Elsevier

Maturitas

Volume 65, Issue 2, February 2010, Pages 117-121
Maturitas

Review
The metabolic syndrome: Validity and utility of clinical definitions for cardiovascular disease and diabetes risk prediction

https://doi.org/10.1016/j.maturitas.2009.11.026Get rights and content

Abstract

The purpose of clinical definitions of the metabolic syndrome is frequently misunderstood. While the metabolic syndrome as a physiological process describes a clustering of numerous age-related metabolic abnormalities that together increase the risk for cardiovascular disease and type 2 diabetes, clinical definitions include obesity which is thought to be a cause rather than a consequence of metabolic disturbance, and several elements that are routinely measured in clinical practice, including high blood pressure, high blood glucose and dyslipidaemia. Obesity is frequently a central player in the development of the metabolic syndrome and should be considered a key component of clinical definitions. Previous clinical definitions have differed in the priority given to obesity. Perhaps more importantly than its role in a clinical definition, however, is obesity in isolation before the hallmarks of metabolic dysfunction that typify the syndrome have developed. This should be treated seriously as an opportunity to prevent the consequences of the global diabetes epidemic now apparent. Clinical definitions were designed to identify a population at high lifetime CVD and type 2 diabetes risk, but in the absence of several major risk factors for each condition, are not optimal risk prediction devices for either. Despite this, the metabolic syndrome has several properties that make it a useful construct, in conjunction with short-term risk prediction algorithms and sound clinical judgement, for the identification of those at high lifetime risk of CVD and diabetes. A recently published consensus definition provides some much needed clarity about what a clinical definition entails. Even this, however, remains a work in progress until more evidence becomes available, particularly in the area of ethnicity-specific waist cut-points.

Introduction

The term “metabolic syndrome” has developed to describe those individuals at increased risk of type 2 diabetes and cardiovascular diseases (CVD) due to the metabolic dysfunction commonly seen in individuals with insulin resistance. Clinical definitions of the metabolic syndrome have been developed in the last two decades, with a primary purpose being to assist in the identification of those at increased diabetes and CVD risk in order to put in place preventive measures that can reduce this risk [1], [2], [3], [4], [5]. As clinical constructs, these do not need to include all of the abnormalities associated with the metabolic dysfunction characteristic of the syndrome, and even include central obesity which is more often thought to be a cause rather than a consequence of metabolic dysfunction. Despite evidence supporting their ability to independently predict both type 2 diabetes and CVD, the various clinical definitions of the metabolic syndrome have been the subject of considerable controversy [6], [7], [8], [9], [10], [11], [12], [13]. Commentators have questioned their validity and utility for use in clinical practice and as a public health tool because of the existence of multiple competing definitions and because other tools appear to be more useful for the prediction of CVD and type 2 diabetes. With the recent publication of a consensus definition of the metabolic syndrome [5], it is timely to review the evidence for its use in the prediction of CVD and diabetes risk.

Section snippets

Issues relating to clinical definitions for the metabolic syndrome

The recent publication of a consensus statement on the definition of the metabolic syndrome, representing the views of six major organisations and societies, will hopefully prove to be a pivotal point in the development of the metabolic syndrome as a tool for clinical and public health use [5]. A major criticism levelled at the metabolic syndrome has been that multiple competing definitions are at best confusing, and at worst represent a syndrome which nobody knows how to define. The consensus

The role of obesity in clinical definitions of the metabolic syndrome

Obesity is frequently cited as being a leading cause of the metabolic syndrome. In a review of the metabolic syndrome after menopause, Lobo commented that the increased prevalence of the metabolic syndrome among women post-menopause is a result chiefly of weight gain and obesity in this group [18]. The major difference between the IDF and AHA/NHLBI metabolic syndrome definitions is the priority given to obesity. In the IDF definition, one cannot be diagnosed without being obese. Critics of this

The metabolic syndrome as a tool for prediction of incident type 2 diabetes and CVD

Numerous studies have quantified the risk for type 2 diabetes and CVD associated with clinical definitions of the metabolic syndrome. A recent meta-analysis of the studies examining risk for incident diabetes showed that for those definitions published prior to the recent consensus statement, the metabolic syndrome conferred a relative risk of between 3.1 and 5.1 [28]. A similar meta-analysis focused on CVD showed that the metabolic syndrome is a comparatively poor predictor of CVD (estimated

Conclusions

The increase in the prevalence of obesity and the metabolic syndrome since the middle of the twentieth century is threatening to prevent achievement of the millennium development goals, with the increasing global burden of non-communicable diseases being described as the new agenda for global public health [37]. Clinical definitions of the metabolic syndrome, while therefore obviously important, have frequently been criticized for being sub-optimal in their ability to predict the development of

Conflict of interest

None declared.

Provenance

Commissioned and externally peer reviewed.

References (37)

  • Executive Summary of The Third Report of The National Cholesterol Education Program (NCEP) Expert Panel on Detection,...
  • S.M. Grundy et al.

    Diagnosis and management of the metabolic syndrome: an American Heart Association/National Heart Lung, and Blood Institute Scientific Statement

    Circulation

    (2005)
  • B. Balkau et al.

    Comment on the provisional report from the WHO consultation European Group for the Study of Insulin Resistance (EGIR)

    Diabet Med

    (1999)
  • K.G. Alberti et al.

    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

    Circulation

    (2009)
  • R. Kahn

    The metabolic syndrome (Emperor) wears no clothes

    Diabetes Care

    (2006)
  • R. Kahn et al.

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

    Diabetes Care

    (2005)
  • N. Sattar

    Why metabolic syndrome criteria have not made prime time: a view from the clinic

    Int J Obes (Lond)

    (2008)
  • P. Greenland

    Critical questions about the metabolic syndrome

    Circulation

    (2005)
  • Cited by (46)

    • Multitarget PPARγ agonists as innovative modulators of the metabolic syndrome

      2019, European Journal of Medicinal Chemistry
      Citation Excerpt :

      Metabolic syndrome (MS) is a clinical multifactorial disorder, commonly found in obesity, characterized by interrelated abnormalities, such as hyperglycemia, hypertension, and dyslipidemia [1]. It represents an important risk factor for the development of type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD) [2]. The MS is often associated with incorrect lifestyle, poor physical exercise, inappropriate diet, stress, and excessive alcohol consumption.

    • Effectiveness of physical activity intervention among government employees with metabolic syndrome

      2017, Journal of Exercise Science and Fitness
      Citation Excerpt :

      Individuals with metabolic syndrome could be an essential group to target for the primary prevention of type 2 diabetes mellitus and cardiovascular disease.1,2 In addition, metabolic syndrome could be a useful screening tool for healthcare professionals to focus on when dealing with the health risks associated with abdominal obesity.3 Hence, a pragmatic early management that can be easily implemented for a large number of people is warranted.

    • Increased Framingham 10-year CVD risk in Chinese patients with schizophrenia

      2013, Schizophrenia Research
      Citation Excerpt :

      MetS has been criticized for its dichotomized variables that do not reflect the continuous spectrum of their contribution towards CVD risk (Aguilar-Salinas et al., 2005). Important cardiovascular risk factors such as age, gender and smoking status have also been omitted from the MetS criteria, further limiting its utility for CVD risk prediction (Cameron, 2010). While it attempts to capture the effect of clustering of metabolic abnormalities, these risk factors have been shown to have a multiplicative rather than a simple additive effect on CVD (Stamler et al., 1993).

    View all citing articles on Scopus
    View full text