Identification of EIMD Level Differences Between Long- and Short Head of Biceps Brachii Using Echo Intensity and GLCM Texture Features.

Purpose: This study aimed to compare the time-course changes of exercise-induced muscle damage (EIMD) levels in the long head of biceps brachii (LHB) and short head of the biceps brachii (SHB) using echo intensity (EI) and to determine the efficiency of the gray level co-occurrence matrix (GLCM) texture parameters. Methods: The participants performed 30 maximal eccentric contractions of the elbow flexor. Along with muscle damage indicators, including circumference, range of motion, muscle soreness, and maximal voluntary isometric contraction (MVIC), the EI and GLCM texture features of the LHB and SHB was also assessed using B-mode ultrasonography. All measurements were assessed pre- and immediately post-exercise and after 24, 48, 72, and 96 h. Results: The muscle damage indicators indicated significant changes after the eccentric contractions (p < 0.01 for circumference, range of motion, muscle soreness, and MVIC). The EI of LHB significantly increased following the contractions (p < 0.01), but that of SHB did not (p > 0.05). In contrast, for the GLCM texture parameters, there were significant changes in the SHB (p < 0.01 for homogeneity, energy, and entropy). Conclusion: Thus, this study demonstrated that EIMD severity is different between LHB and SHB even within the same muscle. In the GLCM features, the time course of SHB after eccentric contraction revealed different patterns compared with those of LHB. Therefore, even if there are no changes in EI within a target muscle following muscle contractions, new information on muscle quality can be obtained through GLCM analysis.

Therapeutic Effects of Functional Electrical Stimulation on Physical Performance and Muscle Strength in Post-stroke Older Adults: A Review.

Stroke-related disabilities cause poor physical performance, especially among older adults, and can lead to sarcopenia. Functional electrical stimulation (FES) has been used to improve physical performance in individuals with neurological disorders and increase muscle mass and strength to counteract muscle atrophy. This review covers the principles, underlying mechanisms, and therapeutic effects of FES on physical performance and skeletal muscle function in post-stroke older adults. We found that FES restored weakened dorsiflexor and hip abductor strength during the swing and stance phases of gait, respectively, to help support weight-bearing and upright posture and facilitate static and dynamic balance in this population. FES may also be effective in improving muscle mass and strength to prevent muscle atrophy. However, previous studies on this topic in post-stroke older adults are scarce, and further studies are needed to confirm this supposition.

Effects of exercise training intensity on cardiac autonomic regulation in habitual smokers.

BACKGROUND: The sympathoexcitatory effects of cigarette smoking cause an autonomic imbalance that may lead to cardiovascular disease. Aerobic training improves autonomic function by developing cardiorespiratory fitness; however, it is still uncertain whether aerobic training ameliorates the compromised autonomic modulation in smokers. This study aimed to investigate the effects of 8 weeks' aerobic training at different exercise intensities on autonomic regulation in habitual smokers. METHODS: Healthy males (n = 34) were randomly assigned to a moderate-intensity aerobic training (MAT, 60% of heart rate reserve [HRR]), a high-intensity training group (HAT, 75% HRR), or a control group (CG). Training groups performed 8 weeks' aerobic training on a treadmill (3 times/week), but all subjects continued to smoke cigarettes as usual. Heart rate variability was monitored to evaluate the effect of aerobic training on autonomic regulation. RESULTS: Aerobic training improved autonomic balance despite the continued smoking. In the time domain, rMSSD and pNN50 were significantly increased in HAT than in CG. On spectral analysis, the absolute and normalized units of high frequency (HF) were significantly increased in HAT, whereas the LF/HF ratio and the normalized unit of LF were significantly decreased compared to that in CG. SD1 and the SD1/SD2 ratio of the Poincaré plot analysis were significantly increased compared to CG. Although MAT showed a similar tendency to HAT in nonlinear indexes, there were no significant differences compared to CG. CONCLUSION: Aerobic training, particularly high-intensity training, increases the parasympathetic contribution to the sympathovagal system, leading to an improvement in autonomic balance despite continued cigarette smoking.

Clinical characteristics of OGTT-derived hepatic- and muscle insulin resistance in healthy young men.

PURPOSE: Insulin inhibits glucose release in the liver but increases glucose absorption in muscles. When insulin cannot properly control glucose, it negatively affects glucose metabolism and, furthermore, contributes to the onset of metabolic syndrome and chronic disease. Therefore, this study's goal is to understand the clinical characteristics of hepatic insulin resistance and muscle insulin sensitivity in healthy young men. METHODS: Twenty-eight healthy young men (age 23.3 ± 0.5; mean ± SE) participated in this study. Liver function and blood lipids were measured by blood sampling from brachial vein after participants fasted the previous day. Hepatic insulin resistance and muscle insulin sensitivity were evaluated using two-hour OGTT along with surrogate index related to insulin sensitivity. The VO2max was evaluated using cycle ergometer. Systemic insulin sensitivity was evaluated using two-hour euglycemic hyperinsulinemic clamp method. RESULTS: Hepatic insulin resistance showed a significant correlation with body fat (r = 0.609, p < 0.05). Also, hepatic insulin resistance showed a significant correlation with GOT (r = 0.467), GPT (r = 0.434), and γ-GTP (r = 0.375), reflecting liver functions, as well as showing a significant correlation with hs-CRP (r = 0.492, p < 0.05). On the other hand, muscle insulin sensitivity had no correlation with neither body fat nor liver function index (p > 0.05), and among surrogate indexes, it showed a significant correlation with Avignon (r = -0.493) and Matsuda index (r = -0.577). Glucose infusion rate, using the clamp method, showed a significant correlation with muscle insulin sensitivity (r = 0.448, p < 0.05). The VO2max had a significant correlation with hepatic insulin resistance (r = -0.435, p < 0.05) and muscle insulin sensitivity (r = 0.474, p < 0.05), respectively. CONCLUSION: For young men in their 20's, the OGTT-based hepatic insulin sensitivity was an indicator of hepatic function and body fat but muscle insulin sensitivity was related to peripheral insulin sensitivity. Also, for young men, higher VO2max indicated lower hepatic insulin resistance and higher muscle insulin sensitivity.

Effects of low calorie diet-induced weight loss on post-exercise heart rate recovery in obese men.

PURPOSE: Heart Rate Recovery (HRR) after maximum exercise is a reactivation function of vagus nerve and an independent risk factor that predicts cardiovascular disease and mortality. Weight loss obtained through dietary programs has been employed as a therapy to reduce risks of cardiovascular disease and obesity. METHODS: Eighteen subjects of middle aged obese men (age 44.8 ± 1.6 yrs, BMI 29.7 ± 0.5 kg/m(2)) were selected for this study. As a weight loss direction, the nutritional direction of low-calorie diet mainly consisted of carbohydrate, protein, and fat has been conducted for 3 months. Blood pressure was measured after overnight fasting, and blood samples were collected from the antecubital vein before and after weight loss program. All the pre- and post-exercise 'HRR decay constant's were assessed by using values of HRR (heart recovery rate; 2 minutes) and HR measured after reached to the maximal oxygen uptake (VO2max) exploited the bicycle ergometer. RESULTS: After the completion of weight loss program, body weight and BMI were significantly decreased, but the Heart Rate (HR) after maximum exercise and in steady state were not changed significantly (p > 0.05). The post-exercise HRR after the weight loss did not show significant changes in perspectives of 30 seconds (-16.6 ± 2.3 to -20.2 ± 2.1 beats/min, p > 0.05) and 60 seconds (-33.5 ± 3.4 to -34.6 ± 2.8 beats/min, p > 0.05) respectively but in perspectives of 90 seconds (-40.9 ± 2.6 to -48.1 ± 3.1 beats/min, p < 0.05) and 120 seconds (-48.6 ± 2.6 to -54.3 ± 3.5 beats/min, p < 0.05), they were decreased significantly. Pre-'HRR decay constant's of 0.294 ± 0.02 %/second were significantly increased to post-values of 0.342 ± 0.03 %/second (p = 0.026). Changes in 'HRR decay constant' were significantly correlated with changes in blood glucose (r = -0.471, p < 0.05) and maximal oxygen consumption (VO2max, r = 0.505, p < 0.05) respectively. CONCLUSIONS: The low-calorie diet directed to obese middle aged men for 3 months significantly improved the HRR after maximum exercise, and this improvement in cardiovascular autonomic nerve system was estimated to be involved with improvements in blood glucose and maximal oxygen consumption.

Palatinose-blended sugar compared with sucrose: different effects on insulin sensitivity after 12 weeks supplementation in sedentary adults.

BACKGROUND: We investigated the effects of daily palatinose intake on the risk factors of metabolic syndrome in sedentary non-obese Japanese adults. METHODS: Japanese adults (40 females and 10 males, age: 53 +/- 9 years, range: 31-72 years old) were randomized into two groups for a double-blind, placebo-controlled intervention study and given either 40 g/day palatinose-blended sugar (PS group) or 40 g/day sucrose (S group) in their diet for 12 weeks. RESULTS: After the intervention, the insulin resistance index (HOMA-IR) had significantly decreased only in the PS group; the inter-group difference was significant at P = 0.006. Although the S group showed a significant increase in the leptin concentration and the systolic blood pressure, the PS group showed no significant changes; the inter-group differences were significant at P = 0.018 and P = 0.037, respectively. CONCLUSION: Palatinose intake possibly improves insulin sensitivity when compared with sucrose intake.

Alternative items for identifying hierarchical levels of physical disability by using physical performance tests in women aged 75 years and older.

AIM: To identify individuals at hierarchical levels of physical disability by using physical performance tests and to determine threshold values for the discriminating of levels of physical disability in women aged 75 years or older. METHODS: A cross-sectional observational study was conducted on 306 community-dwelling women aged 75 years or order (range, 75-99 years). Physical disability was categorized into no disability, mobility disability and activities of daily living (ADL) disability, by evaluating selected ADL and mobility-related functional tasks. Physical function tests comprised nine items (such as strength, balance, mobility and walking ability). To assess the observed threshold values, receiver-operator curves were prepared for all the scales. RESULTS: The results revealed significant differences among all the pairwise group comparisons in all the performance tests, except in the one-legged stance, tandem stance and tandem walk tests. The individuals with ADL disability were unable to perform the one-legged stance (28.9%), tandem stance (32.5%), functional reach (19.3%), tandem walk (61.4%), alternate step (53.0%) and 5-chair sit-to-stand (31.3%) tests. The observed thresholds for discriminating between the no disability and mobility disability groups and between the mobility disability and ADL disability groups were as follows: timed Up & Go test, 8.5 s and 12.7 s; usual gait speed, 1.05 m/s and 0.79 m/s; and grip strength, 19.5 kg and 16.3 kg, respectively. CONCLUSION: Tests for balance and lower extremity strength can be used together to identify or monitor the characteristics of the hierarchical levels of physical disability in women aged 75 years or older.

Air displacement plethysmography for estimating body composition changes with weight loss in middle-aged Japanese men.

AIM: To examine the degree to which air displacement plethysmography (ADP) can track body composition changes in response to weight loss in obese Japanese men. METHOD: 50 men, aged 30-65 years with a mean BMI of 30 kg/m(2), were included in a 3-month weight loss program. Percentage of fat mass (%FM) was determined by dual energy X-ray absorptiometry (DXA) and ADP at baseline and month 3. RESULTS: With 6.2 ± 4.3 kg of weight loss, %FM, as determined by DXA and ADP, significantly decreased by 3.9 ± 2.9% and 3.9 ± 3.3% respectively. There was no mean difference for change (Δ) in %FM between the two methods. DXA-derived Δ%FM significantly correlated with Δ%FM determined by ADP (R(2) = 0.48, p < 0.01). Furthermore, the Bland-Altman plots demonstrated no systematic bias for Δ%FM (r = -0.20, p = 0.17). However, %FM by ADP (r = 0.42) at baseline and Δ%FM by ADP (r = -0.54) were significantly correlated to the differences between Δ%FM by DXA and ADP. CONCLUSION: These results suggest that ADP is comparably accurate for evaluating Δ%FM when compared with DXA, although there were proportional biases.

Epicardial fat tissue: relationship with cardiorespiratory fitness in men.

PURPOSE: To explore the influence of the epicardial fat (EF) tissue on aspects of heart rate recovery (HRR) and cardiorespiratory fitness (V O2peak) in middle-aged men. METHODS: A cross-sectional analysis of EF thickness was performed on 101 overweight or obese men. The men were categorized into low-EF, moderate-EF, and high-EF groups on the basis of ventricular EF thickness, as measured by transthoracic echocardiography. V O2peak was assessed with a graded maximal cycle ergometric test, including measurement of HRR 2 min after test cessation to estimate parasympathetic activity, with assessment of several metabolic parameters. RESULTS: Men in the highest and the middle EF thickness tertile had significantly slower recovery times than subjects in the lowest tertile, respectively (P < 0.05). Subjects with higher EF thickness were more likely to have impaired recovery and to reveal lower cardiorespiratory fitness than low-EF group subjects. There was a significant partial correlation, adjusted by age and body weight, between EF thickness and V O2peak (r = -0.25, P = 0.014). In the hierarchical multiple linear regression analyses, EF thickness was the strongest predicting variable associated with V O2peak in these population (beta = -1.182, P = 0.001). CONCLUSIONS: Higher EF thickness in men is associated with lower HRR at 1 and 2 min, a representation of autonomic dysfunction and poor cardiorespiratory fitness. These data suggest that moderately obese men with thicker EF tissue demonstrate reduced cardiorespiratory fitness and a differing parasympathetic response to exercise testing, as compared with men with lower EF levels.

Mobility performance tests for discriminating high risk of frailty in community-dwelling older women.

We aimed to compare and identify high and low risk of frailty in community-dwelling older women by using five mobility performance tests. The participants were 166 older women at high risk and 171 age-matched controls at low risk of frailty according to the long-term care insurance (LTCI) system (age: 65-90 years). The mobility performance tests included 5-chair sit-to-stand (STS), alternate step, timed up-and-go (TUG), timed rapid gait (TRG), and usual gait speed (UGS). Data analysis showed that high-risk individuals (81.9%) were more likely to be pre-frail than low-risk individuals (55.0%) by Fried's frailty phenotype. The four mobility performance tests, except the 5-chair STS, had the largest areas under the curve (AUC) for discriminating older women at high and low risk (AUC>0.80, p<0.001). The optimal cutpoint (6 s) for the TRG test had the highest sensitivity (78%) and specificity (83%) in identifying high risk of frailty. Our results suggest that walking ability tests are clinically useful in screening older individuals at high risk of frailty. In particular, the TRG test is more likely than other tests to discriminate older women at high risk of frailty based on the LTCI system.

High general self-efficacy is associated with less weight loss under a supervised dietary modification program.

SUMMARY: Self-efficacy is an important prospective predictor for behavior modification. As for weight loss intervention, many studies have shown significant associations between situation-specific self-efficacy and weight loss. In this study, we investigated the association between general self-efficacy and body weight change during a 14-week supervised dietary modification program. In total, 154 obese, middle-aged, Japanese women were selected as the subjects. The intervention program mainly comprised diet counseling. The diet counseling consisted of weekly lectures on weight loss practices and individual counseling by skilled dieticians. All subjects were instructed to choose and consume a well-balanced, 1200 kcal diet per day while also keeping a daily food diary in which they recorded in detail every food they ate during the intervention period. Body weight, waist circumference, and coronary heart disease risk factors were measured before and after the intervention. Energy intake and activity energy expenditure were assessed before and during the intervention. General self-efficacy was assessed with the General Self-Efficacy Scale (GSES) before the intervention. Body weight decreased significantly (-7.8 ± 2.7 kg; -11.4 ± 3.7%) following the intervention. The weight reduction was significantly greater for the low GSES group than for the other GSES groups. Self-efficacy regarding "degree of confidence in one's ability relative to others" especially influenced the association between the weight loss and the GSES score. Subjects' fat intake influenced the weight loss differences among GSES groups. In conclusion, inconsistent with previous studies, high general self-efficacy was associated with less weight loss under a supervised dietary modification program among middle-aged, Japanese women.:

Effect of habitual aerobic exercise on body weight and arterial function in overweight and obese men.

The effect of habitual exercise on vascular function, including central arterial distensibility and endothelial function, in obese subjects has not yet been clarified. We investigated whether aerobic exercise training affects central arterial distensibility and endothelial function in middle-age overweight and obese men. A total of 21 overweight and obese men (age 50 +/- 2 years, body mass index 30 +/- 1 kg/m(2)) completed a 12-week aerobic exercise intervention. Aerobic exercise training significantly reduced their body weight and resulted in a significant decrease in body mass index. After the weight-reduction exercise program, carotid arterial compliance (determined by simultaneous B-mode ultrasonography and arterial applanation tonometry on the common carotid artery) significantly increased; and the beta-stiffness index, an index of arterial compliance adjusted for distending pressure, significantly decreased. The concentrations of plasma endothelin-1, a potent vasoconstrictor peptide produced by vascular endothelial cells, significantly decreased and plasma nitric oxide (measured as the stable end product [nitrite/nitrate]), a potent vasodilator produced by vascular endothelial cells, significantly increased after the weight-reduction exercise program. In conclusion, weight reduction by aerobic exercise training in overweight and obese men increased the central arterial distensibility. This increase might contribute to the improvement in endothelial function, as assessed by a decrease in endothelin-1 and an increase in nitric oxide, after exercise training-induced weight loss.

PPARG genotype accounts for part of individual variation in body weight reduction in response to calorie restriction.

Several studies indicate that expression of the peroxisome proliferator-activated receptor gamma (PPARG) gene is influenced by calorie restriction. The aim of this study was to investigate whether PPARG gene variations are associated with weight reduction and changes in coronary heart disease (CHD) risk factors in response to a 14-week calorie restriction. In total, 95 middle-aged, Japanese women (BMI>or=25 kg/m2) enrolled as subjects for 14 weeks and attended weekly dietary lectures instructing them on how to consume a nutritionally balanced diet of 1,200 kcal/day. Eight single-nucleotide polymorphisms (SNPs) in the PPARG gene (rs1801282 (Pro/Ala), rs2292101, rs2959272, rs1386835, rs709158, rs1175540, rs1175544, and rs1797912) were analyzed. Body weight decreased significantly (-7.7+/-3.1 kg; -11.3+/-4.4%) during the intervention. Six PPARG SNPs (rs2959272, rs1386835, rs709158, rs1175540, rs1175544, and rs1797912) were significantly associated with the weight reduction, with rs1175544 having the strongest association (P=0.004). No differences across the rs1175544 genotypes were observed in any of the blood analyses or in blood pressure. In a multiple regression analysis, the rs1175544 genotypes accounted for 7% of the total weight reduction variance. These data suggest that one SNP of the PPARG genotype accounted for a significant portion of the total body weight reduction variance in response to a short-term intervention consisting of calorie restriction; however, no relationship was found between these SNPs and the changes in CHD risk factors which accompanied weight loss.

Exercise training-induced changes in heart rate recovery in obese men with metabolic syndrome.

BACKGROUND: Heart rate recovery (HRR) as a function of vagal reactivation, which is an independent risk predictor for cardiovascular disease and mortality, is strongly associated with metabolic syndrome. METHODS: Middle-aged obese men (metabolic syndrome, n = 20; non-metabolic syndrome, n = 22) classified on the basis of Adult Treatment Panel III criteria were investigated in this study. Postexercise HRR and the HRR decay constant following a symptom-limited bicycle exercise test were evaluated before and after a 12-week exercise training program (60-70% of maximal heart rate; 60 minutes per day; 3 days per week). RESULTS: Although the peak HR remained unchanged, HR at anaerobic threshold significantly decreased for both groups after exercise training; HR at rest was significantly decreased in the metabolic syndrome group after training (P < 0.05). HRR significantly improved in the metabolic syndrome group (-26.1 +/- 3.6 beats/minute vs. -33.5 +/- 3.8 beats/minute, at 1 minute; -39.9 +/- 4.9 beats/minute vs. -49.5 +/- 4.9 beats/minute, at 2 minute, P < 0.05) with no change for the non-metabolic syndrome group (P > 0.05). HRR decay constant values showed significant improvement in the metabolic syndrome group (0.31 +/- 0.02%/second vs. 0.35 +/- 0.02%/second, P = 0.038) after exercise training but not the non-metabolic syndrome group (P > 0.05). CONCLUSIONS: This study demonstrated that moderate-intensity physical training without caloric restrictions improves HRR in obese men with metabolic syndrome, possibly due to a reduction in the resting HR. Therefore, weight loss-induced exercise training would help in improving the resting HR, and the responsiveness of the autonomic nervous system in obese men with metabolic syndrome.

Aerobic exercise training reduces epicardial fat in obese men.

The purpose of this study was to determine the effects of exercise training on ventricular epicardial fat thickness in obese men and to investigate the relationship of the change in epicardial fat thickness to changes in abdominal fat tissue following exercise training. Twenty-four obese middle-aged men [age, 49.4 +/- 9.6 yr; weight, 87.7 +/- 11.2 kg; body mass index (BMI), 30.7 +/- 3.3 kg/m(2); peak oxygen consumption, 28.4 +/- 7.2 ml.kg(-1).min(-1); means +/- SD] participated in this study. Each participant completed a 12-wk supervised exercise training program (60-70% of the maximal heart rate; 60 min/day, 3 days/wk) and underwent a transthoracic echocardiography. The epicardial fat thickness on the free wall of the right ventricle was measured from both parasternal long- and short-axis views. The visceral adipose tissue (VAT) and subcutaneous adipose tissues were measured by computed tomography. Following exercise training, the epicardial fat thickness was significantly decreased (P < 0.001). The percentage change of epicardial fat thickness was twice as high compared with those of waist, BMI, and body weight of original values (P <0.05). There was a significant relationship (r = 0.525, P = 0.008) between changes in the epicardial fat thickness and VAT with exercise training. Stepwise multiple regression analysis revealed that the change in VAT, change in systolic blood pressure, and change in quantitative insulin sensitivity check index were independently related to the change epicardial fat thickness (P < 0.05). The ventricular epicardial fat thickness is reduced significantly after aerobic exercise training and is associated with a decrease in VAT. These results suggest that aerobic exercise training may be an effective nonpharmacological strategy for decreasing the ventricular epicardial fat thickness and visceral fat area in obese middle-aged men.

Validation of lower extremity performance tests for determining the mobility limitation levels in community-dwelling older women.

BACKGROUND AND AIMS: Assessment of mobility status among community-dwelling older people is important for preventing further deterioration of mobility and identifying changes in mobility as early as possible. We attempted to identify the optimal cut-off values for eight lower extremity performance (LEP) tests in community-dwelling older women with mobility limitation (ML) levels. METHODS: The ML levels of 433 community-dwelling older women, mean age 73.2 years (SD 5.7, range 65-93) were classified according to selfreports. ML levels were identified by face-to-face interviews and according to self-reported difficulty in walking one-quarter of a mile or climbing 10 steps without resting. The LEP tests comprised one-legged stance, tandem stance, functional reach, tandem walk, alternate step, five chair sit-to-stands, timed up-and-go (TUG) and usual gait speed. Receiver-operating characteristic curves were obtained for all scales to assess optimal cut-off values. RESULTS: The optimal cut-off value of 6.52 (s) for the TUG test was shown by the highest sensitivity (74%) and specificity (71%) in the discrimination of no ML from moderate ML, whereas the optimal cut-off value of 1.05 (m/s) in the usual gait speed test showed the highest sensitivity (73%) and specificity (67%) in the discrimination of moderate ML from severe ML. CONCLUSIONS: Among community-dwelling older women, TUG and usual gait speed had the highest sensitivity and specificity in discriminating ML levels.