Article

Plasma homocysteine levels in obese and non-obese subjects with or without hypertension; its relationship with oxidative stress and copper.

Istanbul University, Biochemistry Department of Cerrahpasa Medical Faculty, Istanbul, Turkey.
Clinical Biochemistry (impact factor: 2.08). 08/2003; 36(5):405-8. DOI:10.1016/S0009-9120(03)00059-6 pp.405-8
Source: PubMed

ABSTRACT 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.
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.
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).
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.

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Keywords

atomic absorption spectrophotometer
 
coefficient +/- SE
 
endothelium damage
 
enzyme immunoassay method
 
free radical
 
modest elevation
 
multivariate regression analysis
 
nonobese hypertensives
 
nonobese normotensives
 
obese normotensives
 
obese subjects tHcy
 
permissive role
 
Plasma lipid peroxidation levels
 
Plasma TBARS levels
 
Plasma tHcy
 
Plasma tHcy levels
 
plasma total Homocysteine
 
significant positive correlation
 
thiobarbituric acid reactive substances
 
traditional risk factors
 

Dildar Konukoğlu