Two-hour insulin determination improves the ability of abdominal fat measurement to identify risk for the metabolic syndrome

Effect of Psyllium husk fiber and lifestyle modification on human body insulin resistance

Insulin resistance is a metabolic disorder that is increasing worldwide and is associated with some of the most common diseases affecting modern societies including diabetes, hypertension, obesity, and coronary heart disease. Changes in diet and physical activity have a profound effect on lowering the risk and cost of managing insulin resistance compared to the pharmacological approach. An interventional study of 16 weeks explored the effect of Psyllium husk fiber in combination with lifestyle modification on insulin resistance among the centrally obese school teachers of district Malakand Khyber Pakhtunkhwa. One Hundred twenty school teachers with central obesity, aged 40-60 years, with no chronic disease history were divided into four subgroups (n = 30) with equal gender bifurcation; a control group, lifestyle modification (LSM) group, psyllium husk fiber (PSH) group, and the combined intervention of LSM & PSH group. Fasting serum was collected to analyze fasting blood glucose, and insulin resistance by using the HOMA-IR method at baseline and post-intervention. A significant effect of the intervention was observed on fasting blood glucose. The combined group of LSM&PSH showed the highest mean change of -7.5 ± 2.6 mg/dl (-9%), followed by the PSH group with a mean change of -6.3 ± 2.1 mg/dl, (-7%). Likewise a significant effect (P < 0.05) on HOMA-IR was observed in the combined group of LSM&PSH with a mean of 1.02 ± 0.14 molar units (-58%), followed by the PSH group with a mean of 1.55 ± 0.14 molar units (-33%). The current study was carried out to assess the effect of regular consumption of Psyllium husk fiber in combination with lifestyle modification on insulin resistance and fasting blood glucose.

The Correlation between the Triglyceride to High Density Lipoprotein Cholesterol Ratio and Computed Tomography-Measured Visceral Fat and Cardiovascular Disease Risk Factors in Local Adult Male Subjects

Background

We studied the association between the triglyceride to high-density lipoprotein cholesterol ratio and computed tomography-measured visceral fat as well as cardiovascular risk factors among Korean male adults.

Methods

We measured triglycerides, high density lipoprotein cholesterol, body mass, waist circumference, fasting plasma glucose, hemoglobin A1c, systolic blood pressure, diastolic blood pressure, visceral fat, and subcutaneous fat among 372 Korean men. The visceral fat and subcutaneous fat areas were measured by computed tomography using a single computed tomography slice at the L4-5 lumbar level. We analyzed the association between the triglyceride to high density lipoprotein cholesterol ratio and visceral fat as well as cardiovascular risk factors.

Results

A positive correlation was found between the triglyceride to high density lipoprotein cholesterol ratio and variables such as body mass index, waist circumference, fasting plasma glucose, hemoglobin A1c, visceral fat, and the visceral-subcutaneous fat ratio. However, there was no significant correlation between the triglyceride to high density lipoprotein cholesterol ratio and subcutaneous fat or blood pressure. Multiple logistic regression analyses revealed significant associations between a triglyceride to high density lipoprotein cholesterol ratio ≥3 and diabetes, a body mass index ≥25 kg/m², a waist circumference ≥90 cm, and a visceral fat area ≥100 cm². The triglyceride to high density lipoprotein cholesterol ratio was not significantly associated with hypertension.

Conclusion

There were significant associations between the triglyceride to high density lipoprotein cholesterol ratio and body mass, waist circumference, diabetes, and visceral fat among a clinical sample of Korean men. In the clinical setting, the triglyceride to high density lipoprotein cholesterol ratio may be a simple and useful indicator for visceral obesity and cardiovascular disease.

CORRELATION BETWEEN OBESITY, SAGITTAL BALANCE AND CLINICAL OUTCOME IN SPINAL FUSION

Objective:To correlate obesity with radiographic parameters of spinal and spinopelvic balance in patients undergoing spinal arthrodesis, and to correlate obesity with clinical outcome of these patients.Methods:Observational retrospective study including patients who underwent spinal arthrodesis, with minimum follow-up period of three months. We measured waist circumference, as well as height and weight to calculate body mass index (BMI) and obtained radiographs of the total column. The clinical parameters studied were pain by visual analog scale (VAS) and the Oswestry questionnaire (ODI). Obesity correlated with radiographic parameters of the sagittal and spinopelvic balance and postoperative clinical parameters.Results:32 patients were analyzed. The higher the BMI, the greater the value of VAS found, but without statistical significance (p=0.83). There was also no correlation between BMI and the ODI questionnaire. Analyzing the abdominal circumference, there was no correlation between the VAS and ODI. There was no correlation between BMI or waist circumference and the radiographic parameters of global spinopelvic sagittal alignment. Regarding the postoperative results, there was no correlation between the mean BMI and waist circumference and the postoperative results for ODI and VAS (p=0.75 and p=0.7, respectively).Conclusions:The clinical outcomes of patients who undergone spinal fusion were not affected by the BMI and waist circumference. Also, there was no correlation between radiographic parameters of spinal and spinopelvic sagittal balance with obesity in patients previously treated with arthrodesis of the spine.

Implication of corticotropic hormone axis in eating behaviour pattern in obese and type 2 diabetic participants

In Algeria, eating behaviour has been increasingly deviated from its traditional Mediterranean diet to modern fast food style. The present study examines the interactions between eating behaviour pattern (EBP), corticotropic hormone axis and the metabolic syndrome. Our Algerian population cohort comprised of 410 participants (130 obese, 170 type 2 diabetics and 110 healthy participants). The EBP was evaluated by the Three-Factor Eating Questionnaire test. The anthropometric and metabolic parameters (glucose, TAG, HDL, LDL and cholesterol) and the concentrations of hormones (insulin, adrenocorticotropin hormone (ACTH), cortisol and growth hormone) were determined by biometrics, spectrophotometry and RIA, respectively. Multivariate analyses showed a high correlation between the EBP and the metabolic syndrome, particularly between insulin-resistant state and hypertrophy of visceral adipose tissue. Compared with healthy participants, obese ones showed the hyperphagic type of EBP, i.e. disinhibition and hunger disorders. Conversely, the diabetics showed both the hypophagic and hyperphagic type of EBP. In diabetic and obese participants, cortisol and ACTH secretions were significantly altered, leading to metabolic disorders. The present study confirms the role of EBP in obesity and diabetes.

Indicators of hypertriglyceridemia from anthropometric measures based on data mining

BACKGROUND

The best indicator for the prediction of hypertriglyceridemia derived from anthropometric measures of body shape remains a matter of debate. The objectives are to determine the strongest predictor of hypertriglyceridemia from anthropometric measures and to investigate whether a combination of measures can improve the prediction accuracy compared with individual measures.

METHODS

A total of 5517 subjects aged 20-90 years participated in this study. The numbers of normal and hypertriglyceridemia subjects were 3022 and 653 females, respectively, and 1306 and 536 males, respectively. We evaluated 33 anthropometric measures for the prediction of hypertriglyceridemia using statistical analysis and data mining.

RESULTS

In the 20-90-year-old groups, age in women was the variable that exhibited the highest predictive power; however, this was not the case in men in all age groups. Of the anthropometric measures, the waist-to-height ratio (WHtR) was the best predictor of hypertriglyceridemia in women. In men, the rib-to-forehead circumference ratio (RFcR) was the strongest indicator. The use of a combination of measures provides better predictive power compared with individual measures in both women and men. However, in the subgroups of ages 20-50 and 51-90 years, the strongest indicators for hypertriglyceridemia were rib circumference in the 20-50-year-old group and WHtR in the 51-90-year-old group in women and RFcR in the 20-50-year-old group and BMI in the 51-90-year-old group in men.

CONCLUSIONS

Our results demonstrated that the best predictor of hypertriglyceridemia may differ according to gender and age.

Quantification of visceral adipose tissue using lunar dual-energy X-ray absorptiometry in Asian Chinese

OBJECTIVE

To evaluate the new DXA VAT method on an Asian Chinese population by comparing to a reference method, computed tomography (CT).

DESIGN AND METHODS

In total, 145 adult men and women volunteers, representing a wide range of ages (19-83 years) and BMI values (18.5-39.3 kg/m(2) ) were studied with both DXA and CT.

RESULTS

The coefficient of determination (r(2) ) for regression of CT on DXA values was 0.947 for females, 0.891 for males and 0.915 combined. The 95% confidence interval for r was 0.940-0.969 for the combined data. The Bland-Altman test showed a VAT bias (CT as standard method) of 143 cm(3) for females and 379 cm(3) for males. Combined, the bias was 262 cm(3) with 95% limits of agreement of -232 to 755 cm(3) . While the current DXA method moderately overestimates the VAT volume for the study subjects, a further analysis suggested that the overestimation could be largely contributed to VAT movement due to breath-holding status.

CONCLUSIONS

For Asian Chinese, VAT measured with DXA is highly correlated to VAT measured with CT. Validation of the DXA VAT tool using a reference method (e.g., CT) needs to carefully control the breath-holding protocol.

Abdominal visceral fat measurement using dual-energy X-ray: association with cardiometabolic risk factors

OBJECTIVE

To examine the association between cardiometabolic risk factors and visceral adipose tissue (VAT) measurements using a dual-energy X-ray absorptiometry (DXA) based approach.

DESIGN AND METHODS

An analysis of cross-sectional relationships between DXA VAT measured using CoreScan (GE Healthcare) and cardiometabolic indicators was conducted on a sample of 939 subjects (541 females and 398 males; average age, 56 years; average BMI, 26 kg/m2) who had previously undergone a total body DXA scan as well as measurements of key cardiometabolic risk factors.

RESULTS

Sex-specific, age-adjusted multivariable regression analysis showed that for both men and women, DXA VAT was significantly associated with increased odds of hypertension, impaired fasting glucose, metabolic syndrome, and type 2 diabetes (P < 0.001). After additional model adjustment for BMI and waist circumference, the odds ratio (per SD change in VAT) for type 2 diabetes was 2.07 for women and 2.25 for men. Similarly, the odds ratio for metabolic syndrome for women was 3.46 and for men was 1.75.

CONCLUSIONS

VAT measured using DXA showed a significant association with cardiometabolic risk factors and disease. These relationships persist after statistical adjustment for age, BMI, and waist circumference. DXA VAT may provide a new accessible option for quantifying VAT-related cardiometabolic risk.

Vagus nerve preservation selectively restores visceral fat volume in patients with early gastric cancer who underwent gastrectomy

BACKGROUND

Body weight loss is a well-known complication after gastrectomy, and is mainly due to reduced fat volume. The effect of vagotomy on the postoperative fat volume was investigated in patients with early stage gastric cancer who underwent gastrectomy.

METHODS

Subcutaneous fat area (SFA) and visceral fat area (VFA) were separately measured in a computed tomographic (CT) image at the level of the umbilicus using Fat Scan software. The changes in these two fat areas were determined by comparing CT images taken before and more than 6 mo after gastrectomy, and the ratio of postoperative to preoperative fat area was calculated in 77 patients.

RESULTS

VFA was reduced significantly greater after total gastrectomy (TG) than distal gastrectomy (DG) (P = 0.0003). In 63 patients who underwent DG, the reduction in VFA, but not in SFA, was significantly less in vagus nerve-preserved than in vagus nerve-nonpreserved cases (59.0% ± 24.2% versus 74.9% ± 28.2%, P = 0.027). If compared in each case, VFA showed a significantly greater decrease than did SFA in vagus-nonpreserving, but not in vagus-preserving, gastrectomy (68.2% ± 37.0% versus 52.7% ± 25.2%, P < 0.0001; 76.3% ± 30.0% versus 74.9% ± 28.2%, P = 0.79).

CONCLUSIONS

The vagus nerve has a function to locally regulate the amount of intra-abdominal fat tissue, and selective vagotomy in gastrectomy results in a preferential reduction of visceral fat in gastrectomy. Surgical denervation of vagus may be reconsidered as a reasonable treatment for excessive obesity.

Linkage of angiotensinogen gene polymorphisms with hypertension in a sibling study of Hong Kong Chinese

OBJECTIVE

The angiotensinogen gene has been linked with human essential hypertension in whites but the relationship in Asian populations has been less consistent. This study aimed to examine genetic associations between hypertension and the M235T, T174M, and G-217A polymorphisms of the angiotensinogen gene in Chinese siblings.

METHODS

We studied members of 126 families with a hypertensive proband, including 434 siblings, of which 178 were hypertensive. Parental history of hypertension was recorded. The M235T, T174M, and G-217A polymorphisms were examined using a microarray method, validated by sequencing. The transmission disequilibrium test was applied to identify whether the genetic polymorphism loci were related to hypertension. Haplotype analysis of the combined polymorphisms was applied using the TRANSMIT program. Linkage study was conducted by applying the affected pedigree member method.

RESULTS

A significant overtransmission was observed for the T235 allele at the M235T polymorphism and hypertension (chi2 = 4.41, P = 0.036) but not for the T174M and G-217A polymorphisms. The haplotype analysis showed a significant association with the haplotypes of paired markers (T174 and T235) with chi2 value of 8.131 (P = 0.004; global test chi2 = 9.131, P = 0.028). Linkage between M235T and hypertension was detected (T = -2.25, P = 0.019), and a tendency for linkage with central obesity-related hypertension was found for the M235T and T174M polymorphisms (P = 0.0087 and P = 0.01).

CONCLUSION

The M235T and T174M variants, especially the T235 allele, contribute to an increased risk of hypertension in these Chinese patients.

Postprandial insulin and triglycerides after different breakfast meal challenges: use of finger stick capillary dried blood spots to study postprandial dysmetabolism

BACKGROUND

High levels of insulin and lipids following a meal are recognized risk factors for atherosclerosis. Monitoring such risk factors in the general population is hampered by the inconvenience of venipuncture blood collection, particularly for both premeal and postmeal analyses. This study examined insulin and triglyceride levels in dried blood spots (DBSs) collected after different breakfast meal challenges to assess the potential of this method for risk assessment.

METHODS

Glucose levels were measured using a glucose meter, and insulin and triglycerides were determined in DBS samples collected from 19 healthy volunteers before and at four time points up to 2.5 h after consuming each of five typical breakfast meals varying in nutritional composition.

RESULTS

At 2 h, glucose was within normal postprandial values (<140 mg/dl) for all meals; significantly lower glucose was seen after meal 2 (the lowest carbohydrate content) compared to the other meals. Insulin returned to normal fasting levels (<15 microIU/ml) in significantly more subjects (90%) after meal 2 and significantly fewer subjects (31%) after meal 4 (highest carbohydrate content) than the other meals. Triglycerides were elevated to a similar extent in all subjects, with no significant differences between meals; levels were still rising at 2.5 h.

CONCLUSIONS

Subjects were able to collect blood spots with minimum disruption to their normal daily activities. Relative ease of collection, analyte stability in dried blood, and the close correlation with serum levels that we have previously demonstrated makes DBS a convenient and simple tool for assessing the individual impact of different diets on postprandial dysmetabolism.

Clinical usefulness of quantitative evaluation of visceral fat by ultrasonography

PURPOSE

The aim of this work was to evaluate the usefulness of a proposed method for visceral fat volume assessment by ultrasonography (US) in identifying those at risk of metabolic syndrome, and also to establish the most suitable cutoff level of waist circumference for the diagnosis of visceral adiposity.

METHODS

One hundred and fifty-two outpatients with metabolic diseases such as hypertension, diabetes, or dyslipidemia were studied. The total visceral fat volume (total-VFA) was measured by computed tomography (CT), the visceral fat area at the level of the umbilicus was measured by CT (CT-VFA), and the visceral fat area was also measured by US (US-VFA), as we recently proposed.

RESULTS

Significant correlation coefficients were found between total-VFA and CT-VFA, US-VFA, and waist circumference in men but not in women. The correlation co-efficient between US-VFA and waist circumference was significantly positive in men and weakly positive in women. According to receiver-operator characteristic curves, the cutoff value of waist circumference yielding the maximal sensitivity plus specificity for predicting more than 100 cm(2) of US-VFA was 85 cm in men and 84 cm in women. The change in US-VFA was significantly larger than that in waist circumference after a 6-month interval.

CONCLUSION

The US-measured visceral fat area is more useful than waist circumference in a clinical setting.

Adipose tissue distribution and risk of metabolic disease: does thiazolidinedione-induced adipose tissue redistribution provide a clue to the answer?

The relative effect of visceral and subcutaneous obesity on the risk of chronic metabolic disease has been a matter of long-term dispute. While ample data support either of the fat depots being causative or associative, valid argument for one depot often automatically belittles the other. Paradigms such as the visceral/portal hypothesis and the acquired lipodystrophy/ectopic fat storage and endocrine hypothesis have been proposed. Nevertheless, neither hypothesis alone explains the entire pathophysiological setting. Treatment of diabetes with thiazolidinediones selectively increases fat partitioning to the subcutaneous adipose depot but does not change visceral fat accumulation. This is in contrast to the preferential visceral fat mobilisation by diet and exercise. Surgical removal of visceral or subcutaneous adipose tissue yields relatively long-lasting metabolic improvement only when combined with procedures that ameliorate adipose tissue cell composition. These studies illustrate that human adipose tissue in different anatomic locations does not work in isolation, and that there is a best-fit relationship in terms of volume and function among different fat depots that needs to be met to maintain the systemic energy balance and to prevent the complications related to obesity.

Defective mitochondrial biogenesis: a hallmark of the high cardiovascular risk in the metabolic syndrome?

The metabolic syndrome is a group of risk factors of metabolic origin that are accompanied by increased risk for type 2 diabetes mellitus and cardiovascular disease. These risk factors include atherogenic dyslipidemia, elevated blood pressure and plasma glucose, and a prothrombotic and proinflammatory state. The condition is progressive and is exacerbated by physical inactivity, advancing age, hormonal imbalance, and genetic predisposition. The metabolic syndrome is a particularly challenging clinical condition because its complex molecular basis is still largely undefined. Impaired cell metabolism has, however, been suggested as a relevant pathophysiological process underlying several clinical features of the syndrome. In particular, defective oxidative metabolism seems to be involved in visceral fat gain and in the development of insulin resistance in skeletal muscle. This suggests that mitochondrial function may be impaired in the metabolic syndrome and, thus, in the consequent cardiovascular disease. We have recently found that mitochondrial biogenesis and function are enhanced by nitric oxide in various cell types and tissues, including cardiac muscle. Increasing evidence suggests that this mediator acts as a metabolic sensor in cardiomyocytes. This implies that a defective production of nitric oxide might be linked to dysfunction of the cardiomyocyte metabolism. Here we summarize some recent findings and propose a hypothesis for the high cardiovascular risk linked to the metabolic syndrome.

A Palatinose-Based Balanced Formula Improves Glucose Tolerance, Serum Free Fatty Acid Levels and Body Fat Composition

Palatinose is a disaccharide present in honey, which has the characteristics of delayed digestion and absorption. We developed a palatinose-based balanced formula (PBF) and reported its beneficial effects on metabolic syndrome-related parameters in rats. To examine the effects of PBF in humans, we here conducted a crossover study using twenty-three subjects with impaired glucose tolerance. The subjects were divided into two groups: intervention to control (I/C) and control to intervention (C/I) groups. The I/C group consumed PBF (250 kcal) together with foods that were 250 kcal less than their usual breakfast (intervention meal) for the first 12 weeks, followed by their usual breakfast (control meal) for the last 12 weeks. The protocol for the C/I group was opposite in order: the control meal for the first 12 weeks, followed by the intervention meal for the last 12 weeks. In the first 12-week period, the intervention meal decreased 2-hr plasma glucose levels after 75-g oral glucose tolerance test (-15.7 +/- 20.1% change), while the control meal did not (0.8 +/- 31.6% change). The difference between these changes was significant (p = 0.038). The similar results were obtained from the comparison of the changes between the first and the last 12-week periods in the two groups combined (intervention vs control: -11.8 +/- 22.5 vs 11.2 +/- 30.2% change, p = 0.024). PBF also had the beneficial effects on serum free fatty acids levels and visceral fat area. In conclusion, PBF consumption has beneficial effects on metabolic syndrome-related parameters in humans.

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.

[Visceral fat and metabolic syndrome: more than a simple association]

Metabolic syndrome (MS) is seen nowadays as a worldwide epidemic event associated with high cardiovascular morbi-mortality and high socioeconomic cost. The ponderal gain is an independent predictor for the development of MS, although not all obese individuals present it. On the other hand, some populations with low obesity prevalence present high prevalence of MS and cardiovascular mortality. The distribution of corporal fat is relevant and visceral fat (VF), specifically, seems to be the link between adipose tissue and insulin resistance (IR), a mean feature of MS. Adipose tissue is now considered a complex organ with multiple functions. VF presents metabolic properties, which are different from the gluteo-femoral subcutaneous fat and related to IR. Several studies show the narrow relationship of abdominal adiposity with the glucose tolerance, hyperinsulinemia, hypertriglyceridemia and arterial hypertension. More than a simple association, recently it is thought that the VF plays a central part in the physiopathology of MS. Consequently, the quantification of VF plays an important role to identify individuals with larger risk for development of MS, who should be chosen for early interventions in the attempt of reducing the impact of metabolic abnormalities on cardiovascular mortality. This article discusses particularities of the central distribution of fat in MS context, possible physiopathogenic mechanisms related to the VF and available methods for the evaluation of abdominal adiposity.

Mesenteric fat thickness is an independent determinant of metabolic syndrome and identifies subjects with increased carotid intima-media thickness

OBJECTIVE

Mesenteric fat, a reflection of visceral adiposity, may play an important role in the pathogenesis of metabolic syndrome and cardiovascular diseases (CVD). In this study, we examined the independent relationship between mesenteric fat thickness and metabolic syndrome and defined its optimal cutoff value to identify high-risk subjects for metabolic syndrome and CVD.

RESEARCH DESIGN AND METHODS

A total of 290 Chinese subjects had an ultrasound examination for measurements of thickness of mesenteric, preperitoneal, and subcutaneous fat as well as carotid intima-media thickness (IMT). Anthropometric measurements and metabolic risk profile were assessed by physical examination and blood taking.

RESULTS

Twenty (6.9%) subjects had metabolic syndrome according to the National Cholesterol Education Panel Adult Treatment Panel III criteria with Asian definitions for central obesity (waist circumference >80 cm in women and >90 cm in men). Mesenteric fat thickness had significant correlations (P < 0.05) with various metabolic variables. On multivariate regression, mesenteric fat thickness was an independent determinant of all components of metabolic syndrome after adjustment for age, sex, homeostasis model assessment of insulin resistance, and other fat deposits. The odds ratio of metabolic syndrome was increased by 1.35 (95% CI 1.10-1.66)-fold for every 1-mm increase in mesenteric fat thickness. On receiver-operating characteristic curve analysis, mesenteric fat thickness of > or =10 mm was the optimal cutoff value to identify metabolic syndrome, with sensitivity of 70% and specificity of 75%. Subjects with mesenteric fat thickness > or =10 mm had higher carotid IMT than those with thickness <10 mm (0.73 +/- 0.19 vs. 0.64 +/- 0.16 mm, P = 0.001).

CONCLUSIONS

Mesenteric fat thickness was an independent determinant of metabolic syndrome and identified subjects with increased carotid IMT.

Non-esterified fatty acid concentrations are independently associated with hepatic steatosis in obese subjects

AIMS/HYPOTHESIS

We tested the hypothesis that NEFA concentrations are higher in obese subjects with fatty liver than in obese subjects without fatty liver.

MATERIALS AND METHODS

We recruited 22 obese (BMI>30 kg/m(2)) men aged 42-64 years, in whom liver fat was assessed by ultrasound and classified into categories of no, mild to moderate and severe fatty liver by two independent radiologists. Regional and visceral abdominal fat were assessed by dual-energy X-ray absorptiometry and magnetic resonance imaging, and endogenous glucose production, whole-body glucose disposal during an insulin clamp, and NEFA concentrations were measured, along with NEFA suppression (percent (%) suppression and insulin sensitivity index for NEFA during an OGTT).

RESULTS

Seven subjects had no evidence of fatty liver, nine had mild or moderate fatty liver and six had severe fatty liver. The amount of visceral fat was not associated with the degree of fatty liver. Whole-body glucose disposal was inversely associated with fatty liver (38.4, 26.5 and 23.9 mumol kg(-1) min(-1) for the groups with no fatty liver, mild to moderate fatty liver and severe fatty liver, respectively, p=0.004). NEFA suppression during the OGTT was decreased (62.5, 50.8 and 41%, p=0.03, for no, mild to moderate, and severe fatty liver, respectively) and the insulin sensitivity index for NEFA was decreased (0.80, 0.40 and 0.34, p<0.0001). Regression modelling suggested that NEFA concentrations were associated with fatty liver independently of whole-body glucose production and disposal measurements.

CONCLUSIONS/INTERPRETATION

In obese men, NEFA concentrations during an OGTT are associated with fatty liver independently of classic measures of insulin sensitivity determined by the hyperinsulinaemic clamp. The contribution to this association by factors regulating NEFA concentrations requires further study.

Ultrasonography for the evaluation of visceral fat and the metabolic syndrome

Association between abdominal obesity and cardiovascular disease has been related with visceral adiposity, through the predisposition of developing type 2 diabetes mellitus and metabolic syndrome (MS). Sonography is a simple and reliable method to measure both subcutaneous and visceral fat. To analyze the relationship of anthropometric measurements with abdominal adiposity measured by sonography and to analyze the utility of sonography in the prediction of insulin resistance (IR) and the other components of MS. Visceral fat measurements by sonography correlated better with components of MS than did subcutaneous fat measurements. Preperitoneal circumference (PC) was strongly correlated with all components of MS and with IR expressed as a homeostasis model assessment (HOMA) index for IR. PC was better than waist circumference (WC) in predicting triglyceride levels, apolipoprotein B levels, and HOMA index, but WC was better than PC in predicting high-density lipoprotein cholesterol levels. The area under the receiver operating characteristic curve was 0.699 for PC and 0.684 for WC, in subjects with body mass index 25 kg/m2 or greater (P=.024 and .015, respectively). PC and WC showed good correlation with HOMA index (Spearman correlation coefficient=0.306, P<.001 and .206, P<.001, respectively). Abdominal visceral fat is better correlated with MS than subcutaneous fat; sonography is a useful method to evaluate the abdominal fat; PC is the best sonography parameter correlated with components of MS, and in overweight and obese subjects, PC is better than WC at predicting components of the MS.

Intra-abdominal fat is a major determinant of the National Cholesterol Education Program Adult Treatment Panel III criteria for the metabolic syndrome

The underlying pathophysiology of the metabolic syndrome is the subject of debate, with both insulin resistance and obesity considered as important factors. We evaluated the differential effects of insulin resistance and central body fat distribution in determining the metabolic syndrome as defined by the National Cholesterol Education Program (NCEP) Adult Treatment Panel III. In addition, we determined which NCEP criteria were associated with insulin resistance and central adiposity. The subjects, 218 healthy men (n = 89) and women (n = 129) with a broad range of age (26-75 years) and BMI (18.4-46.8 kg/m2), underwent quantification of the insulin sensitivity index (Si) and intra-abdominal fat (IAF) and subcutaneous fat (SCF) areas. The metabolic syndrome was present in 34 (15.6%) of subjects who had a lower Si [median: 3.13 vs. 6.09 x 10(-5) min(-1)/(pmol/l)] and higher IAF (166.3 vs. 79.1 cm2) and SCF (285.1 vs. 179.8 cm2) areas compared with subjects without the syndrome (P < 0.001). Multivariate models including Si, IAF, and SCF demonstrated that each parameter was associated with the syndrome. However, IAF was independently associated with all five of the metabolic syndrome criteria. In multivariable models containing the criteria as covariates, waist circumference and triglyceride levels were independently associated with Si and IAF and SCF areas (P < 0.001). Although insulin resistance and central body fat are both associated with the metabolic syndrome, IAF is independently associated with all of the criteria, suggesting that it may have a pathophysiological role. Of the NCEP criteria, waist circumference and triglycerides may best identify insulin resistance and visceral adiposity in individuals with a fasting plasma glucose <6.4 mmol/l.