Association between children and adolescents' body composition with family income / Associação entre a composição corporal de crianças e adolescentes e renda familiar

ABSTRACT Objective To evaluate the association between children and adolescents' body composition with family income. Methods Cross-sectional study, participants between 5 and 19 years were included. A standardized questionnaire assessed socioeconomic variables. The outcome variables were z-score of Body Mass Index and bioimpedance parameters (skeletal muscle mass, fat-free mass, and fat percentage) and predictor variables (age, sex, race, place of residence, father's education, birth weight and breastfeeding) were analyzed using the quantile regression model and data from the 50th percentile are presented. The tests were bidirectional and the differences were considered significant with p<0.05. Results Among the 529 participants included, 284 (53.6%) were female and the mean age was 11.41±3.9 years. The Body Mass Index z-score was the only outcome that did not show differences between sexes (p=0.158). In the crude model, lower family income was associated with lower skeletal muscle mass (Difference=-7.70; 95% CI -9.32 to -5.89), p<0.001), lower fat-free mass (Difference= -13.40; 95% CI -16.40 to -10.39, p<0.001) and the lowest percentage of fat was associated with lower family income (Difference= -5.01, 95% CI -9.91 to -0.11, p=0.027). The z-score of BMI was not associated with family income. Conclusion Family income is directly associated with lower fat-free mass, fat percentage, and skeletal muscle mass in children and adolescents.

RESUMO Objetivo Avaliar a associação entre a composição corporal de crianças e adolescentes com a renda familiar. Métodos Estudo transversal, foram incluídos participantes entre 5 e 19 anos. As variáveis socioeconômicas foram avaliadas por meio de questionário padronizado. As variáveis de desfecho foram escore Z do índice de massa corporal e parâmetros de bioimpedância (massa muscular esquelética, massa livre de gordura e percentual de gordura) e variáveis preditoras (idade, sexo, raça, local de residência, escolaridade do pai, peso ao nascer e aleitamento materno) foram analisados pelo modelo de regressão quantílica e são apresentados os dados do percentil 50. Os testes foram bidirecionais, e as diferenças foram consideradas significativas com p<0,05. Resultados Entre os 529 participantes incluídos, 284 (53,6%) eram do sexo feminino e a média de idade foi de 11,41±3,9 anos. O escore Z do índice de massa corporal foi o único desfecho que não apresentou diferenças entre os sexos (p=0,158). No modelo bruto, uma menor renda familiar foi associada a menor massa muscular esquelética (Diferença= -7,70; IC 95% -9,32 a -5,89), p<0,001), menor massa livre de gordura (Diferença= -13,40; IC 95% -16,40 a -10,39, p<0,001) e o menor percentual de gordura associou-se à menor renda familiar (Diferença= -5,01, IC 95% -9,91 a -0,11, p=0,027). O escore Z do IMC não foi associado à renda familiar. Conclusão A renda familiar está diretamente associada à menor massa magra, ao percentual de gordura e à massa muscular esquelética em crianças e adolescentes.

Association between phase angle from bioelectrical impedance analysis and level of physical activity: Systematic review and meta-analysis.

OBJECTIVE: To evaluate the relationship between physical activity and phase angle. DESIGN: Systematic Review and Meta-analysis. DATA SOURCES: Electronic searches of MEDLINE (via PUBMED), EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), SciELO, LILACS, SPORTDiscus, Scopus, and Web of Science from inception to December 10th, 2017. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: The PICOS strategy was defined, in which "P" corresponded to participants of any age, sex or ethnicity, "I" indicated any type of physical activity program, "C" denoted lack of exercise or irregular physical activity, "O" corresponded to the phase angle obtained by bio-impedance, and "S" indicated longitudinal or cross-sectional studies. RESULTS: In cross-sectional studies the phase angle was higher among the active individuals (MD = 0.70; 95% CI: 0.48, 0.92, P < 0.001), with low heterogeneity (I2 = 0%; P = 0.619). In longitudinal studies, the mean of the difference of phase angles from the baseline was significantly higher for the active group than the control group (MD = 0.30; 95% CI: 0.11, 0.49, P = 0.001), with low heterogeneity (I2 = 13%, P = 0.331). No evidence of publication bias was found and the overall risk of bias was moderate to high. SUMMARY/CONCLUSION: The positive association of physical activity with phase angle reinforces the importance of routinely including exercise in health care. We also identified the need for further studies to define with different types, intensities and frequencies of exercises should be conducted in order to find the best dose-effect relationship.

Effects of Diet on Telomere Length: Systematic Review and Meta-Analysis.

BACKGROUND: The goal of this systematic review and meta-analysis is to determine the effect of diet on telomere length. METHODS: We searched the following databases: MEDLINE, Embase, LILACS, CINAHL, ISI Web of Science, and Scopus, as well as the Cochrane Central Register of Controlled Trials and the National Institutes of Health, from inception to December 2016. Articles that assessed effects of diet on telomere length were included. RESULTS: A total of 2,128 studies were identified, 30 were read in full, and 7 were systematically reviewed. Five RCTs were included in the meta-analysis, covering 9 diets; a total of 533 participants were included. Study heterogeneity (I2) was 89%, and differences were not identified regarding average telomere lengths (mean difference 1.06; 95% CI -1.53 to 3.65). CONCLUSION: The available evidence suggests that there is no effect of diet on telomere length, but the strong heterogeneity in the type and duration of dietary interventions does not allow any final statement on the absence of an effect of diet on telomere length.