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

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.

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.

Metabolic syndrome is associated with markers of subclinical atherosclerosis in a French population-based sample

Metabolic syndrome (MetS) is associated with increased risk of cardiovascular disease (CVD). The relation of MetS with early stages of atherosclerosis, more important from a prevention perspective, has not been evaluated extensively. We examined the association of MetS, using WHO and NCEP definitions, with number of carotid and femoral plaques; carotid intima-media thickness (IMT); pulse wave velocity (PWV) in a random population-based sample of 1153 French adults (35-65 year). Impact of inflammatory factors (C-reactive protein and soluble intercellular adhesion molecule-1) on these parameters was also evaluated. Prevalence of MetS was 14.5 (CI: 12.3-16.0) and 17.5 (CI: 15.1-20.2)%, using NCEP and WHO definitions, respectively. MetS significantly predicted number of plaques, IMT, and PWV after adjustment for traditional risk factors (P<0.05). Inflammatory factors predicted peripheral plaques only. The risk of subclinical atherosclerosis was considerably increased with MetS (P<0.05); odds ratios ranged 1.80-2.15 with NCEP definition, and 1.48-1.97 with WHO definition. Individuals meeting both NCEP and WHO definitions had slightly greater risk of increased plaques, IMT, and PWV. MetS was strongly associated with subclinical atherosclerosis and aortic stiffness, and can be used as a surrogate marker for high CVD risk, deserving aggressive treatment.

Risks for all-cause mortality, cardiovascular disease, and diabetes associated with the metabolic syndrome: a summary of the evidence

OBJECTIVE

In recent years, several major organizations have endorsed the concept of the metabolic syndrome and developed working definitions for it. How well these definitions predict the risk for adverse events in people with the metabolic syndrome is only now being learned. The purpose of this study was to summarize the estimates of relative risk for all-cause mortality, cardiovascular disease, and diabetes reported from prospective studies in samples from the general population using definitions of the metabolic syndrome developed by the National Cholesterol Education Program (NCEP) and World Health Organization (WHO).

RESEARCH DESIGN AND METHODS

The author reviewed prospective studies from July 1998 through August 2004.

RESULTS

For studies that used the exact NCEP definition of the metabolic syndrome, random-effects estimates of combined relative risk were 1.27 (95% CI 0.90-1.78) for all-cause mortality, 1.65 (1.38-1.99) for cardiovascular disease, and 2.99 (1.96-4.57) for diabetes. For studies that used the most exact WHO definition of the metabolic syndrome, the fixed-effects estimates of relative risk were 1.37 (1.09-1.74) for all-cause mortality and 1.93 (1.39-2.67) for cardiovascular disease; the fixed-effects estimate was 2.60 (1.55-4.38) for coronary heart disease.

CONCLUSIONS

These estimates suggest that the population-attributable fraction for the metabolic syndrome, as it is currently conceived, is approximately 6-7% for all-cause mortality, 12-17% for cardiovascular disease, and 30-52% for diabetes. Further research is needed to establish the use of the metabolic syndrome in predicting risk for death, cardiovascular disease, and diabetes in various population subgroups.

Lower birth weight predicts metabolic syndrome in young adults: the Atherosclerosis Risk in Young Adults (ARYA)-study

OBJECTIVE

To study the relationship between intrauterine growth and the metabolic syndrome, particularly fasting serum lipids in young adulthood.

METHODS

Seven hundred and forty-four young adults aged 26-31 years participated in the ARYA birth cohort. Birth characteristics were available from charts kept by the Municipal Health Service, Utrecht, The Netherlands. Adult medical history and lifestyle information were assessed by questionnaires. Adult anthropometry, blood pressure, fasting plasma glucose, total cholesterol, HDL-cholesterol, triglycerides were measured, and LDL-cholesterol was calculated.

RESULTS

Subjects in the lower tertiles of birth weight (1250-3209 and 3210-3649 g) had higher risks for metabolic syndrome than those in the highest birth weight tertile (3650-5500 g): odds ratio, 1.8; 95% confidence interval (CI) 1.0-3.5 and 1.4; 0.7-2.7, respectively; p for trend = 0.064, adjusted for gender, cardiovascular disease family history and current education. Birth weight was inversely related to systolic blood pressure (linear regression coefficient, -1.9 mmHg/kg birth weight; 95% CI -3.4 to -0.3) and to (log) triglycerides in mmol/L (-0.03/kg birth weight; 95% CI -0.06 to -0.01), adjusted for gender, current body mass index and current education. Birth weight showed inverse relations to diastolic blood pressure, serum glucose, total and LDL cholesterol and positive relations to waist circumference and HDL cholesterol levels, although not statistically significant. Birth length and ponderal index were not related to the metabolic syndrome or lipid profiles.

CONCLUSION

Lower birth weight indicates a higher risk for metabolic syndrome in young adults, particularly through higher serum triglycerides and higher systolic blood pressure.