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BACKGROUND: Childhood is an important transitional period for the development of healthy physical activity (PA) behaviours, so it is important to understand its impact on a healthy lifestyle. AIM: This study aimed to determine the influences of sex, socioeconomic status (SES) and body composition (BC) on the relationships between PA, motor skills, motor- and health-related physical fitness in 5-8-year-olds. SETTING: Participants were a subsample consisting of 299 children (150 boys, 149 girls, mean age 6.83 ± 0.96 years) from the Exercise, Arterial Modulation and Nutrition in Youth South Africa study (ExAMIN Youth SA). METHODS: Anthropometric measures, health-related physical fitness (HRPF), motor-related physical fitness (MRPF), objectively measured PA and demographic information were determined. RESULTS: Only 66% achieved the recommended 60 min of daily moderate vigorous physical activity (MVPA) with 19% classified as having unhealthy body composition (11% overweight, 8% obese). Fat-free mass and SES revealed small-to-moderate influences on the relationship between MVPA, standing broad jump (SBJ; r = 0.32), predicted VO2max (r = 0.28) and beep levels (r = 0.22). For MRPF, the quality of running (r = 0.12) and balancing were associated with MVPA. Adjusting for sex, BC and SES in the relationship between PA with HRPF and MRPF, reductions in most correlations were observed. CONCLUSION: Moderate vigorous physical activity levels were positively associated with HRPF, MRPF and some motor skills in 5-8-year-olds. Socioeconomic status (lower parental income, employment and education negatively influenced the association between MVPA and fitness [beeps, SBJ, O2max]).Contribution: This study provides knowledge with regard to the use of accelerometer for baseline data for PA, MRPF, HRPF as well as motor skills in South African children.
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Composição Corporal , Exercício Físico , Destreza Motora , Aptidão Física , Humanos , Feminino , Masculino , Aptidão Física/fisiologia , Destreza Motora/fisiologia , Criança , África do Sul , Pré-Escolar , Classe Social , Fatores SexuaisRESUMO
BACKGROUND: Reliable dietary data for children are necessary to investigate associations with health outcomes. The present study aimed to develop and validate a questionnaire to determine the frequency of intakes of specific healthy and unhealthy food groups in young children. METHODS: Participants were 5-9-year-old South African children (n = 920) from 10 urban schools. Their parents completed a demographic questionnaire and the food intake questionnaire with food pictures. Based on the literature, four healthy food groups (fruits, vegetables, milk, meat/fish/poultry/eggs) and six unhealthy food groups (hot and cold sugar-sweetened beverages, candy, salty snacks, cakes and fast foods) were included, with five different frequency responses. Six experienced nutritionists assessed the face validity and content validity. After pilot testing, construct validity and homogeneity were determined in the participants. Convergent validity was determined using urinary sodium and potassium concentrations as biological intake markers. RESULTS: Nutritionists confirmed face and content validity. Caregivers confirmed understanding of the questionnaire. Three factors explained 50.2% of the variance, with most unhealthy food groups as factor 1, fruits and vegetables as factor 2, and animal source protein and milk groups clustered with sugar-sweetened beverages as factor 3. The frequency of milk group, fruits and vegetables intake correlated negatively, whereas the frequency of salty snacks and fast foods intakes correlated positively with the urinary sodium:potassium ratio. CONCLUSIONS: The healthy and unhealthy food group questionnaire has advantages of low respondent burden, as well as acceptable content and convergent validity in South African children. The questionnaire may be used to investigate associations between food intakes and health outcomes.
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Frutas , Verduras , Criança , Animais , Humanos , Pré-Escolar , África do Sul , Inquéritos e Questionários , Potássio , Sódio , Comportamento AlimentarRESUMO
This study aimed to assess the validity of mid-arm circumference (MAC), also known as mid-upper arm circumference (MUAC), for classification of high body fatness in Namibian adolescent girls and women and to test whether classification accuracy of MUAC was higher than the traditional simple proxy for high fatness, the BMI. In 206 adolescent girls aged 13-19 years and 207 adult women aged 20-40 years, we defined obesity conventionally (BMI-for-age Z score ≥ 2·00, adolescents; adults BMI ≥ 30·0 kg/m2) and also defined obesity using published MAC cut-off values. 2H oxide dilution was used to measure total body water (TBW) to define high body fat percentage (≥ 30 % in the adolescents, ≥ 38 % in the adults), and we compared the ability of BMI and MAC to classify high body fatness correctly using sensitivity, specificity and predictive values. In the adolescents, obesity prevalence was 9·2 % (19/206) using BMI-for-age and 63·2 % (131/206) using TBW; sensitivity of BMI-for-age was 14·5 % (95 % CI 9·1, 22·0 %) but was improved significantly using MAC of 22·6 cm (sensitivity 96·9 %; 95 % CI 92·1 %, 99·3 %). In the adults, obesity prevalence was 30·4 % (63/207) using BMI and 57·0 % (118/207) using TBW, and sensitivity of BMI was 52·5 % (95 % CI 43·6, 62·2 %), but using a MAC of 30·6 cm sensitivity was 72·8 % (95 % CI 66·4, 82·6 %). Surveillance of obesity in African adolescent girls and adult women is likely to be improved substantially by use of MAC as an alternative to the BMI-for-age and BMI.
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Tecido Adiposo , Obesidade , Humanos , Adulto , Adolescente , Feminino , Índice de Massa Corporal , Sensibilidade e Especificidade , Estudos Transversais , Obesidade/diagnóstico , Obesidade/epidemiologia , AntropometriaRESUMO
Body composition measurement is useful for assessing percentage body fat (%BF) and medical diagnosis, monitoring disease progression and response to treatment, and is essential in assessing nutritional status, especially in children. However, finding accurate and precise techniques remains a challenge. The study compares %BF determined by bioelectrical impedance analysis (BIA) and calculated from available prediction equations based on skinfolds in young South African children. A cross-sectional study performed on 202 children (83 boys and 119 girls) aged 6-8 years. Height and weight, triceps and subscapular skinfolds were determined according to standard procedures. %BF was determined with BIA and three relevant available equations. SPSS analyzed the data using paired samples tests, linear regression, and Bland-Altman plots. Significant paired mean differences were found for BIA and Slaughter (t201 = 33.896, p < 0.001), Wickramasinghe (t201 = 4.217, p < 0.001), and Dezenberg (t201 = 19.910, p < 0.001). For all of the equations, the standards for evaluating prediction errors (SEE) were above 5. The Bland-Altman plots show relatively large positive and negative deviations from the mean difference lines and trends of systematic under- and over-estimation of %BF across the %BF spectrum. All three equations demonstrated a smaller %BF than the %BF measured by BIA, but the difference was smallest with the Wickramasinghe equation. In comparison, a poor SEE was found in the three %BF predicted equations and %BF derived from BIA. As such, an age-specific %BF equation incorporating criterion methods of deuterium dilution techniques or 'gold-standard' methods is needed to refute these findings. However, in the absence of developed %BF equations or 'gold-standard' methods, the available prediction equations are still desirable.
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Tecido Adiposo , Composição Corporal , Criança , Masculino , Feminino , Humanos , Dobras Cutâneas , Impedância Elétrica , Estudos Transversais , Antropometria/métodos , África do Sul , Tecido Adiposo/metabolismo , Absorciometria de Fóton/métodosRESUMO
OBJECTIVE: To evaluate the performance of a UK based prediction model for estimating fat-free mass (and indirectly fat mass) in children and adolescents in non-UK settings. DESIGN: Individual participant data meta-analysis. SETTING: 19 countries. PARTICIPANTS: 5693 children and adolescents (49.7% boys) aged 4 to 15 years with complete data on the predictors included in the UK based model (weight, height, age, sex, and ethnicity) and on the independently assessed outcome measure (fat-free mass determined by deuterium dilution assessment). MAIN OUTCOME MEASURES: The outcome of the UK based prediction model was natural log transformed fat-free mass (lnFFM). Predictive performance statistics of R2, calibration slope, calibration-in-the-large, and root mean square error were assessed in each of the 19 countries and then pooled through random effects meta-analysis. Calibration plots were also derived for each country, including flexible calibration curves. RESULTS: The model showed good predictive ability in non-UK populations of children and adolescents, providing R2 values of >75% in all countries and >90% in 11 of the 19 countries, and with good calibration (ie, agreement) of observed and predicted values. Root mean square error values (on fat-free mass scale) were <4 kg in 17 of the 19 settings. Pooled values (95% confidence intervals) of R2, calibration slope, and calibration-in-the-large were 88.7% (85.9% to 91.4%), 0.98 (0.97 to 1.00), and 0.01 (-0.02 to 0.04), respectively. Heterogeneity was evident in the R2 and calibration-in-the-large values across settings, but not in the calibration slope. Model performance did not vary markedly between boys and girls, age, ethnicity, and national income groups. To further improve the accuracy of the predictions, the model equation was recalibrated for the intercept in each setting so that country specific equations are available for future use. CONCLUSION: The UK based prediction model, which is based on readily available measures, provides predictions of childhood fat-free mass, and hence fat mass, in a range of non-UK settings that explain a large proportion of the variability in observed fat-free mass, and exhibit good calibration performance, especially after recalibration of the intercept for each population. The model demonstrates good generalisability in both low-middle income and high income populations of healthy children and adolescents aged 4-15 years.
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Análise de Dados , Etnicidade , Adolescente , Calibragem , Criança , Deutério , Feminino , Humanos , Técnicas de Diluição do Indicador , MasculinoRESUMO
Adequate development of Fundamental Motor Skills (FMS) at a young age benefit holistic development and positive health outcomes. This study determined age and sex developmental differences in the state and the relationships between process and product assessments of four fundamental-motor skills (FMS) in five to eight-year-olds. An availability sample of 636 children; 291 boys, 345 girls, mean age of 6.8 ± 0.97 years in the North West Province of South Africa participated in the study. Spearman rank order correlations analyzed relationships between assessments, while sex and age differences were examined using independent t-testing and one-way ANOVA. Age showed significant developmental trajectories in all FMS. Older children were found to be more at risk for not learning FMS to mastery, while unique developmental patterns were also established compared to international trends. Strong to moderate significant practical associations (p < 0.05) emerged between process and product assessments in catching (r = 0.79), jumping (r = 0.40) running (r = −0.33) and kicking (r = 0.20), while also confirming that the strength of the associations varies depending upon the skill type. Associations strengthened with increasing age, were higher in girls in all FMS, while associations between behavioral criteria in all FMS also differed between FMS and sexes. These strong associations, need to be taken into consideration during the development of FMS towards obtaining full mastery.
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Destreza Motora , Corrida , Adolescente , Criança , Pré-Escolar , Exercício Físico , Feminino , Humanos , Masculino , Homens , Caracteres SexuaisRESUMO
BACKGROUND: Globally, the prevalence of metabolic syndrome (MS) is rising because of increased levels of physical inactivity and obesity. In South Africa, information about teachers' physical activity (PA), body fatness and MS is limited. AIM: To assess the relationship between PA, body fatness and MS in urban South African teachers. SETTING: The study setting was in Dr Kenneth Kaunda District in the North West province of South Africa. METHODS: A cross-sectional study was conducted using secondary data drawn from the sympathetic activity and ambulatory blood pressure in Africans (SABPA) study of 216 teachers (aged 25-65 years). Variables included anthropometry, biochemical measurements, objectively measured PA and lifestyle behaviours. RESULTS: Twenty-nine percent of the total participants were classified with MS, with 46% in men compared to 13% in women; 33% were sedentary and 67% participated in light activity. A weak significant negative relationship was found between the mean 7-day awake metabolic equivalent of tasks (METs) and triglycerides (r = -0.29; p = 0.02) and gamma-glutamyl transferase (r = -0.25; p = 0.06), activity energy expenditure (r = -0.24; p = 0.06) and PA level (r = -0.23; p = 0.07). After adjusting for age, self-reported smoking and alcohol use or consumption, a weak significant negative relationship between mean 7-day awake METs and triglycerides (r = -0.28; p 0.01) was observed. CONCLUSION: In the teachers with MS, only one MS marker (triglycerides) showed a negative association with PA. Physical activity could therefore be beneficial in the regulation of triglycerides. Participation in regular PA could be beneficial in the regulation of triglycerides. Focused PA interventions in school teachers that advocate the benefits of PA and healthy lifestyle choices to reduce dietary fat intake (and alcohol) are recommended.
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Síndrome Metabólica , Pressão Sanguínea/fisiologia , Monitorização Ambulatorial da Pressão Arterial , Estudos Transversais , Exercício Físico , Feminino , Humanos , Masculino , Síndrome Metabólica/epidemiologia , Professores Escolares , África do Sul/epidemiologia , TriglicerídeosRESUMO
BACKGROUND: Handgrip strength (HGS) serves as a proxy for the functional ability and its association with body composition (BC) and physical activity (PA) in South African adults are less clear. AIM: We investigated the relationships between PA, body composition and HGS amongst adults. SETTING: Rural and urban population from North West Province, South Africa. METHODS: A cross-sectional study design was performed on 688 (198 men; 490 women) adults aged 35-70 years from the 2015 measurement wave of the Prospective Urban and Rural Epidemiological (PURE) study from the North West province of South Africa. The International Physical Activity Questionnaire-Short Form (IPAQ-SF) assessed and a dynamometer determined HGS in kilogram. Body mass index (BMI) and waist circumference were used as measures of body composition. Spearman correlation coefficients determined the relationship between PA, BMI and HGS. RESULTS: In the study, 22% and 26%, respectively, were overweight and obese with women being more overweight and obese compared to men. Sixty percent of the participants met the recommended 150 min or more of moderate to vigorous PA (MVPA) per week. Handgrip strength of the participants in the study was weaker than the published norms. Handgrip strength significantly (p 0.05) differed by age. A significant positive association was found between HGS and BMI. Age negatively (r = -0.12; p = 0.001) correlated with MVPA per week. CONCLUSION: High prevalence of overweight and obesity exists in the current adults' sample. It was also evident that poor upper limb muscle strength and MVPA were negatively associated with ageing. Given the health implications of poor strength indicators, PA intervention programmes, comprised of strength activities, for an adult population are urgently recommended.
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Força da Mão , Sobrepeso , Adulto , Índice de Massa Corporal , Estudos Transversais , Exercício Físico , Feminino , Humanos , Masculino , Obesidade/epidemiologia , Sobrepeso/epidemiologia , Estudos Prospectivos , África do Sul/epidemiologia , Circunferência da CinturaRESUMO
In the Abstract, in Methods: Ultrasound CIMT imaging was done using the SonoSite Micromaxx. Physical activity was done over seven consecutive days. In the Abstract, in Results: The prevalence of obesity according to BMI and sedentary behaviour was above 30%; hypertension was 38.9% and low-grade inflammation (CRP) was 41.1%.
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[This corrects the article DOI: 10.1371/journal.pone.0237399.].
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To assess the level of agreement between body size self-perception and actual body size determined by body mass index (BMI) z-score and body fatness measured by the deuterium dilution method (DDM) in South African children aged 6-8 years. A cross-sectional sample of 202 children (83 boys and 119 girls) aged 6-8 years from the Body Composition-Isotope Technique study (BC-IT) was taken. Subjective measures of body image (silhouettes) were compared with the objective measures of BMI z-score and body fatness measured by the DDM. The World Health Organization BMI z-scores were used to classify the children as underweight, normal, overweight, or obese. DDM-measured fatness was classified based on the McCarthy centile curves set at 2nd, 85th and 95th in conjunction with fatness cut-off points of 25% in boys and 30% in girls. Data were analyzed using SPSS v26. Of 202 children, 32.2%, 55.1%, 8.8%, and 2.4% perceived their body size as underweight, normal, overweight, and obese, respectively. Based on BMI z-score, 18.8%, 72.8%, 6.9%, and 1.5% were classified as underweight, normal, overweight, and obese, respectively. Body fatness measurement showed that 2.5%, 48.0%, 21.8%, and 29.7% were underweight, normal weight, overweight, and obese, respectively. The application of silhouettes and BMI z-scores resulted in either overestimation or underestimation of own body size. Overall, the levels of agreements (kappa, κ) between body size perception, body fatness, and BMI for age respectively, were small (κ = 0.083, p = 0.053 and κ = 0.154, p<0.001). Level of agreement between body size perception, body fatness, and BMI z-score was poor. The use of silhouettes made children either overestimate their own body size while being underweight or underestimate their own body size while being overweight or obese. Given the potential health implications associated with misclassification of body size during childhood, correct self-assessment of body size is important, and may be key to the adoption of weight control strategies directed at curbing the escalating obesity epidemic in the country. Scalable measures to allow for more accurate self-assessment are urgently needed-one approach is behavior change communication at all levels.
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Composição Corporal , Imagem Corporal/psicologia , Percepção , Criança , Feminino , Humanos , Isótopos , Masculino , África do SulRESUMO
OBJECTIVE: To determine the relationship between objectively measured physical activity (PA) and carotid intima-media thickness (CIMT) in teachers in South Africa. METHODS: A cross-sectional study was conducted among 215 teachers aged 25 to 65 years (mean age 49.67 ± 8.43 years) who participated in the Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) prospective cohort study. CIMT was measured using the SonoSite Micromaxx ultrasound over seven consecutive days. Other measurements obtained included body mass index (BMI), waist circumference, 24-hour ambulatory blood pressure, and C-reactive protein (CRP) and fasting blood total cholesterol levels. Data were analysed using Statistical Package for Social Sciences (SPSS) version 25. RESULTS: The prevalence of obesity according to BMI and sedentary behaviour was above 30%; hypertension was 38.9% and CRP 41.1 mg/dl. Male teachers showed higher mean values for CIMT than female teachers (0.75 ± 0.16 vs 0.66 ± 0.12 mm; p ≤ 0.05). A borderline negative association existed between CIMT and mean seven-day awake metabolic equivalent of task (r = -0.19; p = 0.08) in female teachers in the light-PA group. CIMT was inversely associated with total energy expenditure (r = -0.31; p = 0.05) in sedentary male teachers. CONCLUSIONS: Participation in light PA was associated with lower CIMT values in female teachers. Given the health implications of cardiovascular disease risk among teachers, PA intervention studies are recommended to determine effective interventions to provide information on how to decrease the progression of subclinical atherosclerosis in this population.
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Doenças das Artérias Carótidas/diagnóstico por imagem , Espessura Intima-Media Carotídea , Exercício Físico , Estilo de Vida Saudável , Actigrafia/instrumentação , Adulto , Idoso , Doenças das Artérias Carótidas/epidemiologia , Doenças das Artérias Carótidas/prevenção & controle , Comorbidade , Estudos Transversais , Feminino , Monitores de Aptidão Física , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prevalência , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Professores Escolares , Comportamento Sedentário , Fatores Sexuais , África do Sul/epidemiologiaRESUMO
BACKGROUND: Due to the large mortality from inactivity-related non-communicable diseases in low- and middle- income countries, accurate assessment of physical activity is important for surveillance, monitoring and understanding of physical (in)activity epidemiology in many of these countries. Research on relative performance of self-report physical activity instruments commonly used for epidemiological research in Africa have rarely been reported. The present study compared estimates of physical activity measured with the International Physical Activity Questionnaire - Short Form (IPAQ-SF) and the Baecke Physical Activity Questionnaire (BPAQ) among urban and rural black South African adults. METHODS: Self-reported physical activity data using the IPAQ-SF and BPAQ were collected from a representative sample of 910 urban and rural black South African adults (age = 59.2 ± 9.5 years, 69.7 % women) participating in the 2015 wave of the Prospective Urban and Rural Epidemiological (PURE) study in the North West Province of South Africa. Between-method relationships (pearson correlations [r] and intraclass correlation coefficients [ICCs]) and agreements (Bland-Altman mean difference with 95 % limits of agreement and Kappa coefficient [k]) of IPAQ-SF and BPAQ variables were estimated. Sensitivity and specificity of the BPAQ relative to the IPAQ-SF to classify individuals according to the international guidelines for sufficient physical activity were calculated using chi-square statistics. RESULTS: Correlations between IPAQ-SF scores and BPAQ indices were small (r = 0.08-0.18; ICCs = 0.09-0.18) for BPAQ leisure and sport indices, moderate-to-large for work index (r = 0.42-0.59; ICCs = 0.40-0.62) and total physical activity index (r = 0.52-0.60; ICCs = 0.36-0.51). Between methods mean difference for total physical activity was large (1.85 unit), and agreement in physical activity classifications was poor to moderate (k = 0.16-0.44). The sensitivity of the BPAQ to identify sufficiently active people from the IPAQ-SF was very good (98 %), but its specificity to correctly classify insufficiently active people was weak (23 %). CONCLUSION: Notable disparities in physical activity estimates between methods suggest that utilization of IPAQ-SF and BPAQ for surveillance and epidemiology studies in Africa should depend on research questions and population to be studied. Future studies with objective measures are needed to confirm the relative validity between the two instruments.
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AIM: To evaluate a two-year longitudinal development of health-related fitness, anthropometry and body composition status amongst adolescents in Tlokwe Municipality, Potchefstroom, South Africa. SETTING: A total of 283 high-school learners (111 boys and 172 girls) of ages 14 and 15 years who were part of the ongoing Physical Activity and Health Longitudinal Study (PAHLS) participated in the study. For the purpose of the present study, data collected for 2011 and 2012 for anthropometric, body composition and health-related physical fitness were used. RESULTS: Body mass index (BMI) classification of boys and girls for 2011 and 2012 showed that 24.3% of them were underweight compared with 21% in 2012. In 2011, 50% of boys and girls had normal bodyweight compared with 52% in 2012, whilst 25.5% of the total group of participants were overweight compared with 27% in 2012. Both boys and girls showed significant increases of 5.9% in body fat (BF) and 3.2 kg in body weight over two years' measurements, respectively. Regarding health-related fitness (i.e BAH), boys showed an increase of 14.8 seconds whilst girls gained 9.6 seconds. Significant decreases were found for sit-ups in both boys and girls. A significant VO2max increase of 2.9 mL/kg/min. was found in boys over the time period. A non-significant decrease of -0.5 mL/kg/min. was observed in girls. Regression coefficients showed that changes in BMI were inversely associated with those in health-related physical fitness. The changes in percentage BF were negatively associated with standing broad jump (SBJ), bent arm hang (BAH) and VO2 max in both boys and girls. A low significant positive association was found between changes in waist-to-height ratio (WHtR) and SBJ in both genders, whilst inverse low associations were found between WHtR and BAH in girls and for VO2max in both genders. CONCLUSION: Changes in BMI, %BF and WHtR were negatively associated with strength and running performances in the participating children. The relative increase in overweight, especially in girls, negatively affected their endurance running and static strength performances. The health implications of the observed findings are discussed and recommendations offered for physical activity intervention in school physical education (PE) programmes.
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Antropometria , Composição Corporal/fisiologia , Aptidão Física , Adolescente , Feminino , Humanos , Estudos Longitudinais , Masculino , África do SulRESUMO
BACKGROUND: There is limited data on objectively determined habitual physical activity (PA) in 16-year old South African adolescents. The purpose of this study was to objectively determine the habitual PA of adolescents from the North West Province of South Africa by race and gender. METHODS: Adolescents (137 girls, 89 boys) from the ongoing Physical Activity and Health Longitudinal Study (PAHL study), participated in the present study. Habitual PA was objectively recorded by means of the Actiheart® over a period of 7 days. Time spent in moderate-to-vigorous intensity physical activity (MVPA) was assessed. RESULTS: Average MVPA for the study sample was 50.9 ± 40.3 minutes/day. Girls were significantly more active than boys expending more time in MVPA (61.13 ± 52.2 minutes/day; p < 0.05) than boys (35.0 ± 32.9 minutes/day). Although white adolescents spent more time in MVPA than black adolescents, there was no significant difference in MVPA between black (47.87 ± 39.6 minutes/day; p = 0.58) and white adolescents (59.5 ± 41.8 minutes/day). CONCLUSION: Physical activity varies by both gender and race in adolescents from the North West Province of South Africa. Objectively determined data from our study indicates that girls habitually spend more time in MVPA per day than boys, and that white adolescents habitually engage in more MVPA than black adolescents. Seeing as the average MVPA per day for the entire study sample falls below the recommended daily average of 60 minutes/day, adolescents should be the foremost targets of interventions aimed at enhancing habitual PA.
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Comportamento do Adolescente , Exercício Físico , Comportamentos Relacionados com a Saúde , Estilo de Vida , Esforço Físico , Adolescente , Comportamento do Adolescente/etnologia , População Negra , Feminino , Saúde , Comportamentos Relacionados com a Saúde/etnologia , Humanos , Estudos Longitudinais , Masculino , Atividade Motora , Fatores Sexuais , África do Sul , População BrancaRESUMO
OBJECTIVE: To determine if insulin-like growth factor-1 (IGF-1) is a significant predictor of body fat percentage (%BF), lean body mass, and insulin resistance (IR) in black adolescents presenting with overnutrition and undernutrition. METHODS: A cross-sectional study was undertaken in 181 adolescents (111 girls, 70 boys, 13-20 years old) from a low socio-economic population in the North-West Province, South Africa. Anthropometric measurements were performed, and %BF and lean mass were assessed by air displacement plethysmography. Serum glucose, leptin, insulin, IGF-1 and IGF-binding protein-3 (IGFBP-3) were measured and homeostasis model assessment of IR (HOMA-IR) was calculated. Predictors of body composition and HOMA-IR were determined in multivariate linear regressions. RESULTS: Of the boys, 31% had a %BF >20%, whereas 42% of girls had a %BF >30%. Furthermore, 17.1% male and 18.9% female adolescents were stunted, indicating overnutrition and undernutrition in the same group. IGF-1 showed a negative association with %BF in both sexes, and a positive correlation with height-for-age z-score (HAZ) and lean mass, respectively, in the boys. IGF-1 correlated positively and physical activity correlated negatively with fasting insulin and HOMA-IR in the girls. In both sexes, leptin had the strongest association with %BF in multiple regressions. Leptin and Tanner stage were significant predictors of HOMA-IR in girls, but not in boys. CONCLUSIONS: IGF-1 was positively associated with lean mass and HAZ in boys, indicating a beneficial relationship with linear growth, but with IR in the girls, indicating possible adverse metabolic effects in the presence of high %BF and physical inactivity.
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Adiposidade , Composição Corporal , Resistência à Insulina , Fator de Crescimento Insulin-Like I/genética , Circunferência da Cintura , Adolescente , Estudos Transversais , Feminino , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Desnutrição/epidemiologia , Hipernutrição/epidemiologia , África do Sul/epidemiologia , Adulto JovemRESUMO
BACKGROUND: The dyslipidemia associated with excess weight is a risk for cardiovascular disease. Worldwide and in South Africa adolescent obesity has been reported. OBJECTIVES: To determine the association between dyslipidemia and anthropometric indices in black and white adolescents. METHODS: The study involved 129 black and 69 white adolescents aged 12 to 16 years. Data collected included height, weight, waist circumference (WC) and skinfolds, blood pressure and blood for glucose, insulin, total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein (HDL), triglycerides (Trig) and C - reactive protein (CRP). RESULTS: WC correlated negatively with HDL in both blacks (p=0.042) and whites (p=0.008) and in whites it correlated positively with LDL (p=0.006); TC/HDL (p=<0.001) and LDL/HDL ratio (p<0.0001). WC/Hgt correlated negatively with HDL (p=0.028) and positively with LDL/HDL (p=0.026 and p<0.0001) in both races. In whites positive correlations were between WC/Hgt and TC (p=0.049); LDL (p=0.003) and TC/HDL (p<0.0001). BAZ correlated positively with TC/HDL ratio (p=0.004) and LDL/HDL ratio (p=0.002). The most common abnormalities were HDL and LDL. CONCLUSION: Whites exhibited more associations between dyslipidemia and anthropometric indicators as compared to Blacks, suggesting that there might be differences in the lipid metabolism or even susceptibility to risk factors in adolescents.
Assuntos
Antropometria , População Negra/estatística & dados numéricos , Dislipidemias/etnologia , Dislipidemias/etiologia , População Branca/estatística & dados numéricos , Tecido Adiposo/metabolismo , Adolescente , Pressão Sanguínea , Determinação da Pressão Arterial , Composição Corporal/fisiologia , Constituição Corporal , Estatura/fisiologia , Índice de Massa Corporal , Peso Corporal/fisiologia , Doenças Cardiovasculares/etiologia , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Estudos Transversais , Dislipidemias/sangue , Dislipidemias/complicações , Feminino , Humanos , Masculino , Fatores de Risco , África do Sul/epidemiologia , Triglicerídeos/sangue , População Urbana , Circunferência da CinturaRESUMO
OBJECTIVE: To evaluate demographic variation in the prevalence of overweight (OW) and obesity (OB) among 3240 children and adolescents (girls: n = 1714; boys: n = 1526) aged 9-16 years attending primary and secondary schools in Benue State of Nigeria. METHODS: Participants' anthropometric characteristics (body weight, stature, body mass index: BMI and lean body mass: LBM) were determined using standard protocols. OW and OB were estimated using International Obesity task Force diagnostic criteria. Data were analysed with one-way anova and binary logistic regression method. RESULTS: Overall, 88.5%, 9.7% and 1.8% of the adolescents had normal BMI and were OW and obese, respectively. Prevalence of OW was higher among girls (20.3%) than boys (16.2%), whereas a relatively higher incidence of OB was noted among the boys (3.5%). Girls in urban areas had a significantly higher BMI (t524 = 3.61, P = 0.002) than their rural peers, but the rural girls were more significantly OW than their urban counterparts (BMI: t1186 = 2.506). Logistic regression models assessing the influence of age, gender and location on OW/OB in children (α(2) (3, N = 1014) = 6.185, P = 0.103) and adolescents (α(2) (3, N = 2226) = 1.435, P = 0.697) did not turn up significant results. In the gender-specific analysis, the younger boys' model was also not significant (α(2) (2, N = 488) = 1.295, P = 0.523) in contrast to the girls' (α(2) (2, N = 526) = 15.637, P = 0.0005), thus discriminating between OW and healthy weight among the children. Overall, the model explained 2.9-4.4% of the variance in weight status and correctly classified 76.8% of the cases. Age wise, the model yielded a significant odds ratio of 1.49, suggesting that the likelihood of being OW increases by a factor of 1.5 with a unit increase in age. Also, the likelihood of an urban girl becoming OW or obese was 0.57 times that of a rural girl. CONCLUSIONS: In general, girls in urban areas had higher prevalence of OW and OB than girls in rural settings. Among the boys, similar but less marked trends were found, except that the rural boys tended to be more OW on average than their peers in urban areas. In view of its public health significance, it is important to periodically evaluate the prevalence of weight disorders in children and adolescents so that appropriate preventative strategies can be instituted.
Assuntos
Antropometria , Sobrepeso/epidemiologia , Obesidade Infantil/epidemiologia , Saúde Pública/estatística & dados numéricos , Adolescente , Estatura , Índice de Massa Corporal , Peso Corporal , Criança , Feminino , Humanos , Masculino , Nigéria/epidemiologia , Prevalência , Saúde da População Rural , Fatores Sexuais , Saúde da População UrbanaRESUMO
BACKGROUND: No information exists on the nutritional status of primary school children residing in Makurdi, Nigeria. It is envisaged that the data could serve as baseline data for future studies, as well as inform public health policy. The aim of this study was to assess the prevalence of malnutrition among urban school children in Makurdi, Nigeria. METHODS: Height and weight of 2015 (979 boys and 1036 girls), aged 9-12 years, attending public primary school in Makurdi were measured and the body mass index (BMI) calculated. Anthropometric indices of weight-for-age (WA) and height-for-age (HA) were used to estimate the children's nutritional status. The BMI thinness classification was also calculated. RESULTS: Underweight (WAZ < -2) and stunting (HAZ < -2) occurred in 43.4% and 52.7%, respectively. WAZ and HAZ mean scores of the children were -0.91(SD = 0.43) and -0.83 (SD = 0.54), respectively. Boys were more underweight (48.8%) than girls (38.5%), and the difference was statistically significant (p = 0.024; p < 0.05). Conversely, girls tend to be more stunted (56.8%) compared to boys (48.4%) (p = 0.004; p < 0.05). Normal WAZ and HAZ occurred in 54.6% and 44.2% of the children, respectively. Using the 2007 World Health Organisation BMI thinness classification, majority of the children exhibited Grade 1 thinness (77.3%), which was predominant at all ages (9-12 years) in both boys and girls. Gender wise, 79.8% boys and 75.0% girls fall within the Grade I thinness category. Based on the WHO classification, severe malnutrition occurred in 31.3% of the children. CONCLUSIONS: There is severe malnutrition among the school children living in Makurdi. Most of the children are underweight, stunted and thinned. As such, providing community education on environmental sanitation and personal hygienic practices, proper child rearing, breast-feeding and weaning practices would possibly reverse the trends.