Reduction of visceral fat is associated with decrease in the number of metabolic risk factors in Japanese men

Extent of weight reduction necessary for minimization of diabetes risk in Japanese men with visceral fat accumulation and glycated hemoglobin of 5.6-6.4

Aims/Introduction

Weight reduction improves glycemic control in obese men with glycated hemoglobin (HbA1c) of 5.6–6.4%, suggesting that it can prevent the development of diabetes in these patients. The aim of the present study was to quantify the amount of weight reduction necessary for minimization of diabetes risk in Japanese men with visceral fat accumulation.

Materials and Methods

The study participants were 482 men with an estimated visceral fat area of ≥100 cm², HbA1c of 5.6–6.4%, fasting plasma glucose (FPG) of <126 mg/dL or casual plasma glucose <200 mg/dL. They were divided into two groups based on weight change at the end of the 3-year follow-up period (weight gain and weight loss groups). The weight loss group was classified into quartile subgroups (lowest group, 0 to <1.2%: second lowest group, ≥1.2 to <2.5%: second highest group, ≥2.5 to <4.3%: highest group, ≥4.3% weight loss). The development of diabetes at the end-point represented a rise in HbA1c to ≥6.5% or FPG ≥126 mg/dL, or casual plasma glucose ≥200 mg/dL.

Results

The cumulative incidence of diabetes at the end of the 3-year follow-up period was 16.2% in the weight gain group and 10.1% in the weight loss group (P not significant). The incidence of diabetes was significantly lower in the highest weight loss group (3.1%), but not in the second highest, the second lowest and the lowest weight loss groups (9.7, 10.1 and 18.3%), compared with the weight gain group.

Conclusions

Minimization of the risk of diabetes in Japanese men with visceral fat accumulation requires a minimum of 4–5% weight loss in those with HbA1c of 5.6–6.4%.

Systemic arteriosclerosis and eating behavior in Japanese type 2 diabetic patients with visceral fat accumulation

Background

Visceral fat accumulation is a major etiological factor in the progression of type 2 diabetes mellitus and atherosclerosis. We described previously visceral fat accumulation and multiple cardiovascular risk factors in a considerable number of Japanese non-obese subjects (BMI <25 kg/m²). Here, we investigated differences in systemic arteriosclerosis, serum adiponectin concentration, and eating behavior in type 2 diabetic patients with and without visceral fat accumulation.

Methods

The study subjects were 75 Japanese type 2 diabetes mellitus (age: 64.8 ± 11.5 years, mean ± SD). Visceral fat accumulation represented an estimated visceral fat area of 100 cm² using the bioelectrical impedance analysis method. Subjects were divided into two groups; with (n = 53) and without (n = 22) visceral fat accumulation. Systemic arteriosclerosis was scored for four arteries by ultrasonography. Eating behavior was assessed based on The Guideline for Obesity questionnaire issued by the Japan Society for the Study of Obesity.

Results

The visceral fat accumulation (+) group showed significantly higher systemic vascular scores and significantly lower serum adiponectin levels than the visceral fat accumulation (−) group. With respect to the eating behavior questionnaire items, (+) patients showed higher values for the total score and many of the major sub-scores than (−) patients.

Conclusions

Type 2 diabetic patients with visceral fat accumulation showed 1) progression of systemic arteriosclerosis, 2) low serum adiponectin levels, and 3) differences in eating behavior, compared to those without visceral fat accumulation. Taken together, the findings highlight the importance of evaluating visceral fat area in type 2 diabetic patients. Furthermore, those with visceral fat accumulation might need to undergo more intensive screening for systemic arteriosclerosis and consider modifying their eating behaviors.

Metabolic syndrome and lifestyle modification

A clustering of metabolic abnormalities such as dyslipidemia, hypertension, and diabetes mellitus, all of which are major risk factors for cardiovascular disease (CVD), occurs more often than by chance. Numerous epidemiological studies, as well as basic researches, have revealed that visceral fat accumulation is closely involved in this risk clustering. This morbid condition is now well recognized as the metabolic syndrome. The concept of the metabolic syndrome, i.e., the involvement of visceral adiposity in the clustering of CVD risk factors, implies that an effective CVD risk reduction will be accomplished by an intervention to reduce visceral fat deposits. The primary strategy of the intervention is lifestyle modification, which can be put into practice in healthcare fields, without necessity of medical treatment. Now that CVD is a leading global health burden, the metabolic syndrome attracts increasing attention in the world. To take global action against the syndrome, several working groups developed its internationally unified diagnostic criteria. Most recently, the International Diabetes Federation (IDF) and the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) jointly proposed the criteria, although some cautions will be needed in their practical use. In this review, we mainly focus on the findings observed in clinical and epidemiological studies, to discuss a practical strategy of the management of the metabolic syndrome in healthcare fields.

Structural changes in dermal collagen and oxidative stress levels in the skin of Japanese overweight males

OBJECTIVE

It has been reported that obese people have poorly organized dermal collagen structure because of the degradation of collagen fibers, which is caused by an increase in oxidative stress levels associated with the hypertrophy of subcutaneous adipose cells. However, it is unclear whether an increase in oxidative stress levels caused by the accumulation of subcutaneous adipose tissue and a change in the dermal structure also occur in overweight and obese Japanese people. The objectives of this study are to identify structural changes that occur in the dermis and to measure the levels of oxidative stress in Japanese overweight males.

METHODS

The overweight group included 43 Japanese male volunteers aged between 25 and 64 years and with a body mass index (BMI) of ≥25 and <30. The control group included 47 male volunteers aged between 22 and 64 years and with BMI of <25. The 20-MHz Dermascan C® ultrasound scanner with software for image analyses was used. Echogenicity of the upper and lower dermis was measured. The mRNA expression level of heme oxygenase-1 (HMOX1) in hair follicles was quantitatively analyzed by real-time reverse transcription polymerase chain reaction (RT-PCR) and was used as a marker of oxidative stress. Ultrasonographic imaging and collection of hair follicles were performed at the same site on the thigh, abdomen, and upper arm.

RESULTS

The HMOX1 mRNA expression level in the abdomen and thigh was significantly lower in the overweight group than in the control group. Moreover, the echogenicity of the upper dermis of the abdomen and the lower dermis of the abdomen and thigh was significantly lower in the overweight group than in the control group.

CONCLUSION

We detected an increase in oxidative stress levels and a decrease in the density of dermal collagen at the same site on the thigh, abdomen, and upper arm of Japanese overweight males. These findings suggest the fragility of the dermis of Japanese overweight males, which might have been caused by the accumulation of subcutaneous adipose tissue.

Clinical significance of visceral adiposity assessed by computed tomography: A Japanese perspective

Abdominal obesity, rather than total amount of fat, is linked to obesity-related disorders. Visceral adiposity is an important component of obesity-related disorders in Japanese individuals with a mild degree of adiposity compared with Western subjects. In 1983, our group reported techniques for body fat analysis using computed tomography (CT) and established the concept of visceral fat obesity in which intra-abdominal fat accumulation is an important factor in the development of obesity-related complications, such as diabetes, lipid disorders, hypertension and atherosclerosis. Our group also established ideal imaging conditions for determining abdominal fat area at the umbilical level CT scan. Visceral fat area (VFA) measured in a single slice at L4 level correlated significantly with the total abdominal visceral fat volume measured on multislice CT scan. In a large-scale study of a Japanese population, the mean number of obesity-related cardiovascular risk factors (hypertension, low high-density lipoprotein cholesterolemia and/or hypertriglyceridemia, and hyperglycemia) was greater than 1.0 at 100 cm² of VFA, irrespective of gender, age and body mass index. Our group also demonstrated that reduction of visceral fat accumulation subsequent to voluntary lifestyle modification, “Hokenshido”, correlated with a decrease in the number of obesity-related cardiovascular risk factors. It is important to select the most appropriate subjects from the general population (e.g., non-obese subjects with a cluster of risk factors for the metabolic syndrome) that are most suitable for body weight reduction, with the goal of preventing atherosclerotic cardiovascular diseases.

Predictors of deterioration of glucose tolerance and effects of lifestyle intervention aimed at reducing visceral fat in normal glucose tolerance subjects with abdominal obesity

Aims/Introduction:  The aim of the present study was to determine the predictors of deterioration of glucose tolerance in individuals with normal glucose tolerance (NGT) and abdominal obesity, and whether a lifestyle intervention to reduce visceral fat is effective in these individuals.

Materials and Methods:  The study subjects were 251 individuals who had abdominal obesity with certain risk factors (hypertension, high fasting plasma glucose (FPG), elevated hemoglobin A_1c (HbA_1c), dyslipidemia and hyperuricemia) and underwent oral glucose tolerance test (OGTT) in 2004 and 2005.

Results:  Using the area under the receiver operating characteristic curve, we found that PG at 0 min, 60 min, and area under the curve (AUC) of glucose from 0 to 120 min (AUC [glucose_0–120]) in OGTT were significant predictors of deterioration of glucose tolerance, with optimal cut‐off values of 95 mg/dL, 158 mg/dL and 271 mg h/dL, respectively. Although the rate of deterioration of glucose tolerance didn’t decrease with reductions in visceral fat area (VFA) over the 1‐year period in subjects with NGT, the rate tended to decrease with reductions in VFA in high‐risk NGT subjects (PG at 0 min > 95 or at 60 min > 158, or AUC [glucose_0–120] > 271).

Conclusions:  These results suggest that reduction of visceral fat over 1 year might not be beneficial in all subjects with NGT, but is beneficial in high‐risk NGT. We propose that individuals with values of the aforementioned predictors higher than the cut‐off levels, even those with NGT, should receive a lifestyle intervention program aimed at reducing visceral fat to prevent deterioration of glucose tolerance. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00080.x, 2011)

Fat accumulation and obesity-related cardiovascular risk factors in middle-aged Japanese men and women

OBJECTIVE

A cluster of multiple risk factors has been noted to constitute the background of cardiovascular disease. The purpose of this study was to evaluate the relationship between the visceral fat area (VFA) or subcutaneous fat area (SFA) and a cluster of obesity-related cardiovascular risk factors, including hyperglycemia, dyslipidemia and elevated blood pressure, in middle-aged Japanese men and women.

METHODS

A total of 571 subjects (m=434; f=137; age: 53 ± 9 years) who underwent health examinations with evaluations of body fat distribution using computed tomography scans and assessments of 75-g oral glucose tolerance tests were enrolled in this study.

RESULTS

The VFA and SFA were linearly correlated with the number of risk factors in both men and women. The area under the receiver-operating characteristic curve of VFA (m=0.741, f=0.763) was significantly higher than that of SFA (m=0.636, f=0.689) with respect to the clustering of risk factors (one or more). The men exhibited larger VFA values and smaller SFA values than the women in similar body mass index (BMI) categories. Men with a VFA of ≥100 cm(2) irrespective of BMI and women with a VFA of ≥100 cm(2) and a BMI of ≥25 kg/m(2) demonstrated a high prevalence of diabetes mellitus and impaired glucose tolerance. Men and women with a VFA of ≥100 cm(2) irrespective of BMI demonstrated a high prevalence of type IIb dyslipidemia.

CONCLUSION

These results suggest that the absolute value of VFA rather than SFA is more closely associated with a cluster of risk factors irrespective of sex and is a good marker for selecting subjects to whom weight reduction should be recommended in order to prevent cardiovascular disease in the general population.

Adiponectin and the cardiometabolic syndrome: an epidemiological perspective

Adiponectin is an adipocyte-derived plasma protein with cardio-vasculo-protective and anti-diabetic properties. Plasma adiponectin levels are low in patients with the cardiometabolic syndrome (a cluster of multiple risk factors based on visceral fat accumulation). Routine measurement of plasma adiponectin may be useful to encourage life-style changes.

The utility of dual bioelectrical impedance analysis in detecting intra-abdominal fat area in obese patients during weight reduction therapy in comparison with waist circumference and abdominal CT

An increase in intra-abdominal fat area (IAFA) is an essential component of metabolic syndrome (MetS). Waist circumference (WC) is not a precise measure of IAFA, and computed tomography (CT) is unsuitable for frequent monitoring. Here, we examined utility of a dual bioelectrical impedance analysis (Dual BIA) for measuring IAFA in obese patients during weight reduction. Fat distribution was measured by Dual BIA and CT in 100 obese outpatients. All fat areas including total, IAFA, and subcutaneous fat by Dual BIA were more closely correlated with those by CT than WC. Estimated IAFA by Dual BIA was significantly correlated with number of MetS components as well as CT, but WC was not. Furthermore, in 61 obese patients who received 6-month weight reduction therapy, estimated IAFA by Dual BIA showed an earlier and greater decrease as well as that by CT than WC and BMI. In addition, decrease in estimated IAFA by Dual BIA through weight reduction had a higher correlation with decrease in IAFA by CT, than WC. This study is the first to demonstrate that the change in estimated IAFA by Dual BIA was highly correlated with that in IAFA by CT during weight reduction therapy. Our findings also indicate that estimated IAFA by Dual BIA is, potentially, a better indicator of severity of MetS, cardiovascular risk factors, and effectiveness of weight reduction than WC, and equal to IAFA by CT. Estimated IAFA by Dual BIA may be useful for monitoring the effectiveness of weight reduction therapy in obese patients.

Imaging and estimation of human abdominal fat by electrical impedance tomography using multiple voltage measurement patterns

A measuring device for human abdominal fat from the conductivity image derived by electrical impedance tomography (EIT) is rarely found. This study was aimed to reconstruct precise conductivity images from multiple voltage measurements in different patterns of the combination of current and voltage electrodes. We examined two voltage measuring patterns using electrodes located at upper and lower levels around the abdomen of a subject. In the experiment, after 1024 voltage data were taken from one specified voltage measurement pattern, another 1024 data were also taken continuously using another pattern. The reconstruction of conductivity image was made using entire data. As a result, the tomography image was improved compared with the image obtained from single voltage measurement pattern. We then obtained the histogram of the conductivities and estimated the area of abdominal fat. The present method using multiple voltage measurement patterns would be effective, if the measuring time can be much reduced through future modification of the tomography device.

Vascular complications and changes in body mass index in Japanese type 2 diabetic patients with abdominal obesity

Background

Although many Asian type 2 diabetic patients have been considered to be not obese and have low capacity of insulin secretion, the proportion of obese patients with visceral fat accumulation has increased in recent years. We found previously considerable number of Japanese non-obese subjects (body mass index (BMI) < 25 kg/m²) with visceral fat accumulation and multiple cardiovascular risk factors. The aim of the study was to investigate the difference in clinical features of type 2 diabetic patients with and without visceral fat accumulation, focusing on vascular complications and changes in BMI.

Methods

We enrolled 88 Japanese hospitalized type 2 diabetic patients. Abdominal obesity represented waist circumference (WC) of ≥85 cm for males and ≥90 cm for females (corresponding to visceral fat area of 100 cm²). Subjects were divided into two groups; with or without abdominal obesity.

Results

Hypertension, dyslipidemia and cardiovascular diseases were significantly more in the patients with abdominal obesity. The prevalence of cardiovascular disease in the non-obese patients (BMI < 25 kg/m²) with abdominal obesity were similar in obese patients (BMI ≥25 kg/m²). The mean BMI of the patients with abdominal obesity was < 25 kg/m² at 20 years of age, but reached maximum to more than 30 kg/m² in the course. Furthermore, substantial portion of the type 2 diabetic patients (52% in males and 43% in females) were not obese at 20 year-old (BMI < 25 kg/m²), but developed abdominal obesity by the time of admission.

Conclusion

These results emphasize the need to control multiple risk factors and prevent atherosclerotic disease in patients with abdominal obesity. The significant weight gain after 20 years of age in patients with abdominal obesity stresses the importance of lifestyle modification in younger generation, to prevent potential development of type 2 diabetes and future atherosclerotic cardiovascular disease.

Weight reduction is associated with improvement of glycemic control in Japanese men, whose hemoglobin A1C is 5.6-6.4%, with visceral fat accumulation, but not without visceral fat accumulation

Aims/Introduction

The aim of the present study was to determine whether weight reduction is associated with improvement of glycemic control in non‐obese and obese subjects with or without visceral fat accumulation, whose hemoglobin A1c (A1C) is 5.6–6.4%.

Materials and Methods

A total of 798 male subjects whose A1C levels were between 5.6% and 6.4% were divided into subgroups based on body mass index (BMI) and/or estimated visceral fat area (eVFA), and were analyzed with respect to the relationships between 1‐year changes in BMI (ΔBMI) and A1C (ΔA1C).

Results

In both the BMI ≥25 and BMI <25 groups, ΔA1C correlated positively with ΔBMI (BMI ≥25 (n = 321): r = 0.236, P < 0.0001; BMI <25 (n = 477): r = 0.095, P = 0.0387) although the r‐value was very small for the latter group. In addition, for the group with eVFA ≥100 cm² (n = 436), ΔA1C correlated positively with ΔeVFA (r = 0.150, P = 0.0017), but this correlation was not found for the eVFA <100 cm² group (n = 339, P = 0.3505). Furthermore, ΔA1C positively correlated with ΔBMI for the groups in BMI ≥25 with eVFA >100 cm² (n = 293, r = 0.256, P < 0.0001) and BMI <25 with eVFA ≥100 cm² (n = 145, r = 0.250, P = 0.0024), but not for the groups in BMI ≥25 with eVFA <100 cm² (n = 28, P = 0.6401) nor BMI <25 with eVFA <100 cm² (n = 332, P = 0.6605).

Conclusions

These results suggest that the assessment of visceral fat, rather than BMI, might be more important in identifying subjects in whom lifestyle intervention aiming at weight reduction could be effective to prevent diabetes. This trial was registered with University Hospital Medical Information Network Clinical Trials Registry (no. UMIN 000002391).

The effect of exercise on visceral adipose tissue in overweight adults: a systematic review and meta-analysis

Excessive visceral adipose tissue appears to trigger a cascade of metabolic disturbances that seem to coexist with ectopic fat storage in muscle, liver, heart and the ß-cell. Therefore, the reduction of visceral adipose tissue potentially plays a pivotal role in the treatment of the metabolic syndrome. The purpose of this systematic review and meta-analysis is to describe the overall effect of exercise on visceral adipose tissue and to provide an overview of the effect of different exercise regimes, without caloric restriction, on visceral adipose tissue in obese persons. A systematic literature search was performed according to the PRISMA statement for reporting systematic reviews and meta-analyses. The initial search resulted in 87 articles after removing duplicates. After screening on title, abstract and full-text 15 articles (totalling 852 subjects) fulfilled the a priori inclusion criteria. The quality of each eligible study was assessed in duplicate with “The Critical Review Form for Quantitative Studies”. Using random-effects weights, the standardized mean difference (Hedge's g) of the change in visceral adipose tissue was −0.497 with a 95% confidence interval of −0.655 to −0.340. The Z-value was −6.183 and the p-value (two tailed) was <0.001. A subgroup analysis was performed based on gender, type of training and intensity. Aerobic training of moderate or high intensity has the highest potential to reduce visceral adipose tissue in overweight males and females. These results suggest that an aerobic exercise program, without hypocaloric diet, can show beneficial effects to reduce visceral adipose tissue with more than 30 cm² (on CT analysis) in women and more than 40 cm² in men, even after 12 weeks.

Reduction of visceral fat correlates with the decrease in the number of obesity-related cardiovascular risk factors in Japanese with Abdominal Obesity (VACATION-J Study)

AIM

Visceral fat accumulation is associated with obesity-related cardiovascular risk factor accumulation and atherosclerosis. The present study investigated whether one-year reduction of the visceral fat area (VFA) correlates with a decrease in the number of such factors in Japanese with or without visceral fat accumulation.

METHODS

The study subjects comprised 5,347 Japanese, who underwent health check-ups in 2007 and 2008, including measurements of VFA and subcutaneous fat area (SFA) by computed tomography at 9 centers in Japan. Subjects with one or more such factor(s) were categorized into tertiles based on the one-year change in VFA. We investigated the multivariate age, sex, and one-year change in SFA-adjusted odds ratios (ORs) and 95% confidence intervals (CI) for reductions in the number of risk factors in each of the three categories based on the one-year change in VFA, in subjects with one or more such factors (n= 3,648).

RESULTS

In the entire group (n=3,648), the OR and 95%CI for reductions in the number of risk factors in the first tertile were 0.804 (0.673-0.962, p=0.0172), compared with the second tertile set at 1.0. Subjects with VFA <100cm(2) showed no reduction in the number of risk factors. In subjects with VFA≥100 cm(2), OR in the first tertile was 0.788 (0.639-0.972, p=0.0257) relative to the second tertile set at 1.0.

CONCLUSIONS

In subjects with multiple cardiovascular risk factors, visceral fat reduction correlated with a decrease in the number of such factors in subjects with VFA≥100cm(2), but not in those with VFA<100cm(2).

Resistance training, visceral obesity and inflammatory response: a review of the evidence

Intra-abdominal obesity is an important risk factor for low-grade inflammation, which is associated with increased risk for diabetes mellitus and cardiovascular disease. For the most part, recommendations to treat or prevent overweight and obesity via physical activity have focused on aerobic endurance training as it is clear that aerobic training is associated with much greater energy expenditure during the exercise session than resistance training. However, due to the metabolic consequences of reduced muscle mass, it is understood that normal ageing and/or decreased physical activity may lead to a higher prevalence of metabolic disorders. Whether resistance training alters visceral fat and the levels of several pro-inflammatory cytokines produced in adipose tissue has not been addressed in earlier reviews. Because evidence suggests that resistance training may promote a negative energy balance and may change body fat distribution, it is possible that an increase in muscle mass after resistance training may be a key mediator leading to a better metabolic control. Considering the benefits of resistance training on visceral fat and inflammatory response, an important question is: how much resistance training is needed to confer such benefits? Therefore, the purpose of this review was to address the importance of resistance training on abdominal obesity, visceral fat and inflammatory response.

Visceral adiposity as a target for the management of the metabolic syndrome

Atherosclerosis, the underlying cause of atherosclerotic cardiovascular disease (ACVD), develops due not only to a single cardiovascular risk factor but to a variety of complex factors. The concept of the multiple cardiometabolic risk factor clustering syndrome has been proposed as a highly atherogenic state, independent of hypercholesterolemia and smoking. Body fat distribution, especially visceral fat accumulation, is a major correlate of a cluster of diabetogenic, atherogenic, prothrombotic, and proinflammatory metabolic abnormalities referred to as the metabolic syndrome, with dysfunctional adipocytes and dysregulated production of adipocytokines (hypoadiponectinemia). Medical research has focused on visceral adiposity as an important component of the syndrome in Japanese subjects with a mild degree of adiposity compared with Western subjects. For the prevention of ACVD at least in Japan, it might be practical to stratify subjects with multiple risk factors for atherosclerotic cardiovascular disease based on visceral fat accumulation. Visceral fat reduction through health promotion programs using risk factor-oriented approaches may be effective in reducing ACVD events, as well as producing improvement in risks and hypoadiponectinemia. This review article discusses visceral adiposity as a key player in the syndrome. Visceral fat reduction with life-style modification is a potentially useful strategy in the prevention of ACVD in patients with the metabolic syndrome.

Metabolic syndrome correlates with polyvascular lesions detected by systemic vascular ultrasonography in Japanese people with type 2 diabetes

Atherosclerosis is a systemic disease of blood vessels. We investigated clinical characteristics of Japanese type 2 diabetic patients with polyvascular lesions detected by systemic vascular ultrasonography. The results showed that the metabolic syndrome correlated with polyvascular lesions detected by systemic vascular ultrasonography in Japanese type 2 diabetics.

Plasma amino acid profile is associated with visceral fat accumulation in obese Japanese subjects

What is already known about this subject •  Asians with metabolic complications associated with obesity, a low body mass index and a low waist circumference have a greater proportion of visceral adipose tissue for a given amount of total body fat compared with Europeans. •  Apparent obese humans and obese animal models show an elevation of branched-chain amino acid levels in plasma. •  A multivariate logistic regression model of plasma free amino acids has been used to screen for several types of cancers in clinical settings. What this study adds •  A specific formula incorporating six amino acid values (Ala, Gly, Glu, Trp, Tyr and branched-chain amino acid) was developed for discrimination of subjects with high visceral fat area by multivariate logistic regression analyses. •  The generated amino acid formula was strongly correlated with visceral fat area in both apparent and non-apparent obese subjects. •  Measuring plasma free amino acids can be used to distinguish the non-apparent visceral obesity in clinical settings in Asian populations.

SUMMARY

Metabolic complications associated with obesity are becoming more common among Japanese subjects. However, visceral fat accumulation is not always apparent by measuring body mass index (BMI) or waist circumference in Asian populations because of the physiological characteristics particular to those ethnicities. Excess visceral fat accumulation raises the odds ratio for developing cardiovascular disease. Thus, high-throughput determination of the amount of abdominal adipose tissue is necessary. We hypothesized that accumulating visceral fat alters the peripheral amino acid profile and that a multivariate logistic regression model of plasma free amino acids can distinguish visceral obesity. A total of 1449 Japanese subjects (985 males and 464 females) who had undergone a comprehensive health screening were enrolled in this study. The visceral fat area was determined using computed tomography imaging, and a plasma free amino acid index to identify high visceral fat areas (≥100 cm(2) ) was developed. The sensitivity and specificity values of the generated amino acid index were 80% and 65%, respectively. In particular, the sensitivity of the generated index to identify subjects with non-apparent visceral obesity (BMI < 25 kg m(-2) ; visceral fat area ≥ 100 cm(2) ) was much greater than that of the waist circumference (73% vs. 46%, respectively). This index's high sensitivity and specificity may be the result of specific alterations in the patients' amino acid profiles, which were specifically correlated with the visceral fat areas and not with subcutaneous fat areas. This profile can be used as a predictor of elevated visceral obesity and a risk assessment tool for metabolic complications in Asian populations.

The utility of visceral fat level by bioelectrical impedance analysis in the screening of metabolic syndrome - the results of the Kyushu and Okinawa Population Study (KOPS)

AIM

A simple, non-invasive medical device, using bioelectrical impedance analysis (BIA) for the evaluation of visceral fat level (VFL) was developed recently. The aim of this study was to investigate the utility of VFL by BIA in the screening of metabolic syndrome (MetS).

METHODS

VFL was measured by the BIA device in 1,451 Japanese residents (546 men and 905 women, age range 30-69 years).

RESULTS

VFL had significant positive correlations with waist circumference (WC) and body mass index (r=0.772 and 0.849, all P < 0.0001). The overall MetS prevalence using Japanese Diagnosis Criteria was 19.8%: men 36.3% and women 9.8%. The mean VFL of the participants with MetS was significantly higher than those without MetS (men; 12.1 and 9.4, women; 13.3 and 8.7) (both P < 0.001). VFL significantly correlated with blood pressure, lipid profiles, fasting plasma glucose, and hemoglobin A1c (all P < 0.001). Receiver operating characteristic curve analysis for a diagnosis of two or more MetS risk factors excluding WC resulted in the same cutoff values for the VFL (10.0) of men and women.

CONCLUSIONS

The VFL by BIA is useful for the detection of MetS because it is correlated with all metabolic parameters and shows the same normal limit in both sexes.

Association of subcutaneous and visceral fat mass with serum concentrations of adipokines in subjects with type 2 diabetes mellitus

The goal of the study was to examine the association of subcutaneous and visceral fat mass with serum concentrations of adipokines in 130 subjects with type 2 diabetes mellitus. The levels of serum high sensitivity C-reactive protein (HS-CRP), adiponectin, high-molecular-weight (HMW) adiponectin, interleukin-18, and retinol-binding protein 4 were measured. Percentage body fat was determined by dual energy X-ray absorptiometry, and subcutaneous and visceral fat areas were measured by abdominal CT. HS-CRP had significant positive correlations with percentage body fat and subcutaneous fat area, and a particularly significant positive correlation with visceral fat area. Serum adiponectin had a negative correlation with the subcutaneous and visceral fat areas, with the strongest correlation with the visceral fat area. Similar results were obtained for HMW adiponectin. Serum adiponectin had a negative correlation with visceral fat area in subjects with a visceral fat area < 100 cm², but not in those with a visceral fat area ≥ 100 cm². In contrast, serum HS-CRP showed a positive correlation with visceral fat area in subjects with visceral fat area ≥ 100 cm², but not in those with a visceral fat area < 100 cm². These findings indicate that an increased visceral fat area is associated with inflammatory changes, and that inflammatory reactions may alter the functional properties of visceral fat in type 2 diabetes mellitus.

The effect of high-intensity intermittent exercise on body composition of overweight young males

To determine the effect of a 12-week high intensity intermittent exercise (HIIE) intervention on total body, abdominal, trunk, visceral fat mass, and fat free mass of young overweight males. Participants were randomly assigned to either exercise or control group. The intervention group received HIIE three times per week, 20 min per session, for 12 weeks. Aerobic power improved significantly (P < 0.001) by 15% for the exercising group. Exercisers compared to controls experienced significant weight loss of 1.5 kg (P < 0.005) and a significant reduction in total fat mass of 2 kg (P < 0.001). Abdominal and trunk adiposity was also significantly reduced in the exercising group by 0.1 kg (P < 0.05) and 1.5 kg (P < 0.001). Also the exercise group had a significant (P < 0.01) 17% reduction in visceral fat after 12 weeks of HIIE, whereas waist circumference was significantly decreased by week six (P < 0.001). Fat free mass was significantly increased (P < 0.05) in the exercising group by 0.4 kg for the leg and 0.7 kg for the trunk. No significant change (P > 0.05) occurred in levels of insulin, HOMA-IR, and blood lipids. Twelve weeks of HIIE resulted in significant reductions in total, abdominal, trunk, and visceral fat and significant increases in fat free mass and aerobic power.

Cross-sectional and longitudinal study of association between circulating thiobarbituric acid-reacting substance levels and clinicobiochemical parameters in 1,178 middle-aged Japanese men - the Amagasaki Visceral Fat Study

Background

Circulating thiobarbituric acid-reacting substance (TBARS) levels, a marker of systemic oxidative stress, are predictive of cardiovascular events. However, they has not been evaluated in Japanese, especially with regard to the factors that contribute to the changes in circulating TBARS levels. We investigated the cross-sectional and longitudinal relationships between circulating TBARS levels and various clinicobiochemical parameters in middle-aged men.

Methods

In this population-based study (The Amagasaki Visceral Fat Study), 1,178 Japanese male urban workers who had undergone health check-ups in 2006, 2007 and 2008 and were not on medications for metabolic disorders during the follow-up period, were enrolled. Serum TBARS levels were measured by the method of Yagi. The estimated visceral fat area (eVFA) by bioelectrical impedance was measured annually. After health check-ups, subjects received health education with lifestyle modification by medical personnel.

Results

The number of cardiovascular risk factors (hypertension, hyperglycemia, low HDL-C, hypertriglyceridemia, hyperuricemia, hyper-LDL-C and impaired renal function) augmented with the increases in log-eVFA (p < 0.0001) and log-TBARS (p < 0.0001). The combination of TBARS and eVFA had a multiplicative effect on risk factor accumulation (F value = 79.1, p = 0.0065). Stepwise multiple regression analysis identified log-eVFA, as well as age, log-body mass index (BMI), LDL-C, log-adiponectin, γ-glutamyl transpeptidase (γ-GTP) and uric acid as significant determinants of log-TBARS. Stepwise multiple regression analysis identified one-year changes in eVFA as well as BMI, γ-GTP and estimated glomerular filtration rate (eGFR) as significant determinants of one-year change in TBARS, and biennial changes in eVFA as well as BMI and γ-GTP, eGFR as significant determinants of biennial change in TBARS.

Conclusions

The present study showed a significant cross-sectional and longitudinal correlation between TBARS and eVFA, as well as BMI and γ- GTP, eGFR. Visceral fat reduction may independently associate with the improvement in systemic ROS in middle-aged Japanese men.

Trial Registration

The Amagasaki Visceral Fat Study UMIN000002391.

Clinical significance of visceral fat reduction through health education in preventing atherosclerotic cardiovascular disease - Lesson from the Amagasaki Visceral Fat Study: A Japanese perspective

The metabolic syndrome has received worldwide recognition and is useful clinical aid in early-preventing atherosclerosis. Visceral adiposity is the main component of the metabolic syndrome in Japan, based on ethnic and racial difference in the pattern of adiposity. In the Amagasaki Visceral Fat Study, subjects had undergone annual health check-ups and then received health education by medical personnel. Visceral fat reduction improved hypoadiponectinemia and the number of obesity-related cardiovascular risk factors, and effectively prevented cardiovascular events. The health education that includes voluntary lifestyle modification aimed at reducing visceral fat could be useful in preventing cardiovascular events in the metabolic syndrome.

The concept of metabolic syndrome: contribution of visceral fat accumulation and its molecular mechanism

Although abdominal obesity or visceral obesity is considered to be one of the components of metabolic syndrome and to have an important role in a cluster of cardiovascular risks, there is no consensus about the definition and diagnostic criteria for this syndrome, probably because there is considerable disagreement about the location and definition of abdominal obesity or visceral obesity.In this review article, the important role of visceral fat accumulation in the development of a variety of lifestyle-related diseases is shown, including cardiovascular disease based on our clinical studies using CT scans, and the mechanism of these disorders is discussed, focusing on adipocytokines, especially adiponectin.The importance of diagnosing metabolic syndrome, in which visceral fat accumulation plays an essential role in the development of multiple risk factors, should be emphasized because lifestyle modification for the reduction of visceral fat may be very effective for the reduction of risks of this type, namely metabolic syndrome in the narrow sense.

Health education "Hokenshido" program reduced metabolic syndrome in the Amagasaki visceral fat study. Three-year follow-up study of 3,174 Japanese employees

OBJECTIVE

The aim of this study was to evaluate the effects of health checkup and the health education "Hokenshido" program based on the concept that visceral fat accumulation causes metabolic syndrome (MetS), leading to cardiovascular disease (CVD).

METHODS AND SUBJECTS

Based on the Japanese definition of metabolic syndrome, in the annual health checkup for general subjects, the measurement of waist circumference and use of "Where am I?" chart on the way to develop atherosclerosis were introduced. The study group comprised 3,174 Japanese employees [2,440 males (46±11 years, mean ± SD), 734 females (43±10 years)], who underwent annual health checkup in 2003, 2004, and 2005. The medical staff provided "Hokenshido" for subjects assessed as having MetS and/or at high risk for CVD.

RESULTS

The prevalence of the MetS in 2003, 2004 and 2005 decreased in males (20.8%, 17.2%, 14.4%, p<0.001) and females (3.0%, 2.2%, 1.9%, p=0.359), respectively. Among subjects with MetS at baseline, the number of subjects with MetS significantly decreased in males (508, 287, 247, p<0.0001) and females (22, 8, 6, p<0.0001), respectively. Mean waist loss was 1.6 cm in males (<0.0001) and 1.5 cm in females (<0.001). Among subjects with metabolic syndrome at baseline, the mean waist loss was 2.5 cm in males (<0.0001) and 3.9 cm in females (<0.05). Fatal atherosclerotic vascular events were not recorded in this study period.

CONCLUSION

Health check-up and the "Hokenshido" program reduced the prevalence of the MetS, which might lead to prevention of CVD.

Effects of statins on the epicardial fat thickness in patients with coronary artery stenosis underwent percutaneous coronary intervention: comparison of atorvastatin with simvastatin/ezetimibe

Background

Epicardial fat is a visceral thoracic fat and known to be related with presence of dyslipidemia and coronary arterial stenosis. We evaluated the effects and differences of statins on epicardial fat thickness (EFT) in patients underwent successful percutaneous coronary intervention (PCI).

Methods

In this retrospective cohort study, we enrolled consecutive patients underwent successful PCI and scheduled six to eight-months follow-up coronary angiography from March 2007 to June 2009. EFT was measured by echocardiography twice at the time of PCI and the follow-up coronary angiography. We included 145 patients (58 females; mean, 63.5 ± 9.5 years).

Results

Of the 145 patients, 82 received 20 mg of atorvastatin (atorvastatin group) and 63 medicated with 10 mg of simvastatin with 10 mg of ezetimibe (simvastatin/ezetimibe group). With statin treatments, total cholesterol concentration (189.1 ± 36.1 to 143.3 ± 36.5 mg/dL, p < 0.001), triglycerides (143.5 ± 65.5 to 124.9 ± 63.1 mg/dL, p = 0.005), low density lipoprotein-cholesterol (117.4 ± 32.5 to 76.8 ± 30.9 mg/dL, p < 0.001) and EFT (4.08 ± 1.37 to 3.76 ± 1.29 mm, p < 0.001) were significantly decreased. Atorvastatin and simvastatin/ezetimibe showed similar improvements in the cholesterol profiles. However, atorvastatin decreased EFT more significantly than simvastatin/ezetimibe (EFT change 0.47 ± 0.65 in the atorvastatin vs. 0.12 ± 0.52 mm in the simvastatin/ezetimibe group; p = 0.001).

Conclusion

In this study, the atorvastatin group showed significant reduction in EFT than in the simvastatin/ezetimibe group. This might be originated from the statin difference. More large, randomized study will be needed to evaluate this statin difference.

Absolute value of bioelectrical impedance analysis-measured visceral fat area with obesity-related cardiovascular risk factors in Japanese workers

AIM

The accumulation of Visceral fat is known to precede metabolic disorders and atherosclerosis. This study aimed to determine the relationships between body mass index (BMI), waist circumference (WC), estimated visceral fat area (eVFA) measured by bioelectrical impedance analysis (BIA), and obesity-related cardiovascular risk factors.

METHODS

The study population was 2,870 middle-aged Japanese employees (males/females=2,322/ 548), who had undergone a health check-up.

RESULTS

In the receiver operating characteristic (ROC) curve, the cutoff levels yielding maximal sensitivity plus specificity for predicting the prevalence of ≥ 2 risks were, 24.5 kg/m(2) for BMI, 84.6 cm for WC, and 111 cm(2) for eVFA in males, and 23.6 kg/m(2), 81.5 cm, and 67 cm(2) in females. The average number of risk factors was over 1.0 in those with a BMI ≥ 25 kg/m(2) and with a WC ≥ 85 cm for males, ≥ 28 kg/m(2) and ≥ 95 cm respectively for females, and those with an eVFA ≥ 100 cm(2) for both males and females. In males, it was around 1.0 with cutoff levels of BMI, WC, and eVFA from the ROC curve. However, in females, it was around 0.6, because the prevalence of subjects with obesity and multiple risks was very low.

CONCLUSIONS

These results suggested that the cutoff level for visceral fat reduction should be set based on an absolute value of risk factors, rather than a calculated value. In regular health check-up, it may be useful to set an absolute cutoff value for eVFA at 100 cm(2) as criteria to screen for multiple obesity-related cardiovascular risk factors.

Relationship between visceral fat accumulation and urinary albumin-creatinine ratio in middle-aged Japanese men

OBJECTIVE

Chronic kidney disease including microalbuminuria relates to cardiovascular disease (CVD). Microalbuminuria is also known to be a marker of generalized endothelial dysfunction. The metabolic syndrome which encompasses visceral fat accumulation and various metabolic disorders, has also an increase in albuminuria and relates to CVD. However, the relationship between visceral fat accumulation and albuminuria remains to be defined. The present study investigated the relationship between visceral fat accumulation and urinary albumin-creatinine ratio (UACR) in Japanese men.

METHODS

This study group comprised 1990 Japanese male subjects, who were employees of a city office, had undergone annual health check-up. Urinary albumin was collected from a single spot urine specimen collected anytime between morning and afternoon. Visceral fat area was estimated (eVFA) by the bioelectrical impedance analysis method.

RESULTS

Log-UACR correlated with age, log-body mass index (BMI), log-waist circumference (WC), log-eVFA, log-adiponectin, blood pressure, serum lipids and hemoglobin A1c (HbA1c). Stepwise multiple regression analysis identified log-eVFA, as well as HbA1c, blood pressure, log-TG, and age, as a significant determinant of log-UACR. Moreover, subjects with eVFA > or = 100 cm(2) had significantly higher UACR than those with eVFA <100 cm(2), irrespective of BMI. UACR was significantly worse in subjects with high numbers of metabolic risk factors, and moreover in subjects with eVFA > or = 100 cm(2) than in those with eVFA <100 cm(2).

CONCLUSION

These results suggested that visceral fat accumulation is associated with an increase in UACR. Evaluation of both visceral fat accumulation and urinary albumin may be important for preventing atherosclerotic diseases.

Substantial changes in epicardial fat thickness after weight loss in severely obese subjects

We sought to evaluate the effect of weight loss on echocardiographic epicardial fat thickness, as index of visceral adiposity, and whether epicardial fat change after the weight loss can be proportionally different from overall body weight changes and related to cardiac parameters changes in severely obese subjects. This was an interventional study in 20 severely obese subjects (12 women, 8 men, BMI 45+/-5 kg/m(2), 35+/-10 years) who underwent 6-month very low calorie diet weight loss program. Baseline and after 6-month weight loss anthropometrics, echocardiographic epicardial fat thickness, left ventricular mass (LVM), and diastolic function parameters were assessed. Subjects lost 20% of original body weight, BMI reduced by 19% of original BMI, waist circumference decreased by 23% of initial waist circumference. Epicardial fat thickness decreased from 12.3+/-1.8 to 8.3+/-1 mm P<0.001 after the 6-month very low calorie diet, as -32% of baseline epicardial fat thickness. LVM and diastolic function changes were better correlated with epicardial fat changes. We showed that significant weight loss can be associated with significant reduction in the epicardial fat thickness, marker of visceral adiposity in severely obese subjects. Epicardial fat decrease, therefore visceral fat decrease, can be proportionally higher than overall adiposity decrease. Epicardial fat changes are significantly associated with obesity-related cardiac morphological and functional changes during weight loss. Measurement of echocardiographic epicardial fat thickness may provide an additional tool in understanding the metabolic risk associated with variation in fat distribution.

Impaired early insulin secretion in Japanese type 2 diabetes with metabolic syndrome

Although it is widely believed that type 2 diabetics with metabolic syndrome (MS) have insulin resistance, the beta-cell function of these patients is largely unknown. We evaluated the characteristics of insulin secretion in Japanese type 2 diabetics with MS after minimizing the influence of glucotoxity. A 75-g OGTT was performed in 192 diabetic subjects and 275 subjects with normal glucose tolerance (NGT). Although there was no significant difference of the AUC (insulin(0-120)) between the MS group and the NGT group, the insulinogenic index (I.I.) was significantly lower in MS patients compared with NGT subjects. The BMI, maximum BMI, waist circumference, and VFA were all positively correlated with I.I. in the MS group (r=0.298-0.376). By stepwise multiple regression analysis, the BMI was shown to be an independent determinant of I.I. in the MS group (standardized regression coefficient: 0.376, p=0.0004), and it accounted for 13% of the variance in I.I. The impaired I.I. was also found in the MS group with untreated type 2 diabetes. These results indicate that early insulin secretion is impaired in type 2 diabetics with MS. The positive association between BMI and I.I. in diabetics with MS may be explained by beta-cell compensation for reduced insulin sensitivity.

Relationship between the serum uric acid level, visceral fat accumulation and serum adiponectin concentration in Japanese men

OBJECTIVE

Visceral fat accumulation is an underlying component of the metabolic syndrome (MetS). Hypoadiponectinemia is one of the key molecules of the MetS. In the present study, we investigated the relationship between the serum uric acid level, visceral fat accumulation and serum adiponectin concentration in Japanese men.

PATIENTS AND METHODS

The study group comprised 1,520 Japanese employed men (mean age: 45.6+/-10.4 years, +/- SD), who had undergone an annual health check-up both in 2004 and 2005. In addition to parameters measured in the annual health check-up, visceral fat area (VFA) and serum adiponectin concentration were measured by the bioelectrical impedance analysis method and a sandwich enzyme-linked immunosorbent assay (ELISA) system, respectively.

RESULTS

Visceral fat accumulation was identified in 56.1% of the subjects with hyperuricemia. There was significant positive correlation between visceral fat area and serum uric acid levels (r=0.223, p<0.0001), and negative correlation between serum adiponectin concentration and serum uric acid levels (r=-0.198, p<0.0001). The one-year change in VFA was associated with the one-year change in serum uric acid levels. Stepwise multiple regression analysis showed that VFA and the serum adiponectin concentration were significant explanatory variables for serum uric acid levels.

CONCLUSION

Hyperuricemia is significantly associated with visceral fat accumulation and hypoadiponectinemia in Japanese men.