Rury Holman
Diabetes Trials Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism
United-Kingdom

The Metabolic Syndrome has become a popular term for describing an increasingly prevalent clinical entity in which several major cardiovascular risk factors co-exist in the same individual. Although not a disease in its own right, the Metabolic Syndrome is thought to arise primarily as a consequence of insulin resistance. The characteristic features of abdominal obesity, atherogenic dyslipidaemia, elevated blood pressure, and insulin resistance, with or without glucose intolerance, put people with the Metabolic Syndrome at greatly increased risk of macrovascular complications. The increased insulin demand, secondary to insulin resistance, means also that people with the Metabolic Syndrome who have limitations in b cell function are more likely to become glucose intolerant, to develop type 2 diabetes and to progress to microvascular, in addition to macrovascular, complications.

The publication of standardised criteria by the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) and the WHO defining the clinical features of the Metabolic Syndrome, has simplified the process of identifying individuals who are likely to be at increased risk of cardiovascular disease and/or type 2 diabetes. Finding the very substantial numbers of people who have the features of the Metabolic Syndrome will provide unrivalled potential opportunities to intervene at an earlier stage than usual with therapies which may delay or prevent the development of cardiovascular disease and/or type 2 diabetes. Labelling, largely asymptomatic, people as having the Metabolic Syndrome inevitably will have a downside in increasing anxiety and raising uncertainty about their future wellbeing. These concerns, however, can be offset to a considerable extent by providing those identified as having the Metabolic Syndrome with comprehensive information about the condition and highlighting the possibilities to minimise the consequences.

Since most of the features used to characterise the Metabolic Syndrome are assessed regularly in clinical practice, many individuals who have the syndrome can be identified from clinical records with minimal effort. In addition, those thought to be more likely to have the Metabolic Syndrome because of family or prior medical history can be targeted to ensure that the relevant measurements are made if not already available. It is incumbent on health care systems to utilise routinely this relatively straightforward approach to identifying people at increased risk of cardiovascular disease and/or type 2 diabetes. The management of those found to have the Metabolic Syndrome, however, is likely to depend more specifically on their perceived degree of risk, their particular constellation of risk factors and the health care resources available. More precise cardiovascular disease risk estimates for individuals can be obtained using the Framingham equations in those without diabetes and the UKPDS Risk Engine? in those with diabetes. Appropriate lifestyle advice should be given to everyone found to have the Metabolic Syndrome, as this alone will improve many of their risk factor levels and has been shown to delay the onset of type 2 diabetes in several studies of people with impaired glucose tolerance. The degree to which pharmacological intervention is beneficial in people with the Metabolic Syndrome has yet to be determined. Meanwhile, therapies should be focused on achieving published risk factor guideline targets, particularly in those thought to be at highest overall risk.