[Metabolic syndrome strongly linked to stroke in Chinese]

OBJECTIVE

To assess the association of the metabolic syndrome with stroke in Chinese using the definition of ATP III, and revised definition according to Chinese criteria for abdominal obesity.

METHODS

Multi-center case control study, 1934 first-ever-stroke patients (Atherothrombosis, lacunar infarction, and intracerebral hemorrhage) aged 30 to 74 years were sequentially recruited. And 1839 age, gender and geographically matched subjects were included as controls.

RESULTS

The prevalence of metabolic syndrome defined by either ATP III or Chinese criteria was significantly increasing in patients with lacunar infarction, cerebral atherosclerosis, or intracerebral hemorrhage than control subjects. After age- and sex-adjusted and further adjusted age, sex, total cholesterol, smoking, drinking, and education levels, the metabolic syndrome defined by ATP III criteria was associated with a 2.7 to 4.3 fold and 2.5 to 4.0 fold higher risk of the three stroke subtypes, respectively.

CONCLUSION

the metabolic syndrome defined by ATP III and revised according to Chinese criteria of abdominal obesity was positively associated with the risk of stroke in our case control study. This study underscores the need for well-designed prospective study in Chinese to give further evidence to the link between metabolic syndrome and stroke.

Deleterious Impact of “High Normal” Glucose Levels and Other Metabolic Syndrome Components on Arterial Endothelial Function and Intima-Media Thickness in Apparently Healthy Chinese Subjects: The CATHAY Study

Objective— Endothelial vasodilator dysfunction and carotid intima-media thickening are useful surrogate markers of cardiovascular disease, a major cause of morbidity and mortality in type 2 diabetic patients. However, because most studies reporting the relationships between endothelial function, intima-media thickness (IMT), and hyperglycemia have compared diabetic patients with healthy controls, we report their relationship with glycemia as a continuum.

Methods and Results— Brachial artery endothelial function (flow-mediated dilatation [FMD]) and carotid IMT were measured noninvasively by high-resolution ultrasound B-mode imaging in 228 apparently healthy Chinese subjects recruited from Hong Kong and Macau. FMD and IMT were significantly associated with increasing levels of glycemia, particularly in the “high normal” glycemic range, with IMT increasing and endothelium-independent dilatation decreasing linearly across the glucose tertiles, and endothelium-dependent dilatation significantly lower in the upper glucose tertile compared with the other 2 groups ( P <0.01). Using multiple linear regression, fasting glucose level was identified as an independent predictor of each of these markers of vascular function ( P <0.004). Additionally, other conventional cardiovascular risk factors, including obesity, blood pressure, and an adverse lipid profile, were also related to levels of glycemia ( P <0.05), further contributing to impaired vascular function.

Conclusion— Increasing levels of glycemia and the coexistence of other cardiovascular risk factors in apparently healthy subjects are adversely associated with arterial endothelial dysfunction and intima-media thickening.

Metabolic syndrome is directly associated with gamma glutamyl transpeptidase elevation in Japanese women

AIM: This study aimed to determine whether metabolic syndrome is directly or indirectly, through fatty liver, associated with elevated gamma-glutamyl transpeptidase (GGT) levels in Japanese women.

METHODS: From 4366 women who received their annual health check-up, 4211 women were selected for analysis. All 4211 women were negative for both hepatitis B surface antigen and antibody to hepatitis C virus. Clinical and biochemical variables were examined by using univariate and multivariate analysis.

RESULTS: A raised GGT level ( > 68 IU/L) was seen in 258 (6.1%) of the 4211 women. In univariate analysis, all variables examined (age, body mass index, blood pressure, hemoglobin concentration, fasting blood glucose, glycosylated hemoglobin A1c, cholesterol, triglyceride, and uric acid) were associated with the elevated GGT level, whereas in multivariate analysis, four variables (age ≧ 50 yr, hemoglobin ≧ 14 g/dL, triglyceride ≧ 150 mg/dL, and presence of diabetes) were significantly and independently associated with raised GGT level. Clinical variables predicting the presence of ultrasonographic evidence of fatty liver were also examined by multivariate analysis; four variables were associated with the presence of fatty liver: BMI ≧ 25 kg/m², hemoglobin ≧ 14 g/dL, triglyceride ≧ 150 mg/dL, and uric acid ≧ 7 mg/dL. There was no significant association between the raised GGT level and the presence of fatty liver. Hypertriglyceridemia was significantly and independently associated with both the raised GGT level and the presence of fatty liver.

CONCLUSION: Metabolic syndrome seemed to be directly, not indirectly through fatty liver, associated with the raised GGT level in Japanese women.

Hypofibrinolysis in the insulin resistance syndrome: implication in cardiovascular diseases

Insulin resistance syndrome (IRS) is associated with increased cardiovascular morbidity and mortality. IRS is becoming one of the major health problems as its prevalence grows rapidly. Accelerated atherothrombotic process in the IRS is attributed to metabolic abnormalities, inflammation and to impaired fibrinolysis due to increased plasma plasminogen activator inhibitor type 1 (PAI-1) levels. Proinflammatory cytokines may have an important role in PAI-1 overexpression, particularly in the adipose tissue. Studies in genetically modified mice indicate that PAI-1 might be involved in the aetiopathogenesis of obesity. Modifying PAI-1 expression by PAI-1 inhibitors may open a new field of research and may reveal the true role of PAI-1 in atherosclerotic and insulin resistance processes.

WHO and ATPIII proposals for the definition of the metabolic syndrome in patients with Type 2 diabetes

AIMS

Different criteria have been proposed by the World Health Organization (WHO) and by the Third Report of the National Cholesterol Education Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (ATPIII) for the diagnosis of the metabolic syndrome. Its identification is of particular importance for coronary risk assessment.

METHODS

The prevalence of the metabolic syndrome was determined according to the two different proposals in 1569 consecutive subjects with Type 2 diabetes.

RESULTS

By the WHO proposal, 81% of cases (95% confidence interval, 79-83) were labelled as metabolic syndrome. Microalbuminuria had the highest specificity (99%) and visceral obesity the highest sensitivity (93%). Seventy-eight per cent of patients (95% CI, 76-80) fulfilled the ATPIII criteria for metabolic syndrome, low HDL-cholesterol having the highest specificity (95%), elevated blood pressure having the highest sensitivity. According to both proposals, 1113 patients were positive; 183 were concordantly negative, indicative of a fairly good agreement (k statistics, 0.464). Subjects only positive for the WHO proposal were more frequently males, had a lower BMI and a higher arterial pressure. Only subjects identified by the ATPIII proposal had a significantly higher prevalence of previously detected coronary heart disease.

CONCLUSIONS

Minimum criteria for the metabolic syndrome are met in most patients with Type 2 diabetes. Correct identification of the syndrome is important for an integrated approach to reduce the high costs and the associated disabilities. The ATPIII proposal more clearly identifies the burden of coronary heart disease associated with the metabolic syndrome.

Cardiovascular risk factors in Mexican-American children at risk for type 2 diabetes mellitus (T2DM)

PURPOSE

To assess risk factors for type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD) with the hypothesis that risk for T2DM in children would be associated with an increase in risk factors for CVD.

METHODS

Subjects from a group of Mexican-American school children (aged 10-12 years) identified to be at risk for T2DM, and their siblings, were selected for this study. There were 68 children with acanthosis nigricans (AN+), and 71 without AN (AN-). Both AN+ and AN- children were assessed for T2DM and CVD risk factors. Probands and siblings were evaluated by physical examination, family history, and fasting serum parameters: glucose, insulin, body mass index (BMI), serum lipoproteins, and oxidized lipids. Data were analyzed by descriptive, univariate, and multivariate procedures.

RESULTS

BMI, waist/hip ratio, systolic and diastolic blood pressure were all significantly higher (p <.002) in AN+, whereas Tanner stages were similar in both groups. Fasting serum glucose was in the normal range, whereas insulin was elevated in AN+ compared with AN- (30.0 +/- 1.9 microU/mL vs. 14.8 +/- 1.0 p <.0001). Insulin resistance as assessed by the homeostasis assessment model (HOMA-IR) was elevated in both groups, although higher among AN+ (p <.0001). High-density lipoprotein-cholesterol (HDL-C) was lower (6.2 mg/dL) in the AN+ group (p <.003). The lower HDL-C in AN+ was associated with elevated triglycerides and a higher serum total cholesterol TC/HDL-C ratio when contrasted with the AN- values (145.9 +/- 7.6 mg/dL vs. 97.1 +/- 0.07, p <.0001; 4.1 +/- 0.2 vs. 3.4 +/- 0.1, p <.0001, respectively). In addition to the high prevalence of overweight/obesity (BMI > 85th percentile) in this population (76.3%, 106/139), elevated insulin (59.7% >15 microU/mL), low HDL-C (27.3% <40 mg/dL), and elevated low-density lipoprotein cholesterol (LDL-C) (41.0% >100 mg/dL) were also detected.

CONCLUSIONS

The altered metabolic pattern observed in this group of Mexican-American children is characteristic of metabolic syndrome, a condition associated with obesity and increased risk for both T2DM and CVD in adults. This study points to the value of BMI and acanthosis nigricans as easily accessible markers for children and nuclear families at increased risk for developing T2DM and CVD.

Prevalence of hyperuricemia and relation of serum uric acid with cardiovascular risk factors in a developing country

BACKGROUND

The prevalence of hyperuricemia has rarely been investigated in developing countries. The purpose of the present study was to investigate the prevalence of hyperuricemia and the association between uric acid levels and the various cardiovascular risk factors in a developing country with high average blood pressures (the Seychelles, Indian Ocean, population mainly of African origin).

METHODS

This cross-sectional health examination survey was based on a population random sample from the Seychelles. It included 1011 subjects aged 25 to 64 years. Blood pressure (BP), body mass index (BMI), waist circumference, waist-to-hip ratio, total and HDL cholesterol, serum triglycerides and serum uric acid were measured. Data were analyzed using scatterplot smoothing techniques and gender-specific linear regression models.

RESULTS

The prevalence of a serum uric acid level >420 micromol/L in men was 35.2% and the prevalence of a serum uric acid level >360 micromol/L was 8.7% in women. Serum uric acid was strongly related to serum triglycerides in men as well as in women (r = 0.73 in men and r = 0.59 in women, p < 0.001). Uric acid levels were also significantly associated but to a lesser degree with age, BMI, blood pressure, alcohol and the use of antihypertensive therapy. In a regression model, triglycerides, age, BMI, antihypertensive therapy and alcohol consumption accounted for about 50% (R2) of the serum uric acid variations in men as well as in women.

CONCLUSIONS

This study shows that the prevalence of hyperuricemia can be high in a developing country such as the Seychelles. Besides alcohol consumption and the use of antihypertensive therapy, mainly diuretics, serum uric acid is markedly associated with parameters of the metabolic syndrome, in particular serum triglycerides. Considering the growing incidence of obesity and metabolic syndrome worldwide and the potential link between hyperuricemia and cardiovascular complications, more emphasis should be put on the evolving prevalence of hyperuricemia in developing countries.

The metabolic syndrome as a link between smoking and cardiovascular disease

OBJECTIVE

Smoking is associated with a significant increase in the cardiovascular risk. The possible relationship of smoking with insulin resistance might further enhance the cardiovascular risk of the patients and is therefore of great clinical interest.

DESIGN, SETTING AND SUBJECTS

We have retrospectively evaluated data of 3804 non-diabetic men attending a medical outdoor clinic. Clinical [body mass index (BMI), percentage of body fat, waist-to-hip ratio] and laboratory results were compared between smokers (n = 124) and non-smokers (n = 1915) without cardiovascular disease, as well as between smokers (n = 759) and non-smokers (n = 1006) with cardiovascular disease.

RESULTS

Smokers without clinically manifest cardiovascular disease revealed significantly higher fasting glucose (5.8 +/- 0.6 mmol/l) and triglyceride levels (1.8 +/- 0.9 mmol/l) than non-smokers (fasting glucose: 5.1 +/- 0.7 mmol/l, p < 0.010; triglycerides: 1.5 +/- 0.8 mmol/l, p < 0.030). The adverse metabolic profile of smokers was even more pronounced in patients with cardiovascular disease. An age-matched analysis of smokers could demonstrate that cardiovascular patients revealed higher BMI values (27.3 +/- 2.4 kg/m2) and a higher percentage of body fat (25.5 +/- 5.5%) than those without cardiovascular disease (BMI: 25.7 +/- 2.2 kg/m2, p < 0.010; percentage of body fat: 23.0 +/- 5.5%, p < 0.030).

CONCLUSION

In men with and without clinically manifest cardiovascular disease, smoking was associated with a metabolic profile indicating a higher degree of insulin resistance.

Metabolic syndrome disorders in urban black Zimbabweans with type 2 Diabetes mellitus

OBJECTIVE

The main aim of the study was to determine the prevalence of metabolic syndrome disorders and their interrelations in black Zimbabwean type 2 diabetic patients.

STUDY DESIGN

Prospective cross sectional study.

SETTING

Outpatient diabetic clinics at Harare and Parirenyatwa tertiary hospitals.

MAIN OUTCOME MEASURES

We recruited 109 adult diabetic subjects attending a tertiary hospital Diabetic Clinic. Anthropometric and metabolic parameters were measured by standard methods. Eighty percent of the patients were hypertensive, 32% dyslipidaemic, 32% obese, 50% hyperinsulinaemic, 61% had poor glycaemic control and 43% of the participants had the metabolic syndrome. The means of BMI and triglycerides were significantly different in hyperinsulinaemic versus non-hyperinsulinaemic patients (p < 0.001 and 0.041 respectively), and diastolic blood pressure was significantly raised in the obese group (p = 0.043). The following significant associations were observed, hyperinsulinaemia with the metabolic syndrome (odds ratio = 3.9, p < 0.001) as well with obesity (odds ratio = 4.8, p < 0.001), however, only a weak association was observed between hypertension and hyperinsulinaemia (odds ratio = 2.5, p = 0.064). Patients exhibiting three metabolic disorders (dyslipidaemia, hypertension and obesity) were five times more likely to be hyperinsulinaemic (p = 0.025) and hypertensive patients were almost three times more likely to be hyperinsulinaemic.

CONCLUSION

In comparison to their counterparts from certain ethnic groups, this urban diabetic population is also burdened with a variety of metabolic disorders which are risk factors for coronary artery disease. In this population, hyperinsulinaemia has a relatively weak association with hypertension and the relationship between obesity versus diastolic blood pressure as well as hypertriglyceridaemia versus serum insulin levels requires further investigation.

Clustering of components of the metabolic syndrome and risk for development of type 2 diabetes in Japanese male office workers

To investigate the effects of the clustering of components of the metabolic syndrome (MS) on development of diabetes, we examined 3298 Japanese male office workers aged 35-59 years who did not have type 2 diabetes (a fasting plasma glucose level of > or =7.0 mmol/l or receipt of hypoglycemic medication) or a history of cardiovascular disease. Fasting plasma glucose levels were measured at periodic annual health examinations from May 1994 through May 2001. After adjustment for potential risk factors for diabetes, the multivariate-adjusted relative risk of type 2 diabetes compared with the subjects without components of the MS was 1.58 (95% CI: 1.08-2.32), 2.48 (95% CI: 1.69-3.63), 3.10 (95% CI: 2.05-4.68), and 5.22 (95% CI: 3.49-7.83) (P-value for trend <0.001) for those with 1, 2, 3, and > or =4 components, respectively. Even after the subjects were stratified according to fasting plasma glucose level, the clustering of components of the MS was associated with an increased risk of type 2 diabetes for subjects in all three categories of low-normal fasting glucose (a fasting plasma glucose level of <5.1 mmol/l), high-normal fasting glucose (a fasting plasma glucose level of 5.0-6.0 mmol/l), and impaired fasting glucose (a fasting plasma glucose level of 6.1-6.9 mmol/l). These results indicate that clustering of components of the MS associated with diabetes precedes an increase in the risk of type 2 diabetes in Japanese men.

Aggregation of features of the metabolic syndrome is associated with increased prevalence of chronic complications in Type 2 diabetes

AIMS

To investigate the association of features of the metabolic syndrome with the prevalence of chronic complications.

METHODS

A cross-sectional study was conducted with 548 patients with Type 2 diabetes mellitus (DM). Metabolic syndrome was diagnosed in the presence of at least two of the following: hypertension, dyslipidaemia, obesity, and microalbuminuria.

RESULTS

Patients with the metabolic syndrome (85%) had a higher prevalence of peripheral vascular disease (PVD) (35% vs. 18%), retinopathy (44% vs. 20%), distal sensory neuropathy (DSN) (44% vs. 24%), micro- and macroalbuminuria (38% vs. 28%) and coronary artery disease (CAD) (53% vs. 36%). The more metabolic syndrome features (none/one, two, three or four), the higher the proportion of diabetes complications: PVD 18%, 31%, 37% and 38%; stroke 1.0%, 4.5%, 5.9% and 11.3%; retinopathy 20%, 38%, 42% and 64%; DSN 24%, 32%, 49% and 57%; micro- and macroalbuminuria 28%, 36% and 41%; and CAD 36%, 44%, 52% and 60% (P < 0.05).

CONCLUSIONS

The metabolic syndrome and the aggregation of its components were significantly associated with macro- and microvascular complications in Type 2 DM patients.

What does postprandial hyperglycaemia mean?

AIMS

The potential importance of postprandial glucose (PPG) control in the development of complications in Type 2 diabetes is much debated. The recent American Diabetes Association (ADA) consensus statement discussed the role of postprandial hyperglycaemia in the pathogenesis of diabetic complications and concluded that the relationship between PPG excursions and the well-established risk factors for cardiovascular disease (CVD) should be further examined. Using the ADA statement as a starting point and including the more recent American College of Endocrinology guidelines on glycaemic control, a panel of experts in diabetes met to review the role of PPG within the context of the overall metabolic syndrome, in the development of complications in Type 2 diabetes.

RESULTS

Post-prandial hyperglycaemia is a risk indicator for micro- and macrovascular complications, not only in patients with Type 2 diabetes but also in those with impaired glucose tolerance. In addition, the metabolic syndrome confers an increased risk of CVD morbidity and mortality. The debate focused on the relative contributions of postprandial hyperglycaemia, the metabolic syndrome and, in particular, raised triglyceride levels in the postprandial state, to the development of cardiovascular complications of diabetes.

CONCLUSIONS

The panel recommended that in the prevention and management of microvascular complications of Type 2 diabetes, targeting both chronic and acute glucose fluctuations is necessary. Lowering the macrovascular risk also requires control of (postprandial) triglyceride levels and other components of the metabolic syndrome.

C-Peptide Colocalizes with Macrophages in Early Arteriosclerotic Lesions of Diabetic Subjects and Induces Monocyte Chemotaxis In Vitro

Objective— Increased levels of C-peptide, a cleavage product of proinsulin, circulate in patients with insulin resistance and early type 2 diabetes, a high-risk population for the development of a diffuse and extensive pattern of arteriosclerosis. This study tested the hypothesis that C-peptide might participate in atherogenesis in these patients.

Method and Results— We demonstrate significantly higher intimal C-peptide deposition in thoracic artery specimens from young diabetic subjects compared with matched nondiabetic controls as determined by immunohistochemical staining. C-peptide colocalized with monocytes/macrophages in the arterial intima of artery specimen from diabetic subjects. In vitro, C-peptide stimulated monocyte chemotaxis in a concentration-dependent manner with a maximal 2.3±0.4-fold increase at 1 nmol/L C-peptide. Pertussis toxin, wortmannin, and LY294002 inhibited C-peptide–induced monocyte chemotaxis, suggesting the involvement of pertussis toxin-sensitive G-proteins as well as a phosphoinositide 3-kinase (PI3K)-dependent mechanism. In addition, C-peptide treatment activated PI3K in human monocytes, as demonstrated by PI3K activity assays.

Conclusion— C-peptide accumulated in the vessel wall in early atherogenesis in diabetic subjects and may promote monocyte migration into developing lesions. These data support the hypothesis that C-peptide may play an active role in atherogenesis in diabetic patients and suggest a new mechanism for accelerated arterial disease in diabetes.

The metabolic syndrome in women: implications for therapy

It is becoming increasingly clear that hypertension and metabolic risk factors in women are inter-related and often share underlying causes. Menopause acts explicitly as a risk factor by reducing the direct beneficial effect of ovarian hormones upon cardiovascular functions and indirectly by negatively influencing other risk factors for coronary artery disease--i.e. hyperinsulinaemia, blood cholesterol, blood pressure, coagulation etc. Adverse changes in one factor may induce adverse changes in a variety of other risk factors and it is important to consider co-ordinated changes when evaluating these patients rather than attempt to isolate independent factors. Similarly with treatment, the prevalence of metabolic syndrome in postmenopausal hypertensive women has important implications and some antihypertensive drugs may worsen the already altered metabolic profile of these patients while others may be beneficial. Centrally-acting sympatholytic agents, e.g. moxonidine, are therefore important to consider in hypertensive postmenopausal women who experience other symptoms of metabolic syndrome.

Selective imidazoline agonist moxonidine plus the ACE inhibitor ramipril in hypertensive patients with impaired insulin sensitivity: partners in a successful MARRIAGE?

Hypertension in combination with clinically overt diabetes mellitus is recognized as a particularly powerful combination of risk factors that greatly increases cardiovascular vulnerability. There is also evidence that presumed pre-diabetic conditions such as insulin resistance, hyperinsulinaemia and compensatory hyperglycaemia may amplify overall cardiovascular risk in patients with hypertension, especially when encountered as part of the condition known as metabolic syndrome X (Reaven's syndrome). The long-term benefits of antihypertensive therapy may be compromised if these drugs exert adverse effects on metabolic parameters such as insulin sensitivity, or if they promote a transition from pre-diabetes to overt diabetes. Class differences in the effects of antihypertensives on metabolic indices may therefore be an important consideration when choosing treatment for patients who exhibit these characteristics. Experience from clinical trials suggests that drugs that target the renin-angiotensin system may have metabolic advantages over drugs such as beta-blockers and diuretics, but this conclusion has not been proved definitively. Moxonidine, which selectively targets imidazoline type-1 receptors in the sympathetic vasomotor centres of the rostral-ventrolateral medulla, is an effective antihypertensive and has been reported to exert favourable metabolic effects in preclinical and clinical studies. The MARRIAGE study (Moxonidine And Ramipril Regarding Insulin And Glucose Evaluation) will extend these preliminary observations by comparing the effects of moxonidine and the ACE inhibitor ramipril--and the combination of both drugs--on metabolic and haemodynamic parameters in patients with hypertension and impaired fasting glycaemia. A description is provided of the design and conduct of MARRIAGE.

Obesity Indices and Major Components of Metabolic Syndrome in Young Adult Arab Subjects

BACKGROUND

The major components of metabolic syndrome are atherogenic dyslipidaemia (AD) and insulin resistance (IR), and both predict risk for atherosclerotic cardiovascular disease even in healthy individuals.

AIMS

To assess if, in a group of healthy young adult Arab subjects, a simple classification in high and normal scores on waist-hip ratio (WHR), body mass index (BMI) and waist circumference (WC) scales could predict atherogenic parameters for metabolic syndrome (AD, IR).

SUBJECTS AND METHODS

The subjects [n = 177 (72 M, 105 F), aged 29.7 +/- 8.4 (SD) years], underwent physical evaluation, BP measurement and anthropometry [height (m), weight (kg), waist (WC) and hip circumference (HC, cm)]. The cut-off points for normal/high scores on the indices were: (1) BMI: 30 kg/m(2) (M and F); (2) WHR: 0.80 F, 0.95 M, and (3) WC: 90 cm F, 100 cm M). The biochemical indices measured on fasting serum were: (1) AD: total cholesterol (TC), triglycerides (TG), HDL, LDL, apo B, HDL/TC ratio, and (2) IR: insulin, urate, insulin/glucose ratio (IGR).

RESULTS AND DISCUSSION

In the whole group of subjects, and in women separately considered, those with high indices (BMI, WHR, WC) had significantly increased levels of glucose, LDL, apo B, urate, mean BP, TG, insulin and IGR and lower values for HDL/TC ratio (all p < 0.05). In men, only urate, insulin and IGR levels were increased (p < 0.01) in the high-score groups. None of the indices showed any special superiority in describing the risk of AD or IR.

CONCLUSION

In women, BMI, WHR and WC appeared equally good in identifying individuals at high risk of AD and IR while in men, these indices satisfactorily described the risk of IR but not of AD. It is important to re-emphasise the need to indicate gender distinctions in using anthropometry for CHD risk assessment.

Clinical Importance of Obesity Versus the Metabolic Syndrome in Cardiovascular Risk in Women

Background— Obesity and the metabolic syndrome frequently coexist. Both are associated with cardiovascular disease (CVD). However, the contribution of obesity to cardiovascular risk, independent of the presence of the metabolic syndrome, remains controversial.

Methods and Results— From the WISE study, 780 women referred for coronary angiography to evaluate suspected myocardial ischemia were classified by body mass index (BMI; <24.9=normal, n=184; ≥25.0 to ≤29.9=overweight, n=269; ≥30.0=obese, n=327) and presence (n=451) or absence (n=329) of the metabolic syndrome, further classified by diabetes status. Prevalence of significant angiographic coronary artery disease (CAD; ≥50% stenosis) and 3-year risk of CVD were compared by BMI and metabolic status. The metabolic syndrome and BMI were strongly associated, but only metabolic syndrome was associated with significant CAD. Similarly, unit increases in BMI (normal to overweight to obese) were not associated with 3-year risk of death (adjusted hazard ratio [HR] 0.92, 95% CI 0.59 to 1.51) or major adverse cardiovascular event (MACE: death, nonfatal myocardial infarction, stroke, congestive heart failure; adjusted HR 0.95, 95% CI 0.71 to 1.27), whereas metabolic status (normal to metabolic syndrome to diabetes) conferred an approximate 2-fold adjusted risk of death (HR 2.01, 95% CI 1.26 to 3.20) and MACE (HR 1.88, 95% CI 1.38 to 2.57). Levels of C-reactive protein (hs-CRP) were more strongly associated with metabolic syndrome than BMI but were not independently associated with 3-year risk of death or MACE.

Conclusions— The metabolic syndrome but not BMI predicts future cardiovascular risk in women. Although it remains prudent to recommend weight loss in overweight and obese women, control of all modifiable risk factors in both normal and overweight persons to prevent transition to the metabolic syndrome should be considered the ultimate goal.

Obesity and the Metabolic Syndrome: implications for dietetics practitioners

The Metabolic Syndrome encompasses a set of laboratory and physical findings, including central adiposity, insulin resistance, hypertension, high triglycerides, and low HDL-cholesterol and several abnormalities in clotting and inflammatory markers. Using the definition provided by the Adult Treatment Panel III of the National Cholesterol Education Program, 24% of adult Americans have the Metabolic Syndrome. Central location of fat and release of fatty acids and cytokines from enlarged fat cells located in the intra-abdominal fat tissue provide the major agents that incite this syndrome. From a practical point of view, identifying dietary and lifestyle factors, including low levels of physical activity, are important in designing a diet and exercise program that can help individuals with the Metabolic Syndrome to reduce the associated detrimental health consequences.

The metabolic syndrome and chronic kidney disease in U.S. adults

BACKGROUND

The metabolic syndrome is a common risk factor for cardiovascular disease.

OBJECTIVE

To examine the association between the metabolic syndrome and risk for chronic kidney disease and microalbuminuria.

DESIGN

Cross-sectional study.

SETTING

The Third National Health and Nutrition Examination Survey.

PATIENTS

Participants 20 years of age or older were studied in the chronic kidney disease (n = 6217) and microalbuminuria (n = 6125) analyses.

MEASUREMENTS

The metabolic syndrome was defined as the presence of 3 or more of the following risk factors: elevated blood pressure, low high-density lipoprotein cholesterol level, high triglyceride level, elevated glucose level, and abdominal obesity. Chronic kidney disease was defined as a glomerular filtration rate less than 60 mL/min per 1.73 m2, and microalbuminuria was defined as a urinary albumin-creatinine ratio of 30 to 300 mg/g.

RESULTS

The multivariate-adjusted odds ratios of chronic kidney disease and microalbuminuria in participants with the metabolic syndrome compared with participants without the metabolic syndrome were 2.60 (95% CI, 1.68 to 4.03) and 1.89 (CI, 1.34 to 2.67), respectively. Compared with participants with 0 or 1 component of the metabolic syndrome, participants with 2, 3, 4, and 5 components of chronic kidney disease had multivariate-adjusted odds ratios of 2.21 (CI, 1.16 to 4.24), 3.38 (CI, 1.48 to 7.69), 4.23 (CI, 2.06 to 8.63), and 5.85 (CI, 3.11 to 11.0), respectively. The corresponding multivariate-adjusted odds ratios of microalbuminuria for participants with 3, 4, and 5 components were 1.62 (CI, 1.10 to 2.38), 2.45 (CI, 1.55 to 3.85), and 3.19 (CI, 1.96 to 5.19), respectively.

CONCLUSIONS

These findings suggest that the metabolic syndrome might be an important factor in the cause of chronic kidney disease.

Non-alcoholic steatohepatitis in patients cared in metabolic units

The clinical significance of liver disease is frequently underestimated in patients with metabolic disorders. In patients followed up in a metabolic unit for diabetes, obesity or hyperlipidemia (n=147), we studied the prevalence and the severity of liver disease, and its relationship with the metabolic syndrome (MS). Cases cared for in a liver unit (n=179) were used as controls. Patients in the metabolic series were older and had a higher prevalence of coronary heart disease. Criteria for the metabolic syndrome were fulfilled in 64% and 22% of cases, respectively (P<0.0001). Liver biopsy was obtained in 44 and 66% of cases. Metabolic patients had a more severe steatosis score (P<0.0001), whereas the scores of fibrosis and necroinflammation were less severe (P=0.0059 and 0.0007, respectively). Histological criteria for non-alcoholic steatohepatitis (NASH) were present in 82% of metabolic cases and 68% cases in the liver series (P=0.057). Liver disease in patients routinely cared for in metabolic units is similar to that observed in patients cared for in liver units, and potentially may progress to terminal liver failure. Liver biopsy is recommended for diagnostic and prognostic purposes, as well as for testing treatment effects in controlled trials.

Are there specific components of the insulin resistance syndrome that predict the increased atherosclerosis seen in type 2 diabetes mellitus?

Cardiovascular disease is often present in patients with newly diagnosed type 2 diabetes. It is hypothesized that both type 2 diabetes and cardiovascular disease arise from an underlying insulin resistance syndrome, including impaired glucose tolerance, hypertension, dyslipidemia, and abdominal obesity. We reviewed the literature using various epidemiologic techniques to evaluate the relation between the insulin resistance syndrome components and incident cardiovascular disease. We found that although insulin resistance is likely important in the development of cardiovascular disease seen in diabetes, lipid and blood pressure abnormalities associated with the syndrome appear to be equally important. Future studies are needed to determine the most effective treatment strategies for preventing cardiovascular disease associated with the insulin resistance syndrome and type 2 diabetes.

Nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is being increasingly recognized as a common liver disorder that represents the hepatic manifestation of the metabolic syndrome, a variably defined aggregate of disorders related to obesity, insulin resistance, type II diabetes, hypertension and hyperlipidemia. Nonalcoholic steatohepatitis (NASH) is the progressive form of liver injury that carries a risk for progressive fibrosis, cirrhosis, and end-stage liver disease. Hepatocellular carcinoma (HCC) is a documented complication in an as yet unknown percentage of cases of NASH cirrhosis. The diagnosis of nonalcoholic steatohepatitis requires histopathologic evaluation because the lesions of parenchymal injury and fibrosis cannot be detected by imaging studies or laboratory tests. This article will briefly discuss prevalence studies and the pathophysiology of NAFLD and focus on current discussions related to the specific lesions in the pathology of NASH, including the challenges of pediatric NASH and NASH-related cirrhosis.

Cardiovascular risk associated with the metabolic syndrome

The term metabolic syndrome refers to a clustering of cardiovascular risk factors, most of which also share insulin resistance as an additional feature. Scientific effort has concentrated on understanding why these diverse cardiovascular risks co-occur in individuals and in determining the presumed common environmental or genetic factors that might underpin this. Clinically important developments include publication of standard definitions of the metabolic syndrome and recommendations for the use of type 2 diabetes and the presence of the metabolic syndrome as critical "risk stratifiers" in cardiovascular disease prevention. The remarkable recent secular increases in the prevalence of type 2 diabetes and obesity in many populations mean that the importance of the metabolic syndrome as a determinant of cardiovascular disease is likely to increase until these trends can be reversed.

[Atherosclerosis and metabolic disease]

Cholesterol plays an important role in atherogenesis. Cholesterol-ester that has been carried by circulating low-density lipoprotein particles accumulates in the atherosclerotic plaque. Statins are considered the most potent and effective agents for reducing low-density lipoprotein cholesterol and the incidence of cardiovascular events. Total cholesterol and LDL cholesterol levels, however, are not always a useful marker for distinguishing patients with or without cardiovascular disease. Low levels of high-density lipoprotein cholesterol are the most predictive marker for cardiovascular disease. Low HDL cholesterol levels originate in some genetic and acquired diseases and conditions. Most cases of low HDL cholesterol associated with the development of atherosclerosis are of secondary origin, especially those associated with increasing triglyceride-rich lipoprotein. These conditions are present in insulin-resistant syndrome, namely metabolic syndrome. Type 2 diabetes mellitus and the closely related metabolic syndrome are associated with a significant risk for cardiovascular disease. Recent evidence suggests that both conditions are increasing in epidemic proportions. Dyslipidemia is characterized by increased triglyceride-rich lipoproteins; low high-density lipoprotein cholesterol; small, dense low-density lipoprotein particles; and increased postprandial lipemia. All these lipoprotein disturbances accelerate atherosclerosis. It is likely that many patients will need lipid-modifying therapy to help prevent cardiovascular disease.

Effects of surgical treatment of the metabolic syndrome on liver fibrosis and cirrhosis

BACKGROUND

Both weight loss and gastrointestinal surgery for obesity can cause liver disease, making their role in the treatment of obesity-related liver disease controversial.

METHODS

Six hundred eighty-nine severely obese women (n=551) and men (n=138), BMI=47+/-9 kg.m(-2) (mean+/-SD), without known liver disease, underwent biliopancreatic diversion (BPD) with liver biopsy. Fourteen patients (2%) had cryptogenic cirrhosis, 11 of whom underwent multiple repeat biopsies. After 38+/-18 kg weight loss, 104 of the 689 patients underwent routine second biopsies during reoperations 41+/-25 months after BPD. All biopsy specimens were graded for steatosis, fibrosis, and inflammation by a blinded hepatopathologist.

RESULTS

All 689 patients lost weight accompanied by improvements in the metabolic syndrome. Among the 104 patients who underwent reoperation, severe fibrosis (grade 3-5) decreased in 28 whereas mild fibrosis (grade 1-2) appeared in 42. Increased fibrosis was related to low-normal serum albumin, uncontrolled diarrhea, low intake of alcohol, and menopausal status. Fibrosis and inflammation decreased over time (P<.01). The 11 patients with cirrhosis exhibited decreased fibrosis from a mean grade 5 to grade 3, as well as reduced inflammation, Mallory bodies, and glycogenated nuclei. Seven patients had disappearance and 2 regression of nodules and fibrous bridging.

CONCLUSIONS

The metabolic syndrome of obesity is a determinant of liver fibrosis and cirrhosis, treatable by substantial weight loss after malabsorptive surgery.

Effect of increasing metabolic syndrome score on atherosclerotic risk profile and coronary artery disease angiographic severity

The metabolic syndrome (MS) is a frequent cause of coronary artery disease (CAD), and recently the National Cholesterol Education Program Adult Treatment Panel III suggested its diagnosis in the presence of 3 to 5 quantitatively defined markers. Because the consequences of the MS are likely related to the number and diversity of markers, we studied the relation between the number of markers-the MS score-and the degree of abdominal obesity, risk factor profile, and severity of CAD. One thousand one hundred eight subjects of a mostly white population with symptoms of CAD (793 men and 315 women; 58.1 +/- 9.8 years of age) were divided into 6 groups based on their MS scores. A low high-density lipoprotein cholesterol level was the most frequently observed marker, followed by increased blood pressure, triglycerides, waist circumference, and fasting glucose. As the MS score increased so did abdominal obesity, parameters of "nontraditional" dyslipidemia with surrogate markers of dense low-density lipoprotein and high-density lipoprotein particles, blood pressure, fasting glucose, insulin, and the homeostatic model assessment insulin resistance index. Similarly, an increasing MS score was significantly related to more severe coronary angiographic alterations and higher frequencies of unstable angina, myocardial infarction, percutaneous coronary intervention, and coronary artery bypass grafting. Therefore, the MS score provides a clinically useful index of MS severity and the associated atherosclerotic risk factor profile. It also correlates with the angiographic severity of CAD and its clinical complications.

Hepatic steatosis: a mediator of the metabolic syndrome. Lessons from animal models

Epidemiological studies in humans, as well as experimental studies in animal models, have shown an association between visceral obesity and dyslipidemia, insulin resistance, and type 2 diabetes mellitus. Recently, attention has been focused on the excessive accumulation of triglycerides (TG) in the liver as part of this syndrome. In this review, important principles of the pathophysiological involvement of the liver in the metabolic syndrome obtained in rodent models are summarized. We focus on non-alcoholic causes of steatosis, because the animal experiments we refer to did not include alcohol as an experimental condition. In general, there is continuous cycling and redistribution of non-oxidized fatty acids between different organs. The amount of TG in an intrinsically normal liver is not fixed but can readily be increased by nutritional, metabolic, and endocrine interactions involving TG/free fatty acid (FFA) partitioning and TG/FFA metabolism. Several lines of evidence indicate that hepatic TG accumulation is also a causative factor involved in hepatic insulin resistance. Complex interactions between endocrine, metabolic, and transcriptional pathways are involved in TG-induced hepatic insulin resistance. Therefore, the liver participates passively and actively in the metabolic derangements of the metabolic syndrome. We speculate that similar mechanisms may also be involved in human pathophysiology.