Physical Activity Questionnaire for Children: Validity and Cut-Points to Identify Sufficient Levels of Moderate- to Vigorous-Intensity Physical Activity Among Children and Adolescents Diagnosed With HIV.

PURPOSE: To investigate the validity of the Physical Activity Questionnaire for Older Children (PAQ-C) to assess the moderate- to vigorous-intensity physical activity (MVPA) level of children and adolescents diagnosed with HIV and propose cut-points, with accelerometer measures as the reference method. METHOD: Children and adolescents, aged 8-14 years (mean age = 12.21 y, SD = 2.09), diagnosed with HIV by vertical transmission, participated in the study. MVPA was investigated through the PAQ-C and triaxial accelerometer (ActiGraph GT3X+). Receiver operating characteristic curve and sensitivity and specificity values were used to identify a cut-point for PAQ-C to distinguish participants meeting MVPA guidelines. RESULTS: Fifty-six children and adolescents participated in the study. Among those, 16 met MVPA guidelines. The PAQ-C score was significantly related to accelerometry-derived MVPA (ρ = .506, P < .001). The PAQ-C score cut-point of 2.151 (sensitivity = 0.625, specificity = 0.875) was able to discriminate between those who met MVPA guidelines and those that did not (area under the curve = 0.751, 95% confidence interval, 0.616-0.886). CONCLUSION: The PAQ-C was useful to investigate MVPA among children and adolescents diagnosed with HIV and to identify those who meet MVPA guidelines.

Association between Phase Angle and Body Composition of Children and Adolescents Diagnosed with HIV Infection.

The aim of the study was to investigate how phase angle (PhA) is associated with subtotal and lumbar spine bone mineral density [BMD], lean soft tissue mass [LSTM], total body fat mass, android and gynoid in children and adolescents with HIV according to sex. A cross-sectional study was conducted in Florianópolis, Brazil, involving 64 children and adolescents vertically transmitted with HIV. Resistance and reactance values were obtained using bioelectrical impedance analysis, and PhA was subsequently calculated. Dual emission X-ray absorptiometry was used to assess body composition. Antiretroviral medication, physical activity (accelerometers) and skeletal maturation (wrist-carpal radiography) were used in the adjusted model. In males, PhA was directly associated with subtotal BMD (ßadj: 0.65; R²: 0.38, p < 0.01) and lumbar spine BMD (ßadj: 0.53; R²: 0.22, p = 0.01), directly associated with LSTM (ßadj: 0.76; R²: 0.46, p < 0.01), and inversely associated with gynoid fat (ßadj: -0.47; R²: 0.2, p = 0.01), in adjusted models. In females, PhA was directly associated with subtotal BMD (ßadj: 0.46; R²: 0.17, p < 0.01) and lumbar spine BMD (ßadj: 0.48; R²: 0.19, p < 0.01). It is concluded that PhA was directly associated with subtotal and regional BMD, LSTM, and inversely with gynoid fat in boys with HIV. In girls, PA was directly associated only with subtotal and regional BMD.

Association between lipid and glycemic profile and total body and trunk fat in children and adolescents diagnosed with HIV.

INTRODUCTION: Metabolic alterations and body fat redistribution are common in people living with HIV using antiretroviral therapy and increase the risk of premature cardiovascular diseases. AIM: To verify the presence of difference in the lipid and glycemic profile in relation to different total body and trunk fat phenotypes in children and adolescents diagnosed with HIV+. METHOD: This is a cross-sectional study carried out with 62 children and adolescents diagnosed with HIV+. Lipid and glycemic profiles were obtained from blood samples. Total and trunk fat mass (FM) was obtained by DXA. Analysis of covariance was used to verify if there is difference in the lipid and glycemic profile between total body and trunk fat phenotypes. RESULTS: In males, in the covariate-adjusted model, it was observed that boys with high total FM had higher triglyceride values (mean: 164.9 mg/dl-1 ±31.2) compared to those with low and adequate total FM. In females, in adjusted models, it was observed that girls with high total FM had higher total cholesterol (mean: 181.6 mg/dl-1 ±13.8) and LDL-C values (mean: 111.8 mg/dl-1 ±12.0), compared to those with low and adequate total FM. Girls with trunk FM had higher total cholesterol (mean: 181.6 mg/dl-1 ± 13.8), LDL-C (mean: 71.3 mg/dl-1 ± 9.6) and blood glucose values (91.6 mg/dl-1 ± 2.2). CONCLUSION: Boys with high total FM had higher triglyceride levels, while in females, it was observed that girls with high total FM and high trunk FM had higher total cholesterol, LDL-C and blood glucose values. High body fat in children and adolescents living with HIV is related to metabolic changes in the lipid and glycemic profile, with specificities of sex and fat location.

Home-based interventions to promote physical activity for people living with HIV - a systematic review.

Although physical activity (PA) improves the physical, mental, and social outcomes of people living with HIV (PLH), multiple barriers prevent them from exercising. In this systematic review, we investigated the effect of home-based interventions to promote physical activity (HBI) among PLH. Randomised trials and quasi-experimental studies published in English until March 2020 were sought in five databases. Independent reviewers performed data extraction, risk of bias assessment and pragmatic-explanatory (PRECIS-2) evaluation of study characteristics. Outcomes included engagement in PA, body composition, cardiorespiratory fitness, strength, metabolic disturbances, and quality of life (QoL). Out of 480 retrieved references, six studies met inclusion criteria. Interventions lasted 12-48 weeks and involved 400 individuals (57.8% women). Ninety-eight (24.5%) participants completed interventions, but dropout rates varied considerably (5.0-54.5%). Resulted showed increased PA (two studies) and improved cardiorespiratory fitness or strength (three and two studies, respectively). Four studies demonstrated reduction of waist circumference and increase in lean body mass. QoL improved in two of three studies. We conclude HBI (aerobic and/or resistance exercises) may contribute to improve PA and/or cardiorespiratory fitness, body composition, strength and QoL of PLH. Further investigation using multi-centre standardised protocols is warranted to provide stronger evidence of their effectiveness in health promotion for PLH.

Factors Correlated with Body Image Dissatisfaction in Children and Adolescents Diagnosed with HIV: A Cross-Sectional Study.

(1) Background: The adverse effects of continuous use of antiretroviral therapy can generate dissatisfaction with body image in children and adolescents diagnosed with Human Immunodeficiency Virus infection (HIV) infection. The aim of this study was to verify the prevalence and factors associated with body image dissatisfaction (BI) in children and adolescents diagnosed with HIV infection; (2) This is a cross-sectional study with 60 children and adolescents (32 females; 28 males) aged 8-15 years diagnosed with HIV, carried out in Florianópolis, Brazil. Information on BI was collected through a silhouette scale, as well as sociodemographic information, biological maturation, lifestyle, self-esteem, adherence to antiretroviral treatment and aspects of HIV infection; (3) Results: The results indicated that 53.13% of female patients and 53.57% of male patients were dissatisfied with their BI. Lower subscapular skinfold and higher calf skinfold values were associated with BI dissatisfaction in females. Pre-pubertal maturation stage, higher economic level, lower concentrations of CD4+ lymphocytes, lower viral load, lower level of physical activity and longer time in front of the computer and/or video game were associated with BI dissatisfaction in males; (4) Conclusions: BI dissatisfaction was observed in more than half of patients and morphological, economic, behavioral and HIV infection aspects were associated with BI dissatisfaction.

Muscle strength and its association with cardiometabolic variables in adolescents: does the expression of muscle strength values matter?

BACKGROUND: We investigate the association between different muscle strength (MS) indices with cardiometabolic variables in adolescents. METHODS: Cross-sectional study comprising 351 adolescents (male 44.4%, age 16.6 ± 1.0 years) from Brazil. MS was assessed by handgrip strength and analyzed in five different ways: absolute MS and MS normalized for body weight, body mass index (BMI), height, and fat mass, respectively. Cardiometabolic variables investigated as outcomes were systolic and diastolic blood pressure (DBP), waist circumference (WC), high-sensitive C-reactive protein (hs-CRP), lipid and glucose metabolism markers. Multiple linear regression models adjusted for confounding factors were used. RESULTS: Absolute MS and/or MS normalized for height was directly associated with WC [up to 32.8 cm, standard error (SE) = 4.7] and DBP (up to 8.8 mmHg, SE = 0.8), and inversely associated with high-density lipoprotein cholesterol (up to -8.0 mg/dL, SE = 14.1). MS normalized for body weight, BMI or fat mass was inversely associated with WC (up to -17.5 cm, SE = 2.2). According to sex, MS normalized for fat mass was inversely associated with triglycerides (male: 0.02 times lower, SE = 0.01; female: 0.05 times lower, SE = 0.01) and homeostatic model assessment for insulin resistance (male: 0.02 times lower, SE = 0.01; female: 0.06 times lower, SE = 0.01), and inversely associated with hs-CRP only among male (0.03 times lower, SE = 0.01). CONCLUSION: When normalized for body weight, BMI or fat mass, MS was superior to absolute MS or MS normalized for height in representing adequately cardiometabolic variables among adolescents.

Association between handgrip strength and bone mass parameters in HIV-infected children and adolescents. A cross-sectional study

ABSTRACT BACKGROUND: Low bone mineral content (BMC) and bone mineral density (BMD) have been identified in human immunodeficiency virus (HIV)-infected children and adolescents. The direct adverse effects of HIV infection and combined antiretroviral therapy (ART) negatively contribute to bone metabolism. A direct relationship between muscle strength levels and BMD in HIV-infected adults and older adults has been described. However, it is unknown whether handgrip strength (HGS) is associated with bone mass in pediatric populations diagnosed with HIV. OBJECTIVE: To ascertain whether HGS levels are associated with BMC and BMD in HIV-infected children and adolescents. DESIGN AND SETTING: Cross-sectional study conducted in Florianãpolis, Brazil, in 2016. METHODS: The subjects were 65 children and adolescents (8-15 years) diagnosed with vertically-transmitted HIV. Subtotal and lumbar-spine BMC and BMD were obtained via dual-emission X-ray absorptiometry (DXA). HGS was measured using manual dynamometers. The covariates of sex, ART, CD4+ T lymphocytes and viral load were obtained through questionnaires and medical records. Sexual maturation was self-reported and physical activity was measured using accelerometers. Simple and multiple linear regression were used, with P < 0.05. RESULTS: HGS was directly associated with subtotal BMD (β = 0.002; R² = 0.670; P < 0.001), subtotal BMC (β = 0.090; R² = 0.734; P = 0.005) and lumbar-spine BMC (β = 1.004; R² = 0.656; P = 0.010) in the adjusted analyses. However, no significant association was found between HGS and lumbar-spine BMD (β = 0.001; R² = 0.464; P = 0.299). CONCLUSION: HGS was directly associated with BMD and BMC in HIV-infected children and adolescents.

Association between handgrip strength and bone mass parameters in HIV-infected children and adolescents. A cross-sectional study.

BACKGROUND: Low bone mineral content (BMC) and bone mineral density (BMD) have been identified in human immunodeficiency virus (HIV)-infected children and adolescents. The direct adverse effects of HIV infection and combined antiretroviral therapy (ART) negatively contribute to bone metabolism. A direct relationship between muscle strength levels and BMD in HIV-infected adults and older adults has been described. However, it is unknown whether handgrip strength (HGS) is associated with bone mass in pediatric populations diagnosed with HIV. OBJECTIVE: To ascertain whether HGS levels are associated with BMC and BMD in HIV-infected children and adolescents. DESIGN AND SETTING: Cross-sectional study conducted in Florianãpolis, Brazil, in 2016. METHODS: The subjects were 65 children and adolescents (8-15 years) diagnosed with vertically-transmitted HIV. Subtotal and lumbar-spine BMC and BMD were obtained via dual-emission X-ray absorptiometry (DXA). HGS was measured using manual dynamometers. The covariates of sex, ART, CD4+ T lymphocytes and viral load were obtained through questionnaires and medical records. Sexual maturation was self-reported and physical activity was measured using accelerometers. Simple and multiple linear regression were used, with P < 0.05. RESULTS: HGS was directly associated with subtotal BMD (ß = 0.002; R² = 0.670; P < 0.001), subtotal BMC (ß = 0.090; R² = 0.734; P = 0.005) and lumbar-spine BMC (ß = 1.004; R² = 0.656; P = 0.010) in the adjusted analyses. However, no significant association was found between HGS and lumbar-spine BMD (ß = 0.001; R² = 0.464; P = 0.299). CONCLUSION: HGS was directly associated with BMD and BMC in HIV-infected children and adolescents.

Association Between Body Fat Distribution Assessed by Different Techniques and Body Image Perception in HIV-Infected Children and Adolescents.

PURPOSE: verify whether there is difference in body fat values assessed by different methods according to the body image perception of HIV-infected children and adolescents. DESIGN AND METHODS: This is a cross-sectional study with 65 HIV-infected children and adolescents (aged 8-15 years). Total fat mass, trunk fat mass, arm fat mass and leg fat mass were obtained through dual-energy X-ray absorptiometry (DXA). Anthropometric variables were measured according to international standardization. Body image was assessed using a scale of body silhouettes. Bone age covariates were assessed using carpal wrist X-rays and physical activity by accelerometers. Information regarding viral load and use of combined antiretroviral therapy was obtained from medical records. In males, no significant difference in body fat values and body image categories was observed. RESULTS: In the model with covariates, girls who desired to reduce body weight had higher BMI (18.96 kg / m2 ± 2.47, R2 adj: 0.613), total fat mass (14.25 kg ± 1.37, R2 adj: 0.589), trunk fat mass (6.50 kg ± 0.66, R2 adj: 0.611) and leg fat mass values (6.01Kg ± 0.57, R2 adj: 0.503) in comparison to girls who were satisfied and to those who desired to increase body weight. CONCLUSIONS: HIV + girls who desired to reduce body weight had greater amount of BMI, total fat mass, trunk fat mass and leg fat mass compared to those who were satisfied and those who desired to increase body weight. PRACTICE IMPLICATIONS: These data can be used to assist in the process of coping and accepting body image.

Association between phase angle and isolated and grouped physical fitness indicators in adolescents.

OBJECTIVE: Examine association between phase angle and isolated and grouped physical fitness indicators in adolescents. METHODS: The sample consisted of 353 adolescents, aged 10-16 years. Phase angle was calculated based on crude resistance and reactance values (50 kHz frequency) obtained by tetrapole electrical bioimpedance (BIA). Fat mass and lean mass were estimated by means of anthropometric equations. Hydraulic dynamometer was used to measure handgrip strength and aerobic fitness was obtained by means of the 20-m back-and-forth test. The z-score for isolated and grouped physical fitness indicators was calculated. Covariates were age, habitual physical activity and screen time (obtained by questionnaire), and sexual maturation (self-reported). RESULTS: For males, phase angle was directly associated with lean mass (ß = 0.02, p < 0.01), handgrip strength (ß = 0.03, p < 0.01), and aerobic fitness (ß = 0.01, p = 0.05), even adjusting for covariates. For females, phase angle was directly associated with lean mass (ß = 0.02; p = 0.04) after adjusting for covariates. Phase angle was directly associated with composite physical fitness z-score in both sexes (male, ß = 0.09, p < 0.01, female, ß = 0.03, p = 0.05), even adjusting for covariates. CONCLUSIONS: Phase angle was directly associated with isolated and grouped physical fitness indicators in adolescents. In this way, the phase angle can be used to monitor the health of adolescents.

Phase angle is associated with the physical fitness of HIV-infected children and adolescents.

The objective of this study was to identify the association of phase angle with physical fitness in children and adolescents infected with HIV. Sixty-four children and adolescents infected with HIV (8-15 years old) were tested for vertical transmission. The electrical bioimpedance was used to obtain the phase angle. Body fat (BF) and lean soft tissue mass (LSTM) were measured by x-ray absorptiometry, and the manual grip strength was evaluated by dynamometry. The peak oxygen consumption (VO2 peak) was measured by respiratory change in a submaximal incremental test. Moderate-vigorous physical activity (MVP) and sedentary behavior were measured using accelerometers and were used as covariates. Multiple linear regression was used. The linear correlation analyses demonstrated that the phase angle was inversely proportional to relative BF (r = -0.26), but was not associated with absolute body fat (r = -0.02). The phase angle was directly associated with LSTM (r = 0.57), handgrip strength, and (r = 0.43) peak VO2 (r = 0.55). The phase angle was not associated with absolute BF (ß = -0.017, P = 0.413) and relative (ß = -0.014, P = 0.175). The phase angle presented a direct association with LSTM (ß = 0.041, P = 0.019) and peak VO2 (ß = 0.005; P = 0.019), regardless of age, sex, sexual maturation, MVPA, sedentary behavior, antiretroviral drugs, and viral load. No association was found between phase angle and handgrip strength (ß = 0.153; P = 0.199). It was concluded that phase angle was associated with LSTM and the aerobic fitness in HIV-infected children and adolescents.

Prediction of peak V˙ O2 in Children and Adolescents With HIV From an Incremental Cycle Ergometer Test.

PURPOSE: To examine the capacity of physiological variables and performance to predict peak oxygen consumption (peak V˙ O2) in children and adolescents living with HIV. METHOD: Sixty-five children and adolescents living with HIV (30 boys) aged 8-15 years, participated in the study. Peak V˙ O2 was measured by breath-by-breath respiratory exchange during an incremental cycle ergometer until volitional exhaustion. Information on the time to exhaustion, maximal power output (Pmax), and peak heart rate (peak HR) were also recorded. RESULTS: Predictive models were developed and all equations showed the ability of performance variables to predict peak V˙ O2. However, Model 1 was based only on Pmax by following equation: Y = 338.8302 + (Pmax [W] * 11.16435), R2 = 0.90 and standard error of estimation (SEE) = 180 ml ⋅ min-1. CONCLUSION: The V˙ O2 peak can be predicted simply by the Pmax obtained from the incremental cycle ergometer test. This protocol is a valid and useful tool for monitoring the aerobic fitness of children and adolescents living with HIV, especially in resource-limited settings.

Aerobic fitness and physical activity are inversely associated with body fat, dyslipidemia and inflammatory mediators in children and adolescents living with HIV.

This study aimed to investigate if moderate to vigorous physical activity (MVPA) and aerobic fitness are associated with cardiovascular risk factors in HIV+ children and adolescents. Sixty-five children and adolescents (8 to 15 years) provided minutes of MVPA measured by accelerometers and peak oxygen uptake (peak VO2) by breath-by-breath respiratory exchange. Cardiovascular risk factors were characterized by body fat, blood pressure, total cholesterol, HDL-c, LDL-c, triglycerides, glucose, insulin, C-reactive protein (CRP), interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α) and carotid intima-media thickness. Results indicated that higher MVPA was associated with lower values of total (ß =  -3.566) and trunk body fat (ß = -3.495), total cholesterol (ß = -0.112) and LDL-c (ß = -0.830). Likewise, higher peak VO2 was associated with lower total (ß = -0.629) and trunk body fat values (ß = -0.592) and levels of CRP (ß = -0.059). The physically active participants had lower total cholesterol (-24.4 mg.dL-1) and LDL-c (-20.1 mg.dL-1) compared to participants judged to be insufficiently active. Moreover, participants with satisfactory peak VO2 showed lower total (-4.1%) and trunk (-4.3%) body fat, CRP (-2.3 mg.L-1), IL-6 (-2.4 pg.mL-1) and TNF-α (-1.0 pg.mL-1) compared to low peak VO2 peers. High levels of MVPA and aerobic fitness may prevent developing of cardiovascular risk factors in children and adolescents HIV+.

Anthropometric measures associated with fat mass estimation in children and adolescents with HIV.

To verify the association between anthropometric indicators and body fat percentage estimated by dual X-ray absorptiometry (DXA) and air displacement plethysmography (ADP) in children and adolescents diagnosed with human immunodeficiency virus (HIV). This cross-sectional study was carried out with 62 children and adolescents with HIV (aged 8 to 15 years). Body fat percentage was estimated by DXA and ADP. Anthropometric indicators were skinfolds (abdominal, triceps, subscapular, calf), perimeter relaxed arm (PRA), waist circumference (WC), perimeter neck, body mass index (BMI), waist-to-height ratio, conicity index, and body adiposity index. Linear regressions were performed with 5% significance level. In boys (adjusted R2 (R2adj) = 0.38 to R2adj = 0.67) and girls (R2adj = 0.41 to R2adj = 0.57), all anthropometric indicators were associated with body fat percentage estimated by DXA. For boys, skinfolds were associated with body fat percentage estimated by ADP (R2adj = 0.18 to R2adj = 0.35). In girls, skinfolds (R2adj = 0.27 to R2adj = 0.44, BMI (R2adj = 0.31), PRA (R2adj = 0.36), and WC (R2adj = 0.26) were associated to body fat percentage by ADP. Abdominal skinfold was the indicator that most explained the variation in body fat percentage measured by DXA and ADP in both sexes. Anthropometric indicators are strongly associated with body fat, measured by reference methods, and can assist health professionals in monitoring the health of children and adolescents with HIV.

Are adolescents really being sedentary or inactive when at school? An analysis of sedentary behaviour and physical activity bouts.

This study analysed physical activity (PA) and sedentary behaviour (SB) performed in bouts during schooltime. Adolescents of two schools answered a questionnaire, had their height and weight measured and wore accelerometers during schooltime. Moderate-to-vigorous intensity PA was estimated in bouts of 2, 5 and 10 min, and SB in bouts of 5, 10, 30 and 60 min. Body mass index was calculated, and adolescents were classified as overweight or normal weight. Frequency, duration and volume of PA and SB were calculated for the whole sample and for those who performed at least one bout weekly. PA and SB differences between gender and weight status were tested using Mann-Whitney and t tests. A total of 415 adolescents (54% girls, 12.3 ± 1.3 years old, 34.6% overweight) performed 0.1 (± 0.2), 0.2 (± 0.5) and 0.4 (± 0.6) bouts of 10, 5 and 2 min of PA, and 10.6 (± 2.0), 6.0 (± 1.3), 1.1 (± 0.9) and 0.4 (± 0.5) bouts/day of 5, 10, 30 and 60 min of SB, respectively. Boys accumulated less SB and more PA in bouts. No differences were found for weight status.Conclusion: Adolescents hardly engaged in bouted PA and accumulated more SB in smaller bouts during schooltime. Bouted PA and SB were not associated with weight status. What is Known: • Adolescents are not engaging in enough PA and are accumulating large volumes of SB, which might negatively impact their health. • Schools play an important role in daily overall PA, with opportunities such as PE classes and recesses. But most classes are still undertaken in seated positions. What is New: • Adolescents hardly engage in bouted (> 10 m) PA when at school., and most SB is accumulated in short bouts (≤ 10m). • Weight status was not associated with bouted PA or SB at school.

Aerobic Fitness and Moderate to Vigorous Physical Activity in Children and Adolescents Living with HIV.

PURPOSE: To examine aerobic fitness, total moderate to vigorous physical activity (MVPA) and also patterns in terms of MVPA between children and adolescents with human immunodeficiency virus (HIV) and controls, and to determine whether differences, if any, are associated with HIV, sex and highly active antiretroviral therapy (HAART). METHOD: A cross-sectional analysis was carried out with 130 children and adolescents, aged between 8 and 15 years, divided into two groups (HIV group= 65 patients, control group= 65 healthy participants). Total MVPA was measured by accelerometers and 5 and 10-min bouts were estimated. The peak oxygen uptake (peak VO2) was measured by breath-by-breath respiratory exchange in an incremental cycle ergometer test. RESULTS: HIV-positive participants had lower peak VO2 (39.2 ± 6.8 vs. 44.5 ± 9.1 ml.kg-1min-1), lower bouts of MVPA of 5-min (19.7 ± 16.6 vs. 26.6 ± 23.5) and 10-min (3.6 ± 3.9 vs. 5.8 ± 7.2), but similar total MVPA (49.5 ± 28.9 vs. 49.1 ± 30.6 min.day-1). HIV infection in untreated, nonprotease inhibitors (PI)- based HAART and PI-based HAART patients was associated with lower 8.5 (95%CI= 12.5-4.6), 7.1 (95%CI= 10.6-3.6) and 4.5 (95%CI= 7.0-2.0) ml.kg-1min-1 of peak VO2. CONCLUSION: Children and adolescents with HIV demonstrated lower aerobic fitness compared with the controls and the absence of HAART may increase peak VO2 impairment. Lower bouts of MVPA were also observed in HIV group despite the similar values of total MVPA of controls.

Orientações para utilização de acelerômetros no Brasil / Instructions for accelerometer use in Brazil

O objetivo do presente estudo foi apresentar um conjunto de orientações para a utilização de acelerômetros no Brasil. O método consistiu na revisão e síntese de artigos que utilizaram acelerômetros como instrumento de medida objetiva da atividade física. Com base nesses estudos, buscou-se apresentar orientações para as fases pré-coleta (seleção do acelerômetro; testagem da calibração dos acelerômetros, atualização de firmware; estudo piloto; e definição de protocolo), coleta (distribuição dos acelerômetros; contato com participantes; e devolução dos acelerômetros) e pós-coleta (processamento; transformação e interpretação dos dados; e comparabilidade dos dados) do uso de acelerômetros. São descritos procedimentos para facilitar as tomadas de decisões relacionadas ao uso desses dispositivos, bem como para obtenção de dados de acelerometria válidos e reprodutíveis. As orientações são uma iniciativa de pesquisadores da área a fim de proporcionar um avanço metodológico nas medidas objetivas da atividade física. A adoção das orientações pode facilitar a padronização dos procedimentos empregados e a comparabilidade de resultados entre estudos com acelerômetros no Brasil.

The aim of this study was to develop instructions for using accelerometers to measure physical activity in Brazil. This manuscript is a review and synthesis of scientific papers that have used accelerometers for objective physical activity assessment in different age groups as well as studies providing directions for using activity monitors in large-scale studies. In this study, we present instructions for the pre-data collection (selection of monitor; unit calibration, firmware update, pilot study, protocol definition), data collection (monitor distribution, contacting participants, monitor return) and post-data collection (data processing, transformation and interpretation) phases. We describe procedures for facilitating decision making related to using accelerometers, as well as for obtaining valid and reliable accelerometer physical activity data. This set of instructions is an initiative of a group of physical activity researchers with the purpose of contributing to methodologically advance the field of objective physical activity measurement in Brazil. The current set of instructions intend to facilitate the standardization of procedures for collecting physical activity data with accelerometers in Brazil and, thus, for ascertaining future comparability of data collected in different studies.

[High blood pressure in adolescents: prevalence and associated factors]. / Pressão arterial elevada em adolescentes: prevalência e fatores associados.

The aim of this study was to assess the prevalence and associated factors of high Blood Pressure (BP) among adolescents in a Brazilian city. A cross-sectional study was conducted with 653 adolescents (57.9% female) of high school level between 14 and 19 years of age. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) of all subjects were measured. Social and demographic variables and lifestyle factors and body mass index were obtained. Binary logistic regression, crude and adjusted, was employed with a significance level of 5%. The mean SBP and DBP were 111.9 mmHg and 69.9 mmHg, respectively. The prevalence of high BP levels was 12.4%. The multivariable analysis revealed that males (OR: 2.37, 95% CI: 1.45, 3.90), adolescents with maternal education < 8 years (OR: 1.84, 95% CI: 1.03, 3.30) and overweight (OR: 3.79, 95% CI: 2.23, 6.43) had greater indices of high BP. The interaction term between males and overweight represented the subgroup with greater indices of high BP (OR: 6.41, 95% CI: 3.00, 13.16). High BP affects adolescents from Ponta Grossa, State of Paraná, and the groups with greater indices of high BP were males, with low maternal educational level and overweight.