The metabolic syndrome and 11-year risk of incident cardiovascular disease in the atherosclerosis risk in communities study

The metabolic syndrome and nonfatal ischemic heart disease; a population-based study

OBJECTIVES

Metabolic syndrome comprises insulin resistance, abdominal fat distribution, dyslipidemia and hypertension. The metabolic syndrome is expected to be diagnosed in millions of subjects in the near future worldwide. There are very few data in literature clearly documenting that subjects with metabolic syndrome have an increased cardiovascular risk.

DESIGN

Cross-sectional, population-based study.

MATERIALS AND METHODS

We used National Cholesterol Education Program (NCEP)-Adult Treatment Panel (ATP)-III criteria and Minnesota Code of a 12-lead resting electrocardiogram (EKG) to assess the association of metabolic syndrome and nonfatal ischemic heart disease in 3723 subjects, aged 25 years and over, selected by cluster random sampling in three Iranian ports in the northern Persian Gulf. Electrocardiogram with evidence of IHD (IHD EKG) was defined as myocardial infarction (codes 1.1 and 1.2) and ischemia (codes 1.3, 4.1-4.4, 5.1-5.3 and 7.1) together.

RESULTS

An estimated 49.08% (52.04% of males and 46.34% of females) were identified as fulfilling NCEP-ATP III criteria for diagnosing the metabolic syndrome. Prevalence of EKG with evidence of ischemic heart disease (IHD EKG) was 12.7% (10.4% for men and 14.7% for women, p<0.0001). In multiple logistic regression analysis, metabolic syndrome was found to have a significant association with IHD EKG [OR=1.35, CI (1.09-1.66), p=0.005] after adjusting for sex and age. Of the metabolic syndrome components, elevated blood sugar (OR=2.69, p<0.001), high blood pressure (OR=1.79, p=0.001) and low HDL-C (OR=1.27, p=0.02) had significant independent association with IHD EKG.

CONCLUSION

The metabolic syndrome, which occurs very frequently in the general population, has a significant association with nonfatal ischemic heart disease by electrocardiogram criteria.

Prevalence of vascular disease in metabolic syndrome using three proposed definitions

BACKGROUND

There are a number of definitions available for the diagnosis of the metabolic syndrome (MetS). The MetS-associated increase in cardiovascular disease (CVD) risk may depend on the definition used.

AIM

To investigate which of the 3 recently proposed definitions of MetS [the National Cholesterol Education Program-Adult Treatment Panel-III (NCEP-ATP-III), the International Diabetes Federation (IDF) and the American Heart Association/National Heart Lung and Blood Institute (AHA/NHLBI)] is related to excessive CVD risk and thus may be more appropriate to implement in clinical practice.

METHODS

A cross-sectional analysis of a representative sample of Greek adults (n=9669).

RESULTS

The age-adjusted CVD prevalence was 11.4% in the whole study population, 23.3% in the NCEP-ATP-III (+) subjects, 22.6% in AHA/NHLBI (+) subjects and 18.3% in IDF (+) subjects [p<0.001 for the comparison between the whole study population and all MetS groups and p<0.0001 for the comparison between IDF (+) and either NCEP-ATP-III (+) or AHA/NHLBI (+) MetS]. However, the CVD prevalence was only 11.2% in the IDF (+) but NCEP-ATP-III (-)/AHA/NHLBI (-) MetS subjects [p<0.0001 vs. either NCEP-ATP-III (+) or AHA/NHLBI (+)], which was not different compared with the whole study population. Furthermore, subjects with NCEP ATP III (+) or AHA/NHLBI (+) MetS but not diabetes (DM) had a persistently higher prevalence of CVD compared with the whole study population. However, there was no significant difference regarding CVD prevalence between the whole study population and IDF (+)/DM (-) MetS subjects.

CONCLUSIONS

CVD prevalence was increased in the presence of MetS irrespective of the definition used. However, this increase was more pronounced when the NCEP-ATP-III and AHA/NHLBI criteria were implemented compared with the IDF definition. Furthermore, the IDF definition included a large proportion of subjects who did not have increased CVD prevalence compared with the whole study population. These findings may have implications regarding which definition should we use to diagnose the MetS.

Epidemiological evidence for the non-random clustering of the components of the metabolic syndrome: multicentre study of the Mediterranean Group for the Study of Diabetes

OBJECTIVE

To determine: (a) whether the components of metabolic syndrome (MetS) cluster more frequently than predicted by chance alone and (b) whether increased risk for MetS is associated also with values of each component below, but close to the cutoff points defining MetS.

RESEARCH DESIGN AND METHODS

Anthropometrical and biochemical measurements were performed and a dietary questionnaire was filled-in in 1833 randomly selected non-diabetic subjects, 916 men and 917 women, 20-74 years old, in nine centres in five Mediterranean countries. The prevalence of MetS and of possible combinations of its individual components was measured. The expected frequencies of the above combinations were calculated according to the mathematical formula of probabilities.

RESULTS

The overall prevalence of MetS was 27.2%, but varied greatly among countries, from 5.8% in Algeria to 37.3% in Greece. The observed prevalence of each combination diagnostic of MetS was higher than the expected by chance. Thus, the observed overall prevalence of MetS was also higher than the expected, 27.2 vs 24.0%, P=0.03. Furthermore, for each individual component (except high-density lipoprotein), as values in the normal range, approached the cutoff point, the risk of having MetS (i.e. clustering of the other components) increased significantly (odds ratio 2.2-4.6, P<0.001).

CONCLUSIONS

The MetS is not related to the Mediterranean type of diet and its prevalence varies greatly among five Mediterranean countries. The clustering of the components defining the MetS is not due to chance and moreover even 'high normal' levels of each component confer increased risk for the syndrome.

Insulin resistance and atherosclerosis

Considerable evidence supports the association between insulin resistance and vascular disease, and this has led to wide acceptance of the clustering of hyperlipidemia, glucose intolerance, hypertension, and obesity as a clinical entity, the metabolic syndrome. While insulin resistance, by promoting dyslipidemia and other metabolic abnormalities, is part of the proatherogenic milieu, it is possible that insulin resistance itself in the vascular wall does not promote atherosclerosis. Recent findings suggest that insulin resistance and atherosclerosis could represent independent and ultimately maladaptive responses to the disruption of cellular homeostasis caused by the excess delivery of fuel.

Cardiometabolic risk assessment: an approach to the prevention of cardiovascular disease and diabetes mellitus

An alarming increase in the development of cardiovascular disease (CVD) during the past 5 decades has led to intensive research on the epidemiology and pathogenesis of CVD, resulting in dramatic improvements in treatment. Today, there is an alarming increase in obesity and diabetes mellitus (DM), with a concomitant increase in diabetes-related complications, including CVD. Researchers have found that the risk of CVD becomes greater with increasing hyperglycemia and insulin resistance that occur in people long before the onset of clinical DM. Lifestyle modification with moderate weight loss has been shown to prevent or delay the onset of DM in patients who are at high risk for developing this disease. Unfortunately, the current guidelines for risk assessment provided by medical societies and national organizations are numerous, confusing, and inconsistent in their basic approach to identify specific risk factors for CVD and DM in patients. Extending routine systematic assessment from cardiovascular risk to cardiometabolic risk--that is, risk for developing CVD and/or DM--and increasing our understanding of the basic mechanisms that regulate energy balance and metabolic risk factors are needed to address this impending epidemic of DM.

Plasma aldosterone is independently associated with the metabolic syndrome

The aim of this study was to analyze the associations of plasma aldosterone and plasma renin activity with the metabolic syndrome and each of its components. We analyzed data from a family based study in the Seychelles made up of 356 participants (160 men and 196 women) from 69 families of African descent. In multivariable models, plasma aldosterone was associated positively (P < 0.05) with blood pressure in older individuals (interaction with age, P < 0.05) and with waist circumference in men (interaction with sex, P < 0.05) and negatively with high-density lipoprotein cholesterol, in particular in individuals with elevated urinary potassium excretion (interaction with urinary potassium, P < 0.05); plasma renin activity was significantly associated with triglycerides and fasting blood glucose. Plasma aldosterone, but not plasma renin activity, was associated with the metabolic syndrome per se, independently of the association with its separate components. The observation that plasma renin activity was associated with some components of the metabolic syndrome, whereas plasma aldosterone was associated with other components of the metabolic syndrome, suggests different underlying mechanisms. These findings reinforce previous observations suggesting that aldosterone is associated with several cardiovascular risk factors and also suggest that aldosterone might contribute to the increased cardiovascular disease risk in individuals of African descent with the metabolic syndrome.

Effects of PPAR gamma agonists on cardiovascular function in obese, non-diabetic patients

Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors, and when activated by their ligands, they induce perixosome proliferation. Three receptors have been identified: PPAR gamma, PPAR delta, and PPAR alpha, all with different tissue expression. PPAR gamma is predominantly expressed in adipose tissue and regulates the formation of fat cells and their function. The effect of PPAR gamma activation is to enhance the action of insulin in insulin-sensitive tissue by increasing peripheral glucose disposal and decreasing hepatic glucose production. The thiazolidinediones (TZDs) are a class of medications used for treatment and possibly the prevention of type 2 diabetes, which are potent agonists for the PPAR gamma receptor. Because the thiazolidinediones target insulin resistance, these agents may improve many of the risk factors associated with obesity and insulin resistance including dyslipidemia, hypertension, impaired fibrinolysis, and atherosclerosis. The impact of the thiazolidinediones on cardiovascular mortality is currently unclear but it appears that the thiazolidinediones exert numerous non-glycemic effects that may improve cardiovascular outcomes. Several non-TZD PPAR gamma agonists and combined PPAR gamma/alpha effect on cardiovascular disease are also being evaluated. These drugs have anti-inflammatory and vascular properties and are currently the subject of numerous studies targeting the primary and secondary prevention of macrovascular disease in patients with diabetes and insulin resistance and might be developed as anti-atherogenic agents on the basis of their actions.

Coronary artery disease in South Asians: an emerging risk group

Coronary artery disease (CAD) is a leading cause of morbidity and mortality worldwide and was responsible for 7.2 million deaths in 2003. Various studies have pointed out that South Asians have a higher prevalence of CAD as compared with other ethnicities. South Asians may have a genetic predisposition to CAD; however, environmental, nutritional, and lifestyle factors may also be responsible. South Asians have a much higher prevalence of metabolic syndrome, diabetes, insulin resistance (and resultant hyperinsulinemia), central obesity, dyslipidemias (lower high-density lipoprotein, increased lipoprotein[a], higher triglyceride levels), increased thrombotic tendency (increased plasminogen activator inhibitor-1 and decreased tissue plasminogen activator levels), decreased levels of physical activity, and low birth weights ("fetal origins hypothesis"). In addition, the dietary indiscretions and sedentary lifestyle practiced by most South Asians puts them at a higher risk. A multidisciplinary approach involving the population at risk, healthcare personnel, and the government is required to diminish the incidence. Educational programs regarding the genetic predisposition as well as risk factors for CAD, physical activity, and dietary modifications need to be encouraged. There is a need for implementation of newer guidelines as well as a lower threshold for initiating therapeutic interventions in this population. Mass media should be involved to bring about behavioral changes, and these changes should be reinforced at the physician's level.

Role of lifestyle modification in the management of polycystic ovary syndrome

Overweight and obesity are common findings in polycystic ovary syndrome (PCOS). Obesity-particularly central obesity-is strongly indicated as a cause of insulin resistance, a central feature of PCOS. The prevalence of obesity is reaching epidemic proportions in many developed countries, and this increase is of particular concern in adolescent women. Obesity worsens both the metabolic and endocrine profiles in PCOS and may decrease the response to treatment. In the short term, weight reduction improves both metabolic and endocrine aspects of PCOS as well as clinical markers such as ovulation. However, extreme non-surgical efforts to lose weight are rarely successful and are associated with high rates of weight regain. Lifestyle modification with modest weight loss goals of 5-10% appear to be equally effective in restoring fertility and may be more compatible with long-term success; however, further research is needed.

Gender disparity in outcomes of care and management for diabetes and the metabolic syndrome

Although diabetes lies among the major risk factors for cardiovascular disease (CVD) in both men and women, current evidence suggests that it has a much stronger effect on the risk of coronary heart disease (CHD) in women than in men. Moreover, diabetic women have not experienced the decline in CHD mortality observed in diabetic men and individuals without diabetes over the past three decades. Apart from a more pronounced direct effect of diabetes on the vascular wall, this greater impact of diabetes on CHD risk in women could be associated with a heavier burden of other traditional cardiovascular risk factors within the context of the metabolic syndrome, a stronger effect of the metabolic syndrome on CVD, and a less aggressive management of the various risk factors in diabetic women compared with men. This article discusses the recent evidence on the gender differences in the outcomes of CVD and the management of risk factors associated with diabetes and the metabolic syndrome, highlighting the need for better treatment strategies of diabetes and the other components of the metabolic syndrome in diabetic women.

Increased level of cardiorespiratory fitness blunts the inflammatory response in metabolic syndrome

OBJECTIVE

The presence of metabolic syndrome is associated with a higher degree of inflammation. We sought to assess whether the higher levels of cardiorespiratory fitness attenuate the levels of inflammation in people with metabolic syndrome.

RESEARCH DESIGN AND METHODS

We studied 449 consecutive asymptomatic men (47+/-7 years) who underwent a maximal treadmill exercise test according to the Bruce protocol. Cardiorespiratory fitness was divided into tertiles based on metabolic equivalents (METs). White blood cells (WBC) (x10(9) cells/L) count was used as marker of inflammation.

RESULTS

In our study population, 23% of the participants had the metabolic syndrome. The WBC count increased (p < 0.0001 for trend) with increasing number of risk factors for metabolic syndrome; however there was an inverse relationship (p < 0.0001 for trend) with increasing tertiles of fitness (6.47 cells x 10(9) cells/L for lowest tertile and 5.7 x 10(9) cells/L for highest tertile). Multiple linear regression analyses demonstrated that as compared to individuals with no MS risk factor, the WBC count remained significantly higher in men with metabolic syndrome in first tertile (regression coefficient: 1.2, 95% CI 0.4-2.0, p = 0.003) and second tertile (regression coefficient: 0.61, 95% CI 0.4-2.0, p = 0.02) of cardiorespiratory fitness, respectively. However, in the highest tertile of fitness no increase in level of WBC count was observed with increasing metabolic syndrome risk factors.

CONCLUSION

Our findings suggest that in people with metabolic syndrome an increased level of physical fitness might exert its beneficial effect via attenuating inflammation.

Importance of diagnosing and treating the metabolic syndrome in reducing cardiovascular risk

Applying the criteria for the metabolic syndrome serves as a simple and inexpensive tool for identifying patients at high risk for diabetes and coronary heart disease, particularly those who do not fall into traditional risk categories. Several independent physiological processes underlie the non-random risk-factor clustering that defines the metabolic syndrome, including insulin resistance, central obesity, dyslipidemia, impaired glucose tolerance, and hypertension. Other non-classic risk factors, such as abnormal oxidized low-density lipoprotein-cholesterol, adiponectin, and C-reactive protein levels, are highly correlated with the metabolic syndrome. Use of the metabolic syndrome criteria for assessment is comparable with other risk-scoring systems in accurately predicting cardiovascular disease risk and is simpler to implement in the clinic. Further research is needed to define the etiology of the metabolic syndrome.

How well does the metabolic syndrome defined by five definitions predict incident diabetes and incident coronary heart disease in a Chinese population?

We evaluate the ability of the metabolic syndrome (MetS) defined by five definitions for predicting both incident CHD and diabetes combined, diabetes alone, and CHD alone in a Chinese population. The screening survey for type 2 diabetes was conducted in 1994. A follow-up study of 541 high-risk non-diabetic individuals who were free of CHD at baseline was carried out in 1999 in Beijing area. The MetS was defined by the World Health Organization (WHO), European Group for the Study of Insulin Resistance (EGIR), American College of Endocrinology (ACE), the International Diabetes Federation (IDF), and the National Cholesterol Education Program and the American Heart Association (AHA) (updated NCEP) criteria. From a multiple logistic regression adjusting for age, sex, education, occupation, smoking, family history of diabetes, and total cholesterol, the relative risk of the ACE-defined MetS for incident diabetes alone (67 cases) was 2.29 (95% CI, 1.20-4.34). The MetS defined by the five definitions was associated with a 1.8-3.9 times increased risk for both incident CHD and diabetes combined (59 cases), and with a 1.9-3.0 times for total incident diabetes (126 cases). None of the five definitions predicted either incident CHD alone (177 cases) or total incident CHD (236 cases). In conclusion, the MetS defined by the current definitions appears to be more effective at predicting incident diabetes.

Effects of etanercept in patients with the metabolic syndrome

BACKGROUND

Adipose-derived cytokines, including tumor necrosis factor alpha, may contribute to the inflammation that occurs in the metabolic syndrome. We investigated the effects of inhibition of tumor necrosis factor alpha with etanercept in patients with the metabolic syndrome.

METHODS

Fifty-six subjects with the metabolic syndrome were randomized to administration of either etanercept or identical placebo, 50 mg subcutaneously once a week for 4 weeks. The C-reactive protein level was the primary end point. Effects on other inflammatory markers (including fibrinogen, interleukin 6, and adiponectin), insulin sensitivity, lipid levels, and body composition were also determined.

RESULTS

Baseline characteristics were similar between the groups. Two subjects dropped out of each group, and etanercept was well tolerated throughout the study. The C-reactive protein levels decreased significantly in the treated compared with the placebo group (-2.4 +/- 0.4 vs 0.5 +/- 0.7 mg/L; P<.001). Adiponectin levels rose significantly in the etanercept group compared with the placebo group (0.8 +/- 0.4 vs -0.3 +/- 0.3 microg/mL; P = .03). Fibrinogen levels decreased (-68 +/- 16 vs -2 +/- 31 mg/dL [-2.0 +/- 0.47 vs -0.06 +/- 0.91 micromol/L]; P = .04) and interleukin 6 levels tended to decrease (-1.2 +/- 0.8 vs 0.5 +/- 0.5 ng/L; P = .07) in the etanercept-treated subjects compared with placebo, respectively. No changes occurred in body composition parameters or insulin sensitivity, but high-density lipoprotein levels tended to decrease in the etanercept group (-1 +/- 1 vs 2 +/- 1 mg/dL [-0.03 +/- 0.03 vs 0.05 +/- 0.03 mmol/L]; P = .06) compared with the placebo group.

CONCLUSIONS

Etanercept reduces C-reactive protein levels and tends to improve other inflammatory cardiovascular risk indexes in patients with the metabolic syndrome. Etanercept may interrupt the inflammatory cascade that occurs with abdominal obesity. Further, longer-term studies are needed to determine the effects of tumor necrosis factor alpha inhibition on cardiovascular disease in patients with the metabolic syndrome.

Drug therapy of the metabolic syndrome: minimizing the emerging crisis in polypharmacy

The metabolic syndrome--a collection of factors associated with increased risk for cardiovascular disease and diabetes--is becoming increasingly common, largely as a result of the increase in the prevalence of obesity. Although it is generally agreed that first-line clinical intervention for the metabolic syndrome is lifestyle change, this is insufficient to normalize the risk factors in many patients, and so residual risk could be high enough to justify drug therapy. However, at present there are no approved drugs that can reliably reduce all of the metabolic risk factors over the long term, and so there is growing interest in therapeutic strategies that might target multiple risk factors more effectively, thereby minimizing problems with polypharmacy. This review summarizes current understanding of the nature of the metabolic syndrome, and discusses each of the risk factors of the metabolic syndrome as possible primary drug targets; potential secondary or tertiary targets are also considered.

Metabolic syndrome--a new world-wide definition. A Consensus Statement from the International Diabetes Federation

AIMS

To establish a unified working diagnostic tool for the metabolic syndrome (MetS) that is convenient to use in clinical practice and that can be used world-wide so that data from different countries can be compared. An additional aim was to highlight areas where more research into the MetS is needed.

PARTICIPANTS

The International Diabetes Federation (IDF) convened a workshop held 12-14 May 2004 in London, UK. The 21 participants included experts in the fields of diabetes, public health, epidemiology, lipidology, genetics, metabolism, nutrition and cardiology. There were participants from each of the five continents as well as from the World Health Organization (WHO) and the National Cholesterol Education Program-Third Adult Treatment Panel (ATP III). The workshop was sponsored by an educational grant from AstraZeneca Pharmaceuticals.

CONSENSUS PROCESS

The consensus statement emerged following detailed discussions at the IDF workshop. After the workshop, a writing group produced a consensus statement which was reviewed and approved by all participants.

CONCLUSIONS

The IDF has produced a new set of criteria for use both epidemiologically and in clinical practice world-wide with the aim of identifying people with the MetS to clarify the nature of the syndrome and to focus therapeutic strategies to reduce the long-term risk of cardiovascular disease. Guidance is included on how to compensate for differences in waist circumference and in regional adipose tissue distribution between different populations. The IDF has also produced recommendations for additional criteria that should be included when studying the MetS for research purposes. Finally, the IDF has identified areas where more studies are currently needed; these include research into the aetiology of the syndrome.

Different impact of the metabolic syndrome on left ventricular structure and function in hypertensive men and women

Metabolic syndrome (MS) is increasingly recognized as an important cardiovascular risk factor in hypertension, but its influence on left ventricular (LV) mass and function in the 2 genders has not been specifically addressed. Among 618 nondiabetic, untreated hypertensive subjects, echocardiographically detected LV mass was significantly greater in subjects with MS. A significant interaction was observed between sex and the MS (P<0.003 for the multiplicative interaction term). Compared with women without the MS, those with the syndrome had a 24% greater LV mass (49.5+/-12 versus 40.0+/-10 g x m(-2.7); P<0.001), whereas the difference was only 9% in men (50.3+/-12 versus 46.1+/-10 g x m(-2.7); P=0.003). A greater prevalence of LV hypertrophy was found in women (37% versus 14%; P<0.001) but not in men (39% versus 29%; P=0.09) with the MS. After adjustment for the effect of age, body mass index, 24-hour systolic blood pressure, and several confounders, the MS was independently associated with a greater LV mass index in women (regression coefficient, 4.80; P<0.001) but not in men. Women with the MS also had a greater LV relative wall thickness (0.42+/-0.07 versus 0.39+/-0.07; P=0.004) and a depressed afterload-corrected midwall fractional shortening (94.0+/-12% versus 101.0+/-13%; P<0.001) than women without the syndrome, whereas no differences emerged in men. We conclude that, in untreated hypertension, MS has a different impact on LV hypertrophy and function in men and women. The effect of MS is more pronounced in women and is partly independent from the effect of several hemodynamic and nonhemodynamic determinants of LV mass.

Clustering of insulin resistance with vascular dysfunction and low-grade inflammation in type 2 diabetes

Vascular dysfunction, low-grade inflammation, insulin resistance, and impaired fibrinolysis have each been reported to be present in type 2 diabetes, but their relationships, and the role of obesity, have not been investigated. We measured insulin sensitivity (euglycemic clamp), forearm blood flow responses to graded local acetylcholine (Ach) and sodium nitroprusside (SNP) infusions, plasma concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, von Willebrand factor (vWF), plasminogen activator inhibitor (PAI)-1, tissue plasminogen activator (tPA), and high-sensitivity C-reactive protein (hs-CRP) in 81 diabetic patients. When patients were stratified by insulin resistance, more severe insulin resistance was associated (P < 0.05) with overweight, central fat distribution, hypertension, and dyslipidemia (with similar sex distribution, age, fasting plasma glucose, and HbA1c). With regard to vascular function, both endothelium-dependent (Ach) (-22, -40, and -52%; P < 0.0001) and -independent (SNP) (-3, -7, and -27%; P < 0.02) vasodilatation were progressively reduced across insulin resistance tertiles. In multivariate analysis, inflammatory markers (IL-6, hs-CRP, and TNF-alpha) were independently associated with insulin resistance and fasting glycemia, fibrinolytic markers PAI-1 and tPA with insulin resistance and central fat distribution, and vascular indexes (vWF, Ach, and SNP vasodilation) with insulin resistance and obesity or cytokines (TNF-alpha or IL-6). In type 2 diabetes, insulin resistance is associated with vascular dysfunction/damage, impaired fibrinolysis, and low-grade inflammation independently of obesity and poor glycemic control.

Análise dos critérios de definição da síndrome metabólica em pacientes com diabetes melito tipo 2

O objetivo deste estudo é comparar em pacientes com diabetes melito tipo 2 (DM2) a proporção de síndrome metabólica de acordo com a definição da Organização Mundial de Saúde (OMS) e a do National Cholesterol Education Program (NCEP), e analisar qual se associa mais à presença das complicações do DM2. Foram avaliados 753 pacientes com DM2 em atendimento ambulatorial, quanto a parâmetros étnicos, antropométricos, laboratoriais e presença das complicações: nefropatia diabética, cardiopatia isquêmica, acidente vascular cerebral, retinopatia diabética e vasculopatia periférica. A resistência insulínica foi estimada através do HOMA-IR. A síndrome metabólica esteve presente em 671 (89%) e 657 (87%) dos pacientes utilizando a definição da OMS e do NCEP, respectivamente. No grupo total, houve uma concordância moderada entre as duas definições (k= 0,54; IC 95% 0,490,59), porém foi melhor para negros (k= 0,69; IC 95% 0,60,78) do que para brancos (k= 0,54; IC 95% 0,480,6) e mulatos (k= 0,26; IC 95% 0,090,43). Pacientes com síndrome metabólica pela definição do NCEP apresentaram valores de HOMA-IR maiores que os pacientes sem síndrome metabólica (p= 0,001). Esta diferença não foi encontrada utilizando a definição da OMS (p= 0,152). A proporção das complicações do DM2 foi semelhante nas duas definições. Em conclusão, em relação ao risco de complicações, as duas definições são equivalentes. Entretanto, existe variação na concordância entre as duas definições de acordo com a etnia.

Metabolic Syndrome: Connecting and Reconciling Cardiovascular and Diabetes Worlds

The metabolic syndrome is a constellation of risk factors of metabolic origin that are accompanied by increased risk for cardiovascular disease and type 2 diabetes. These risk factors are atherogenic dyslipidemia, elevated blood pressure, elevated plasma glucose, a prothrombotic state, and a proinflammatory state. The two major underlying risk factors for the metabolic syndrome are obesity and insulin resistance; exacerbating factors are physical inactivity, advancing age, and endocrine and genetic factors. The condition is progressive, beginning with borderline risk factors that eventually progress to categorical risk factors. In many patients, the metabolic syndrome culminates in type 2 diabetes, which further increases risk for cardiovascular disease. Primary treatment of the metabolic syndrome is lifestyle therapy--weight loss, increased physical activity, and anti-atherogenic diet. But as the condition progresses, drug therapies directed toward the individual risk factors might be required. Ultimately, it might be possible to develop drugs that will simultaneously modify all of the risk factors. At present such drugs are in development but so far have not reached the level of clinical practice.

Low ankle-brachial pressure index predicts increased risk of cardiovascular disease independent of the metabolic syndrome and conventional cardiovascular risk factors in the Edinburgh Artery Study

OBJECTIVE

To investigate whether a low ankle-brachial pressure index (ABI) predicts increased risk of cardiovascular disease (CVD) independent of the metabolic syndrome and conventional cardiovascular risk factors.

RESEARCH DESIGN AND METHODS

The Edinburgh Artery Study is a population-based cohort study in which subjects were followed up until their death or for approximately 15 years. Low ABI at baseline was defined as <0.9; subjects with ABI >1.4 (n = 13) were excluded from the analyses. We used a modified version of the definition of the metabolic syndrome published in the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults, replacing waist circumference criteria with BMI criteria. Data on relevant parameters were available for 1,467 men and women ages 55-74 years at baseline. Cox proportional hazards models were used to study cardiovascular morbidity and mortality before and after adjusting for potential confounding factors.

RESULTS

We determined that 25% of the study population had the metabolic syndrome and that a low ABI was more prevalent among people with than without the metabolic syndrome (24 vs. 15%; P < 0.001). During the follow-up period, there were 226 deaths from CVD and 462 nonfatal cardiovascular events. The hazard ratio (95% CI) for low ABI after adjusting for age, sex, baseline CVD, diabetes, smoking status, LDL cholesterol, and metabolic syndrome was 1.5 (1.1-2.1) for CVD mortality and 1.5 (1.2-1.8) for all CVD outcomes.

CONCLUSIONS

Low ABI is associated with increased risk of CVD independent of the metabolic syndrome and other major CVD risk factors.

Exercise, fitness, and cardiovascular disease risk in type 2 diabetes and the metabolic syndrome

This article highlights research supporting the concept that increased physical activity and cardiorespiratory fitness attenuate risk of cardiovascular disease, type 2 diabetes, and the metabolic syndrome. Increased activity and fitness also attenuate risk of developing cardiovascular disease in persons who have type 2 diabetes or the metabolic syndrome. Although controversial, relationships between physical activity/physical fitness and type 2 diabetes/metabolic syndrome are largely independent of body weight. Thus, physical inactivity and poor cardiorespiratory fitness are not only important determinants of cardiovascular and metabolic diseases, but they can also be considered common features of these conditions, much like traditional risk factors such as obesity and insulin resistance.

Soluble P-selectin and CD40L levels in subjects with prediabetes, diabetes mellitus, and metabolic syndrome--the Chennai Urban Rural Epidemiology Study

The aim of the study was to determine whether the levels of soluble P-selectin (sP-selectin) and soluble CD40L (sCD40L) are elevated in Asian Indian subjects with impaired glucose tolerance (IGT), diabetes, and metabolic syndrome (MS). Study subjects were recruited from the Chennai Urban Rural Epidemiology Study (CURES), an ongoing population-based study on a representative population of Chennai city in southern India, and were grouped as follows: group 1, normal glucose tolerance (NGT) (n = 60); group 2, IGT (n = 60); and group 3, type 2 diabetes mellitus (n = 60). Normal glucose tolerance, IGT, and diabetes were defined using World Health Organization consulting group criteria. The inclusion criteria were nonsmokers; normal resting 12-lead electrocardiogram; absence of angina, myocardial infarction, or history of any known vascular, infectious, or inflammatory diseases; and subjects not on statins or aspirin. Insulin resistance was calculated using the homeostasis assessment model using the formula: fasting insulin (microIU/mL) x fasting glucose (mmol/L)/22.5. Soluble P-selectin and sCD40L were estimated by enzyme-linked immunosorbent assay. Metabolic syndrome was defined using Adult Treatment Panel III guidelines. Subjects with diabetes and IGT were older (diabetes: 53 +/- 9 years, P < .01; IGT: 51 +/- 10 years, P < .05) compared with the NGT group (48 +/- 10 years). Subjects with diabetes and IGT had higher levels of sP-selectin (diabetes: 162 +/- 79 ng/mL, P < .001; IGT: 102 +/- 37 ng/mL, P < .001) compared with the NGT group (55 +/- 48 ng/mL). Soluble CD40L levels were also higher in those with diabetes and IGT (diabetes: 3.2 +/- 2.0 ng/mL, P < .001; IGT: 2.0 +/- 1.3 ng/mL, P < .001) compared with the NGT group (1.1 +/- 0.9 ng/mL). Subjects with MS had significantly higher levels of sP-selectin (with MS, 118 +/- 76 ng/mL; without MS, 95 +/- 66 ng/mL; P = .028) and sCD40L (with MS, 2.4 +/- 1.8 ng/mL; without MS, 1.9 +/- 1.5 ng/mL; P = .036) compared with subjects without MS. Among subjects with NGT and IGT, the mean levels of sP-selectin (tertile I, 65.0 ng/mL; tertile II, 80.0 ng/mL; tertile III, 91.0 ng/mL) and sCD40L levels (tertile I, 1.2 ng/mL; tertile II, 1.7 ng/mL; tertile III, 1.8 ng/mL) increased with increase in tertiles of homeostasis assessment model-insulin resistance, and the difference reached statistical significance in the last tertile compared with the first tertile (P < .05). This study demonstrates that increased levels of sP-selectin and sCD40L are seen in Asian Indian subjects with IGT, type 2 diabetes mellitus, MS, and insulin resistance.

Should all patients with metabolic syndrome be treated with statins?

The metabolic syndrome is a constellation of cardiovascular risk factors that include atherogenic dyslipidemia, elevated blood pressure, abdominal/truncal obesity, and glucose intolerance. Current National Cholesterol Education Program (NCEP) recommendations for specific treatment of the metabolic syndrome are centered on therapeutic lifestyle changes. A recent publication from the NCEP Adult Treatment Panel III suggests pharmacologic intervention for parameters of metabolic syndrome, including dyslipidemia, hypertension, and hyperglycemia, to prevent cardiovascular disease, based on risk category. This review looks at the clinical trial evidence to support the use of statins in metabolic syndrome.

Metabolic Syndrome as an Independent Risk Factor of Silent Brain Infarction in Healthy People

BACKGROUND AND PURPOSE

Metabolic syndrome (MetS) is associated with an increased risk of the subsequent development of cardiovascular disease or stroke. Moreover, a silent brain infarction (SBI) can predict clinical overt stroke or dementia. We examined the associations between SBI and MetS in apparently healthy individuals.

METHODS

We evaluated 1588 neurologically healthy subjects (927 males and 661 females) who underwent brain MRI at Seoul National University Hospital Healthcare System Gangnam Center. MetS was defined using the criteria of the National Cholesterol Education Program Adult Treatment Panel III. We examined associations between full syndrome (> or =3 of the 5 conditions) as well as its components and SBI by controlling possible confounders.

RESULTS

Eighty-eight (5.5%) were found to have > or =1 SBI on MRI. Age was found to be significantly related to SBI prevalence (odds ratio [OR], 1.06; 95% CI, 1.04 to 1.09). A history of coronary artery disease was associated with an elevated odds ratio of SBI (OR, 2.83; 95% CI, 1.38 to 5.82), and MetS was significantly associated with SBI (OR, 2.18; 95% CI, 1.38 to 3.44). The components model of MetS showed a strong significance between an elevated blood pressure (OR, 3.75; 95% CI, 2.05 to 6.85) and an impaired fasting glucose (OR, 1.74; 95% CI, 1.08 to 2.80) and the risk of SBI.

CONCLUSIONS

MetS was found to be significantly associated with SBI. This finding has clinical utility in terms of identifying healthy people at increased risk of developing SBI.

A fixed-dose combination of pioglitazone and metformin: A promising alternative in metabolic control

BACKGROUND

When type 2 diabetes is managed with glucose-lowering monotherapy, glycemic control ultimately deteriorates due to the inability of the beta-cell to overcome insulin resistance. Combining drugs with different complementary mechanisms of action improves long-term glycemic control and may lower the risk of vascular complications. A fixed-dose combination of pioglitazone (a thiazolidinedione) and metformin has been approved for use in the US (Actoplus met) and in Europe (Competact).

SCOPE

This review (based upon MEDLINE and EMBASE searches from January 1990 to April 2006) discusses the potential benefits of co-formulating metformin and pioglitazone with respect to compliance and targeting glycemia, as well as other metabolic parameters.

FINDINGS

Pioglitazone increases insulin sensitivity, while metformin reduces hepatic gluconeogenesis and improves peripheral glucose uptake. Both agents reduce hyperglycemia and hyperinsulinemia, and appear to protect beta-cell function. Their similar pharmacokinetic time profiles have facilitated a co-formulation bioequivalent to their separate administration. In randomized studies, pioglitazone and metformin administered separately provided significantly better glycemic control than metformin monotherapy or metformin plus gliclazide. Pioglitazone and metformin have complimentary benefits on diabetic dyslipidemia; pioglitazone primarily improves high-density lipoprotein cholesterol and triglyceride levels (to a greater extent than rosiglitazone does), while metformin mainly improves total cholesterol. Pioglitazone and metformin also modulate other atherosclerosis biomarkers, including inflammatory mediators, coagulation thrombosis components, and carotid intima media thickness. Together, these pleiotropic effects have the potential to confer a reduced risk of cardiovascular disease in patients with type 2 diabetes. Pioglitazone and metformin are well tolerated in combination, with low rates of hypoglycemia, and the convenience of a single tablet may be expected to aid dosing compliance.

CONCLUSION

The co-formulation of pioglitazone and metformin is a rational approach that maximizes the established, complimentary benefits of these agents, while potentially improving compliance.

Proteinuria and metabolic syndrome as predictors of cardiovascular death in non-diabetic and type 2 diabetic men and women

AIMS/HYPOTHESIS

Proteinuria predicts cardiovascular disease (CVD), but it is unclear whether this is explained by the association of the metabolic syndrome with proteinuria. Therefore, we investigated proteinuria and the metabolic syndrome as independent predictors of CVD death in men and women.

METHODS

The cohort comprised 574 non-diabetic men, 707 non-diabetic women, 371 diabetic men and 349 diabetic women, all free of CVD at baseline. Modified World Health Organization criteria were used to define the metabolic syndrome, and a urinary protein concentration of >or=0.1 g/l (or >or=0.2 g/l) to define proteinuria. The endpoint was CVD mortality during the 18-year follow-up.

RESULTS

Among non-diabetic men, CVD mortality per 1,000 person-years was as follows: no metabolic syndrome, no urinary protein group: 5.3; no metabolic syndrome, positive for urinary protein: 8.9; positive for metabolic syndrome, no urinary protein: 13.3; and positive for metabolic syndrome and urinary protein: 14.9. For non-diabetic women the corresponding values were: 0.9, 2.3, 4.9 and 7.9, respectively. Among diabetic men, CVD mortality per 1,000 person-years was 15.2, 32.5, 23.6 and 42.0 for the respective groups. Among diabetic women it was 25.3, 38.0, 26.3 and 40.3 (urinary protein in all cases defined as >or=0.1 g/l). In multivariate Cox models including both urinary protein and metabolic syndrome, the hazard ratios (HRs, 95% CI) of proteinuria for CVD mortality were 1.5 (0.9-2.4) in non-diabetic men, 1.8 (0.8-4.2) in non-diabetic women, 1.6 (1.0-2.6) in diabetic men and 1.6 (1.1-2.3) in diabetic women. Urinary protein as a continuous variable was associated with CVD mortality in all groups. The corresponding HRs for metabolic syndrome were: 1.6 (0.9-2.7), 4.0 (1.7-9.7), 1.5 (1.1-2.0) and 1.1 (0.8-1.5).

CONCLUSIONS/INTERPRETATION

Proteinuria predicted CVD mortality independently of the presence of metabolic syndrome in non-diabetic and diabetic subjects. Metabolic syndrome predicted CVD mortality in non-diabetic women and in diabetic men, independently of the presence of proteinuria.

The metabolic syndrome and cardiovascular disease

The metabolic syndrome, which is very common in the general population, is defined by the clustering of several classic cardiovascular risk factors, such as type 2 diabetes, hypertension, high triglycerides and low high-density lipoprotein cholesterol (HDL). Central obesity and insulin resistance, which are the two underlying disorders of the syndrome, are further risk factors for cardiovascular disease. Moreover, a panel of novel (non-traditional) risk factors are ancillary features of the metabolic syndrome. They include biomarkers of chronic mild inflammation (e.g. C-reactive protein, CRP), increased oxidant stress (e.g. oxidized low density lipoprotein, LDL), thrombophilia (e.g. plasminogen activator inhibitor-1, PAI-1) and endothelial dysfunction (e.g. E-selectin). Therefore, subjects with the metabolic syndrome are potentially at high risk of developing atherosclerosis and clinical cardiovascular events.In recent years several longitudinal studies have confirmed that subjects with the metabolic syndrome present with atherosclerosis and suffer from myocardial infarction and stroke at rates higher than subjects without the syndrome. The risk of cardiovascular disease (CVD) is particularly high in women with the syndrome and in subjects with pre-existing diabetes, CVD and/or high CRP. However, an increased risk is already present in subjects with a cluster of multiple mild abnormalities. The risk related to the metabolic syndrome is definitely higher when subjects affected are compared to subjects free of any metabolic abnormality.

Relationship between serum uric acid concentration, metabolic syndrome and carotid atherosclerosis

OBJECTIVE

Carotid intima-media thickness (IMT) is a useful surrogate marker of cardiovascular disease. Associations between hyperuricemia, metabolic syndrome and carotid IMT have been reported, but few of the studies have been conducted in a Japanese population.

METHODS

A total of 1,128 subjects (498 men aged, 68+/-14 years and 630 women aged 72+/-12 years) were divided into 4 groups according to serum uric acid (SUA) quartiles. We first investigated the association between SUA concentrations and metabolic syndrome; then, we assessed whether there is an independent association of SUA with carotid IMT in a population subdivided according to gender and metabolic syndrome status.

RESULTS

In women, the prevalence of visceral obesity and metabolic syndrome were significantly increased with increased SUA quartiles, but not in men. After adjusting for age, smoking status, LDL-cholesterol, creatinine and history of diabetes mellitus, the odds ratios (95% CI) of sex-specific quartiles of SUA for metabolic syndrome were 1.0, 1.37 (0.79-2.37), 1.37 (0.79-2.38), and 1.80 (1.03-3.15) in men, and 1.0, 1.04 (0.56-1.94), 2.35 (1.30-4.22), and 2.20 (1.16-4.20) in women. After adjusting for various known risk factors, the prevalence of carotid atherosclerosis (IMT> or =1.0 mm) was higher in subjects in the second, third and fourth quartiles of SUA concentration with odds ratios (95% CI) of 2.41 (1.08-5.37), 3.33 (1.49-7.42), and 2.73 (1.17-6.35), respectively in men without metabolic syndrome but not in men with metabolic syndrome or in women with or without metabolic syndrome.

CONCLUSION

The prevalence of metabolic syndrome was significantly increased according to SUA values only in women. In men without metabolic syndrome, SUA was found to be an independent risk factor for incidence of carotid atherosclerosis.

Impact of metabolic syndrome criteria on cardiovascular disease risk in people with newly diagnosed type 2 diabetes

AIMS/HYPOTHESIS

We investigated the prognostic implication of metabolic syndrome according to modified National Cholesterol Education Program criteria and the implication of individual features of metabolic syndrome on cardiovascular disease (CVD) and CHD in a 5-year community-based study of people with newly diagnosed type 2 diabetes.

METHODS

We entered 562 participants, aged 30-74 years, into a cross-sectional analysis and 428 participants (comprising those who were CVD-free at study entry) into a prospective analysis. In both analyses, the association of metabolic syndrome features with CVD/CHD was studied. Binary logistic regression, a Cox regression model and Fisher's exact test were used for statistical analyses.

RESULTS

At diagnosis of type 2 diabetes, metabolic syndrome was independently associated with CVD (odds ratio [OR] 2.54; p=0.006) and CHD (OR 4.06; p=0.002). In the 5-year follow-up, metabolic syndrome at baseline was an independent predictor of incident CVD (hazard ratio [HR] 2.05; p=0.019). An increase in the number of individual features of the metabolic syndrome present at the time of diagnosis of type 2 diabetes was associated with a linear increase in incident CVD risk (trend p=0.044) with an almost five-fold increase when all five features were present, compared with hyperglycaemia alone (HR 4.76; p=0.042). Increasing age (HR 1.07; p<0.001), female sex (HR 0.62; p=0.032), total cholesterol (HR 1.43; p=0.01) and lipid-lowering therapy (HR 0.32; p<0.001) were also independent predictors of risk.

CONCLUSIONS/INTERPRETATION

Metabolic syndrome at baseline is associated with an increased risk of incident CVD in the 5 years following diagnosis of type 2 diabetes. CVD-free survival rates declined incrementally as the presence of metabolic syndrome features increased. Thus, identifying the features of metabolic syndrome at diagnosis of type 2 diabetes is potentially a useful prognostic tool for identifying individuals at increased risk of CVD.

Increased small low-density lipoprotein particle number: a prominent feature of the metabolic syndrome in the Framingham Heart Study

BACKGROUND

Levels of LDL cholesterol (LDL-C) are frequently not elevated in individuals with the metabolic syndrome (MetSyn). However, the atherogenic potential of LDL may depend on the number and size of LDL particles in addition to the cholesterol content of LDL.

METHODS AND RESULTS

We examined the sex-specific cross-sectional relations of small LDL particle number (determined by nuclear magnetic resonance spectroscopy) to the presence of MetSyn and its components in 2993 Framingham Heart Study participants (mean age, 51 years; 53% women) without cardiovascular disease (CVD) and the relations of small LDL particle number to CVD incidence in people with MetSyn. The MetSyn (> or =3 of 5 traits as defined by the National Cholesterol Education Adult Treatment Panel III) was present in 27% of men and 17% of women. In both sexes, small LDL particle number increased from 0 to 5 MetSyn traits, a pattern partly accounted for by strong correlations between small LDL particle number and serum triglycerides (r=0.61, P<0.0001) and HDL-C (r=-0.55, P<0.0001). Compared with participants without the MetSyn, those with the MetSyn had a higher CVD event rate. However, among participants with the MetSyn, CVD rates were similar for groups with an elevated versus a lower number of small LDL particles (defined by the sex-specific median).

CONCLUSIONS

Small LDL particle number is elevated in the MetSyn, increases with the number of MetSyn components, and most prominently is correlated with triglycerides and HDL-C. Whereas increased small LDL particle number identified the MetSyn with high sensitivity, a higher small LDL particle number was not associated with greater CVD event rates in people with the MetSyn.

Metabolic syndrome amplifies the LDL-cholesterol associated increases in carotid atherosclerosis

OBJECTIVE

Carotid intima-media thickness (IMT) is a useful surrogate marker of cardiovascular disease. In addition to low-density lipoprotein cholesterol (LDL-C), metabolic syndrome has been linked to the pathogenesis of atherosclerosis. The present study investigated whether the clustering of multiple components of metabolic syndrome has a greater impact on vascular parameters than individual components of metabolic syndrome, and assessed the association between carotid IMT and LDL-C and metabolic syndrome.

METHODS

Carotid IMT was evaluated on B-mode ultrasonography in 760 patients (340 men aged 64+/-16 years and 420 women aged 69+/-13 years) in the Medical Department of Seiyo Municipal Nomura Hospital. The subjects did not demonstrate any clinical signs of cardiovascular disease. We investigated the association between carotid IMT and confounding risk factors including LDL-C and metabolic syndrome using the 2005 Japanese criteria.

RESULTS

Carotid IMT increased with increasing numbers of metabolic syndrome components (p for trend<0.001). Multiple regression models, including age, sex, body mass index, smoking status, LDL-C, diabetes mellitus as well as each individual component of metabolic syndrome as continuous variables, showed that both metabolic syndrome (beta=0.100; p=0.029) and LDL-C (beta=0.210, p<0.001) were independent determinants of carotid IMT. Metabolic syndrome amplified the LDL-C associated increases in carotid atherosclerosis.

CONCLUSIONS

Even after taking into account each individual component of MS, the clustering of visceral obesity with at least 2 of the 3 components, and LDL-C are independently associated with increased carotid IMT. This suggests that the components of metabolic syndrome interact to synergistically impact vascular thickness.

Metabolic syndrome as a precursor of cardiovascular disease and type 2 diabetes mellitus

BACKGROUND

The incidence of cardiovascular disease (CVD), coronary heart disease (CHD), and type 2 diabetes mellitus (T2DM) has not been well defined in persons with the metabolic syndrome (at least 3 of the following: abdominal adiposity, low HDL cholesterol, high triglycerides, hypertension, and impaired fasting glucose). The objective was to investigate risk for CVD, CHD, and T2DM according to metabolic syndrome traits.

METHODS AND RESULTS

The study followed a cohort of 3323 middle-aged adults for the development of new CVD, CHD, and T2DM over an 8-year period. In persons without CVD or T2DM at baseline, the prevalence of the metabolic syndrome (> or =3 of 5 traits) was 26.8% in men and 16.6% in women. There were 174 incident cases of CVD, 107 of CHD, and 178 of T2DM. In men, the metabolic syndrome age-adjusted relative risk (RR) and 95% CIs were RR=2.88 (95% CI 1.99 to 4.16) for CVD, RR=2.54 (95% CI 1.62 to 3.98) for CHD, and RR=6.92 (95% CI 4.47 to 10.81) for T2DM. Event rates and RRs were lower in women for CVD (RR=2.25, 95% CI 1.31 to 3.88) and CHD (RR=1.54, 95% CI 0.68 to 3.53), but they were similar for T2DM (RR=6.90, 95% CI 4.34 to 10.94). Population-attributable risk estimates associated with metabolic syndrome for CVD, CHD, and T2DM were 34%, 29%, and 62% in men and 16%, 8%, 47% in women.

CONCLUSIONS

Metabolic syndrome is common and is associated with an increased risk for CVD and T2DM in both sexes. The metabolic syndrome accounts for up to one third of CVD in men and approximately half of new T2DM over 8 years of follow-up.

The metabolic syndrome and type 2 diabetes: epidemiological figures and country specificities

Over the last 20 years, the prevalence of the metabolic syndrome has steadily increased in all populations worldwide, changing slowly the phenotype of the human race and potentially our concept of physiological normality. Our affluent phenotype reflects progressive adaptation to the external environment, which in turn changes the standards of the metabolic variables such as body weight, blood pressure, lipid values and glucose homeostasis. The human survivors of the difficult times of the hunter-gatherer period have probably benefited from genes which have allowed for more efficient food utilization, fat deposition and weight gain, a concept referred to as the 'thrifty gene' hypothesis. This genetic background has now become detrimental in our society of high energy consumption, little physical activity and lifestyles that favour stress and anxiety. These genetic and environmental interactions explain the explosion in the prevalence of the metabolic syndrome and diabetes. If future estimates for the number of patients with diabetes and impaired glucose tolerance are valid, this will have a major and adverse impact on the number of stroke patients globally.

Metabolic syndrome and cardiovascular disease

Metabolic syndrome is a constellation of clinical findings that identify individuals at higher than normal risk of developing diabetes mellitus or cardiovascular disease. There are two principal definitions, one emerging from the American National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults, and the other from the World Health Organization. Both definitions share the common elements of abdominal obesity, hypertriglyceridaemia, low HDL-cholesterol, hypertension and abnormal glucose regulation. The syndrome is relatively common across continents, and also among those without marked obesity. It is even more common among patients with major mental health disorders such as schizophrenia. Metabolic syndrome can be used to assess risk for cardiovascular disorder and death, and is an alternative to Framingham Risk Calculations. C-reactive protein may play an additional role in risk prediction. Ongoing monitoring for all components of the metabolic syndrome is necessary. Individuals at high risk require multimodal interventions, including lifestyle interventions and targeted medications as appropriate.

The prevalence of the metabolic syndrome did not increase in Mexico City between 1990-1992 and 1997-1999 despite more central obesity

OBJECTIVE

Trends in the metabolic syndrome might follow trends in obesity. We examined this hypothesis in the Mexico City Diabetes Study (MCDS), a study that showed rising trends in obesity, and the effect of the metabolic syndrome on the risk of coronary heart disease (CHD).

RESEARCH DESIGN AND METHODS

Designed as a population-based study, the MCDS enrolled subjects in 1990-1992 (n = 2,282). Follow-up visits were held in 1993-1995 (n = 1,764) and 1997-1999 (n = 1,754). We used the revised metabolic syndrome definition of the National Cholesterol Education Program and the Framingham equations to estimate the 10-year CHD risk.

RESULTS

In men, the age-adjusted prevalence of the metabolic syndrome was 38.9% in 1990-1992, 43.4% in 1993-1995, and 39.9% in 1997-1999; in women, the prevalences were 65.4, 65.7, and 59.9%, respectively. The prevalence did not change in men (P = 0.349) between 1990-1992 and 1997-1999, but decreased in women (P < 0.001). A prevalence increase was demonstrated for elevated waist circumference (men, P < 0.001; women, P < 0.050), elevated fasting glucose value (men and women, P < 0.001), and low HDL cholesterol level (men, P < 0.050; women, P < 0.010); a prevalence decrease was seen for high blood pressure (men and women, P < 0.001) and hypertriglyceridemia (men, P < 0.001; women, P < 0.010). CHD risk decreased marginally in men (P < 0.050) but did not change in women (P = 0.943).

CONCLUSIONS

Neither the prevalence of the metabolic syndrome nor CHD risk has increased in Mexico City. Lower blood pressure and triglyceride values appear to have counteracted increases in central obesity and fasting glucose.

Lipids, metabolic syndrome, and risk factors for future cardiovascular disease among HIV-infected patients

The availability of potent combination antiretroviral therapy has changed the long-term prognosis for people living with HIV/AIDS. There is increasing concern, however, about the effect of HIV therapy on lipid disorders and subsequent development of coronary artery disease. Virtually all classes of antiretroviral drugs have been associated with some aspect of atherogenic changes in the lipid profiles. This article reviews the current literature on HIV-associated dyslipidemias and the metabolic syndrome, their potential effect on future coronary heart disease, and reviews strategies for management.

Metabolic syndrome as a predictor of ischemic stroke in elderly persons

OBJECTIVE

To estimate the prevalence and risk of ischemic stroke associated with metabolic syndrome.

METHODS AND PATIENTS

In 197 stroke patients (80 cases of atherothrombotic infarction, 97 lacunar infarction, 16 cardioembolic infarction, 4 others) and 356 age- and sex-matched control subjects aged 65 years and older in Seiyo Municipal Nomura Hospital, we investigated the association between metabolic syndrome and risk factor-dependent augmentation of ischemic stroke in subjects with several risk factors for atherosclerosis. The diagnosis of cerebral infarction in each patient was confirmed by CT findings of the brain and metabolic syndrome was defined as at least 3 of the 5 following conditions: visceral obesity, hypertension (HT), hypertriglyceridemia, low HDL-cholesterol and diabetes mellitus (DM).

RESULTS

After adjustment for sex, age, and smoking, metabolic syndrome was significantly related to atherothrombotic infarction (odds ratio, 3.08; 95% confidence interval, 1.69-5.61). Of the individual components, visceral obesity, HT and DM were independent risk factors for atherothrombotic infarction. Increased risk for atherothrombotic infarction was also associated with increases in the 5 component conditions of the metabolic syndrome.

CONCLUSION

The clustering of cardiovascular risk factors called metabolic syndrome increases the risk of cardiovascular morbidity, and its identification may thus be important in risk assessment and treatment of patients.

The metabolic syndrome: time for a critical appraisal: joint statement from the American Diabetes Association and the European Association for the Study of Diabetes

The term "metabolic syndrome" refers to a clustering of specific cardiovascular disease (CVD) risk factors whose underlying pathophysiology is thought to be related to insulin resistance. Since the term is widely used in research and clinical practice, we undertook an extensive review of the literature in relation to the syndrome's definition, underlying pathogenesis, and association with CVD and to the goals and impact of treatment. While there is no question that certain CVD risk factors are prone to cluster, we found that the metabolic syndrome has been imprecisely defined, there is a lack of certainty regarding its pathogenesis, and there is considerable doubt regarding its value as a CVD risk marker. Our analysis indicates that too much critically important information is missing to warrant its designation as a "syndrome." Until much needed research is completed, clinicians should evaluate and treat all CVD risk factors without regard to whether a patient meets the criteria for diagnosis of the "metabolic syndrome."

An exploratory analysis of criteria for the metabolic syndrome and its prediction of long-term cardiovascular outcomes: the Hoorn study

Studies have shown an increased risk of cardiovascular outcomes with the metabolic syndrome, but information on predictive properties of the National Cholesterol Education Program Adult Treatment Panel 3 (NCEP) criteria is sparse. The authors used data from the Hoorn population-based study in the Netherlands including 2,484 participants aged 50-75 years examined in 1989 and followed for cardiovascular morbidity and mortality through 2000 to assess NCEP criteria, excluding known diabetes or cardiovascular disease. Cluster analyses explored whether NCEP identifies a mixture of heterogeneous groups. For each gender, participants meeting NCEP criteria seemed to be divided into clusters distinguished primarily by triglycerides or high density lipoprotein cholesterol. Cutpoints for components predicting cardiovascular events using classification and survival tree methodology varied by endpoint and gender, but Cox model hazards ratios were relatively comparable regardless of cutpoints (range: 1.3-2.5). Clear gradation in risk of cardiovascular outcomes was evident with increasing number of components, with statistically elevated risk for >or=3 (NCEP) components in men but for >or=2 components in women. Exploratory analyses of alternative metabolic syndrome criteria suggest cardiovascular risk estimates comparable to those derived by using NCEP, but criteria evaluating risk on more of a continuum would potentially allow consideration of alternative definitions by gender or for patients with other risk factors.

The metabolic syndrome: time for a critical appraisal. Joint statement from the American Diabetes Association and the European Association for the Study of Diabetes

BACKGROUND

The term 'metabolic syndrome' refers to a clustering of specific cardiovascular disease (CVD) risk factors whose underlying pathophysiology is thought to be related to insulin resistance.

METHODS

Since the term is widely used in research and clinical practice, we undertook an extensive review of the literature in relation to the syndrome's definition, underlying pathogenesis, association with cardiovascular disease and to the goals and impact of treatment.

DISCUSSION

While there is no question that certain CVD risk factors are prone to cluster, we found that the metabolic syndrome has been imprecisely defined, there is a lack of certainty regarding its pathogenesis, and there is considerable doubt regarding its value as a CVD risk marker. Our analysis indicates that too much critically important information is missing to warrant its designation as a 'syndrome'.

CONCLUSION

Until much-needed research is completed, clinicians should evaluate and treat all CVD risk factors without regard to whether a patient meets the criteria for diagnosis of the 'metabolic syndrome'.

Metabolic syndrome: Demographic features, etiology, and clinical management

The metabolic syndrome, also known as the dysmetabolic syndrome, syndrome X, or the insulin resistance syndrome, refers to the clustering of cardiovascular disease risk factors that are present in many individuals who are at increased risk for cardiovascular events and/or type 2 diabetes. The criteria for metabolic syndrome include a combination of categorical and borderline risk factors that can be readily measured in clinical practice. Although the Adult Treatment Panel III of the National Cholesterol Education Program set the criteria to identify cardiovascular risk, the syndrome had already been well recognized in the endocrine community as identifying people at risk for diabetes. Recently, the International Diabetes Federation proposed a worldwide definition with ethnic-specific criteria for waist circumference. Therapies targeted to specific components of the metabolic syndrome, such as improving glycemic control, managing dyslipidemia, and reducing the prothrombotic state, should help to minimize cardiovascular risk, particularly if initiated early.