Shigeharu Numao

Influence of acute aerobic exercise on adiponectin oligomer concentrations in middle-aged abdominally obese men

Exercise intensity may induce changes in total adiponectin and adiponectin oligomer levels. However, the effects of acute aerobic exercise on total adiponectin and adiponectin oligomers in middle-aged abdominally obese men remain unknown. The purpose of this study was to investigate the influence of aerobic exercise intensity on changes in the concentrations of total adiponectin and adiponectin oligomers (high-molecular weight [HMW] and middle- plus low-molecular weight [MLMW] adiponectin), and the endocrine mechanisms involved in exercise-induced changes in adiponectin oligomer profiles in middle-aged abdominally obese men. Using a crossover design, 9 middle-aged abdominally obese men (age, 54.1 ± 2.4 years; body mass index, 27.9 ± 0.6 kg/m²) underwent 2 trials that consisted of 60 minutes of stationary cycle exercise at either moderate-intensity (ME) or high-intensity (HE) aerobic exercise (50% or 70% of peak oxygen uptake, respectively). Blood samples were collected to measure the concentrations of adiponectin oligomers, hormones (catecholamines, insulin, and growth hormone), metabolites (free fatty acid, glycerol, triglyceride, and glucose), and cytokines (interleukin-6 and tumor necrosis factor-α). After exercise, plasma catecholamine concentrations were higher during HE than during ME (P < .05). Total adiponectin concentration decreased at the end of HE (P < .05), but remained unchanged after ME. The HMW adiponectin concentration did not change at either intensity, whereas the MLMW concentration decreased at the end of HE (P < .05). The ratio of HMW to total adiponectin concentration increased significantly (P < .05), whereas the ratio of MLMW to total adiponectin concentration decreased significantly (P < .05), at the end of HE. The percentage changes in epinephrine concentration from baseline to the end of exercise were correlated with the percentage changes in total adiponectin concentration (r = -0.67, P < .05) and MLMW adiponectin concentration (r = -0.82, P < .05) from baseline to the end of HE. Our results indicate that the change in total adiponectin was mainly due to a change in MLMW adiponectin concentration during high-intensity exercise in middle-aged abdominally obese men. Epinephrine may partially regulate the decrease in total and MLMW adiponectin concentrations during high-intensity exercise.

Effects of acute aerobic exercise on high-molecular-weight adiponectin.

INTRODUCTION Few studies have reported the response of high-molecular-weight (HMW) adiponectin to acute aerobic exercise. PURPOSE The purpose of this study was to investigate the influence of acute aerobic exercise on HMW adiponectin in healthy men. METHODS Eight healthy men (age, 24.9 +/- 1.8 yr; BMI, 21.9 +/- 0.5 kg x m) participated in this study. They performed two trials. Trial 1 [exercise trial (EX)] consisted of 60-min stationary cycle exercise (50% peak oxygen uptake) followed by 30-min rest. Trial 2 [control trial (CON)] was 90-min rest. Blood samples were drawn to assess hormones (catecholamine and insulin), metabolites (free fatty acid [FFA], glycerol, and glucose), and total and HMW adiponectin concentration. RESULTS There were significant trial x group interactions in serum FFA and glycerol concentrations (P < 0.05). Serum FFA and glycerol concentrations were higher in EX than in CON (P < 0.05). There were significant trial x group interactions in plasma insulin and glucose concentration (P < 0.05). Plasma insulin and glucose concentrations were lower in EX than in CON (P < 0.05). Total adiponectin, HMW adiponectin concentration, and the ratio of HMW to total adiponectin concentration, however, were unchanged during aerobic exercise and postexercise. Also, those changes did not differ between EX and CON. CONCLUSION Our results indicate that total adiponectin and HMW adiponectin concentrations are not regulated by the change of hormones or metabolites during acute moderate-intensity aerobic exercise and postexercise in healthy young men.

Effects of obesity phenotype on fat metabolism in obese men during endurance exercise

Objective:The effects of obesity phenotype on fat metabolism during endurance exercise are unclear. This study aimed to investigate in obese men whether body fat distribution would influence plasma fat availability and oxidation during endurance exercise.Design:Fourteen sedentary men (body mass index (BMI)>25 kg/m2) were divided into two groups by visceral fat (VF) area: VF obese (VF-Ob) (n=7, age; 52.0±2.5 (s.e.) years) and abdominal subcutaneous fat obese (SF-Ob) (n=7, age; 57.3±2.8 (s.e.) years). All participants performed stationary cycling exercise for 60 min at 50% of peak oxygen uptake.Measurements:Blood and respiratory gas samples were taken for analysis of hormone, metabolite and substrate oxidation in each participant at rest and during exercise.Results:There is a significant group × time interaction in the plasma concentration of free fatty acid (FFA) (P<0.05) and glycerol (P<0.05) during the exercise bout. In addition, total plasma concentration of FFA (area under the curve) was 59.2% higher in VF-Ob compared with SF-Ob men during endurance exercise (1.99±0.24 and 1.25±0.13 mEq/l/min, respectively; P<0.05). Total plasma concentration of glycerol (area under the curve) was 102.3% higher in VF-Ob than SF-Ob men during the exercise (69.6±12.5 and 34.4±5.1 mg/dl/min, respectively; P<0.05). However, fat oxidation was not different throughout the exercise between VF-Ob and SF-Ob men (176.5±25.7 and 183.0±12.8 kcal/60 min, respectively).Conclusion:During moderate endurance exercise, plasma fat availability may be higher in men with VF obesity compared to men with SF obesity. However, total fat oxidation is similar between obesity phenotype.

Effects of a single bout of aerobic exercise on short-term low-carbohydrate/high-fat intake-induced postprandial glucose metabolism during an oral glucose tolerance test

OBJECTIVE A single bout of exercise can improve acute postprandial glucose metabolism aggravated by short-term low-carbohydrate/high-fat diet (HFD). The purpose of this study was to investigate the effect of a single bout of aerobic exercise on short-term HFD-induced postprandial glucose and incretin metabolism during an oral glucose tolerance test (OGTT). MATERIALS/METHODS Eleven healthy young men (age [mean±SE] 27±1 years; body mass index, 22±1 kg/m(2)) performed three, 3-day interventions in randomized order: (1) a normal diet (ND: ~22% fat), (2) an HFD (~69% fat) and (3) an HFD with a single bout of aerobic exercise (HFDEx). The exercise (50% peak oxygen consumption; ~200 kcal) was performed on the third day in HFDEx. An OGTT was performed after each 3-day dietary intervention. RESULTS The incremental area under the curve (iAUC) of plasma glucose levels during the OGTT was significantly higher in the HFD and HFDEx trials than in the ND trial (P=0.001). In addition, the iAUC of glucagon-like peptide-1 (GLP-1) level was significantly higher in the HFD trial than in the ND and HFDEx trials (P=0.04). The first-phase insulin secretion indexes were significantly lower in the HFD (P=0.01 and 0.002) and HFDEx trials (P=0.05 and 0.008) than in the ND trial. CONCLUSION A single bout of aerobic exercise did not improve the short-term HFD-induced aggravation of postprandial glucose and insulin metabolism during the OGTT. However, it did normalize the increased postprandial GLP-1 level induced by HFD.

Effects of Exercise Training on Circulating Retinol-Binding Protein 4 and Cardiovascular Disease Risk Factors in Obese Men

Introduction: The purpose of this study was to investigate the effects of 12-week exercise training on circulating retinol-binding protein 4 (RBP4) concentration and cardiovascular disease (CVD) risk factors in obese men. Methods: 29 obese men (age 48 ± 2 years; BMI 29.6 ± 0.7 kg/m2) participated in a 12-week exercise program (50–70% maximal heart rates; 3 times/week) without calorie restriction. Anthropometric parameters, CVD risk factors (total cholesterol, high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol, triglycerides (TG), and quantitative insulin sensitivity check index), and circulating RBP4 and adipokine (adiponectin, leptin, and interleukin-6 (IL-6)) concentrations were measured. Results: Exercise training significantly improved in absolute peak oxygen consumption (p < 0.05), and CVD risk factors (p < 0.05), with the exception of HDLC. There was a significant decrease in circulating RBP4, leptin, and IL-6 concentrations (p < 0.05). Stepwise regression analysis revealed that changes in RBP4 concentration were independently related to the changes in TG concentration (β = 0.46, p < 0.05). Conclusion: These results demonstrate that exercise training without calorie restriction improves several CVD risk factors and circulating RBP4 and adipokine concentrations. Moreover, the change in circulating RBP4 may be more associated with the improvements in TG concentration in obese men.

Appetite after rope skipping may differ between males and females

SUMMARY BACKGROUND When previously sedentary males and females follow the same exercise training programs with ad libitum feeding, males reduced body mass, but females do not, which suggests that females may increase appetite in response to exercise training compared with males. Rope skipping is traditional exercise modality that everyone had experienced during elementary school years in Japan. The purpose of this study was to determine whether there is a sex difference on appetite after acute rope skipping exercise. METHODS AND RESULTS Thirteen healthy young males (22.5 ± 0.8 years, 172.2 ± 1.7 cm, 68.8 ± 2.3 kg, 18.4 ± 0.9%) and 13 females (22.9 ± 0.8 years, 160.6 ± 1.5 cm, 52.9 ± 1.6 kg, 25.0 ± 1.0%) participated in this study. Subjects consumed their lunch by 13:00, and performed a total of 20 min rope skipping exercise (2 sets × 10 min with 5 min interval) from 16:00. In females, appetite significantly increased from immediately after the exercise to 30 min after the exercise (from 13 mm to 30 mm), but remained unchanged in males. Although heart rate, ratings of perceived exertion, and lactate concentrations increased from baseline to immediately after exercise, there were no differences in the increase between males and females. Blood glucose concentrations at baseline and 30 min after exercise were higher in females than in males. CONCLUSION These results indicated that rope skipping exercise induces an increase in appetite in females, but not in males. This increased appetite in females after the rope skipping exercise was induced without change in blood glucose concentrations.

Aotake: a modified stepping exercise as a useful means of improving lower-extremity functional fitness in older adults.

Aim:  Poor functional fitness of the lower extremities is a potentially modifiable risk factor for falls. This study compared the Aotake stepping exercise, a unique indoor program, to walking and examined improvements in lower‐extremity functional fitness.

Sex differences in substrate oxidation during aerobic exercise in obese men and postmenopausal obese women.

The aim of this study was to compare substrate oxidation during aerobic exercise in obese men and postmenopausal obese women. Ten obese men (mean age, 55.4 +/- 2.2 years; body mass index, 27.5 +/- 0.4 kg/m(2); peak oxygen uptake [Vo(2)peak], 44.4 +/- 1.9 mL/kg fat-free mass/min; mean +/- SE] and 10 postmenopausal obese women (mean age, 57.2 +/- 1.2 years; body mass index, 27.9 +/- 0.5 kg/m(2); VO(2)peak, 39.9 +/- 1.3 mL/kg fat-free mass/min) performed a 40-minute bout of cycling exercise at 50% VO(2)peak. Blood samples were collected for assessment of metabolic variables and 17beta-estradiol concentration at baseline and during aerobic exercise. Breath samples were collected to estimate carbohydrate and fat oxidation using a digital computer-based breath-by-breath exercise analysis system during aerobic exercise. Serum 17beta-estradiol concentration was not significantly different between the men and women subjects at baseline (P > .05). Serum free fatty acid concentration tended to be higher in the men than in the women (P = .07) during the exercise, but the respiratory exchange ratio during exercise was lower in women than in men (P < .05). Fat oxidation adjusted for fat-free mass was higher (P < .05) in women than in men. These results suggest that fat utilization was higher during aerobic exercise in postmenopausal obese women than in obese men and did not depend on resting serum 17beta-estradiol concentration.

Response of Coronary Heart Disease Risk Factors to Changes in Body Fat during Diet-Induced Weight Reduction in Japanese Obese Men: A Pilot Study

Objective: Serial measurements were used to examine the response of coronary heart disease (CHD) risk factors to regional fat changes during weight reduction. Methods: Nine Japanese obese men participated in a diet-induced weight loss program. Regional fat masses, abdominal visceral fat area (VFA), subcutaneous fat area (SFA) and CHD risk factors, including total (TC), high (HDLC)- and low-density lipoprotein cholesterol (LDLC), triglycerides (TG), fasting plasma glucose, immunoreactive insulin, homeostasis model assessment of insulin resistance (HOMA-IR), and glycosylated hemoglobin A1c (HbA1c) were assessed at baseline and after 1, 2 and 3 months. Results: Meanweight reduction during the study was –11.9 ± 4.2 kg, which was associated with a gradual, significant decrease (p < 0.05) in arm, leg and trunk fat masses, VFA and SFA. The levels of TC, LDLC and TG decreased significantly within 1 month and remained at these values, whereas HDLC, HOMA-IR, and HbA1c did not change. There was no significant correlation between changes in regional fat masses and CHD risk factors in any period studied. Conclusions: CHD risk factors do not necessarily respond in the same manner as changes in body fat during diet-induced moderate weight reduction.