It has been suggested that exercise has preferential effects on visceral fat reduction. However, the dose-response effect remains unclear because of limited evidence from individual studies. The ...purpose of this study was to systematically review the current literature to establish whether reduction of visceral fat by aerobic exercise has a dose-response relationship.
A database search was performed (PubMed, 1966-2006) with appropriate keywords to identify studies exploring the effects of aerobic exercise as a weight loss intervention on visceral fat reduction. Visceral fat reduction was expressed as the percentage of visceral fat change per week (%DeltaVF/w). The energy expenditure by aerobic exercise was expressed as Sigma (metabolic equivalents x h per week (METs x h/w)).
Nine randomized control trials and seven non-randomized control trials were selected. In most of the studies, the subjects performed aerobic exercise generating 10 METs x h/w or more. Among all the selected groups (582 subjects), visceral fat decreased significantly (P<0.05) in 17 groups during the intervention, but not in the other 4 groups. There was no significant relationship between METs x h/w from aerobic exercise and %DeltaVF/w in all the selected groups. However, when subjects with metabolic-related disorders were not included (425 subjects), METs x h/w from aerobic exercise had a significant relationship with %DeltaVF/w (r=-0.75). Moreover, visceral fat reduction was significantly related to weight reduction during aerobic exercise intervention, although a significant visceral fat reduction may occur without significant weight loss.
These results suggest that at least 10 METs x h/w in aerobic exercise, such as brisk walking, light jogging or stationary ergometer usage, is required for visceral fat reduction, and that there is a dose-response relationship between aerobic exercise and visceral fat reduction in obese subjects without metabolic-related disorders.
In this study of Japanese men and women, we determine reference values for sarcopenia and test the hypothesis that sarcopenia is associated with risk factors for cardiovascular disease, independent ...of waist circumference. A total of 1,488 Japanese men and women aged 18–85 years participated in this study. Appendicular muscle mass (AMM) was measured by dual-energy X-ray absorptiometry. Reference values for classes 1 and 2 sarcopenia (skeletal muscle index: AMM/height
2
, kg m
−2
) in each sex were defined as values one and two standard deviations below the sex-specific means of reference values obtained in this study from young adults aged 18–40 years. The reference values for class 1 and class 2 sarcopenia were 7.77 and 6.87 kg m
−2
in men and 6.12 and 5.46 kg m
−2
in women. In subjects both with class 1 and class 2 sarcopenia, body mass index and % body fat were significantly lower than in normal subjects. Despite whole-blood glycohaemoglobin A1c in men with class 1 sarcopenia was significantly higher than in normal subjects, and brachial-ankle pulse wave velocity in women both with class 1 and class 2 sarcopenia were significantly higher than in normal subjects, using one-way ANCOVA with adjustment for the covariate of waist circumference. Although sarcopenia is associated with thin body mass, it is associated with more glycation of serum proteins in men and with greater arterial stiffness in women, independent of waist circumference.
Little information is available regarding the interactions of sarcopenia and metabolic syndrome (MetS) in the risks of these age-associated diseases in women. The present cross-sectional study was ...performed to investigate whether the coexistence of sarcopenia and MetS further increases the risks of lifestyle-related diseases in Japanese women.
Healthy Japanese women (n=533) aged 30-84 participated in this study. MetS was defined as higher body mass index, fasting plasma glucose, systolic or diastolic blood pressure and blood lipid abnormalities. Appendicular muscle mass and bone mineral density (BMD) were measured using dual-energy X-ray absorptiometry. The criterion of low muscle mass and strength defined median skeletal muscle index (appendicular muscle mass/height², kg/m²) and handgrip strength.
Two-way ANCOVA with adjustment for age, body fat percentage and whole-body lean tissue mass indicated that sarcopenia and MetS interacted to produce a significant effect on HbA1c, systolic blood pressure, triglycerides and brachial-ankle pulse wave velocity in Japanese women. The systolic blood pressure, triglycerides and brachial-ankle pulse wave velocity were significantly higher in women with coexisting sarcopenia and MetS than in healthy controls or in those with sarcopenia or MetS alone. The HbA1c in the coexisting sarcopenia and MetS group was higher than in healthy controls and sarcopenia subjects.
The coexistence of sarcopenia and MetS further increases the risks of cardiovascular diseases, such as type 2 diabetes mellitus, hypertension, arterial stiffness and hyperlipidemia even adjustment of age and body composition in adult Japanese women.
Introduction: Basal metabolic rate (BMR) or sleeping metabolic rate (SMR) is the largest component of total energy expenditure (EE). An accurate prediction of BMR or SMR is needed to accurately ...predict total EE or physical activity EE for each individual. However, large variability in BMR and SMR has been reported. Objectives: This study was designed to develop prediction equations using body size measurements for the estimation of both SMR and BMR and to compare the prediction errors with those in previous reports. Methods: We measured body size, height, weight and body composition (fat mass and fat-free mass) from skinfold thickness in adult Japanese men (n=71) and women (n=66). SMR was determined as the sum of EE during 8 h of sleep (SMR-8h) and minimum EE during 3 consecutive hours of sleep (SMR-3h) measured using two open-circuit indirect human calorimeters. BMR was determined using a human calorimeter or a mask and Douglas bag. Results: The study population ranged widely in age. The SMR/BMR ratio was 1.010.09 (range 0.82-1.42) for SMR-8h and 0.940.07 (range 0.77-1.23) for SMR-3h. The prediction equations for SMR accounted for a 3-5% larger variance with 2-3% smaller standard error of estimate (SEE) than the prediction equations for BMR. Discussion: SMR can be predicted more accurately than previously reported, which indicates that SMR interindividual variability is smaller than expected, at least for Japanese subjects. The prediction equations for SMR are preferable to those for BMR because the former exhibits a smaller prediction error than the latter.
Objective: To validate reported energy intake (rEI) with a self-administered diet history questionnaire (DHQ) against total energy expenditure (TEE) by the doubly labeled water (DLW) method. ...Subjects: A total of 140 healthy Japanese adults (67 men and 73 women) aged 20-59 years living in four areas in Japan. Methods: Energy intake was assessed twice with DHQ over a 1-month period before and after TEE measurement (rEI(DHQ1) and rEI(DHQ2), respectively). TEE was measured by DLW during 2 weeks (TEE(DLW)). Results: Mean rEI(DHQ1) was lower than those of TEE(DLW) by 1.92.4 MJ/day (16.4%, P<0.001) for men and 0.61.9 MJ/day (6.0%, P<0.01) for women. In men and women together, 62 subjects (44%) were defined as underreporters (rEI(DHQ1)/TEE(DLW) <0.84), 58 (41%) as acceptable reporters (0.84-1.16) and 20 (14%) as over-reporters (>1.16). Pearson correlation coefficient was 0.34 for men and 0.22 for women. After adjustment for the dietary and non-dietary factors related to rEI(DHQ1)/TEE(DLW), the correlation coefficient improved to 0.42 and 0.37, respectively. Conclusion: The energy intake assessed with DHQ correlated low to modestly with TEE measured by DLW. In addition, DHQ underestimated energy intake at a group level. Caution is needed when energy intake was evaluated by DHQ at both individual and group levels.
Objective: To measure total energy expenditure (TEE) for normal healthy Japanese by the doubly labelled water (DLW), and to compare the physical activity level (PAL) among categories classified by ...the categories used in daily reference intake (DRI), Japan and the International Physical Activity Questionnaire (IPAQ). Subjects and methods: A total of 150 healthy Japanese men and women aged 20- to 59-year-old living in four districts of Japan. TEE was measured by the DLW method, and the PAL was calculated from TEE divided by basal metabolic rate. Simultaneously with TEE measurement, the PAL was assessed employing the categories used in DRI, Japan and IPAQ. Results: The average TEE and PAL were 10.781.67 MJ/day and 1.720.22 for males and 8.371.30 MJ/day and 1.720.27 for females, respectively. The subjects in the highly active categories assessed by both DRI and IPAQ showed significantly higher PAL compared with less active categories. However, PALs among light and moderate categories by DRI, and insufficient and sufficiently active by IPAQ were not significantly different. Conclusions: In developed countries, highly active subjects could be assessed by a simple questionnaire. However, the questionnaire should be improved to clarify the sedentary to moderately active subjects by assessing carefully very light to moderate physical activity.
Exercise training induces various adaptations in skeletal muscles. However, the mechanisms remain unclear. In this study, we conducted 2D-DIGE proteomic analysis, which has not yet been used for ...elucidating adaptations of skeletal muscle after high-intensity exercise training (HIT). For 5 days, rats performed HIT, which consisted of 14 20-s swimming exercise bouts carrying a weight (14% of the body weight), and 10-s pause between bouts. The 2D-DIGE analysis was conducted on epitrochlearis muscles excised 18 h after the final training exercise. Proteomic profiling revealed that out of 800 detected and matched spots, 13 proteins exhibited changed expression by HIT compared with sedentary rats. All proteins were identified by MALDI-TOF/MS. Furthermore, using western immunoblot analyses, significantly changed expressions of NDUFS1 and parvalbumin (PV) were validated in relation to HIT. In conclusion, the proteomic 2D-DIGE analysis following HIT-identified expressions of NDUFS1 and PV, previously unknown to have functions related to exercise-training adaptations.
Objectives: The purpose of this study was to investigate the effects of 20 days’ bed rest on the viscoelastic properties of human tendon structures in knee extensor and plantar flexor muscles in ...vivo. Methods: Eight healthy men (age: 24±4 years, height: 172±9 m, body mass: 69±13 kg) carried out a 6° head-down bed rest for 20 days. Before and after bed rest, elongation (L) of the tendon and aponeurosis of vastus lateralis (VL) and medial gastrocnemius muscles (MG) during isometric knee extension and plantar flexion, respectively, were determined using real-time ultrasonic apparatus, while the subjects performed ramp isometric contraction up to the voluntary maximum, followed by ramp relaxation. The relationship between estimated muscle force (Fm) and tendon elongation (L) was fitted to a linear regression, the slope of which was defined as stiffness. The hysteresis was calculated as the ratio of the area within the Fm-L loop to the area beneath the load portion of the curve. Results: L values above 100 N were significantly greater after bed rest for VL, while there were no significant differences in L values between before and after for MG. The stiffness decreased after bed rest for VL (70.3±27.4 v 50.1±24.8 N/mm, before and after bed rest, respectively; p = 0.003) and MG (29.4±7.5 v 25.6±7.8 N/mm, before and after bed rest, respectively; p = 0.054). In addition, hysteresis increased after bed rest for VL (16.5±7.1% v 28.2±12.9%, before and after bed rest, respectively; p = 0.017), but not for MG (17.4±4.4% v 17.7±6.1%, before and after bed rest, respectively; p = 0.925). Conclusions: These results suggested that bed rest decreased the stiffness of human tendon structures and increased their hysteresis, and that these changes were found in knee extensors, but not the plantar flexors.
Arterial stiffening, hypertension and left ventricular (LV) remodelling are associated with increased risk of cardiovascular disease. Cardiorespiratory fitness is associated with cardiovascular ...function and reduced risk of cardiovascular disease. This cross-sectional study was carried out to determine the relationships between cardiorespiratory fitness, arterial stiffness, blood pressure (BP) and LV remodelling in women. On the basis of peak oxygen uptake, a total of 159 premenopausal (young) and postmenopausal (older) women were categorized into either low (unfit) or high (fit) cardiorespiratory fitness groups. The arterial stiffness and LV remodelling were measured by brachial-ankle pulse wave velocity (baPWV) and carotid augmentation index (AI) and LV relative wall thickness (RWT). Two-way analysis of variance indicated a significant interaction between age and cardiorespiratory fitness in baPWV, carotid AI, BP and RWT. In the older group, arterial stiffness (baPWV; 1401+/-231 vs 1250+/-125 cm s(-1), P<0.01, AI; 32.9+/-9.9 vs 24.8+/-10.1%, P<0.01), systolic blood pressure (SBP) (130+/-22 vs 117+/-15 mm Hg, P<0.01) and RWT (0.47+/-0.08 vs 0.42+/-0.04, P<0.05) in fit women were lower than in unfit women. In older women, RWT was significantly related to baPWV (r=0.46, P<0.01), carotid AI (r=0.29, P<0.05), SBP (r=0.57, P<0.01) \V(2peak) (r=-0.32, P<0.05). In young women, they were not significant correlations, except for a weak correlation between RWT and SBP (r=0.21, P<0.05). These results suggest that higher cardiorespiratory fitness is associated with lower arterial stiffness, BP and RWT in older women.
Skinless polymer foam was prepared by treating poly(methyl methacrylate) (PMMA) with supercritical carbon dioxide (scCO2). The film was immersed in scCO2 with ethanol to nucleate, and then incubated ...in a hot water bath to induce nuclear growth and to prepare skinless PMMA foam. The obtained polymer foam had a low density and cells were connected to each other to make channels through the skin layer. Low molecular weight PMMA formed skinless foam with larger cells through expansion. PMMA film containing tin meso-tetraphenyl porphyrin was also foamed with same procedure and the foam was used for photoinduced hydrogen evolution. A larger amount of hydrogen evolved from the photocatalyst on the skinless PMMA foam in comparison with the foam with skin. Enlargement of effective surface area of solid support and light scattering within the foam could enhance turnover number (TON) of photocatalyst.
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