Contribution of visceral fat accumulation to the development of coronary artery disease in non-obese men

Relationship of high-molecular-weight adiponectin levels to visceral fat accumulation in hemodialysis patients

OBJECTIVE

High molecular weight adiponectin (HMW ADPN) plays an important role in the regulation of insulin resistance and atherogenic processes. However, the role of HMW ADPN remains to be determined in hemodialysis (HD) patients.

PATIENTS AND METHODS

We measured serum HMW ADPN in 49 HD patients (age: 62.4+/-12.0 years, time on HD: 8.4+/-6.4 years, male/female=30/19), and examined the association between HMW ADPN and visceral fat area (VFA) estimated by abdominal CT scans.

RESULTS

Serum HMW ADPN concentrations were weakly and inversely correlated with serum TG (r=-0.271, p=0.0598), but significantly and positively correlated with HDL cholesterol (r=0.392, p=0.0050). Serum HMW ADPN levels were positively correlated with BMI (r=0.472, p=0.0084) in male patients, and the HMW ADPN levels were positively correlated with serum levels of HDL cholesterol (r=0.514, p=0.0243) and TG (r=0.605, p=0.0061).The regression coefficient between VFA and HMW ADPN was -0.491 (p<0.003). Multiple stepwise regression analyses showed that VFA was the most significant and independent determinant of serum HMW ADPN concentration.

CONCLUSION

These findings suggest that HMW ADPN may be inversely associated with visceral fat accumulation in HD patients.

Involvement of visceral fat in the pathogenesis of albuminuria in patients with type 2 diabetes with early stage of nephropathy

BACKGROUND

Visceral obesity has been implicated in the pathogenesis of diabetic nephropathy. Waist circumference has been used as a surrogate measure of visceral fat mass; however, subcutaneous fat mass is also correlated with waist circumference. We therefore conducted this cross-sectional study to clarify the relationship between directly measured sizes of visceral and subcutaneous fat and microalbuminuria in patients with type 2 diabetes (T2DM).

METHODS

We studied a total of 208 adult Japanese individuals with T2DM, 99 women and 109 men, with a mean +/- standard deviation (SD) age of 56 +/- 13 years. Patients with macroalbuminuria, defined as a urinary albumin-to-creatinine ratio (ACR) >or=300 mg/g creatinine, and those with an estimated glomerular filtration rate <15 ml/min/1.73 m(2) were excluded. Visceral and subcutaneous fat areas were measured by abdominal computed tomography.

RESULTS

In the univariate correlational analysis, logarithmically transformed urinary ACR was significantly associated with visceral fat area (r = 0.14, p = 0.047) but not with subcutaneous fat area (r = 0.08, p = 0.237). In the multiple regression analysis with stepwise selection procedure, visceral fat area but not subcutaneous fat area was selected as an independent variable that was statistically associated with urinary ACR.

CONCLUSION

This cross-sectional study suggests that increased visceral but not subcutaneous fat is independently associated with microalbuminuria in Japanese adult patients with T2DM.

Intake of 1-deoxynojirimycin suppresses lipid accumulation through activation of the beta-oxidation system in rat liver

It was recently shown that administration of 1-deoxynojirimycin (DNJ) extracted from mulberry suppresses an increase in postprandial blood glucose in humans. These findings are of interest, but other physiological functions of DNJ are unknown. This study examined the effects of oral administration of DNJ (1 mg/kg of body weight/day) or mulberry extracts enriched in DNJ (meDNJ; 100 or 200 mg of extract/kg of body weight/day, equivalent to 0.53 or 1.06 mg of DNJ/kg of body weight/day) in male Sprague-Dawley rats for 4 weeks. DNJ and meDNJ enhanced expression of adiponectin mRNA in white adipose tissue; increased plasma adiponectin levels, enhanced expression of AMPK mRNA, activated the beta-oxidation system, and suppressed lipid accumulation in the liver. Intake of DNJ and meDNJ did not cause hepatic dysfunction and led to a reduction of oxidative stress. These results indicate the efficacy and safety of DNJ and meDNJ.

Visceral obesity and hypoadiponectinemia are significant determinants of hepatic dysfunction: An epidemiologic study of 3827 Japanese subjects

BACKGROUND AND AIM

Adiponectin is an anti-inflammatory and insulin-sensitizing adipocytokine, and its serum concentrations are reduced in obesity with visceral fat accumulation. Visceral fat accumulation is an independent determinant of elevated serum liver enzymes. Hypoadiponectinemia plays important roles in the clinical progression of nonalcoholic steatohepatitis. The aim of this study was to evaluate the relation between visceral fat area (VFA), serum adiponectin concentration, and biochemical liver tests, such as aspartate aminotransferase, alanine aminotransferase (ALT), and gamma-glutamyltransferase (GGT) in normal subjects.

METHODS

The study group comprised 3827 Japanese subjects [mean age+/-SD; 47.6+/-10.7 y: 2854 males (48.4+/-10.7 y), 973 females (45.3+/-10.1 y)], who underwent annual health checkup in 2004. In addition to parameters measured in the annual health checkup, VFA and serum adiponectin concentration were measured by the bioelectrical impedance analysis method and a latex particle-enhanced turbidimetric assay system, respectively.

RESULTS

Pearson's correlation analysis showed a significant correlation between VFA and the levels of the above 3 liver enzymes in both sexes, and a significant negative correlation between adiponectin and all biochemical liver tests in men and with ALT and GGT in women. Stepwise multiple regression analysis showed that VFA was a significant determinant of serum liver tests in both sexes. Moreover, serum adiponectin concentration significantly and negatively influenced male ALT and GGT and female GGT.

CONCLUSIONS

Both visceral obesity and hypoadiponectinemia are significant determinants of subtle and asymptomatic hepatic dysfunction in normal Japanese subjects.

The role of fat topology in the risk of disease

Clustering of multiple risk factors such as impaired glucose metabolism, lipid disorders and hypertension has been shown to be the major background of atherosclerotic diseases, and disease entities such as the metabolic syndrome represent a highly atherogenic state. Although these common risks may generally co-exist by accident in one individual, clustering of multiple risk factors in the metabolic syndrome does not occur by accident, and there should be a key player for the syndrome. In 1983, we reported the method for fat analysis using computed tomography scan, which enables us to analyze intra-abdominal visceral adiposity as well as subcutaneous fat. Visceral fat accumulation has been shown to cause impaired glucose metabolism, lipid disorders, and hypertension, and therefore it is considered to be a key player in the metabolic syndrome. To clarify the mechanism by which visceral fat accumulation causes a variety of metabolic and vascular diseases, we studied the molecular characteristics of adipose tissue and adipocytes by investigating expressed genes in visceral and subcutaneous adipocytes and revealed that adipocytes, especially visceral adipocytes, secrete a variety of bioactive substances, the so-called adipocytokines. We showed that visceral fat accumulation causes abnormalities in adipocytokine secretion, such as hypersecretion of plasminogen activator inhibitor 1, which is related to thrombogenic vascular diseases. More importantly, we discovered an important benign adipocytokine named adiponectin, which protects against the development of diabetes mellitus, hypertension, inflammation, and atherosclerotic vascular diseases. Plasma levels of adiponectin decreased in individuals with visceral fat accumulation, and hypoadiponectinemia caused by visceral fat accumulation might be one of the major causes of metabolic syndrome.

Carotid atherosclerosis mediated by visceral adiposity and adipocytokines in type 2 diabetic subjects

The aim of this study was to verify the possible association of visceral fat accumulation with carotid atherosclerosis in order to identify the practical and feasible determinants for each parameter of atherosclerosis in type 2 diabetic subjects. The subjects were 151 diabetic (DM) and age-matched 83 nondiabetic subjects (C), without atherosclerotic disease. Visceral fat area (VFA) on a CT scan at the umbilicus level was measured. Ambulatory 24-h blood pressure (BP) was recorded. Stiffness index beta, intima-media thickness (IMT) and plaque formation of carotid arteries were measured by ultrasonography. Insulin sensitivity was estimated by homeostasis model assessment (HOMA). Serum levels of adiponectin and tumor necrosis factor (TNF)-alpha were determined. Male gender, HOMA, serum non-HDL-Cholesterol (Chol) and TNF-alpha/adiponectin ratio were higher, and VFA was larger in DM than in C. The IMT, stiffness index beta and plaque formation in DM were more pronounced than in C, even after adjusting for age, sex and 24-h systolic BP (sBP). VFA was positively correlated with TNF-alpha/adiponectin ratio and serum non-HDL-Chol in DM. Furthermore, multiple regression analysis revealed that, in DM, serum non-HDL-Chol was associated with IMT, VFA probably via an increase in TNF-alpha/adiponectin ratio was associated with stiffness index beta, and 24-h sBP, HOMA and VFA were associated with plaque formation independently of age and sex, respectively, although any association was not observed in C. Thus, we conclude that visceral fat-associated alterations in adipokines may be mediating the development and progression of atherosclerosis in type 2 diabetic subjects, compared with nondiabetic subjects.

Study of intra-abdominal fat distribution in sigmoid colon cancer in Japanese patients by use of MDCT data

To assess the relationship between intra-abdominal fat and sigmoid colon cancer, we investigated the intra-abdominal fat distribution in 172 examples of sigmoid colon cancer and 767 examples of various other pathologies by using data from multidetector-row computed tomography. One significant finding was that the intra-abdominal fat area in sigmoid colon cancer presents a small secondary peak in the pelvis on the profile of the intra-abdominal fat, which we called the pelvic sub-peak. The presence or absence of the pelvic sub-peak was determined based on the sub-peak ratio, which was calculated by dividing the maximum peak by the sub-peak value on the profile of the intra-abdominal fat area. The pelvic sub-peak was defined as having a sub-peak ratio >or=0.1. The pelvic sub-peak frequency was higher for all male patients than for female patients. The frequency of the pelvic sub-peak in sigmoid colon cancer was 77.5% (79/102) for men and 50.0% (35/70) for women. Among both men and women, frequencies of the pelvic sub-peak were significantly higher in patients with sigmoid colon cancer than in non-tumor cases (P < 0.001). Furthermore, the frequency of the pelvic sub-peak was almost the same in sigmoid colon cancer as in rectal cancer. No causal relationship between sigmoid colon cancer and a pelvic sub-peak could be confirmed in the present study; however, patients with sigmoid colon cancer tended to exhibit a unique pattern of fat accumulation.

Healthy obesity

PURPOSE OF REVIEW

To introduce the healthy obese phenotype, characterized by favorable cardiometabolic risk factors despite excess adipose tissue. The epidemiology of the healthy obese phenotype is presented, including associated risk of cardiovascular disease (CVD), and potential biologic mechanisms which may give rise to the phenotype are discussed.

RECENT FINDINGS

Although it appears that approximately 30% of obese individuals maintain healthy cardiometabolic profiles, little published data exist examining the healthy obese phenotype. The healthy obese do not appear to be at increased risk of incident CVD events compared with at-risk obese, and the location of adipose tissue and the metabolic characteristics of the fat in a given location, including the presence of ectopic fat and associated adipocytokine response, may give rise to the phenotype. Recent data also suggest that weight loss among healthy obese may adversely impact their favorable cardiometabolic profile.

SUMMARY

A high prevalence of the healthy obese phenotype has been reported, and these individuals appear to be at no increased risk of CVD. Further research is needed into the mechanisms that allow these individuals to maintain low risk of CVD despite excess adiposity and appropriate weight loss recommendations for this group.

Circulating angiotensin II is associated with body fat accumulation and insulin resistance in obese subjects with type 2 diabetes mellitus

Adipocytes express all components of the renin-angiotensin system, and the renin-angiotensin system is involved in obesity and insulin resistance. Circulating angiotensin II (Ang II) is detectable in blood, but its significance in human obesity remains unknown. The aim of this study was to investigate plasma Ang II in obese patients with type 2 diabetes mellitus (T2D) and the change during weight loss. Fifty Japanese obese subjects with T2D (body weight, 75.0 +/- 14.1 kg; body mass index, 29.1 +/- 3.7 kg/m(2); visceral fat area [VFA], 169.3 +/- 54.3 cm(2); hemoglobin A(1c), 7.6% +/- 1.5%) were enrolled. The subjects were prescribed a diet of daily caloric intake of 20 kcal/kg for 24 weeks. Plasma Ang II was measured by radioimmunoassay. Leptin, adiponectin, and lipoprotein lipase mass in preheparin serum were also measured as adipocyte-derived factors. After 24 weeks of weight reduction diet, the mean body weight, VFA, and hemoglobin A(1c) decreased significantly by 2.3%, 7.0%, and 8.3%, respectively. The mean plasma Ang II decreased by 24% (P < .0001) and correlated with body weight both at baseline (r = 0.425, P = .0018) and at 24 weeks (r = 0.332, P = .0181). The change in Ang II correlated with changes in body weight (r = 0.335, P = .0167) and VFA (r = 0.329, P = .0191). The change in Ang II also correlated positively with change in leptin (r = 0.348, P = .0127) and tended to correlate negatively with change in lipoprotein lipase mass in preheparin serum (r = -0.260, P = .0683), which is a marker of insulin sensitivity. Plasma Ang II is associated with body weight, decreases during weight loss, and is associated with markers of insulin resistance in obese subjects with T2D.

Effects of cardiac rehabilitation in patients with metabolic syndrome after coronary artery bypass grafting

BACKGROUND

Cardiac rehabilitation (CR) has numerous beneficial effects, including the modification of coronary risk factors and improvement of the prognosis, in patients with coronary artery disease (CAD). Limited data are available regarding the effects of CR on the physical status and risk factors in patients with metabolic syndrome (MetS) after coronary artery bypass grafting (CABG).

METHODS AND RESULTS

We enrolled 32 patients with MetS after CABG, who participated in a supervised CR program for 6 months. Metabolic parameters, blood chemistry, exercise tolerance, and muscle strength of the thigh were measured before and after CR. After CR: (1) the body mass index, waist circumference, and fat weight significantly decreased; (2) peak V O(2) and anaerobic threshold were significantly increased; (3) isokinetic peak torques of knee extensor and flexor muscles significantly increased; (4) metabolic scoring defined by the number of the modified Adult Treatment Panel criteria of the US National Cholesterol Education Program was significantly improved; (5) serum concentration of high-sensitivity C-reactive protein also significantly decreased.

CONCLUSIONS

These results suggest that CR might be useful for patients with MetS after CABG.

Carotid arterial elasticity is a sensitive atherosclerosis value reflecting visceral fat accumulation in obese subjects

BACKGROUND

We previously reported the arterial elasticity value we measured to reflect the characteristic features of vessel walls, and to possibly be useful for detecting early stage atherosclerosis in type 2 diabetes. Obesity, especially visceral adiposity, is well known to play a crucial role in the development of metabolic disorders and atherosclerosis. To assess whether arterial elasticity value reflects the effect of obesity on atherosclerosis, we examined the associations of obesity characteristics with atherosclerosis values including arterial elasticity, carotid intima-media thickness (IMT) and pulse wave velocity (PWV).

METHODS

Three atherosclerosis values were measured in 78 obese subjects (body mass index >/=30). We investigated the associations of atherosclerosis values with obesity-related parameters including abdominal fat accumulation determined by computed tomography.

RESULTS

Arterial elasticity values were positively related to established atherosclerosis values, carotid IMT and PWV, in obese subjects. Age, systolic blood pressure and hypertension also correlated with these atherosclerosis values. Single regression analysis showed all three atherosclerosis values to correlate significantly with visceral fat area. Intriguingly, visceral fat area is an independent variable affecting arterial elasticity, but not IMT or PWV. Furthermore, multiple regression analysis revealed that arterial elasticity correlates strongly with visceral fat area.

CONCLUSIONS

Arterial elasticity value we measure is a new parameter for evaluating atherosclerosis in subjects with visceral adiposity and more sensitive than the currently established atherosclerosis values, carotid IMT and PWV. Measuring arterial elasticity has the potential to reveal minute vascular changes, and may have broad clinical applications for evaluating early stage atherosclerosis.

Role of aquaporin-7 and aquaporin-9 in glycerol metabolism; involvement in obesity

The discovery of aquaporin (AQP) has had a great impact on life sciences. So far, 13 AQPs have been identified in human. AQP3, 7, 9, and 10 are subcategorized as aquaglyceroporins which permeabilize glycerol as well as water. Many investigators have demonstrated that AQPs play a crucial role in maintaining water homeostasis, but the physiological significance of some AQPs as a glycerol channel has not been fully understood. Adipocyte is considered to be a major source of glycerol which is one of substrates for hepatic gluconeogenesis. This review focuses on recent studies of glycerol metabolism through AQP7 and AQP9, and discusses the importance of glycerol channel in adipose tissues and liver.

Cardiovascular risk assessment in the metabolic syndrome: results from the Prospective Cardiovascular Munster (PROCAM) Study

OBJECTIVES

We aimed (1) to construct a modified PROCAM risk algorithm, which incorporates BMI/waist circumference in a model for predicting coronary events; (2) to evaluate how accurate this and the previously established PROCAM risk algorithm predict coronary risk in individuals with metabolic syndrome.

DESIGN

Prospective Cardiovascular Münster (PROCAM) Study, a prospective study of men and women at work in the northwest of Germany.

SUBJECTS

A total of 7134 men aged 35-65 years at study entry.

MEASUREMENTS

On the basis of 404 major coronary events (defined as nonfatal MI and coronary deaths), which occurred within 10 years of follow-up, a modified PROCAM risk algorithm was constructed by incorporating BMI/waist circumference as fixed variable in a Cox proportional hazards model for predicting coronary events. The metabolic syndrome was defined according to the latest recommendations proposed by the NCEP-ATP III Panel.

RESULTS

Men who were classified as having the metabolic syndrome (n=2325, prevalence: 32.6%) were 2.59-fold more likely to experience a major coronary event within 10 years of follow-up than men not having the metabolic syndrome. In men with metabolic syndrome, the observed major coronary event rate of 9.6% corresponded well with their estimated global risk according to the modified BMI-based PROCAM risk algorithm (10.2%). Comparative calculations performed with the previously published fully adjusted PROCAM algorithm yielded very similar results.

CONCLUSION

Both PROCAM algorithms provide very accurate means to ascertain coronary risk in male patients with metabolic syndrome.

The metabolic syndrome as a concept of adipose tissue disease

The metabolic syndrome is a constellation of interrelated metabolic risk factors that appear to directly promote the development of diabetes and cardiovascular disease. However, in 2005, the American Diabetes Association and the European Association for the Study of Diabetes jointly stated that no existing definition of the metabolic syndrome meets the criteria of a syndrome, and there have been endless debates on the pros and cons of using the concept of this syndrome. The controversy may stem from confusion between the syndrome and obesity. Obesity is an epidemic, essentially contagious disease caused by an environment of excess nutritional energy and reinforced by deeply rooted social norms. The epidemic of obesity should be prevented or controlled by social and political means, similar to the approaches now being taken to combat global warming. The diagnosis of metabolic syndrome is useless for this public purpose. The purpose of establishing criteria for diagnosing metabolic syndrome is to find individuals who are at increased risk of diabetes and cardiovascular disease and who require specific therapy including diet and exercise. The syndrome may be an adipose tissue disease different from obesity; in that case, it would be characterized by inflammation clinically detected through systemic inflammatory markers such as high-sensitivity C-reactive protein and insulin resistance reflecting histological changes in adipose tissue. However, many problems in defining the optimal diagnostic criteria remain unresolved.

Association of general and abdominal obesities and metabolic syndrome with subclinical atherosclerosis in asymptomatic Chinese postmenopausal women

OBJECTIVE

This study aimed to investigate the relationships between obesity, especially abdominal obesity, andmetabolic syndrome (MS) with carotid intima-media thickness (IMT) and plaque, markers of subclinical atherosclerosis, in asymptomatic Chinese postmenopausal women in Hong Kong.

DESIGN

A total of 518 postmenopausal women aged 50 to 64 years were recruited through random telephone dialing. Body mass index (BMI), waist circumference, waist-to-hip ratio, sociodemographic characteristics, blood pressures, medical, biochemical and lifestyle factors were obtained. MS was defined on the basis of the National Cholesterol and Education Program, Adult Treatment Panel III criteria. Subclinical atherosclerosis was determined by measuring IMT and plaque using high-resolution B-mode ultrasonography.

RESULTS

Women with a BMI of 25 kg/mor greater, a waist circumference of 80 cm or greater, a waist-to-hip ratio of 0.85 or greater, or MS were observed to have higher IMT values and prevalence of plaque. Multivariate analyses revealed that waist circumference was significantly associated with IMT independent of age, hormone therapy, lifestyle and sociodemographic factors, and BMI (P < 0.05), whereas a waist-to-hip ratio of 0.85 or greater was significantly associated with plaque (odds ratio = 1.7; 95% CI: 1.0-2.8) after controlling for age, hormone therapy, lifestyle and sociodemographic factors, BMI, and the traditional cardiovascular risk factors. MS was also associated with IMT after adjustment for age, hormone therapy, lifestyle and sociodemographic factors, and BMI (P < 0.05), whereas its association with plaque was also significant (odds ratio = 1.7; 95% CI: 1.0-2.6) after controlling for age.

CONCLUSIONS

Abdominal obesity and MS are independent of general obesity markers of subclinical atherosclerosis in Chinese postmenopausal women.

Visceral adipose tissue and the ratio of visceral to subcutaneous adipose tissue are greater in adults with than in those without spinal cord injury, despite matching waist circumferences

BACKGROUND

Abdominal obesity, particularly visceral adipose tissue (VAT), is associated with an increased risk of coronary heart disease (CHD). Despite an elevated risk of CHD mortality in persons with spinal cord injury (SCI), neither abdominal adipose tissue accumulation nor the validity of waist circumference (WC) has been determined in persons with SCI.

OBJECTIVES

The objectives of this study were to compare total adipose tissue (TAT), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and the ratio of VAT to SAT (VAT:SAT) between adults with SCI and age-, sex-, and WC-matched able-bodied (AB) controls and to determine the relation between WC and VAT in both groups.

DESIGN

Thirty-one men and women (n = 15 SCI and 16 AB) with a mean (+/-SD) age of 38.9 +/- 7.9 y participated in this cross-sectional study. Abdominal adipose tissue was quantified by computed tomography at L4-L5. WC was measured at 3 sites: lowest rib, iliac crest, and the midpoint between the lowest rib and iliac crest.

RESULTS

Persons with SCI had a 58% greater mean VAT (P = 0.003), 48% greater mean VAT:SAT (P = 0.034), and 26% greater mean TAT (P = 0.055) than did matched AB controls after differences in weight were accounted for. Mean SAT was not significantly different between groups. WC at all sites was correlated with VAT in both groups (SCI: 0.905 < or = r < or = 0.925; AB: 0.838 < or = r < or = 0.877; both P < 0.001).

CONCLUSIONS

High levels of VAT exist in young people with SCI who classify themselves as active and healthy. WC may be a valid surrogate measure of VAT in this population and serve as a tool for clinicians to identify those at risk of CHD.

Relationship between body mass index and gray matter volume in 1,428 healthy individuals

OBJECTIVE

To investigate any correlation between BMI and brain gray matter volume, we analyzed 1,428 healthy Japanese subjects by applying volumetric analysis and voxel-based morphometry (VBM) using brain magnetic resonance (MR) imaging, which enables a global analysis of brain structure without a priori identification of a region of interest.

METHODS AND PROCEDURES

We collected brain MR images from 690 men and 738 women, and their height, weight, and other clinical information. The collected images were automatically normalized into a common standard space for an objective assessment of neuroanatomical correlations in volumetric analysis and VBM with BMI.

RESULTS

Volumetric analysis revealed a significant negative correlation in men (P < 0.001, adjusting for age, lifetime alcohol intake, history of hypertension, and diabetes mellitus), although not in women, between BMI and the gray matter ratio, which represents the percentage of gray matter volume in the intracranial volume. VBM revealed that, in men, the regional gray matter volume of the bilateral medial temporal lobes, anterior lobe of the cerebellum, occipital lobe, frontal lobe, precuneus, and midbrain showed significant negative correlations with BMI, while those of the bilateral inferior frontal gyri, posterior lobe of the cerebellum, frontal lobes, temporal lobes, thalami, and caudate heads showed significant positive correlations with BMI.

DISCUSSION

Global loss and regional alterations in gray matter volume occur in obese male subjects, suggesting that male subjects with a high BMI are at greater risk for future declines in cognition or other brain functions.

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.

Association of obesity and visceral fat distribution with intima-media thickness of carotid arteries in middle-aged and older persons

OBJECTIVE

The association between obesity and atherosclerotic disease is controversial. We examined whether common carotid intima-media thickness (IMT), a precursor to preclinical atherosclerosis, was associated with total body fatness or the accumulation of fat mass in the abdominal region in middle-aged and older persons.

METHODS

Participants were consecutively enrolled from patients aged >or=50 years, and were 623 men aged 73+/-10 (mean+/-standard deviation) years and 835 women aged 76+/-10 years. Demographic data were collected and maximal preperitoneal fat thickness (PFT(max)) and carotid intima-media thickness (IMT) were evaluated on B-mode ultrasonography. Subjects were divided into 3 groups on the basis of body mass index (BMI), a marker of general obesity.

RESULTS

It was shown by multiple regression analysis for IMT that age, smoking status, hypertension and uric acid were significantly associated with IMT in subjects in the lowest BMI group (<20 kg/m(2)), and age, hypertension, dyslipidemia and uric acid in middle BMI group (20-22.9 kg/m(2)). Moreover, man sex, age, BMI, PFT(max), smoking status, hypertension and uric acid were significantly associated with IMT in subjects with highest BMI group (>or=23 kg/m(2)). Analysis of covariance showed that interaction between BMI and visceral obesity (f=7.202, p=0.007) was significantly associated with IMT, in addition to age, visceral obesity, smoking status, hypertension, dyslipidemia and uric acid.

CONCLUSION

The present study indicates a graded and independent association between general and visceral obesity and preclinical carotid artery changes in patients aged >or=50 years with a BMI >or=23 kg/m(2).

Globular adiponectin but not full-length adiponectin induces increased procoagulability in human endothelial cells

Adiponectin (APN), a recently discovered adipocytokine, is present in human serum in a full length (fAPN) and a globular form (gAPN). gAPN is a proteolytic cleavage product of fAPN and seems to show independent biological activities compared to the properties of fAPN. The influence of gAPN and fAPN on procoagulability of cells is still unknown. This study examined the effect of gAPN and fAPN on the expression of tissue factor (TF), the initiator of the extrinsic coagulation system, in human umbilical vein endothelial cells (HUVECs). TF activity was measured by a chromogenic assay, TF mRNA by real-time PCR and TF protein by western blot. We found TF activity to be increased after activation by gAPN (3 microg/mL) compared to a non-stimulated control (169.0+/-19.23 U versus 501.9+/-38.95 U, p<0.001). Furthermore, TF mRNA and TF protein was increased dose-dependently after gAPN stimulation. The gAPN-induced rise of TF activity and TF mRNA was significantly reduced by inhibition of the MAP kinases ERK1/2, p38 and JNK. Contrary to gAPN, stimulation with fAPN did not lead to these procoagulant effects. In conclusion, gAPN increased TF transcription, expression and activity in HUVECs. Therefore, our data support the theory that gAPN but not fAPN supports the cellular procoagulability via TF upregulation.

The effects of physiological and pharmacological weight loss on adiponectin and leptin mRNA levels in the rat epididymal adipose tissue

In subjects with obesity, diabetes and coronary artery disease, circulating levels of leptin increased while that of adiponectin is decreased. In this study we have investigated effects of physiological and pharmacological weight reduction on leptin and adiponectin mRNA expression. Wistar rats were fed either standard laboratory chow for 16 weeks (chow-fed) or given a fat-enriched, glucose-enriched diet (diet-fed) for 8 weeks. After 8 weeks, diet-fed group was subdivided into three subgroups, namely, an untreated obese, or were returned to chow diet, or treated with fenofibrate for further 8 week. After 16 weeks, compared with chow-fed group, diet-fed rats had significantly higher body weight, epididymal fat pad mass, and plasma levels of insulin, leptin, adiponectin, non-esterified fatty acids and triglycerides (P<0.001, for all). Moreover, untreated obese rats had significantly (P<0.01, for both) raised levels of Ob mRNA but reduced adiponectin mRNA levels in epididymal fat pads compared with chow-fed group. These changes were corrected by chronic removal of the high-energy diet and fenofibrate treatment. These findings indicate that physiological or pharmacological lowering of body weight together with circulating plasma lipids play a significant role in leptin and adiponectin synthesis and metabolism.

Clinical significance of fatty liver associated with metabolic syndrome

AIM

Metabolic syndrome (MS) has been recognized as a high-risk disorder that leads to life-threatening diseases, such as coronary vascular disease. The aim of the present study was to investigate the association of fatty liver (FL) with MS in order to establish an effective treatment for FL.

METHODS

One thousand two hundred and fifty-four individuals (694 males, 560 females) who visited the Department of General Medicine, International Medical Center of Japan for a human dry dock annual check-up from 2000 to 2004 were analyzed.

RESULTS

FL was diagnosed in 41.5% of the males and 10.7% of the females, with the prevalence rate increasing in postmenopausal females over 55 years old. High body mass index and waist circumference were observed in those with FL, whereas body mass index reduction was strongly correlated with a decrease in alanine aminotransferase level (R = 0.6,P < 0.01). MS complications were more common in subjects with FL and the most common initial events of MS were shown to be obesity, hyperlipidemia and FL, followed by glucose intolerance and hypertension. Subjects with FL showed a higher level of high-sensitivity C-reactive protein (hs-CRP) (normal: FL = 0.38: 0.73 mg/L, P < 0.05), which was strongly correlated with serum markers that indicated lipid and glucose metabolism in females with FL (R = 0.61-0.77, P < 0.05).

CONCLUSIONS

FL could be a part of or, at least, a predictor of MS. Further, bodyweight reduction is an effective treatment for FL.

Effect of dietary omega 3 phosphatidylcholine on obesity-related disorders in obese Otsuka Long-Evans Tokushima fatty rats

Recent reports have shown that dietary phosphatidylcholine (PC) has various beneficial biological effects. Omega 3 polyunsaturated fatty acids (omega3 PUFAs) have also been reported to have lipid-lowering effects in animal models and human studies. In the present study, we investigated the effect of omega3 PUFAs containing PC (omega3-PC) on obesity-related disorders in Otsuka Long-Evans Tokushima fatty (OLETF) rats. Rats were fed semisynthetic diets that contained either 5% corn oil and 2% egg-PC or 5% corn oil and 2% omega3-PC for 4 weeks. During this 4 week feeding of the omega3-PC, the OLEFT rats showed a decrease of omental white adipose tissue weight. In addition, the omega3-PC diet significantly decreased liver weight and hepatic lipid levels in OLETF rats. These changes were attributable to the significant suppression of fatty acid synthase activity and significant enhancement in the activities of carnitine palmitoyltransferase and peroxisomal beta-oxidation. Moreover, the omega3-PC diet reduced serum glucose levels concomitant with the increase of serum adiponectin levels. These results show that compared with egg-PC, omega3-PC can prevent or alleviate obesity-related disorders through the suppression of fatty acid synthesis, enhancement of fatty acid beta-oxidation, and increase of the serum adiponectin level in OLETF rats.

Visceral adipose tissue, a potential risk factor for carotid atherosclerosis: results of the Multicultural Community Health Assessment Trial (M-CHAT)

BACKGROUND AND PURPOSE

The association between abdominal obesity and atherosclerosis is believed to be due to excess visceral adipose tissue (VAT), which is associated with traditional risk factors. We hypothesized that VAT is an independent risk factor for atherosclerosis.

METHODS

Healthy men and women (N=794) matched for ethnicity (aboriginal, Chinese, European, and South Asian) and body mass index range (<25, 25 to 29.9, or > or =30 kg/m(2)) were assessed for VAT (by computed tomography scan), carotid atherosclerosis (by ultrasound), total body fat, cardiovascular risk factors, lifestyle, and demographics.

RESULTS

VAT was associated with carotid intima-media thickness (IMT), plaque area, and total area (IMT area and plaque area combined) after adjusting for demographics, family history, smoking, and percent body fat in men and women. In men, VAT was associated with IMT and total area after adjusting for insulin, glucose, homocysteine, blood pressure, and lipids. This association remained significant with IMT after further adjustment for either waist circumference or the waist-to-hip ratio. In women, VAT was no longer associated with IMT or total area after adjusting for risk factors.

CONCLUSIONS

VAT is the primary region of adiposity associated with atherosclerosis and likely represents an additional risk factor for carotid atherosclerosis in men. Most but not all of this risk can be reflected clinically by either the waist circumference or waist-hip ratio measures.

Serum C-reactive protein levels correlates better to metabolic syndrome defined by International Diabetes Federation than by NCEP ATP III in men

The International Diabetes Federation (IDF) proposed a new definition for metabolic syndrome (MS) in 2005. We conducted this study to compare the association of MS by IDF and ATP III definition to various metabolic variables. In 2005, we enrolled 654 Chinese people in a screening program in Taiwan. Anthropometric and biochemical profiles, including high-sensitivity C-reactive protein (hsCRP), were measured. Serum hsCRP levels were higher in those with MS by IDF definition (2.4+/-1.9mg/l versus 1.3+/-1.4mg/l, p<0.0001). Serum hsCRP levels increase with the number of components of MS they met (p for trend<0.001). Serum LDL levels were higher in those with MS by IDF definition (131+/-39 versus 125+/-32, p<0.05) but not in those with MS by ATP III definition (p=0.2). Serum hsCRP levels correlate significantly to MS by ATP III definition, after adjusting for age, sex, smoking, body mass index, serum apolipoprotein A1 and LDL levels. Adding MS status by IDF definition in this model significantly increased model fitness in men (MS by IDF definition, partial r=0.18, p<0.05, MS by ATP III definition, partial r=0.12, p=0.071). In conclusion, IDF definition of MS has a stronger relationship with serum hsCRP than ATP III definition in men.

Possible beneficial effects of health counseling, given less frequently than ordinary, on blood pressure

This study was initiated to investigate the effects of health counseling under Total Health Promotion Plan (THP). The study populations consisted of 1,655 working men who had an initial THP-based counseling and a follow-up 3 yr later (the THP group; the counseling was given on a once-three year basis), and 1,655 age- and body mass index (BMI)-matched controls (working men who had no health counseling; the control group). In the THP group, systolic blood pressure (SBP) and the prevalence of excessive alcohol drinking were decreased, and nutritional score was improved, although BMI was increased. In contrast, SBP, BMI and the ratio of excessive drinkers were all increased in the controls. Multiple regression analysis of the THP group showed that the reduction in SBP was positively associated with the increase in maximal oxygen consumption (VO(2max)) and physical activity scores, as well as the decrease in BMI. In sub-group analyses of the THP group, VO(2max) and physical activity scores were increased, and BMI did not change in the sub-group with marked BP decrease. In the sub-group with marked BP increase, however, BMI was increased, and VO(2max) was decreased. The ratio of excessive drinkers was reduced only in the sub-group with marked BP decrease. The obese-hypertensive subjects in the THP group showed decreases in BMI and BP, and increases in VO(2max). Thus, these results appeared to suggest that health counseling given even at a low frequency of once in three years prevented the age-associated increase in BP through improvement of physical endurance, decrease in alcohol intake and reduction in body weight.

Preperitoneal fat thickness by ultrasonography and obesity-related disorders

PURPOSE

To determine optimal cutoff values for preperitoneal fat thickness measured by ultrasonography as indicators for obesity-related disorders.

METHODS

We studied 276 men aged 60 ± 13 years and 307 women aged 64 ± 11 years. Participants were consecutively enrolled from inpatients aged ≤75 years. Demographic data were collected and maximal preperitoneal fat thickness (PFTmax) and carotid intima-media thickness were evaluated on B-mode ultrasonography. Receiver operating characteristic (ROC) curve analysis was performed to determine optimal cutoff values for PFTmax.

RESULTS

Multiple regression analysis using one or more obesity-related disorders as an objective variable showed that the tertile on the basis of PFTmax was a significant independent contributing factor in both men and women. Receiver operating characteristic curve analysis identified the cutoff points of 6.1 mm for PFTmax in men (sensitivity, 66.7%; specificity, 62.5%) and 8.7 mm for PFTmax in women (sensitivity, 56.6%; specificity, 63.6%) as discriminator values corresponding to the presence of one or more obesity-related disorders. Using the new criteria to diagnose visceral obesity, we found that adjusted carotid intima-media thickness was significantly higher in men and women with visceral obesity and two or more obesity-related disorders than in those without them.

CONCLUSIONS

These findings suggested that PFTmax measured on ultrasonography was useful in screening for indicators of cardiovascular risk factors.

Super CitriMax (HCA-SX) attenuates increases in oxidative stress, inflammation, insulin resistance, and body weight in developing obese Zucker rats

Super CitriMax (HCA-SX) is a novel calcium/potassium salt of (-)-hydroxycitric acid extracted from the dried fruit rind of the plant Garcinia cambogia, and commonly consumed as weight loss dietary supplement. In the present study, we investigated the effect of HCA-SX on inflammation, oxidative stress and insulin resistance in developing obese Zucker rats, an animal model of type II diabetes associated with inflammation and oxidative stress. Male Zucker rats (5-week old) were supplemented with vehicle (control) and HCA-SX in drinking water for 7 weeks. Oxidative stress markers, including malondialdehyde (MDA), protein carbonyl (DNPH), and protein tyrosine nitration (tyr-NO(2)) were measured in the liver and kidney tissues using biochemical and immunoblotting techniques. Compared to controls, the levels of MDA, DNPH and tyr-NO(2) were lower in the liver and kidney of HCA-SX-treated animals. Furthermore, the levels of C-reactive protein and interleukin-6, markers of inflammation measured by ELISA, were lower in the plasma of HCA-SX-supplemented animals compared to controls, as were levels of fasting plasma insulin, glucose, and triglycerides. Interestingly, insulin resistance did not develop in HCA-SX-supplemented rats. Food-intake and body weight gain was also lower in rats supplemented with HCA-SX compared to their control counterparts. These results suggest that HCA-SX supplementation in obese Zucker rats reduces food-intake, body weight gain, and also attenuates the increases in inflammation, oxidative stress, and insulin resistance observed in untreated animals. Therefore, HCA-SX may be used as an intervention to overcome obesity-related complications, including inflammation, oxidative stress, and insulin resistance.

Preheparin serum lipoprotein lipase mass might be a biomarker of metabolic syndrome

Lipoprotein lipase mass in preheparin serum (preheparin LPL mass) is assumed to reflect some of the LPL production in the whole body and insulin sensitivity. While metabolic syndrome is a common underlying condition for cardiovascular diseases, biological marker of this syndrome has not been fully established. To clarify the characteristics of preheparin LPL mass in metabolic syndrome, 362 Japanese subjects were studied to examine the relationship between symptoms of metabolic syndrome and preheparin LPL mass and compare with plasma adiponectin. Furthermore the relation with urinary 8-hydroxydeoxyguanosine (8-OHdG) that reflects oxidative stress to DNA was also studied. Both preheparin LPL mass and plasma adiponectin correlated positively with HDL-cholesterol and negatively with body weight and triglyceride. Only preheparin LPL mass showed a negative correlation with fasting blood glucose and HbA1c. Both mean preheparin LPL mass and plasma adiponectin decreased with an increase in severity of the metabolic syndrome with/without obesity and with/without diabetes. The correlation coefficient between preheparin LPL mass and plasma adiponectin was r=0.562. A negative correlation between preheparin LPL mass and urinary 8-OHdG was observed. These results suggest that low preheparin LPL mass may reflect systemic oxidative stress and also a biomarker of the severity of metabolic syndrome.

Prognostic value of the metabolic syndrome for long-term outcomes in patients undergoing percutaneous coronary intervention

BACKGROUND

The prevalence of metabolic syndrome (MS), regarded as an important risk factor for coronary artery disease, is growing. However, the relationship between MS and long-term outcomes after percutaneous coronary intervention (PCI) in the Japanese patient population remains unknown.

METHODS AND RESULTS

Seven-hundred and forty-eight consecutive patients who underwent PCI were assessed. Patients were categorized by the presence or absence of MS using the NCEP-ATPIII definition (for obesity, a body mass index >or=25 kg/m(2) was used). Kaplan-Meier estimation and Cox proportional hazards model were used for unadjusted and adjusted analyses for all cause mortality and cardiac events. The progress of 318 (42.5%) patients with MS and 430 (57.5%) patients without MS was analyzed. The mean follow-up was 12.0+/-3.6 years. Overall, there were 88 (11.8%) deaths from all causes, and there were no significant differences between the 2 groups. The occurrence of cardiac events was significantly higher in the MS group than that in the no MS group (25.5% vs 15.6%, hazard ratio 2.23; 95% confidence interval 1.59-3.11; p<0.001).

CONCLUSIONS

The presence of MS significantly increased the risks of subsequent cardiac events among patients who underwent PCI.

Metabolic syndrome: clinical concept and molecular basis

The metabolic syndrome is a cluster of insulin resistance, elevated blood pressure, and atherogenic dyslipidemia and is a common basis of cardiovascular diseases (CVD). Although the precise mechanism remains to be elucidated, a practical definition is needed. A worldwide definition that considers increased waist circumference as an essential component has been settled. Visceral fat locates upstream of the liver. Free fatty acids and glycerol derived from visceral fat reach the liver and stimulate lipoprotein synthesis and gluconeogenesis, respectively. The adipose tissue produces a variety of bioactive substances conceptualized as 'adipocytokines'. Overproduction of plasminogen activator inhibitor-1 and tumor necrosis factor- seems to relate to the thrombotic and inflammatory tendency. On the other hand, adiponectin, which has antiatherogenic and antidiabetic activities, is reduced in subjects with metabolic syndrome. In Japan, the waist circumference criterion based on visceral fat accumulation has been adopted. The concept of this syndrome has been widely publicized, and health promotion programs based on the concept have commenced in various areas of the country. Such 'Adipo-Do-It' movement is an incentive to encourage physical exercise to reduce visceral fat and is a big challenge to prevent life-style-related diseases and CVD.

Relationship between Visceral Fat and Cardiovascular Disease Risk Factors: The Tanno and Sobetsu Study

We assessed the amount of visceral fat using ultrasonography (US) and studied its relationship to cardiovascular disease risk factors, particularly blood pressure. The subjects in the first study were 45 male and 61 female outpatients. We measured the visceral fat area (VFA) of each subject using abdominal CT and waist circumference (WC), and visceral fat distance (VFD) using US. The subjects in the second study were 353 male and 457 female inhabitants of a rural community, for whom VFD and WC were measured. We divided subjects into tertiles based on VFD and WC, and studied the relationship between each group and individual risk factors. In an analysis of outpatient subjects, the correlation coefficient between VFA and VFD was satisfactory: r=0.660 for men and r=0.643 for women. In the analysis of the rural subjects, the high VFD group had a significantly higher odds ratio than the low VFD group in high blood pressure (HBP) and hypertriglyceridemia (HTG) for men and in HBP, HTG and low high-density lipoprotein cholesterolemia (LHDL) for women. Moreover, adjusting VFD for body mass index revealed that, in comparison to WC, VFD was significantly related to risk factors. VFD was used as an independent variable in multiple regression analysis with blood pressure level as a dependent variable; no significant association between WC and blood pressure was obtained. Visceral fat assessment by US may be useful for epidemiological study and for clinics with no abdominal CT equipment for identifying high-risk individuals, such as those with metabolic syndrome.

Serum lipoprotein lipase mass: clinical significance of its measurement

Lipoprotein lipase (LPL) is a lipolytic enzyme involved in catalyzing hydrolysis of triglycerides (TG) in chylomicrons and very low-density lipoprotein (VLDL) particles. Over the last decade, increasing attention has been paid to the clinical significance of measuring serum LPL protein mass without heparin injection to the study subjects. In earlier studies, this marker was utilized to classify LPL deficient subjects, which is an extremely rare metabolic disorder with a frequency of one in one million. Later, researchers paid more attention to the clinical significance of measuring this parameter in more common metabolic disorders. Studies have shown that pre-heparin plasma or serum LPL mass has significant relationships with serum lipids and lipoproteins, visceral fat area, insulin resistance, and even the development of coronary atherosclerosis in cross-sectional studies, although this might be a metabolic surrogate marker with almost no catalytic activities, which does not appear to be involved in catalyzing hydrolysis of TG in TG-rich lipoproteins. Recently, a prospective study has demonstrated that low serum LPL concentration predicts future coronary events. Taken together, we suggest that pre-heparin LPL mass in plasma or sera provide us with useful and important information on the development of metabolic disorders leading to atherosclerotic disease.

Systemic oxidative stress is associated with visceral fat accumulation and the metabolic syndrome

BACKGROUND

The metabolic syndrome (MetS) is a major target for prevention of atherosclerotic cardiovascular diseases and visceral fat accumulation is an underlying component of MetS. The aim of this study was to investigate the association of systemic oxidative stress with visceral fat accumulation and MetS.

METHODS AND RESULTS

The study group consisted of Japanese men (n=44; 51.2+/-11.4 years) and women (n=61; 55.4 +/-13.4 years). Urinary 8-epi-prostaglandin F2alpha (8-epi-PGF2 alpha) concentration, a biomarker of systemic oxidative stress, was significantly high in the subjects with MetS. As the urinary concentration of 8-epi-PGF2alpha increased, the number of criteria for MetS were significantly met (abdominal obesity, hypertriglyceridemia, low high-density lipoprotein-cholesterol, hypertension, and high fasting glucose). Among parameters associated with MetS, the correlation coefficient of visceral fat area (VFA) with urinary 8-epi-PGF2alpha concentration was the highest (r=0.636, p<0.0001). In non-obese subjects, the correlation coefficient of VFA with urinary 8-epi-PGF2alpha concentration was higher (r=0.728, p<0.0001), although there was no significant correlation between subcutaneous fat area and urinary 8-epi-PGF2 alpha. Stepwise multiple regression analysis identified VFA as the strongest and independent determinant of urinary 8-epi-PGF2 alpha (p<0.0001) followed by adiponectin (p=0.0212) and, high sensitive C-reactive protein (p=0.0365).

CONCLUSIONS

Systemic oxidative stress, as measured by urinary 8-epi-PGF2alpha , is strongly associated with visceral fat accumulation and MetS.

Differential regulation of intestinal lipid metabolism-related genes in obesity-resistant A/J vs. obesity-prone C57BL/6J mice

The effects of high-fat (HF) feeding on gene expression in the small intestine were examined using obesity-resistant A/J mice and obesity-prone C57BL/6J (B6) mice. Both strains of mice were maintained on low-fat (LF; 5% fat) or HF (30% fat) diets for 2 wk. Quantitative reverse transcription-PCR analysis revealed that lipid metabolism-related genes, including carnitine palmitoyltransferase (CPT) I, liver fatty acid binding protein, pyruvate dehydrogenase kinase-4, and NADP(+)-dependent cytosolic malic enzyme, were upregulated by HF feeding in both strains of mice. The upregulated gene expression levels were higher in A/J mice than in B6 mice, suggesting more active lipid metabolism in the small intestine of A/J mice. The prominent upregulation of the lipid metabolism-related genes were specific to the small intestine; the expression levels were little or unchanged in the liver, muscle, and white adipose tissue. The increase by HF feeding and predominant expression of the intestinal lipid metabolism-related genes in A/J mice were reflected in the enzyme activities; malic enzyme, CPT, and beta-oxidation activities were increased by HF feeding, and the upregulated malic enzyme and CPT activities were significantly higher in obesity-resistant A/J mice compared with those in obesity-prone B6 mice. These findings suggest that intestinal lipid metabolism is associated with susceptibility to obesity.

Hypoadiponectinemia: A common basis for diseases associated with overnutrition

Adiponectin is a plasma protein derived from adipose tissue, which we discovered from a human adipose cDNA project. Adiponectin exists in circulating plasma at concentrations ranging from 4 to 30 microg/mL, which is much higher than the concentrations of various other hormones and cytokines. Adiponectin has a sticky nature, binding to collagen I, III, and V, which are present in vascular intima. Adiponectin exhibits various antiatherogenic effects on vascular cells, suppressing the expression of adhesion molecules in vascular endothelial cells, proliferation of smooth muscle cells, and cholesteryl-ester accumulation in macrophages. However, its plasma levels are low in subjects with excess intra-abdominal fat. Adiponectin also has antidiabetic properties, and plasma adiponectin levels correlate positively with insulin sensitivity. Several clinical studies have demonstrated that hypoadiponectinemia is a risk factor for new-onset diabetes. Recent studies suggest that hypoadiponectinemia may partly contribute to the development of salt-sensitive hypertension and hypertensive heart failure, and can be also a risk factor for overnutrition-related cancers such as breast, colon, uterine, and prostate cancers. Hypoadiponectinemia might be at least in part the molecular basis of various diseases associated with overnutrition.

Topical ER36009, a RARgamma-selective retinoid, decreases abdominal white adipose tissue and elicits changes in expression of genes related to adiposity and thermogenesis

Chronic topical treatment of rats with a new RARgamma-selective retinoid, ER36009, resulted in a significant reduction of epididymal white adipose tissue and a significant increase of interscapular brown adipose tissue without affecting food intake. ER36009 markedly decreased PPARgamma, 11beta-HSD1, and Bcl-2 mRNA levels, and increased Bax mRNA in white adipose tissue, while it upregulated UCP1 and UCP3 mRNAs in brown adipose tissue and UCP3 mRNA in gastrocnemial muscle. These results suggest that ER36009 has multiple effects on adipose tissue biology and the energy balance. Topically applied ER36009 may have potential for the treatment of obesity.

Adiponectin, insulin resistance and clinical expression of the metabolic syndrome in patients with Type 2 diabetes

BACKGROUND

Obesity and the metabolic syndrome have emerged as clinical and public health crises in many populations, but not all obese patients have the syndrome. As adipocytes produce several adipokines that modulate insulin action as well as glucose and lipid metabolism, we postulate that estimation of adipokines may be useful addition to the criteria used to identify obese individuals with the metabolic syndrome.

OBJECTIVE

To evaluate the determinants and associations of plasma adiponectin in relation to the metabolic syndrome in patients with Type 2 diabetes.

DESIGN

Cross-sectional study.

SETTING

General Teaching Hospital.

PATIENTS

One hundred and thirty five (57 M, 78 F) patients with Type 2 diabetes mellitus.

MEASUREMENTS

Adiponectin, leptin, high-sensitivity C-reactive protein (hs-CRP), fasting plasma insulin, glucose, glycated hemoglobin and full lipid profile. Patients were classified on the basis of the degree of adiposity, insulin resistance (IR) (homeostasis model assessment of insulin resistance (HOMA-IR)) and the number of the American Heart Association and the National Heart, Lung and Blood Institute criteria of the metabolic syndrome.

RESULTS

Adiponectin levels were inversely correlated with age, indices of obesity, IR and hs-CRP. Overweight/obese and non-obese insulin-sensitive patients had significantly higher (P<0.05) adiponectin levels than those with IR despite similar body mass index and waist circumference. Therefore, within each category of obesity stratification, lower adiponectin levels were associated with IR. Adiponectin showed stepwise decrease with increasing number of the criteria for diagnosis of the metabolic syndrome. Using multiple logistic regression, the odds ratio of the metabolic syndrome as predicted by adiponectin was 0.73 (95% confidence interval 0.53-0.96; P=0.04). At cutoff point of 18 ng/ml, the diagnostic sensitivity and specificity of adiponectin for the metabolic syndrome were 83 and 65%, respectively, in male patients and 92 and 41%, respectively, in female patients. Receiver operating characteristic analysis showed that adiponectin had significantly higher area under the curve compared with leptin, leptin:adiponectin ratio and triglycerides for the detection of the metabolic syndrome.

CONCLUSIONS

In patients with Type 2 diabetes, adiponectin concentrations are closely related to IR and the components of the metabolic syndrome. Adiponectin concentration may be a useful addition to the criteria used for identifying obese subjects with the metabolic syndrome.