Plasma leptin and its relationship with lipid peroxidation and nitric oxide in obese female patients with or without hypertension.
BACKGROUND
Recent evidence suggested that leptin-induced oxidative stress in human endothelial cells in vivo and increased oxidative stress in human essential hypertension may further contribute to both the development of atherosclerosis and other cardiovascular diseases. We investigated the association of plasma leptin levels with plasma lipid peroxidation and nitric oxide metabolites (NOx) in obese hypertensive atherosclerosis model.


METHODS
Plasma leptin, lipid peroxidation and NOx levels were determined in age-matched non-obese normotensive female subjects (n = 30), obese normotensive female subjects (n = 45), and obese hypertensive female subjects (n = 50). Plasma leptin levels were determined by immunoradiometric method. Lipid peroxidation was determined as thiobarbituric acid reactive substances (TBARS) using spectrophotometric method. NOx levels were determined using enzymatic method.


RESULTS
We found that plasma leptin and TBARS levels were increased in obesity, and obese hypertensives have significantly higher plasma leptin and TBARS levels than obese normotensives (p <0.001 and p <0.001). Obese hypertensives have significantly lower plasma NOx levels than obese normotensives (p <0.001). In univariate and multivariate regression analysis, plasma leptin levels were significantly correlated with TBARS (p <0.01 and p <0.01) in obese subjects. Plasma TBARS were also inversely correlated with NOx in hypertensive obese subjects (r = -0.412, p <0.01).


CONCLUSIONS
Our results have shown that elevated leptin levels may be associated with increased oxidative stress and free-radical-induced decreased NOx levels. Therefore, hyperleptinemia may be an important contributor to the generation of hypertension in obesity.
Konukoglu
Dildar
D
Department of Biochemistry, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey. dkonuk@istanbul.edu.tr
Serin
Ozden
O
Turhan
Mehtap Sultan
MS
D050197:Atherosclerosis / Q000097:blood / Q000209:etiology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000150:complications; D020738:Leptin / Q000097:blood*; D015227:Lipid Peroxidation; D008875:Middle Aged; D009569:Nitric Oxide / Q000097:blood*; D009765:Obesity / Q000097:blood* / Q000150:complications; D018384:Oxidative Stress
D020738:Leptin; D009569:Nitric Oxide