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

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

Visceral fat thickness determined using ultrasonography is associated with anthropometric and clinical parameters of metabolic syndrome

The aim of this study is to find out the relation between the ultrasonographic (USG) measurements of the abdominal fat thickness and cardiovascular risk factors in metabolic syndrome. The thickness of subcutaneous fat (SF), visceral fat (VF) and preperitoneal fat (PF) was measured using USG in 75 subjects (35 women and 40 men) with metabolic syndrome. The body mass index (BMI), waist circumference (WC), systolic (SBP) and diastolic (DBP) blood pressures, fasting plasma glucose, fasting insulin and lipid parameters of all participants were recorded. Insulin resistance was estimated using HOMA-IR formula. BMI (p < 0.05), WC (p < 0.01), SBP (p < 0.001), DBP (p < 0.05), fasting insulin (p < 0.05), total cholesterol (p < 0.001) and triglyceride (p < 0.001) levels were found in correlation with VF thickness in the female group. There was a positive association between WC and SF thickness (p < 0.05) in the same group. In the male patients, BMI (p < 0.001), WC (p < 0.01), SBP (p < 0.05), DBP (p < 0.05) and triglyceride level (p = 0.01) were significantly correlated with VF thickness. SF thickness was associated with BMI (p < 0.001) and WC (p < 0.01) in this group. There was no relation between PF thickness and clinical variables in both groups (p > 0.05). It can be concluded that VF thickness may have a significant pathophysiological role in the development of the metabolic syndrome.     

Abdominal Visceral Fat Thickness Measured by Ultrasonography Predicts the Presence and Severity of Coronary Artery Disease

Abdominal visceral fat plays a critical role in the pathogenesis of metabolic syndrome, which is a risk factor for coronary artery disease (CAD). Ultrasonography (US) distinctively quantifies visceral fat and subcutaneous fat. We measured the maximum preperitoneal visceral fat thickness (Vmax) and the minimum subcutaneous fat thickness (Smin) by US in 185 patients who underwent coronary angiography. Although the 144 patients with CAD had larger Vmax (8.8 ± 3.6 vs. 6.4 ± 2.8 mm; p < 0.001) than those without, there was no difference in Smin. Vmax of 6.9 mm or higher was an independent predictor of CAD (odds ratio, 3.710, p = 0.008) by multiple logistic regression analysis. Vmax significantly correlated with the number of diseased vessels. Assessment of abdominal visceral fat by US gives us incremental information beyond conventional risk factors for predicting CAD in routine clinical practice. (E-mail: matsumur@kochi-u.ac.jp)     

运脾化浊颗粒对代谢综合征患者内脏脂肪的影响

目的 观察运脾化浊颗粒对代谢综合征(MS)患者内脏脂肪的影响.方法 将符合临床研究要求的80例患者按照随机数字表分为对照组和观察组,各40例.两组均给予生活方式干预(包括健康教育、控制饮食、加强运动等),对照组给予口服二甲双胍,观察组给予运脾化浊颗粒.观察两组治疗前、后体重(W)、腰围(WC)、体重指数(BMI)、腰臀...     

The usefulness of mesenterium thickness as an index of visceral fat accumulation

Visceral fat syndrome, which includes visceral fat accumulation, glucose intolerance, hyperlipidemia, and hypertension, refers to a highly atherogenic state with a cluster of risk factors secondary to visceral fat accumulation. Although X-ray computed tomography (CT) is used commonly in diagnosis of visceral fat accumulation, it is expensive and exposes the patient to radiation. Some indices obtained using ultrasonography, which is fast and easy to use, have been reported. The ratio of the maximum thickness of preperitoneal fat (P) to the minimum thickness of subcutaneous fat (S), the abdominal wall fat index (P/S), is widely used in ultrasonographic diagnosis, however, this ratio tends to vary largely according to examiners. To establish a more reliable ultrasonographic index of visceral fat accumulation, we measured the thickness of the mesenterium, and tried to examine the relation between its thickness and maximum thickness of preperitoneal fat, minimum thickness of subcutaneous fat, and abdominal wall fat index, as well as body mass index, systolic and diastolic blood pressure, and levels of serum triglyceride, high-density lipoprotein cholesterol, total cholesterol, and blood sugar. The subjects were 131 individuals, 98 males and 33 females, averaging 47.0±7.9 years, with a mean body mass index of 24.1±2.6. The mesenterium was measured with a 3.5 or 3.75 MHz convex probe by longitudinal scanning on the left side of the umbilicus of the patient in the supine position. The thickness of the mesenterium correlated positively with maximum thickness of the preperitoneal fat, abdominal wall fat index, body mass index, and levels of serum triglyceride, total cholesterol, and blood sugar, and negatively with levels of high-density lipoprotein cholesterol. When the subjects were divided into a high-M group and a normal-M group, body mass index, triglyceride level, and blood sugar levels in the high-M group were significantly higher and level of high-density lipoprotein cholesterol was significantly lower than in the normal-M group. These results suggest that the thickness of mesenteium measured by ultrasonography may be useful in the diagnosis of accumulation of visceral fat.     

内脏脂肪组织在克罗恩病发病、诊断及治疗中的作用

克罗恩病(Crohn's disease,CD)是一种慢性炎性肉芽肿性疾病,多发于末端回肠和临近结肠,呈节段性分布。CD肠道病变的机制尚不完全明确,与遗传、免疫和环境等多种因素有关。脂肪组织在CD的发病中发挥重要作用,最新研究发现内脏脂肪组织(visceral adipose tissue,VAT),特别是其肠系膜成分,亦称为爬行脂肪,可通过免疫调节特性影响CD进程。本文主要综述VAT在CD发病、诊断及治疗中的研究进展,以期为临床诊疗提供理论依据。     

Visceral fat accumulation is a significant risk factor for white matter lesions in Japanese type 2 diabetic patients

Background The presence of white matter lesions (WML) is an important prognostic factor for the development of stroke. The elevated visceral fat accumulation (VFA) has been reported to be closely related to the development of atherosclerosis. This preliminary study was therefore designed to test the hypothesis that the presence of WML correlates with VFA and insulin resistance in type 2 diabetic patients not receiving insulin treatment. Material and methods Based on brain magnetic resonance imaging (MRI), 95 type 2 diabetic patients were divided into two groups: WML‐positive group (aged 59 ± 7 years, mean ± SD n = 37) and WML‐negative group (aged 58 ± 5, years, n = 58). The level of blood glucose was assessed by fasting plasma glucose (FPG), fasting immunoreactive insulin, homeostasis model assessment (HOMA) index, and haemoglobin A1c. The fat distribution was evaluated by measuring the visceral fat accumulation by abdominal computerized tomography at the umbilical level. Results The body mass index was higher in the WML‐positive group than in the WML‐negative group (P < 0·005). Plasma levels of triglycerides were higher while high‐density lipoprotein cholesterol was lower in the WML‐positive group than in the WML‐negative group (P < 0·05 and P < 0·01, respectively). FPG (P < 0·01), insulin concentrations (P < 0·0001), HOMA index (P < 0·0001) and VFA (<0·0001) levels were higher in the WML‐positive group than in the WML‐negative group. Multivariate logistic analysis revealed that WML was independently predicted by the high VFA and insulin resistance (P < 0·001, P < 0·0001, respectively). Conclusions The results of this preliminary study indicate that the presence of WML was associated with the high VFA and insulin resistance in Japanese patients with type 2 diabetes mellitus. Further larger cohort studies are warranted to confirm these findings.     

Effect of pronounced weight loss on visceral fat, liver steatosis and adiponectin isoforms

Background Weight loss induced by bariatric surgery is an effective method to reverse obesity and comorbidities. The aim of this prospective weight loss study was to investigate changes of body fat distribution in relation to adiponectin and its isoforms and further to investigate the influence of both body fat distribution and adiponectin on the degree of liver steatosis. Design Fifteen severely obese female patients (body mass index 43·1 ± 4·1, mean age 34·5 ± 8·6 years) were examined before and after surgical treatment. Grading of fatty liver disease and the subcutaneous and visceral fat diameters were determined by abdominal ultrasonography. Metabolic parameters were determined using standard methods; serum total adiponectin and its isoforms were detected by enzyme immuno assay (EIA). Results Mean weight loss was 28·3 kg, which was mostly due to a loss in fat mass, accompanied by an increase in total adiponectin and the high molecular weight (HMW) adiponectin isoform. Visceral adipose tissue (VAT) diameter was highly correlated with liver steatosis, even more strongly than the parameters of liver function. In addition, liver steatosis correlated negatively with HMW adiponectin and binary logistic regression revealed that changes in fat mass, HMW adiponectin and alanine aminotransferase (ALT) were the best predictors for changes in the degree of hepatic steatosis. Conclusions Our results suggest that circulating HMW adiponectin is associated with both VAT and liver steatosis. In summary, the major findings were that the VAT diameter is highly correlated with liver steatosis, even stronger than the parameters of liver function and the association of HMW adiponectin with liver steatosis was better than with total adiponectin.     

Blockade of the Superior Hypogastric Plexus Block for Visceral Pelvic Pain

Abstract: Visceral pelvic pain is a common problem with variable etiology. The sympathetic nervous system plays an important role in the transmission of visceral pain independent of its etiology. Five major pathways by which pelvic pain is transmitted can be identified. One of them, the superior hypogastric plexus, an extension of the preaortic plexus, is easily assessable to blockade by local anesthetics and neurolytic agents. Several techniques have been described. Long-lasting pain relief with this procedure has been achieved in patients with pelvic cancer pain. However, there is a discrepancy between diagnostic and therapeutic blockade in patients with nonmalignant pain. Because a diagnostic blockade can give significant pain relief in a large variety of patients, it is worthwhile to investigate new methods that provide lasting neural blockade of the superior hypogastric plexus and long-lasting relief of this devastating condition.     

The metabolic syndrome: metabolic changes with vascular consequences

Despite criticism regarding its clinical relevance, the concept of the metabolic syndrome improves our understanding of both the pathophysiology of insulin resistance and its associated metabolic changes and vascular consequences. Free fatty acids (FFA) and tumour necrosis factor-alpha (TNF-alpha) play prominent roles in the development of insulin resistance by impairing the intracellular insulin signalling transduction pathway. Obesity is an independent risk factor for cardiovascular disease and strongly related to insulin resistance. In case of obesity, FFAs and TNF-alpha are produced in abundance by adipocytes, whereas the production of adiponectin, an anti-inflammatory adipokine, is reduced. This imbalanced production of pro- and anti-inflammatory adipokines, as observed in adipocyte dysfunction, is thought to be the driving force behind insulin resistance. The role of several recently discovered adipokines such as resistin, visfatin and retinol-binding protein (RBP)-4 in the pathogenesis of insulin resistance is increasingly understood. Insulin resistance induces several metabolic changes, including hyperglycaemia, dyslipidaemia and hypertension, all leading to increased cardiovascular risk. In addition, the dysfunctional adipocyte, reflected largely by low adiponectin levels and a high TNF-alpha concentration, directly influences the vascular endothelium, causing endothelial dysfunction and atherosclerosis. Adipocyte dysfunction could therefore be regarded as the common antecedent of both insulin resistance and atherosclerosis and functions as the link between obesity and cardiovascular disease. Targeting the dysfunctional adipocyte may reduce the risk for both cardiovascular disease and the development of type 2 diabetes. Although lifestyle intervention remains the cornerstone of therapy in improving insulin sensitivity and its associated metabolic changes, medical treatment might prove to be important as well.     

The metabolic syndrome and the risk of venous thrombosis: a case–control study

OBJECTIVE: The results of recent studies have suggested that patients with idiopathic venous thromboembolism (VTE) might be at increased risk of asymptomatic atherosclerosis and cardiovascular events. The metabolic syndrome is a cluster of risk factors for atherosclerosis. Its impact on VTE is unknown. METHODS: In a case-control study, consecutive patients with objectively confirmed deep vein thrombosis (DVT) and control subjects with objectively excluded DVT underwent clinical assessment for the presence of the metabolic syndrome according to the National Cholesterol Education Program criteria. The presence of known risk factors for DVT was documented. Patients with DVT secondary to cancer were excluded. The prevalence of the metabolic syndrome was compared between patients with idiopathic DVT and controls. RESULTS: We enrolled 93 patients with a first episode of idiopathic DVT and 107 controls. The mean age was 65.1 and 63.7 years, respectively. The metabolic syndrome was diagnosed in 50.5% of patients with idiopathic DVT and in 34.6% of controls [odds ratio (OR) 1.93; 95% confidence interval (CI) 1.05, 3.56]. After adjustment for age, sex, body mass index, and smoke, the metabolic syndrome remained independently associated with idiopathic DVT (OR 1.94; 95% CI 1.04, 3.63). In patients with secondary DVT, the prevalence of the metabolic syndrome was 27%. CONCLUSIONS: The metabolic syndrome may play a role in the pathogenesis of idiopathic DVT and may act as link between venous thrombosis and atherosclerosis.