The effects of melatonin and magnesium in a novel supplement delivery system on sleep scores, body composition and metabolism in otherwise healthy individuals with sleep disturbances.

The purpose of this study was to investigate the effects of a novel dietary supplement, including melatonin and magnesium, delivered via coffee pods on sleep quality, resting metabolic rate (RMR), and body composition in individuals with poor sleep quality disturbances. Using a double-blinded, randomized, crossover trial, we recruited 35 participants to a 4-week intervention with both supplements (1.9 mg melatonin + 200 mg elemental magnesium before sleep) and placebo conditions, considering a 7d washout period between treatments. The Pittsburgh Sleep Quality Index (PSQI) questionnaire was applied, RMR (kcal) was measured using indirect calorimetry (canopy ventilated open-circuit system) and body composition was assessed using dual-energy X-ray absorptiometry. Decreases in PSQI and anger - hostility scores, as well as in energy intake and fat mass, were observed (p < 0.05) for both conditions, from baseline to the end of each 4-week intervention. Differences between conditions were also observed for these parameters along with energy spent in activity, number of sedentary breaks, sleep efficiency, latency time, time in bed, total sleep time, awakening time, and movement index (p < 0.05) favouring the supplement condition. However, the final PSQI questionnaire scores still indicated poor sleep quality on average (PSQI > 5), in both conditions, with no changes regarding RMR. A melatonin-magnesium supplement, in a coffee pod format, showed improvements in sleep quality in otherwise healthy individuals with sleep disturbances, however PSQI questionnaire scores still indicated poor quality on average (PSQI > 5).

Validação da bioimpedância elétrica por multifrequência em atletas / Validation of multifrequency bioelectrical impedance analysis in athletes

É reconhecida a importância de avaliar a composição corporal na população atlética. Para o efeito é preciso utilizar técnicas válidas na determinação dos principais componentes moleculares. A Densitometria Radiológica de Dupla Energia (DXA) é um método preciso e válido para avaliação decomposição corporal. No entanto, a DXA é uma técnica ainda pouco acessível em contextos não laboratoriais. Desta forma, é importante utilizar técnicas mais simples e práticas como a bioimpedância eléctrica (BIA). No entanto poucos estudos validaram a BIA especialmente de multifrequência na avaliação da composição corporal em atletas. Assim, o objetivo desta investigação é testar a validade da BIA de multifrequência (Tanita, modelo MC-180) na determinação do conteúdo mineral ósseo (CMO),massa gorda (MG) e massa isenta de gordura e osso (MIGO) em atletas. Um total de 79 atletas (35 homens) foram avaliados pela BIA e pela DXA. Comparação de médias, coeficiente de correlação de concordância, regressão múltipla, e o método Bland-Altman foram realizados. A Tanita apresentou um poder explicativo de 76 %, 72%, 95% e 73% da variabilidade total observada a partir do método de referência para a MG (kg), MG (%), MIGO e CMO, respectivamente. O coeficiente de correlação de concordância para a MIGO apresentou uma força de concordância substancial de 0.927. Observaram-selimites de concordância relativamente elevados na estimativa dos vários componentes corporais. Em conclusão, a Tanita MC-180 é uma alternativa válida especialmente na estimação da massa isenta de gordura e de osso, num grupo de atletas. Contudo, devido aos limites de concordância obtidos na determinação das vários componentes este equipamento apresenta uma validade limitada na estimação individual da composição corporal...

It is recognized the importance of assessing body composition in athletic populations.Therefore, it is necessary to use valid techniques for the determination of the main molecular components.Dual-energy X-ray absorptiometry (DXA) is a precise and valid method for assessing body composition.However, DXA is still not available at the clinical and field settings. Thus, it is important to use simpletechniques such as electrical bioimpedance analysis (BIA) but few studies validated this techniquespecifically multifrequency BIA in body composition assessment in athletes. Therefore, the aim of thisresearch is to test the validity of multifrequency BIA (Tanita, Model MC-180) in the determination ofbone mineral content (BMC), lean soft tissue (LST) and fat mass (FM) in athletes. A total of 79 eliteathletes (35 males) were assessed by DXA and BIA. Comparison of means, concordance coefficientcorrelation, multiple regression and Bland–Altman analysis were performed. Tanita explained 76%, 72%,95% and 73% of the total variability observed from the reference method for FM (kg), FM (%), LST andBMC, respectively. The concordance coefficient correlation for MIGO presented a substantial strength ofagreement of 0,927. However, relatively larger limits of agreement were found between BIA and DXA forthe several body components. These findings reveal that the Tanita MC-180 is a valid alternative,particularly in the estimation of LST, in a group of athletes. However, due to the limits of agreementobtained in the determination of the body components this equipment presents a more limited validity inthe estimation of individual body composition...