Hatamoto Y., Tanoue Y., Tagawa R., Yasukata J., Shiose K., Kose Y., Watanabe D., Tanaka S., Chen K.Y., Ebine N., Ueda K., Uehara Y., Higaki Y., Sanbongi C., Kawanaka K. . Greater energy surplu2024 · 記述言語: 日本語 掲載種別: 研究論文(学術雑誌) 出版者・発行元: Clinical Nutrition Background & aims: Caloric overfeeding combined with adequate protein intake increases not only body fat mass but also fat-free mass. However, it remains unclear whether the increase in fat-free mass due to overfeeding is associated with an increase in total body protein mass. We evaluated the hypothesis that overfeeding would promote an increase in total body protein mass. Methods: In our randomized controlled trial, 23 healthy young men were fed a diet equivalent to their energy requirements with a +10 % energy surplus from protein alone or a +40 % energy surplus (+10 % from protein, +30 % from carbohydrate) for 6 weeks. We estimated total body protein mass by a four-compartment model using dual-energy X-ray absorptiometry, deuterium dilution, and hydrostatic underwater weighing. Results: The 40 % energy surplus over 6 weeks significantly increased body protein mass compared to baseline by 3.7 % (0.44 kg; 95 % confidence interval [CI], 0.21–0.67 kg; P = 0.003); however, the 10 % energy surplus did not result in a significant change (0.00 kg; 95 % CI, −0.38–0.39 kg; P = 0.980). A significant interaction between intervention duration (time) and energy surplus (group) was observed for total body protein mass (P = 0.035, linear mixed-effects model), with a trend toward a significant difference in total body protein mass gain between groups (P = 0.059, Wilcoxon rank sum test). The increase in body protein mass due to the energy surplus was correlated with an increase in fat mass (r = 0.820, p = 0.002). Conclusions: A higher energy intake was found to promote an increase in body protein mass in healthy men consuming excess protein, suggesting the importance of energy surplus in body protein accumulation. This effect of energy surplus may be related to factors such as increased body fat mass and the associated secretion of adipokines. Trial registration: The trial was registered with the University Hospital Medical Information Network Clinical Trial Registry as UMIN000034158. DOI: 10.1016/j.clnu.2024.09.035 Scopus PubMed
Iwasaka C., Yamada Y., Nishida Y., Hara M., Yasukata J., Miyoshi N., Shimanoe C., Nanri H., Furukawa T., Koga K., Horita M., Higaki Y., Tanaka K. . Association of appendicular extracellular-to2023 · 記述言語: 英語 掲載種別: 研究論文(学術雑誌) 出版者・発行元: Archives of Gerontology and Geriatrics Background: The appendicular extracellular-to-intracellular water ratio (Ap ECW/ICW) has recently gained attention as a non-invasive measurable marker of muscle quality. However, there is a lack of basic evidence regarding age-related changes, sex differences, contribution to muscle strength independent of skeletal muscle mass (SMM), and potential improvement through physical activity (PA) in Ap ECW/ICW. Methods: This cross-sectional study enrolled 8,018 middle-aged and older Japanese individuals (aged 45–75 years). The Ap ECW/ICW and SMM were measured using segmental bioelectrical impedance spectroscopy. Muscle strength was evaluated by measuring the handgrip strength (HGS) with a dynamometer, and the PA level (PAL) was measured with an accelerometer. We performed a linear regression analysis of the associations of the Ap ECW/ICW with age, HGS, and PAL. Results: The Ap ECW/ICW increased by 0.019 for men and 0.014 for women per 5-year increase in age (p < 0.001), and the age-related increase was greater in men than in women (p for interaction <0.001). The Ap ECW/ICW was more strongly associated with the HGS than with the SMM in both men and women (p < 0.001). PAL showed a significant inverse association with the Ap ECW/ICW in both men and women (p < 0.001). Conclusions: Ap ECW/ICW is higher with age, and it varies by sex. The Ap ECW/ICW may reflect muscle strength more than the SMM, suggesting that the Ap ECW/ICW may be improved by PA. The findings from this study may provide a framework for further Ap ECW/ICW research. DOI: 10.1016/j.archger.2023.104931 Scopus PubMed
Sagayama H., Kondo E., Tanabe Y., Uchizawa A., Evans W.J., Shankaran M., Nyangau E., Hellerstein M., Shiose K., Yoshida T., Yasukata J., Higaki Y., Ohnishi T., Takahashi H., Yamada Y. . Compar2023 · 記述言語: 英語 掲載種別: 研究論文(学術雑誌) 出版者・発行元: Journal of Nutrition Background: Bioelectrical impedance analysis (BIA) is a minimally invasive, safe, easy, and quick technology used to determine body composition. Objectives: We compared the relationship among impedance indices obtained using single-frequency BIA, multi-frequency BIA, bioelectrical impedance spectroscopy (BIS), and skeletal muscle mass (SMM) of physically active young men and athletes using the creatine (methyl-d3) dilution method. We also compared the SMM and intracellular water (ICW) of athletes and active young men measured using a reference stable isotope dilution and BIS method, respectively. Methods: We analyzed data from 28 men (mean age, 20 ± 2 y) who exercised regularly. Single-frequency BIA at 5 kHz and 50 kHz (R5 and R50), multi-frequency BIA (R250–5), and BIS (RICW) methods of determining the SMM were compared. The deuterium and sodium bromide dilution methods of obtaining the total body water, ICW, and extracellular water measurements were also used, and the results were compared to those acquired using bioimpedance methods. Results: The correlation coefficients between SMM and L2/R5, L2/R50, L2/R250–5, and L2/RICW were 0.738, 0.762, 0.790, and 0.790, respectively (P < 0.01). The correlation coefficients between ICW and L2/R5, L2/R50, L2/R250–5, and L2/RICW were 0.660, 0.687, 0.758, and 0.730, respectively (P < 0.001). However, the correlation coefficients of L2/R50, L2/R250–5, and L2/RICW for SMM and ICW were not significantly different. Conclusions: Our findings suggest that single-frequency BIA at L2/R50, multi-frequency BIA, and BIS are valid for assessing the SMM of athletes and active young men. Additionally, we confirmed that the SMM and ICW were correlated with single-frequency BIA, multi-frequency BIA, and BIS. Bioimpedance technologies may be dependable and practical means for assessing SMM and hydration compartment status of active young adult males; however, cross-validation is needed. DOI: 10.1016/j.tjnut.2023.07.010 Scopus PubMed