Increased low-density lipoprotein S-homocysteinylation in chronic kidney disease.
BACKGROUND
Since low-density lipoprotein (LDL) S-homocysteinylation has been recently reported to enhance atherogenicity of lipoprotein, we have investigated the levels of homocysteine (Hcy) linked to LDL in chronic proteinuric patients in which lipid abnormalities highly contribute to the excess of morbidity and mortality.


METHODS
We used capillary electrophoresis to measure LDL-bound thiol Hcy, cysteine (Cys), cysteinylglycine (Cys-Gly), glutathione (GSH), and glutamylcysteine (Glu-Cys) in 30 chronic kidney disease (CKD) individuals and 60 healthy volunteers.


RESULTS
We found more elevated levels of total plasma Hcy, Cys, GSH and Glu-Cys in patients than in controls and also found that Hcy and Cys bound to LDL were significantly increased in nephropathic subjects. By multiple linear regression, we found that in healthy people, total Hcy was the most important determinant of LDL-bound Hcy and Cys-Gly was negatively associated with apoB-Hcy concentrations. In CKD the most important determinant of homocysteinylation was creatinine while total plasma Hcy is weakly associated with apoB-Hcy.


CONCLUSIONS
The increased levels in Hcy-LDL observed in CKD patients might account, at least in part, for the excess of cardiovascular risk; thus LDL S-homocysteinylation can be considered a key marker of risk for cardiovascular disease in these individuals.
Zinellu
Angelo
A
Loriga
Giacomina
G
Scanu
Bastianina
B
Pisanu
Elisabetta
E
Sanna
Manuela
M
Deiana
Luca
L
Satta
Andrea Ercole
AE
Carru
Ciriaco
C
D000368:Aged; D001055:Apolipoproteins B / Q000097:blood* / Q000737:chemistry; D050197:Atherosclerosis / Q000209:etiology; D002318:Cardiovascular Diseases / Q000209:etiology; D002908:Chronic Disease; D050171:Dyslipidemias / Q000150:complications / Q000209:etiology; D005260:Female; D006710:Homocysteine / Q000097:blood* / Q000737:chemistry; D006801:Humans; D007674:Kidney Diseases / Q000150:complications / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000097:blood* / Q000737:chemistry; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D011507:Proteinuria; D012307:Risk Factors
D001055:Apolipoproteins B; D008077:Lipoproteins, LDL; D006710:Homocysteine