetS) was observed in 8.7% of adolescents. Higher MR was less prevalent among non-white adolescents (PR: 0.96; 95% CI: 0.93; 0.99). Adolescents living in rural areas had a lower prevalence of the following metabolic variables; low HDL-C (PR: 0.95; 95% CI: 0.94; 0.97), elevated TG (PR: 0.95; 95% CI: 0.92; 0.99), elevated glucose (PR: 0.96; 95% CI: 0.95; 0.98), and low CRF levels (PR: 0.88; 95% CI: 0.85; 0.92). Whereas, SBP was higher in those living in rural areas (PR: 1.11; 95% CI: 1.05; 1.17). In girls, there was a higher prevalence of raised TG (PR: 1.06; 95% CI: 1.02; 1.10) and lower levels of CRF (PR: 1.20; 95% CI: 1.16; 1.24), but a lower prevalence of elevated glucose (PR: 0.97; 95% CI: 0.97; 0.99). Conclusion: Higher MR prevalence was lower in those self-reporting non-white skin color and selected MR factors were less prevalent in those living in rural areas. The identification of groups at higher MR is important for early prevention and monitoring strategies for both Type 2 diabetes and later cardiovascular disease. Future studies should be conducted to assess the socio-cultural aspects of the relationships between MR and socio-cultural and lifestyle variables

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

Background: A better understanding of how cardiorespiratory ftness (CRF) and adiposity interact to associate with arterial blood pressure over time remains inconclusive. Thus, the aim of the present study was to examine whether changes in CRF moderates the association between body fat percentage (BF%) and arterial blood pressure in children and adolescents. Methods: This is an observational longitudinal study with 407 children and adolescents aged 8–17 years followed-up for three years from a city in Southern Brazil. Participants were evaluated in 2011 and 2014. CRF was measured by validated feld-based tests following the Projeto Esporte Brazil protocols and peak oxygen uptake (VO2peak) was estimated. BF% was determined by the measures of tricipital and subscapular skinfolds using equations according to sex. Systolic and diastolic blood pressure (SBP, DBP) were measured with a sphygmomanometer according to standard procedures. Moderation analyses included multiple linear regression models adjusted for sex, age, pubertal status, height, socioeconomic level, skin color, and the arterial blood pressure variable itself at baseline. Results: It was observed a signifcant inverse association between VO2peak at baseline with SBP (β=−0.646 CI95%=−0.976 −0.316) and DBP (β=−0.649 CI95%=−0.923 −0.375) at follow-up and a positive association between BF% at baseline with SBP (β=0.274; CI95%=0.094 0.455) and DBP (β=0.301; CI95%=0.150 0.453) at follow-up. In addition, results indicated a signifcant interaction term between changes in VO2peak and BF% at baseline with both SBP (p=0.034) and DBP at follow-up (p=0.011), indicating that an increase of at least 0.35 mL/kg/min and 1.78 mL/kg/min in VO2peak attenuated the positive relationship between BF% with SBP and DBP. Conclusion: CRF moderates the relationship between BF% and SBP and DBP in children and adolescents

From pregnancy to breastfeeding : adequate maternal body mass index is essential to prevent a high body mass index in your children

Objectives: To verify the associations between prenatal and perinatal factors with offspring body mass index (BMI) and the moderator role of maternal BMI in this relationship. Methods: Cross-sectional study developed with 1,562 children and adolescents aged between 6 and 17 years, as well as their mothers, from southern Brazil. The prenatal and perinatal factors, weight, and height for the calculation of maternal BMI were self-reported. For the calculation of BMI, weight and height of the child/adolescent were measured on an anthropometric scale with a coupled stadiometer. Linear regression models were used for the moderation analysis. All analyzes were adjusted for the mother’s and child’s age, sex, sexual maturation, skin color/race, and educational level. Results: cesarean as type of delivery (β=0.66; 95% CI=0.22 1.04; p=0.002) and pregnancy complications (β=0.60; 95% CI=0.15 1.04; p=0.002) were positively associated with offspring BMI. Schoolchildren who were breastfed for 4–6 months showed −0.56 kg/m2 of BMI (95% CI=−1.06– 0.06; p=0.02). Birth weight was also associated with BMI, with low weight being inversely (β=−0.59; 95% CI=−1.03– 0.15; p=0.008), while overweight was positively related (β=0.84; 95% CI=0.08 1.60; p=0.02). The moderation analysis indicated a positive interaction between the mother’s BMI and cesarean, pregnancy complications, and smoking with the offspring’s BMI. On the other hand, there was an inverse association between breastfeeding from 7 to 12 months and the offspring BMI, only in mothers with high BMI. Conclusions: Adequate maternal BMI is essential to prevent a high BMI in their children, especially when considering the influence of prenatal and perinatal risk factors

Otimização da extração assistida por ultrassom dos compostos antioxidantes da folha de moringa (moringa oleifera lam) usando metodologia de superfície de resposta / Optimization of ultrasover assisted extraction of the antioxidant compounds of the moringa leaf (moringa oleifera lam) using response surface methodology

A Moringa oleifera Lam é uma planta nativa da Índia. Suas folhas contêm nutrientes importantes como proteínas, vitamina C, além destes nutrientes as folhas contêm uma série de substâncias com capacidade antioxidante. Para se extrair os compostos antioxidante existe técnicas convencionais como Soxhlet e a maceração e as técnicas de extração não convencionais como extração assistido por Ultrassom. Assim, este trabalho teve como objetivo otimizar o processo de extração dos compostos antioxidantes das folhas da moringa. A otimização da extração, foi realizado por meio do planejamento fatorial 3², utilizando como variáveis independentes a concentração de solvente e o tempo de extração e como variáveis dependentes a atividade antioxidante frente ao radical ABTS e ao potencial redutor de ferro (FRAP). O extrato que apresentou maior atividade antioxidante pelos métodos ABTS e FRAP foi o obtido com etanol 70% (%v/v), na extração por ultrassom e agitação mecânica durante 30 min de extração

COVID-19 outcomes in people living with HIV: Peering through the waves

Objective: To evaluate clinical characteristics and outcomes of COVID-19 patients infected with HIV, and to compare with a paired sample without HIV infection. Methods: This is a substudy of a Brazilian multicentric cohort that comprised two periods (2020 and 2021). Data was obtained through the retrospective review of medical records. Primary outcomes were admission to the intensive care unit, invasive mechanical ventilation, and death. Patients with HIV and controls were matched for age, sex, number of comorbidities, and hospital of origin using the technique of propensity score matching (up to&nbsp;4:1). They were compared using the Chi-Square or Fisher's Exact tests for categorical variables and the Wilcoxon for numerical variables. Results: Throughout the study, 17,101&nbsp;COVID-19 patients were hospitalized, and 130&nbsp;(0.76%) of those were infected with HIV. The median age was&nbsp;54&nbsp;(IQR:&nbsp;43.0;64.0) years in&nbsp;2020 and 53&nbsp;(IQR:&nbsp;46.0;63.5) years in&nbsp;2021, with a predominance of females in both periods. People Living with HIV (PLHIV) and their controls showed similar prevalence for admission to the ICU and invasive mechanical ventilation requirement in the two periods, with no significant differences. In&nbsp;2020, in-hospital mortality was higher in the PLHIV compared to the controls (27.9%&nbsp;vs.&nbsp;17.7%; p&nbsp;=&nbsp;0.049), but there was no difference in mortality between groups in&nbsp;2021 (25.0%&nbsp;vs.&nbsp;25.1%; p &gt; 0.999). Conclusions: Our results reiterate that PLHIV were at higher risk of COVID-19 mortality in the early stages of the pandemic, however, this finding did not sustain in&nbsp;2021, when the mortality rate is similar to the control group

Avaliação da hemodinâmica em pacientes com doença cardíaca persistente: uma revisão bibliográfica

Introdução: A avaliação da hemodinâmica em pacientes com cardiopatia persistente é um tópico complexo e multifacetado que requer uma compreensão abrangente da fisiopatologia subjacente e dos fatores de risco associados. Esta revisão bibliográfica fornece um resumo valioso da pesquisa atual no campo e destaca vários temas-chave que surgiram de estudos recentes. Metodologia: foi realizada uma revisão de literatura conduzida para investigar os aspectos clínicos, fisiológicos, patológicos e hemodinâmicos em pacientes com cardiopatia persistente. Foram realizadas buscas em várias bases de dados entre 2010 e 2022, utilizando termos específicos. Os critérios de inclusão foram estudos de coorte, estudos de caso-controle e revisões sistemáticas com amostras maiores que 10 indivíduos. Após uma triagem inicial, 33 artigos foram selecionados para análise. Os artigos foram avaliados quanto à qualidade metodológica e os dados foram agrupados e analisados qualitativamente. Os resultados foram apresentados de forma descritiva, destacando as principais informações encontradas sobre os aspectos clínicos, fisiológicos, patológicos e hemodinâmicos em pacientes cardiopatas resistentes.&nbsp; Discussão: Uma descoberta notável é que a insuficiência cardíaca crônica continua sendo um grande problema de saúde pública, com quase 5 milhões de casos relatados apenas nos EUA. Apesar dos avanços no tratamento, a taxa de mortalidade dessa condição permanece alta, enfatizando a necessidade de pesquisas contínuas sobre os mecanismos subjacentes e intervenções mais eficazes. Além disso, a revisão identifica vários fatores de risco potenciais para doença cardíaca persistente, incluindo doença renal crônica, obesidade e inflamação. Esses achados sugerem que uma abordagem multidisciplinar para o manejo da doença, incorporando intervenções médicas e de estilo de vida, pode ser mais eficaz para melhorar os resultados dos pacientes. Conclusão: No geral, esta revisão ressalta a necessidade crítica de pesquisas contínuas sobre a fisiopatologia, fatores de risco e tratamento de doenças cardíacas persistentes e fornece informações valiosas sobre possíveis caminhos para futuras investigações