Leptin and vascular function: friend or foe?

Abstract

Leptin is the protein product of the adipocyte ob gene. Leptin levels are related to the amount of body fat, and leptin was viewed primarily as a modulator of appetite control and energy homeostasis. However, leptin receptors have been also identified in various peripheral tissues, including in the cardiovascular system and in human coronary arteries. Although the exact role of leptin in cardiac and vascular homeostasis is still not fully understood, most clinical studies consistently support the notion of leptin as a cardiovascular risk factor, with higher leptin levels associated with worse cardiovascular prognosis. For example, two nested case-referent studies reported that leptin might be a risk factor for myocardial infarction and stroke.1,2 Although no association between leptin levels and coronary events was found in the Quebec Cardiovascular Study population,3 leptin was reported to be an independent predictor of coronary events (myocardial infarction or coronary revascularization) over a 5-year follow-up in the larger WOSCOPS population.4 This prospective study examined leptin's interaction with cardiovascular outcomes in moderately hypercholesterolaemic men, without a history of myocardial infarction or any other major manifestations of CAD. In addition to being predictive of outcome in the relatively low-risk WOSCOPS population, leptin was also found to have prognostic implications in higher risk patients with established and angiographically confirmed coronary atherosclerosis. Wolk et al .5 studied 382 subjects undergoing clinically indicated coronary angiography and followed up for a median of 4 years. Leptin (both unadjusted and adjusted for body mass) had a significant association with … *Corresponding author. Tel: +1 507 255 1144; fax: +1 507 255 7070. E-mail address : somers.virend{at}mayo.edu