Definition of Metabolic Syndrome: Report of the National Heart, Lung, and Blood Institute/American Heart Association Conference on Scientific Issues Related to Definition

The National Cholesterol Education Program’s Adult Treatment Panel III report (ATP III)1 identified the metabolic syndrome as a multiplex risk factor for cardiovascular disease (CVD) that is deserving of more clinical attention. The cardiovascular community has responded with heightened awareness and interest. ATP III criteria for metabolic syndrome differ somewhat from those of other organizations. Consequently, the National Heart, Lung, and Blood Institute, in collaboration with the American Heart Association, convened a conference to examine scientific issues related to definition of the metabolic syndrome. The scientific evidence related to definition was reviewed and considered from several perspectives: (1) major clinical outcomes, (2) metabolic components, (3) pathogenesis, (4) clinical criteria for diagnosis, (5) risk for clinical outcomes, and (6) therapeutic interventions

Clinical Management of Metabolic Syndrome: Report of the American Heart Association/National Heart, Lung, and Blood Institute/American Diabetes Association Conference on Scientific Issues Related to Management

"The National Cholesterol Education Program’s Adult Treatment Panel III report (ATP III)1 identified the metabolic syndrome as a multiplex risk factor for cardiovascular disease (CVD) that is deserving of more clinical attention. Subsequently, the National Heart, Lung, and Blood Institute (NHLBI), in collaboration with the American Heart Association (AHA), convened a conference to examine scientific issues related to definition of the metabolic syndrome.2 The present report summarizes a second conference devoted to clinical management of the metabolic syndrome, which was sponsored by the AHA in partnership with the NHLBI and cosponsored by the American Diabetes Association (ADA). This latter conference considered the following issues: (1) pathogenesis and presentation of the metabolic syndrome, (2) management of underlying risk factors, (3) management of metabolic risk factors, and (4) unresolved issues and research challenges. The conference on definition2 confirmed CVD as a major clinical outcome of metabolic syndrome and identified 6 major components of the syndrome: abdominal obesity, atherogenic dyslipidemia, elevated blood pressure, insulin resistance ± glucose intolerance, a proinflammatory state, and a prothrombotic state. The follow-up conference on management was structured around therapies for these components. Clinical recognition of the metabolic syndrome is generally based on finding several well-recognized signs in clinical practice: abdominal obesity, elevated triglycerides, reduced HDL cholesterol, raised blood pressure, and elevated plasma glucose. In addition, research shows that other components not routinely measured commonly aggregate with the major components: elevated apolipoprotein B, small LDL particles, insulin resistance and hyperinsulinemia, impaired glucose tolerance (IGT), elevated C-reactive protein (CRP), and variation in coagulation factors (eg, plasminogen activator inhibitor [PAI]-1 and fibrinogen). The conference on definition2 also emphasized that risk for type 2 diabetes is higher in persons with metabolic syndrome and that diabetes is a major risk factor for CVD. It also examined various criteria for a clinical diagnosis of the metabolic syndrome. The diagnostic scheme developed by ATP III is shown in the Table. Clinical criteria proposed by the World Health Organization3 and American Association of Clinical Endocrinologists4 also were reviewed. These latter criteria overlap with those of ATP III but differ by requiring direct evidence of insulin resistance for diagnosis. Both the World Health Organization and the American Association of Clinical Endocrinologists recommend an oral glucose tolerance test (OGTT) in patients without an elevated fasting glucose. In other words, in the absence of impaired fasting glucose (IFG), IGT detected by OGTT is considered as one metabolic risk factor defining the metabolic syndrome. ATP III does not recommend OGTT in such persons, even through IGT is a high-risk condition for type 2 diabetes (independent of IFG) and correlates with increased risk for CVD. ATP III, however, held that the information gained by OGTT does not outweigh its costs and inconvenience in routine practice. The present conference on management moved from the issue of definition of the metabolic syndrome to the wide issues of clinical management.

Definition of metabolic syndrome: report of the National Heart, Lung, and Blood Institute/American Heart Association conference on scientific issues related to definition

The National Cholesterol Education Program’s Adult Treatment Panel III report (ATP III)1 identified the metabolic syndrome as a multiplex risk factor for cardiovascular disease (CVD) that is deserving of more clinical attention. The cardiovascular community has responded with heightened awareness and interest. ATP III criteria for metabolic syndrome differ somewhat from those of other organizations. Consequently, the National Heart, Lung, and Blood Institute, in collaboration with the American Heart Association, convened a conference to examine scientific issues related to definition of the metabolic syndrome. The scientific evidence related to definition was reviewed and considered from several perspectives: (1) major clinical outcomes, (2) metabolic components, (3) pathogenesis, (4) clinical criteria for diagnosis, (5) risk for clinical outcomes, and (6) therapeutic interventions

ACC/AHA/NHLBI clinical advisory on the use and safety of statins

The voluntary withdrawal of cerivastatin (Baycol) from the U.S. market on August 8, 2001, by the manufacturer, in agreement with the Food and Drug Administration (FDA), has prompted concern on the part of physicians and patients regarding the safety of the cholesterol-lowering class of drugs called HMG CoA reductase inhibitors, more commonly known as “statins.” This American College of Cardiology/American Heart Association/National Heart, Lung and Blood Institute (ACC/AHA/NHLBI) Clinical Advisory is intended to summarize for professionals the current understanding of statin use, focused on myopathy, and to provide updated recommendations for the appropriate use of statins, including cautions, contraindications, and safety monitoring for statin therapy. Its purpose is not to discourage the appropriate use of statins, which have life-saving potential in properly selected patients, particularly those with established coronary heart disease (CHD) and others at high risk for developing CHD. Included are recent myopathy information compiled by the FDA, information from clinical trials, and summaries from the recently released report of the Adult Treatment Panel III (ATP III) of the National Cholesterol Education Program (NCEP)

ACC/AHA/NHLBI clinical advisory on the use and safety of statins

The voluntary withdrawal of cerivastatin (Baycol) from the U.S. market on August 8, 2001, by the manufacturer, in agreement with the Food and Drug Administration (FDA), has prompted concern on the part of physicians and patients regarding the safety of the cholesterol-lowering class of drugs called HMG CoA reductase inhibitors, more commonly known as “statins.” This American College of Cardiology/American Heart Association/National Heart, Lung and Blood Institute (ACC/AHA/NHLBI) Clinical Advisory is intended to summarize for professionals the current understanding of statin use, focused on myopathy, and to provide updated recommendations for the appropriate use of statins, including cautions, contraindications, and safety monitoring for statin therapy. Its purpose is not to discourage the appropriate use of statins, which have life-saving potential in properly selected patients, particularly those with established coronary heart disease (CHD) and others at high risk for developing CHD. Included are recent myopathy information compiled by the FDA, information from clinical trials, and summaries from the recently released report of the Adult Treatment Panel III (ATP III) of the National Cholesterol Education Program (NCEP)

Harmonizing the Metabolic Syndrome: A Joint Interim Statement of the International Diabetes Federation Task Force on Epidemiology and Prevention; National Heart, Lung, and Blood Institute; American Heart Association; World Heart Federation; International Atherosclerosis Society; and International Association for the Study of Obesity

A cluster of risk factors for cardiovascular disease and type 2 diabetes mellitus, which occur together more often than by chance alone, have become known as the metabolic syndrome. The risk factors include raised blood pressure, dyslipidemia (raised triglycerides and lowered high-density lipoprotein cholesterol), raised fasting glucose, and central obesity. Various diagnostic criteria have been proposed by different organizations over the past decade. Most recently, these have come from the International Diabetes Federation and the American Heart Association/National Heart, Lung, and Blood Institute. The main difference concerns the measure for central obesity, with this being an obligatory component in the International Diabetes Federation definition, lower than in the American Heart Association/National Heart, Lung, and Blood Institute criteria, and ethnic specific. The present article represents the outcome of a meeting between several major organizations in an attempt to unify criteria. It was agreed that there should not be an obligatory component, but that waist measurement would continue to be a useful preliminary screening tool. Three abnormal findings out of 5 would qualify a person for the metabolic syndrome. A single set of cut points would be used for all components except waist circumference, for which further work is required. In the interim, national or regional cut points for waist circumference can be used

Implications of recent clinical trials for the National Cholesterol Education Program Adult Treatment Panel III guidelines

The Adult Treatment Panel III (ATP III) of the National Cholesterol Education Program issued an evidence-based set of guidelines on cholesterol management in 2001. Since the publication of ATP III, 5 major clinical trials of statin therapy with clinical end points have been published. These trials addressed issues that were not examined in previous clinical trials of cholesterol-lowering therapy. The present document reviews the results of these recent trials and assesses their implications for cholesterol management. Therapeutic lifestyle changes (TLC) remain an essential modality in clinical management. The trials confirm the benefit of cholesterol-lowering therapy in high-risk patients and support the ATP III treatment goal of low-density lipoprotein cholesterol (LDL-C) less than 100 mg/dL. They support the inclusion of patients with diabetes in the high-risk category and confirm the benefits of LDL-lowering therapy in these patients. They further confirm that older persons benefit from therapeutic lowering of LDL-C. The major recommendations for modifications to footnote the ATP III treatment algorithm are the following. In high-risk persons, the recommended LDL-C goal is less than 100 mg/dL, but when risk is very high, an LDL-C goal of less than 70 mg/dL is a therapeutic option, ie, a reasonable clinical strategy, on the basis of available clinical trial evidence. This therapeutic option extends also to patients at very high risk who have a baseline LDL-C less than 100 mg/dL. Moreover, when a high-risk patient has high triglycerides or low high-density lipoprotein cholesterol (HDL-C), consideration can be given to combining a fibrate or nicotinic acid with an LDL-lowering drug. For moderately high-risk persons (2+ risk factors and 10-year risk 10% to 20%), the recommended LDL-C goal is less than 130 mg/dL, but an LDL-C goal less than 100 mg/dL is a therapeutic option on the basis of recent trial evidence. The latter option extends also to moderately high-risk persons with a baseline LDL-C of 100 to 129 mg/dL. When LDL-lowering drug therapy is employed in high-risk or moderately high-risk persons, it is advised that intensity of therapy be sufficient to achieve at least a 30% to 40% reduction in LDL-C levels. Moreover, any person at high risk or moderately high risk who has lifestyle-related risk factors (eg, obesity, physical inactivity, elevated triglycerides, low HDL-C, or metabolic syndrome) is a candidate for TLC to modify these risk factors regardless of LDL-C level. Finally, for people in lower-risk categories, recent clinical trials do not modify the goals and cutpoints of therapy

Implications of recent clinical trials for the National Cholesterol Education Program Adult Treatment Panel III Guidelines.

"The Adult Treatment Panel III (ATP III) of the National Cholesterol Education Program issued an evidence-based set of guidelines on cholesterol management in 2001. Since the publication of ATP III, 5 major clinical trials of statin therapy with clinical end points have been published. These trials addressed issues that were not examined in previous clinical trials of cholesterol-lowering therapy. The present document reviews the results of these recent trials and assesses their implications for cholesterol management. Therapeutic lifestyle changes (TLC) remain an essential modality in clinical management. The trials confirm the benefit of cholesterol-lowering therapy in high-risk patients and support the ATP III treatment goal of low-density lipoprotein cholesterol (LDL-C) less than 100 mg/dL. They support the inclusion of patients with diabetes in the high-risk category and confirm the benefits of LDL-lowering therapy in these patients. They further confirm that older persons benefit from therapeutic lowering of LDL-C. The major recommendations for modifications to footnote the ATP III treatment algorithm are the following. In high-risk persons, the recommended LDL-C goal is less than 100 mg/dL, but when risk is very high, an LDL-C goal of less than 70 mg/dL is a therapeutic option, ie, a reasonable clinical strategy, on the basis of available clinical trial evidence. This therapeutic option extends also to patients at very high risk who have a baseline LDL-C less than 100 mg/dL. Moreover, when a high-risk patient has high triglycerides or low high-density lipoprotein cholesterol (HDL-C), consideration can be given to combining a fibrate or nicotinic acid with an LDL-lowering drug. For moderately high-risk persons (2+ risk factors and 10-year risk 10% to 20%), the recommended LDL-C goal is less than 130 mg/dL, but an LDL-C goal less than 100 mg/dL is a therapeutic option on the basis of recent trial evidence. The latter option extends also to moderately high-risk persons with a baseline LDL-C of 100 to 129 mg/dL. When LDL-lowering drug therapy is employed in high-risk or moderately high-risk persons, it is advised that intensity of therapy be sufficient to achieve at least a 30% to 40% reduction in LDL-C levels. Moreover, any person at high risk or moderately high risk who has lifestyle-related risk factors (eg, obesity, physical inactivity, elevated triglycerides, low HDL-C, or metabolic syndrome) is a candidate for TLC to modify these risk factors regardless of LDL-C level. Finally, for people in lower-risk categories, recent clinical trials do not modify the goals and cutpoints of therapy.

Diagnosis and management of the metabolic syndrome: An American Heart Association/National Heart, Lung, and Blood Institute scientific statement

"The metabolic syndrome has received increased attention in the past few years. This statement from the American Heart Association (AHA) and the National Heart, Lung, and Blood Institute (NHLBI) is intended to provide up-to-date guidance for professionals on the diagnosis and management of the metabolic syndrome in adults. The metabolic syndrome is a constellation of interrelated risk factors of metabolic origin—metabolic risk factors—that appear to directly promote the development of atherosclerotic cardiovascular disease (ASCVD).1 Patients with the metabolic syndrome also are at increased risk for developing type 2 diabetes mellitus. Another set of conditions, the underlying risk factors, give rise to the metabolic risk factors. In the past few years, several expert groups have attempted to set forth simple diagnostic criteria to be used in clinical practice to identify patients who manifest the multiple components of the metabolic syndrome. These criteria have varied somewhat in specific elements, but in general they include a combination of both underlying and metabolic risk factors. The most widely recognized of the metabolic risk factors are atherogenic dyslipidemia, elevated blood pressure, and elevated plasma glucose. Individuals with these characteristics commonly manifest a prothrombotic state and a pro-inflammatory state as well. Atherogenic dyslipidemia consists of an aggregation of lipoprotein abnormalities including elevated serum triglyceride and apolipoprotein B (apoB), increased small LDL particles, and a reduced level of HDL cholesterol (HDL-C). The metabolic syndrome is often referred to as if it were a discrete entity with a single cause. Available data suggest that it truly is a syndrome, ie, a grouping of ASCVD risk factors, but one that probably has more than one cause. Regardless of cause, the syndrome identifies individuals at an elevated risk for ASCVD. The magnitude of the increased risk can vary according to which components of the syndrome are present plus the other, non-metabolic syndrome risk factors in a particular person.

Diagnosis and management of the metabolic syndrome: An American Heart Association/National Heart, Lung, and Blood Institute scientific statement. Executive summary

"This Executive Summary is a synopsis of the full scientific statement from the American Heart Association (AHA) and the National Heart, Lung, and Blood Institute (NHLBI), which is intended to provide up to date guidance for professionals on the diagnosis and management of the metabolic syndrome in adults. The metabolic syndrome has received increased attention in the past few years. It consists of multiple, interrelated risk factors of metabolic origin that appear to directly promote the develop- ment of atherosclerotic cardiovascular disease (ASCVD). This constellation of metabolic risk factors is strongly associated with type 2 diabetes mellitus or the risk for this condition. The metabolic risk factors consist of atherogenic dyslipidemia (elevated triglycerides and apolipoprotein B, small LDL particles, and low HDL cholesterol [HDL-C] concentrations), elevated blood pressure, elevated plasma glucose, a prothrombotic state, and a proinflammatory state. At present, it is not clear whether the metabolic syndrome has a single cause, and it appears that it can be precipitated by multiple underlying risk factors. The most important of these underlying risk factors are abdominal obesity and insulin resis- tance. Other associated conditions include physical inactivity, aging, hormonal imbalance, and genetic or ethnic predisposition. Prospective population studies show that the metabolic syndrome confers an [almost equal to]2-fold increase in relative risk for ASCVD events, and in individuals without established type 2 diabetes mellitus, an [almost equal to]5-fold increase in risk for developing diabetes as compared with people without the syndrome. This finding implies that the meta- bolic syndrome imparts a relatively high long-term risk for both ASCVD and diabetes. In the absence of diabetes, the absolute short-term (10-year) risk for major coronary heart disease (CHD) events is not necessarily high. In the Framingham Heart Study data, the 10-year risk for CHD depends on other risk factors in addition to the metabolic syndrome components contained in Framingham scoring (ie, blood pressure, HDL-C). These other risk factors are age, sex, serum total or LDL-C, and smoking status. For individuals with the metabolic syndrome who do not have established ASCVD or type 2 diabetes mellitus, the absolute 10-year risk is best assessed by Framingham risk scoring.