Evaluating CMR

WHO definition and criteria

In 1998, the World Health Organization (WHO) was the first major organization to propose a definition of the metabolic syndrome (Table) (1). In accordance with the syndrome X concept introduced by Reaven (2) (a combination of elevated fasting triglyceride and insulin concentrations, reduced HDL cholesterol levels, and raised blood pressure, with insulin resistance as a common denominator), the WHO definition also identified insulin resistance as the most common etiological factor behind the clustering abnormalities of the metabolic syndrome (2). An index of glucose intolerance, impaired glucose tolerance, or diabetes and/or insulin resistance (insulin sensitivity measured under euglycemic-hyperinsulinemic conditions) was therefore a necessary WHO criterion for clinical diagnosis of the metabolic syndrome. Insulin resistance also had to be accompanied by at least two other criteria from among the following: raised blood pressure (≥140/90 mmHg), increased plasma triglyceride (≥1.7 mmol/l (150 mg/dl) and/or reduced HDL cholesterol levels (<0.9 mmol/l (35 mg/dl) for men and < 1.0 mmol/l (39 mg/dl) for women), obesity as estimated by waist-to-hip ratio (>0.90 for men and >0.85 for women) and/or body mass index (BMI) >30 kg/m² for both genders, and microalbuminuria (urinary excretion rate ≥ 20 μg/min or albumin-creatinine ratio ≥30 mg/g).