Leptin, obesity and cardiovascular disease.
OBJECTIVE
Obesity is a risk factor for cardiovascular diseases. Leptin levels are increased in obesity and leptin exhibits cardiovascular actions that may contribute to increased cardiovascular risk. We review the sympathetic, renal and vascular actions of leptin and their relevance to cardiovascular disease.


RESULTS
Leptin possesses cardio-renal actions potentially contributing to obesity-related hypertension including generalized sympathoactivation. However, given that leptin resistance occurs in obesity, it has been difficult to link hyperleptinemia with hypertension. One possibility is that leptin resistance is confined to the metabolic effects of leptin, with preservation of its sympathoexcitatory actions. Other mechanisms may contribute to the pressor effects of leptin. For instance, angiotensin II induces leptin generation. Leptin also potentiates the pressor effect of insulin. Therefore, interactions between angiotensin II and insulin with leptin could have deleterious cardiovascular effects in obesity. Additionally, leptin appears to stimulate vascular inflammation, oxidative stress and hypertophy. These actions may contribute to the pathogenesis of hypertension, atherosclerosis, and left ventricular hypertrophy.


CONCLUSIONS
The potential actions of leptin in the pathophysiology of cardiovascular complications of obesity are diverse, despite evidence of leptin resistance to its metabolic actions. However, most information about cardiovascular actions of leptin derives from in-vitro and animal studies. Future research in humans is widely awaited.
Correia
Marcelo Lima de Gusmao
ML
General Clinical Research Center and Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA.
Haynes
William Geoffrey
WG
D001342:Autonomic Nervous System Diseases / Q000150:complications / Q000503:physiopathology; D002318:Cardiovascular Diseases / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D007674:Kidney Diseases / Q000150:complications / Q000503:physiopathology; D020738:Leptin / Q000502:physiology*; D009765:Obesity / Q000150:complications / Q000503:physiopathology*
D020738:Leptin