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  • Author: Bruna R. Silva x
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Cutoff points of BMI for classification of nutritional status using bioelectrical impedance analysis

Abstract

The objective of this study was to improve the cutoff points of the traditional classification of nutritional status and overweight / obesity based on the BMI in a Brazilian sample. A cross-sectional study was conducted on 1301 individuals of both genders aged 18 to 60 years. The subjects underwent measurement of weight and height and bioelectrical impedance analysis. Simple linear regression was used for statistical analysis, with the level of significance set at p < 0.05. The sample consisted of 29.7% men and 70.3% women aged on averaged 35.7 ± 17.6 years; mean weight was 67.6 ± 16.0 kg, mean height was 164.9 ± 9.5 cm, and mean BMI was 24.9 ± 5.5 kg/m2. As expected, lower cutoffs were found for BMI than the classic reference points traditionally adopted by the WHO for the classification of obesity, i.e., 27.15 and 27.02 kg/m2 for obesity for men and women, respectively. Other authors also follow this tendency, Romero-Corral et al. (2008) suggested 25.8 to 25.5 kg/m2 for American men and women as new values for BMI classification of obesity. Gupta and Kapoor (2012) proposed 22.9 and 28.8 kg/m2 for men and women of North India. The present investigation supports other literature studies which converge in reducing the BMI cutoff points for the classification of obesity. Thus, we emphasize the need to conduct similar studies for the purpose of defining these new in populations of different ethnicities.

Open access
Genetic diversity and spatial genetic structure in populations of Orbignya phalerata Mart. under different exploitation intensities in the Brazilian savanna

Abstract

Genetic studies in tropical tree species have found signs of decreased genetic diversity and increased levels of inbreeding and spatial genetic structure (SGS) in fragmented and exploited populations. The aim of this paper was to investigate genetic diversity, structure, and intrapopulation SGS using eight microsatellite loci for three Orbignya phalerata populations that have undergone different intensities of seed harvesting. From each population, we georeferenced and sampled 30 seedlings, 30 juveniles, and 30 adult trees. The total number of alleles over all loci (k), and observed (Ho) and expected heterozygosity (He) presented lower values for the population experiencing more intense fruit harvesting than less heavily exploited populations, suggesting that fruit harvesting may decrease genetic diversity. Null alleles were detected in practically all loci among seedlings, juveniles, and adults in all populations, indicating that the estimates of Ho, He, and fixation index (F) are biased. When corrected for null alleles (FNull), the fixation index decreased for all samples, resulting in significantly higher than zero results for seedlings of all populations, but not for juveniles and adults of all populations. The comparison of FNull values between cohorts in the most heavily exploited population (ESP) suggests that inbred individuals are eliminated between seedling and adult stages. Significant SGS was detected up to 60 m in all populations, which indicates short distance seed dispersal. Genetic differentiation (G’ST) between pairwise populations was related to spatial distance between populations, with the greatest difference between more distant populations.

Open access