Abdominal obesity, insulin resistance, and cardiovascular risk in pre-diabetes and type 2 diabetes

Cardiovascular (CV) disease remains the leading source of premature mortality in western populations. There is an increasing prevalence of obesity, particularly abdominal obesity. Nine states in the USA now report a prevalence of obesity [body mass index (BMI) > 30 kg/m(2)] of 25% or more, and the prevalence of abdominal obesity (waist circumference > 102 cm for men and 88 cm for women) has increased by 20% in men and 14% in women in a single decade. The intra-abdominal adiposity associated with abdominal obesity increases cardiometabolic risk directly, via altered secretion of adipokines, and indirectly, via promotion insulin resistance, diabetes and the cluster of cardiometabolic risk factors associated with the metabolic syndrome. Patients with type 2 diabetes, or subjects with pre-diabetic dysglycaemia are at greater risk of CV events, compared with normoglycaemic subjects. A large and growing body of evidence indicates that abdominal obesity is a more powerful predictor of adverse CV outcomes than BMI. Measurement of waist circumference as an index of intra-abdominal adiposity should be included in routine evaluations of overall cardiometabolic risk.