Ethnic differences in body fat distribution among Asian pre-pubertal children: A cross-sectional multicenter study

Background Ethnic differences in body fat distribution contribute to ethnic differences in cardiovascular morbidities and diabetes. However few data are available on differences in fat distribution in Asian children from various backgrounds. Therefore, the current study aimed to explore ethnic differences in body fat distribution among Asian children from four countries. Methods A total of 758 children aged 8-10 y from China, Lebanon, Malaysia and Thailand were recruited using a non-random purposive sampling approach to enrol children encompassing a wide BMI range. Height, weight, waist circumference (WC), fat mass (FM, derived from total body water [TBW] estimation using the deuterium dilution technique) and skinfold thickness (SFT) at biceps, triceps, subscapular, supraspinale and medial calf were collected. Results After controlling for height and weight, Chinese and Thai children had a significantly higher WC than their Lebanese and Malay counterparts. Chinese and Thais tended to have higher trunk fat deposits than Lebanese and Malays reflected in trunk SFT, trunk/upper extremity ratio or supraspinale/upper extremity ratio after adjustment for age and total body fat. The subscapular/supraspinale skinfold ratio was lower in Chinese and Thais compared with Lebanese and Malays after correcting for trunk SFT. Conclusions Asian pre-pubertal children from different origins vary in body fat distribution. These results indicate the importance of population-specific WC cut-off points or other fat distribution indices to identify the population at risk of obesity-related health problems

Admixture Mapping of 15,280 African Americans Identifies Obesity Susceptibility Loci on Chromosomes 5 and X

The prevalence of obesity (body mass index (BMI) ≥30 kg/m2) is higher in African Americans than in European Americans, even after adjustment for socioeconomic factors, suggesting that genetic factors may explain some of the difference. To identify genetic loci influencing BMI, we carried out a pooled analysis of genome-wide admixture mapping scans in 15,280 African Americans from 14 epidemiologic studies. Samples were genotyped at a median of 1,411 ancestry-informative markers. After adjusting for age, sex, and study, BMI was analyzed both as a dichotomized (top 20% versus bottom 20%) and a continuous trait. We found that a higher percentage of European ancestry was significantly correlated with lower BMI (ρ = −0.042, P = 1.6×10−7). In the dichotomized analysis, we detected two loci on chromosome X as associated with increased African ancestry: the first at Xq25 (locus-specific LOD = 5.94; genome-wide score = 3.22; case-control Z = −3.94); and the second at Xq13.1 (locus-specific LOD = 2.22; case-control Z = −4.62). Quantitative analysis identified a third locus at 5q13.3 where higher BMI was highly significantly associated with greater European ancestry (locus-specific LOD = 6.27; genome-wide score = 3.46). Further mapping studies with dense sets of markers will be necessary to identify the alleles in these regions of chromosomes X and 5 that may be associated with variation in BMI

Avaliação nutricional de adultos da coorte de nascimentos de 1982, Pelotas, RS Evaluación nutricional de adultos de la cohorte de nacimientos de 1982, Pelotas, Sur de Brasil Nutritional evaluation follow-up of the 1982 birth cohort, Pelotas, Southern Brazil

OBJETIVO: Estimar a prevalência de desnutrição por déficit ou excesso de peso e sua associação com fatores demográficos e socioeconômicos. MÉTODOS: Estudo longitudinal de coorte de jovens nascidos em 1982 em Pelotas, RS. Em 2004-5 foram entrevistados 4.198 dos 5.914 indivíduos dessa coorte, que tiveram suas medidas de peso e estatura coletadas para cálculo do índice de massa corporal (IMC). Definiu-se baixo peso pelo valor de IMC inferior a 18,5 kg/m²; excesso de peso, pelo IMC entre 25 e 30kg/m²; e obesidade pelo IMC>30kg/m². Os efeitos de variáveis socioeconômicas (renda familiar e escolaridade), demográfica (cor da pele), peso ao nascer e amamentação sobre baixo peso, excesso de peso e obesidade foram analisados utilizando regressão de Poisson separadamente para homens e mulheres. RESULTADOS: As prevalências de baixo peso, obesidade e excesso de peso foram 6,0%, 8,2% e 28,9%, respectivamente. Na análise ajustada somente o peso ao nascer manteve-se associado com baixo peso em homens e mulheres. Homens pobres tiveram maior risco de baixo peso, mas ficaram protegidos da obesidade e do excesso de peso. Por outro lado, o risco de obesidade e excesso de peso foi maior entre as mulheres pobres. CONCLUSÕES: Os resultados reforçam a importância da determinação socioeconômica sobre o estado nutricional, chamando atenção como esses fatores agem de forma distinta em homens e mulheres de diferentes situações nutricionais, indicando atenção no que se refere a medidas específicas na prevenção, melhorando o acesso à informação sobre educação alimentar e nutricional para toda população.<br>OBJETIVO: Estimar la prevalencia de desnutrición por déficit o exceso de peso y su asociación con factores demográficos y socioeconómicos. MÉTODOS: Estudio longitudinal de cohorte de jóvenes nacidos en 1982 en Pelotas (Sur de Brasil). En 2004-5 fueron entrevistados 4.198 de los 5.914 individuos de esa cohorte, que tuvieron sus medidas de peso y estatura colectadas para cálculo del índice de masa corporal (IMC). Se definió bajo peso por el valor de IMC inferior a 18,5 kg/m²; exceso de peso por el IMC entre 25 y 30 30kg/m²; y obesidad por el IMC>30kg/m². Los efectos de variables socioeconómicas (renta familiar y escolaridad), demográfica (color de piel), peso al nacer y amamantamiento sobre bajo peso, exceso de peso y obesidad fueron analizados utilizando regresión de Poisson separadamente para hombres y mujeres. RESULTADOS: Las prevalencias de bajo peso, obesidad y exceso de peso fueron 6,0%, 8,2% y 28,9%, respectivamente. En el análisis ajustado solamente el peso al nacer se mantuvo asociado con bajo peso en hombres y mujeres. Hombres pobres tuvieron mayor riesgo de bajo peso, pero estuvieron protegidos de la obesidad y del exceso de peso. Por otro lado, el riesgo de obesidad y exceso de peso fue mayor entre las mujeres pobres. CONCLUSIONES: Los resultados refuerzan la importancia de la determinación socioeconómica sobre el estado nutricional, llamando la atención de cómo esos factores actúan de forma distinta en hombres y mujeres de diferentes situaciones nutricionales, indicando atención en lo que se refiere a medidas específicas en la prevención, mejorando el acceso a la información sobre educación alimentar y nutricional para toda la población.<br>OBJECTIVE: To estimate the prevalence of over/underweight and its association with demographic and socioeconomic factors. METHODS: Longitudinal cohort study of youths born in 1982 in Pelotas, Southern Brazil. In 2004-5 we interviewed 4,198 of the 5,914 cohort subjects, obtaining weight and stature measurements that were used to calculate body mass index (BMI). Underweight was defined as BMI lower than 18,5 kg/m²; overweight as BMI between 25 and 30kg/m²; and obesity as BMI IMC > 30kg/m². The effects of socioeconomic (family income and schooling) and demographic (skin color) variables, birthweight, and breastfeeding on underweight, overweight, and obesity were analyzed separately for men and women using Poisson regression. RESULTS: Prevalence of underweight, obesity, and overweight were 6.0%, 8.2%, and 28.9%, respectively. In adjusted analysis, only birthweight remained associated with underweight among men and women. Poor men showed higher risk of underweight, but were protected from obesity and overweight. By contrast, risk of obesity and overweight was higher among poor women. CONCLUSIONS: The present results underscore the importance of socioeconomic determinants on nutritional status, with special emphasis on the distinct effects these factors have among men and women in different nutritional conditions