Plasma homocysteine levels in obese and non-obese subjects with or without hypertension; its relationship with oxidative stress and copper.
OBJECTIVE
The relationship between plasma total Homocysteine (tHcy) and oxidative stress and plasma levels of lipids, insulin and copper levels were investigated in obese and nonobese hypertensives.


METHODS
Plasma tHcy levels were determined by an enzyme immunoassay method. Plasma lipid peroxidation levels were measured as thiobarbituric acid reactive substances (TBARS) by spectrophotometric methods. Plasma levels of copper and insulin were measured by atomic absorption spectrophotometer and electrochemiluminescence method, respectively.


RESULTS
Plasma tHcy, copper and insulin levels did not differ in nonobese hypertensives compared to nonobese normotensives. Plasma TBARS levels were significantly increased in nonobese hypertensives when compared to nonobese normotensives (p < 0.001). Plasma tHcy, TBARS, copper and fasting insulin levels were significantly higher in obese normotensives and hypertensives than in nonobese normotensives and hypertensives, respectively (for each comparison; p < 0.001). There was a significant difference in plasma tHcy, TBARS and copper levels between obese subjects with or without hypertension (for each comparison p < 0.01). The univariate analyses demonstrated a significant positive correlation between tHcy and TBARS (coefficient +/- SE, 0.411 +/- 0.115, p < 0.01) and copper (coefficient +/- SE, 0.425 +/- 0.135, p < 0.01) in obese subjects. In a multivariate regression analysis in obese subjects tHcy was positively correlated with TBARS (coefficient +/- SE, 0.480 +/- 0.155, p < 0.01) and copper (coefficient +/- SE, 0.486 +/- 0.140, p < 0.01).


CONCLUSIONS
We hypothesize that in the presence of other traditional risk factors, Hcy may have a permissive role in the endothelium damage even within the normal range and this role may be related to free radical generating systems. Therefore, modest elevation of plasma Hcy may causally be involved in the pathogenesis of atherosclerosis and/or cardiovascular disease.
Konukoğlu
Dildar
D
Istanbul University, Biochemistry Department of Cerrahpasa Medical Faculty, Istanbul, Turkey. dkonuk@yahoo.com
Serin
Ozden
O
Ercan
Meltem
M
Turhan
Mehtap Sultan
MS
D003300:Copper / Q000097:blood*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000209:etiology; D007328:Insulin / Q000097:blood; D008055:Lipids / Q000097:blood; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000150:complications; D018384:Oxidative Stress; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis
D007328:Insulin; D008055:Lipids; D017392:Thiobarbituric Acid Reactive Substances; D006710:Homocysteine; D003300:Copper