¹Department of Therapeutics and Pharmacology, Queen's University Belfast, Belfast, UK

Correspondence: Dr CE Quinn, Department of Therapeutics and Pharmacology, Queen's University Belfast, Whitla Medical Building, 97, Lisburn Road, Belfast BT9 7BL, UK. E-mail: cathyquinn25@hotmail.com

Received 24 April 2007; Revised 10 August 2007; Accepted 13 August 2007; Published online 1 October 2007.

Abstract

Thiazolidinediones (TZDs) have been used for the treatment of hyperglycaemia in type 2 diabetes for the past 10 years. They may delay the development of type 2 diabetes in individuals at high risk of developing the condition, and have been shown to have potentially beneficial effects on cardiovascular risk factors. TZDs act as agonists of peroxisome proliferator-activated receptor- (PPAR-) primarily in adipose tissue. PPAR- receptor activation by TZDs improves insulin sensitivity by promoting fatty acid uptake into adipose tissue, increasing production of adiponectin and reducing levels of inflammatory mediators such as tumour necrosis factor-alpha (TNF-), plasminogen activator inhibitor-1(PAI-1) and interleukin-6 (IL-6). Clinically, TZDs have been shown to reduce measures of atherosclerosis such as carotid intima-media thickness (CIMT). However, in spite of beneficial effects on markers of cardiovascular risk, TZDs have not been definitively shown to reduce cardiovascular events in patients, and the safety of rosiglitazone in this respect has recently been called into question. Dual PPAR-/ agonists may offer superior treatment of insulin resistance and cardioprotection, but their safety has not yet been assured.