Insulin resistance and cardiovascular disease

Insulin resistance is characterised by a decreased rate of insulin-mediated glucose uptake and is associated with adverse changes in cardiovascular risk factors, such as high triglyceride levels, low levels of high-density lipoprotein cholesterol, raised blood pressure, obesity and increased levels of plasminogen activator inhibitor 1. The term `insulin resistance syndrome' (IRS) is used to describe the complex of factors associated with insulin resistance that is found in patients both with and without type 2 diabetes. Although the presence of insulin resistance syndrome is generally considered to be a risk factor for cardiovascular disease, there is a lack of definitive evidence for a causal link. Recently, however, a statistical method known as factor analysis has been applied to the cluster of cardiovascular risk factors associated with IRS. This has been able to show that the `insulin resistance factor' (high plasma insulin and glucose levels, body mass index, waist-to-hip ratio and triglyceride levels) predicted coronary heart disease events in elderly non-diabetic men as well as in patients with type 2 diabetes. Therefore, treatment of insulin resistance whether by pharmacological (eg. thiazolidinediones) or nonpharmacological means has the potential to offer both improvements in glycaemic control and in cardiovascular events.