Using Receiver Operating Characteristic Curve Analysis in Detecting Excess Adiposity in 9-13-year Old South African Children

Objective: Little is known concerning the applicability of receiver operating characteristic (ROC) curve analysis in detecting excess adiposity in preadolescent South African children. Therefore the purpose of this study was to evaluate the sensitivity and specificity of body mass index (BMI) and skinfold thickness:BMI (subcutaneous to overall fat) in detecting excess adiposity in preadolescent urban South African school children. Methods: This was a cross-sectional survey of 1136 randomly selected children (548 boys and 588 girls) aged 9-13 years old in urban (Pretoria Central) South Africa. Body mass, stature, skinfolds (subscapular, triceps, supraspinale and biceps) and waist circumference were measured. Receiver operating characteristic curve analysis was used to assess the sensitivity and specificity of BMI, and log10 SF4:BMI to detect excess adiposity. Excess adiposity was defined as levels of log10 SF4 greater than the internally derived 85th percentile (log10 SF4 > 85th percentile). Results: Compared to log10 SF4:BMI, BMI had a high specificity (0.88; 95% CI 0.84, 0.90). The log10 SF4:BMI identified excess adiposity with a sensitivity and specificity of 0.62 (95% CI 0.60, 0.67) and 0.68 (95% CI 0.64, 0.70), respectively. Besides, a decrease in overall misclassification with the use of log10 SF4:BMI instead of BMI at the 95th percentile (9.7% versus 27.1%) was observed. Conclusion: Similar to other studies, although with varying degrees, the present study confirms that log10 SF4:BMI at conventional cut-off points has a relatively high sensitivity and specificity in detecting excess adiposity, and therefore could be used to identify the excess adiposity in South African children. As such, defining obesity based on population-specific percentiles rather than using cut-off points derived from other geographical settings with contrasting levels of socio-economic development becomes imperative. Keywords: Adiposity, body mass index, children, obesity, receiver operating characteristic (ROC) curve analysis, sensitivity, specificit

Gender differences in aerobic fitness of pre-adolescent school children in Makurdi, Nigeria

No Abstract.South African Journal for Physical, Health Education, Recreation and DanceVol. 12(4) 2006: pp. 356-36

Overweight, obesity and underweight in rural black South African children

Background: The objective was to estimate the prevalence of overweight, obesity and underweight conditions among rural black children in South Africa. A cross-sectional study was undertaken. The setting was Mankweng and Toronto, both rural settlements in Capricorn district, Limpopo province, South Africa. Participants were 1 172 school children (541 boys and 631 girls) aged 10-16 years.Method: The prevalence of overweight, obesity and underweight was examined, using the Centers for Disease Control and Prevention (CDC) body mass index (BMI) cut-off points. Height and body weight were measured using standard techniques. Results were analysed with student t-test statistics, with probability level set at p-value ≤ 0.05.Results: The percentage of children who were at risk of overweight were higher in girls (11%) than boys (9.1%), whereas obesity occurred more among the boys (5.5%), compared with the girls (4.4%). Applying the CDC cut-off points of 5th < percentile to define underweight, 25 (4.6%) and 35 (5.2%) of boys and girls respectively were underweight.Conclusion: Similar to previous studies, this study indicates that overweight and obesity are high among South African children, even in rural settings. The study also demonstrates that underweight is prevalent among the sampled children. This supports the notion of a double burden of disease in developing countries

Sex differences in body fatness in Nigerian children

ABSTRACT Childhood and adolescent obesity tends to extend into adulthood and predisposes the individual to some chronic diseases in later life. Body composition is a good parameter for evaluating obesity and nutritional status of children. This study aimed to investigate differences in body fat of Nigerian school children in Makurdi, Nigeria. The study sample consisted of a cross-sectional study of 979 boys and 1036 girls who were aged 9-12 years. Anthropometric measures of stature, body mass, triceps, subscapular and medial calf skinfolds were assessed. Percentage body fat in girls ranged from 15.2-17.4%, which was consistently higher than that in boys, i.e. 10.3- 11.9%. Generally, the girls had higher measures of adipose tissue (sum of skinfolds and percentage body fat) than boys. The Nigerian girls at all ages had higher percentage body fat compared to the boys, which indicates gender differences in the children’s body fatness. The study provides a baseline assessment of body fatness in Nigerian children. Future studies on tracking of percentage body fat in relation to nutritional and fitness levels in Nigerian children are needed so that the children, parents and teachers can obtain reliable information about body composition and health related fitness

Musculoskeletal fitness in Nigerian school children

Summary Aim. The purpose of this study was to examine age and gender differences in muscular strength and flexibility among primary school children and to compare the findings with data for school-going children from other countries. Method. A cross-sectional survey was conducted among 2 015 primary school children in Makurdi, Nigeria (N.=979 boys; N.=1 036 girls) aged 9-12 years, who performed the FITNESSGRAM (CIAR, 2000) physical fitness tests. Results. A non-significant difference in flexibility was found between boys (mean: 27.1±4.4 cm) and girls (mean: 26.9±4.6 cm) (P=0.851; P>0.05). ANOVA test indicated no significant sex main effect on flexibility test scores (F(1, 2007)=0.027; P>0.05), whereas this yielded a substantial age main effect (F(3, 2007)=3.407; P<0.05). On average, boys had a slight, but significantly superior push-up performance (9.1±3.9) compared to girls (8.6±3.5) (P=0.04; P<0.05). Results also indicated substantial age difference in push-up scores among boys and girls (F(1, 3)=11.1; P<0.05). There were no significant age/ sex interaction effect (F(3, 2007)=1.396; P>0.05) and sex main effect in the sit-up performances for the boys and girls (P=0.188; P>0.05). Boys had significantly (P<0.05) higher mean sit-up values, at ages 10 and 12, whereas no statistically significant sex main effect was found regarding the children’s sit-up scores (F(1, 2007)=1.134; P>0.05). Conclusion. Whereas the study showed non-significant sex and age differences in flexibility between boys and girls, marked age- and gender- related discrepancies were found regarding muscular strength. The muscular endurance component showed inconsistent results across age groups

Sex Differences In Anthropometric Characteristics Of Nigerian School Children Aged 9-12 Years

The aim of this study was to assess the anthropometric and body composition profiles of Nigerian school children. A cross-sectional study was carried out involving 1036 girls and 979 boys aged 9-12 years. Anthropometric measurements, including body mass, stature, triceps, subscapular and medial calf skinfold thickness, as well as waist and hip circumferences were measured on the children. Body mass index (BMI), percent body fat, fat mass (FM), fat-free mass (FFM), waist-to-hip ratio (WHR), and subscapular/triceps skinfold ratio (STR) were also calculated. Sexual dimorphism that appears to be related to differential changes in body composition in the older children was observed. Findings showed that the Nigerian children have a low level of adiposity whether assessed by BMI, skinfold or percent body fat, compared to their peers in developed countries. The health implications of the findings were discussed. Keywords: Anthropometry, school children, percentage body fat, sex differences. African Journal for Physical, Health Education, Recreation and Dance Vol. 14 (2) 2008: pp.130-14

Gender differences in waist circumference in Nigerian children

The aim of this study was to develop age- and sex-specific reference values for waist circumference (WC) based on a sample of 2015 primary school children (i.e. 979 boys and 1036 girls aged 9-12 years) who were randomly selected from 19 primary schools in Makurdi, Benue State of Nigeria. Waist and hip circumferences were measured wi th a flexibleanthropometric tape according to the protocol of the International Society for the Advancement of Kinanthropometry (ISAK). Mean WC was higher in girls than in boys, and these differences were statistically signi ficant from age 10 onwards. Similarly, hip circumference was significantly higher (

Centripetal fat patterning in Nigerian children

The purpose of this study was to examine age and gender differences in waist-stature ratio (WSR) as a measure of centripetal fat patterning in Nigerian children. A cross-sectional study of 2015 children, aged 9-12 years of age who were attending primary schools in Makurdi, Nigeria was undertaken. Anthropometric measurements included body mass, stature and waist circumference. WSR decreased with age in boys (p &le; 0.05) with the mean WSR being significantly higher at age nine (p &le; 0.05) compared to girls. The girls had significant lower WSR (p &le; 0.001) at age 11 compared to boys. No significant differences in WSR were found at ages 10and 12 in both boys and girls. The proportion of children whose WSR exceeded the 0.500 boundary value was for boys, 9.85% and girls 17.75%. Compared to the boys, girls had higher proportional WSR (5.28% and 6.56%) exceeding 0.500 cut-off values at ages 10 and 11, respectively. Inconsistent gender differences in WSR &le; 0.500 were observed in both categories of children at all ages. The prevalence of WSR &le; 0.500 was evident in this sample at all ages, suggesting the existence of central body fatness in the children. The findings demonstrate thatWSR can be used as an alternative measure to body mass index to screen children for risk of metabolic disorders.Key words: Waist circumference, waist-to-stature ratio, central fatness, children