Miki Eto

Association of plasma pentraxin 3 with arterial stiffness in overweight and obese individuals.

BACKGROUND Obesity and increased arterial stiffness are independent risk factors for cardiovascular disease. The degree of arterial stiffness in obese individuals is greater than that in normal-weight subjects. Pentraxin 3 (PTX3) is mainly produced by vascular tissues and exerts a cardioprotective effect. However, the relationship between PTX3 and arterial stiffness in obese individuals has not yet been clarified. In this study, we examined the relationships between obesity, arterial stiffness, and PTX3 levels in 282 subjects. METHODS All participants were classified as normal weight, overweight, or obese on the basis of their body mass index. We measured the brachial-ankle pulse wave velocity (baPWV; an index of arterial stiffness) and plasma PTX3 concentrations in all subjects. Additionally, the carotid-femoral PWV (cfPWV) was measured in 173 subjects. RESULTS We found that baPWV and cfPWV in overweight and obese subjects were significantly higher than those in normal-weight subjects. Plasma PTX3 concentrations in normal-weight subjects were significantly higher than those in overweight and obese subjects. Moreover, PTX3 had a significant negative correlation with baPWV. However, stepwise multivariable linear regression analysis did not indicate any associations between these parameters. CONCLUSIONS Arterial stiffness is increased in overweight and obese individuals. The increase in arterial stiffness may, at least in part, be associated with an obesity-related reduction in plasma PTX3 concentrations.

Best single-slice measurement site for estimating visceral adipose tissue volume after weight loss in obese, Japanese men

BackgroundAlthough the measurement site at L4–L5 for visceral adipose tissue (VAT) has been commonly accepted, some researchers suggest that additional upper sites (i.e., L1–L2 and L2–L3) are useful for estimating VAT volume. Therefore, determining the optimum measurement site remains challenging and has become important in determining VAT volume. We investigated the influence of a single-slice measurement site on the prediction of VAT volume and changes in VAT volume in obese Japanese men.MethodsTwenty-four men, aged 30–65 years with a mean BMI of 30 kg/m2, were included in a 12-week weight loss program. We obtained continuous T1-weighted abdominal magnetic resonance images from T9 to S1 with a 1.5-T system to measure the VAT area. These VAT areas were then summed to determine VAT volume before and after the program.ResultsSingle-slice images at 3–11 cm above L4–L5 had significant and high correlations with VAT volume at baseline (r = 0.94–0.97). The single-slice image with the highest correlation coefficient with respect to VAT volume was located at 5 cm above L4–L5 (r = 0.97). The highest correlation coefficient between the individual changes in VAT area and changes in VAT volume was located at 6 cm above L4–L5 (r = 0.90).ConclusionsIndividual measurement sites have different abilities to estimate VAT volume and changes in VAT volume in obese Japanese men. Best zone located at 5–6 cm above L4–L5 may be a better predictor of VAT volume than the L4–L5 image in terms of both baseline and changes with weight loss.

Multiple-slice magnetic resonance imaging can detect visceral adipose tissue reduction more accurately than single-slice imaging.

Background/Objective:Imaging methods by magnetic resonance imaging are being increasingly used to quantify visceral adipose tissue (VAT), but there is no clear consensus as to a standardized protocol. We compared the ability of two commonly used imaging protocols (multiple slice versus single slice) to detect changes in VAT with diet or exercise.Subjects/Methods:We utilized data from the participants who completed our diet (n=22) or exercise (n=35) based weight-loss interventions. The intervention mainly comprised of weekly dietary modification sessions or aerobic exercise sessions over 12 weeks. Multiple-slice images obtained from T9 to S1 and a single-slice image at L4–L5 were compared using the effect size of the VAT change. In addition, we calculated the sample size needed to compare the two imaging protocols’ ability to detect significant changes in VAT.Results:VAT and subcutaneous adipose tissue volumes and areas, and other anthropometry decreased significantly after both the diet and exercise interventions. For VAT, a single-slice image had a lower effect size (diet: 1.23; exercise: 0.49) than the multiple-slice images (diet: 1.81; exercise: 0.90). The sample size required for multiple slice was substantially lower than for the single-slice with both weight-loss interventions.Conclusions:The different image protocols may lead to different results in relative VAT changes. Furthermore, single-slice imaging required a substantially larger sample size than multiple-slice imaging, and for researchers to detect smaller changes in VAT with single-slice imaging, a larger sample size would be needed. Thus, multiple-slice imaging has advantages for assessing VAT change in future clinical research.

Lifestyle modification decreases arterial stiffness and plasma asymmetric dimethylarginine level in overweight and obese men.

BackgroundIncreased arterial stiffness is an independent risk factor for cardiovascular disease. Arterial stiffness is higher in obese individuals than in nonobese individuals. Lifestyle modifications (i.e. exercise and dietary modification) decrease arterial stiffness in obese individuals. Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase, an enzyme responsible for the generation of nitric oxide. AimThe aim of this study was to examine whether lifestyle modifications affect circulating levels of ADMA in overweight and obese men and, if they do, whether ADMA is involved in the mechanism underlying the decrease in arterial stiffness with lifestyle modification. MethodsSeventeen overweight and obese men (BMI: 29.8±0.8 kg/m2) completed a 12-week lifestyle modification program, which included aerobic exercise and dietary modification. Before and after the intervention, we evaluated brachial-ankle pulse wave velocity (baPWV), an index of arterial stiffness, and plasma ADMA concentration in all participants. ResultsAfter the 12-week lifestyle modification program, BMI and baPWV decreased significantly and the plasma ADMA concentration decreased markedly in overweight and obese men. There was a significant positive correlation between percent change in baPWV and plasma ADMA concentration. ConclusionLifestyle modifications reduce arterial stiffness and plasma ADMA concentration in overweight and obese individuals. A decrease in arterial stiffness was associated with a corresponding reduction in plasma ADMA concentrations. These results suggest that reductions in ADMA may be an important mechanism underlying the beneficial effect of lifestyle modification on arterial stiffness.

Effects of lifestyle modification on central blood pressure in overweight and obese men.

ObjectiveIt has recently been recognized that increased central blood pressure is a predictor of cardiovascular disease. Central blood pressure is higher in obese individuals than in nonobese individuals. However, the effect of lifestyle modification on central systolic blood pressure in obese individuals is unclear. The aim of this study was to determine whether lifestyle modification decreases central blood pressure in overweight and obese men. MethodsThirty-nine overweight and obese men (age, 49±2 years; BMI, 30±1 kg/m2) were recruited into our study. We measured central systolic blood pressure and brachial-ankle pulse wave velocity (baPWV), an index of arterial stiffness, before and after a 12-week lifestyle modification that included aerobic exercise and dietary modification. ResultsAfter the 12-week program, body mass, BMI, and waist circumstance decreased significantly. Central systolic blood pressure and baPWV were significantly decreased after the lifestyle modification in overweight and obese men. Furthermore, there was a significant correlation between the lifestyle modification-induced change in central systolic blood pressure and that in baPWV. ConclusionThis study showed for the first time that lifestyle modification-induced weight loss decreases central systolic blood pressure in overweight and obese men. The decrease in central systolic blood pressure was associated with the reduction in arterial stiffness. These results suggest that lifestyle modification-induced reduction in arterial stiffness may contribute toward the decreased central systolic blood pressure in overweight and obese men.

The effects of vigorous physical activity on intra-abdominal fat levels: A preliminary study of middle-aged Japanese men

AIM To examine the effects of vigorous physical activity (PA) on intra-abdominal fat (IF) levels in obese men. METHODS Thirty-seven obese men (mean age: 47.6+/-8.6 years) engaged in a 12-week aerobic exercise program on a regular basis (3 days/week). We divided them into low volume of vigorous PA group (n=19) or high volume of vigorous PA group (n=18), based on the median time spent (34.3min/week) in vigorous PA (over 6.1 metabolic equivalents assessed by a single-axis accelerometer) throughout the program. RESULTS Regular exercise reduced IF levels (measured by computed tomography) from 188.1+/-53.9cm(2) to 170.3+/-46.6cm(2) for the low volume of vigorous PA group and from 167.9+/-44.3cm(2) to 137.9+/-40.6cm(2) for the high volume of vigorous PA group. Two-way (time x group) ANOVA revealed no significant interactions for the IF level. However, correlation analysis for all participants showed that time spent in vigorous PA throughout the program significantly correlated to IF reductions after adjusting for initial levels of IF, vigorous PA and weight changes (r=-0.42, P=0.02). CONCLUSION This study suggests that vigorous PA may affect IF reductions in obese men.

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.

Acceleration training for improving physical fitness and weight loss in obese women

BACKGROUND Reducing body weight and visceral adipose tissue (VAT) are the primary goals for maintaining health in obese individuals as compared to those of normal weight, but it is also important to maintain physical fitness for a healthy life after weight-loss. Acceleration training (AT) has recently been indicated as an alternative to resistance training for elite athletes and also as a component of preventive medicine. However, it is unclear whether combining AT with a weight-loss diet will improve physical fitness in obese individuals. The present study aimed to determine the synergistic effects of AT on body composition and physical fitness with weight-loss program in overweight and obese women. METHODS Twenty-eight obese, middle-aged women were divided into two groups as follows: diet and aerobic exercise group (DA; BMI: 29.3 ± 3.0 kg/m2); and diet, aerobic exercise and acceleration training group (DAA; BMI: 31.2 ± 4.0 kg/m2). Both groups included a 12-week weight-loss program. Body composition, visceral adipose tissue (VAT) area and physical fitness (hand grip, side-to-side steps, single-leg balance with eyes closed, sit-and-reach and maximal oxygen uptake) were measured before and after the program. RESULT Body weight, BMI, waist circumference and VAT area decreased significantly in both groups. Hand grip (2.1 ± 3.0 kg), single-leg balance (11.0 ± 15.4 s) and sit-and-reach (6.5 ± 4.8 cm) improved significantly only in the DAA group. CONCLUSIONS Our findings indicate that combining AT with classical lifestyle modifications is effective at reducing VAT, and it may enhance muscle strength and performance in overweight and obese women.

Effect of weight loss on maximal fat oxidation rate in obese men

SUMMARY INTRODUCTION The hallmark features of obesity include insulin resistance and an impaired ability to oxidize lipids. As compared to exercise training, it remains relatively unclear if diet-induced weight loss can also induce fat metabolism. This study was undertaken to examine the effects of diet-induced weight loss on fat metabolism during a single session of exercise in middle-aged obese men. METHODS Fifteen obese men who were otherwise healthy (average age of 53.5 ± 6.9 yr and average body mass index of 27.8 ± 1.6 kg/m(2)) participated in a 12-wk weight loss program primarily consisting of dietary modification. Maximal fat oxidation (MFO) rates, MFO per lean body mass (MFOLBM) and insulin resistance (HOMA-IR) were measured before and after the program. Participants performed a 24-min graded exercise test on a cycle ergometer, with 15-W increments every 4 min. Expired gas analysis was performed by indirect calorimetry, and nonprotein respiratory quotient equations were used to calculate fat oxidation rates. RESULTS The weight (-8.3 ± 3.8 kg), fat mass (-4.5 ± 1.9 kg), and lean body mass (-3.8 ± 2.4 kg) (P < 0.001 for all measurements) of the participants were decreased at the end of the 12-wk program. The MFO tended to increase by 19% (P = 0.08) and MFOLBM significantly increased by 28.8% (P = 0.02). Although insulin resistance also significantly decreased by 49% (P < 0.001), changes in fat oxidation variables did not correlate with changes in insulin resistance. CONCLUSION Diet-induced weight loss improves fat metabolism with the improvement in insulin resistance.:

New Approach for Obesity Treatment Incorporating Individual Self- Management Education

Background: Obesity is a global issue, and its prevalence is a major public health concern. To help resolve this obesity epidemic, we propose an education program for positive behavior change. This program incorporates diet and exercise behaviors at the individual level. Objective: To demonstrate the effects of a new approach for treating obesity by improving individual selfmanagement through investigating, i) behavior modification in the treatment of obesity, ii) the change of obesity states and physical performance capacity, and iii) the risk factors to be diagnosed with metabolic syndrome. Design: Twenty-four men during the 2011 and thirty-three men during the 2012 intervention contributed to the current study. Over 12 weeks, a total of 57 subjects participated in individual self-management education program. Results: For a short-term program, in both the years 2011 and 2012 subjects showed a decrease in daily energy intake (-30.1% and -27.7%) accompanied by an increase in daily energy expenditure (+5.7% and +5.9%), suggesting an ability of individuals to keep obesity under control through behavior therapy. Subjects also showed a marked change in obesity states and physical capacity such as decreased body weight (-12.1% and -13.6%), and higher VO2max (+22.0% and +21.4%). Further, our comprehensive protocol led to a improvement in components for metabolic syndrome; reduction in waist circumference (-10.4% and -11.7%), blood pressure (systolic: -12.9% and -9.8%; diastolic: -14.6% and -9.6%), fasting plasma glucose (-8.6%, -7.6%), and triglyceride (-60.6% and -46.7%) along with an increase in the levels of HDL-C (+16.5% and +10.5%) was seen. Conclusion: Under our protocol, subjects achieved optimal results for treating obesity during two consecutive years. We recognize that these results are due to an acquired ability like broader perspective and greater acumen about individual obesity management. Therefore, the methods and delivery of our new public approach are useful to the general public.