Association of nitrotyrosine levels with cardiovascular disease and modulation by statin therapy.
BACKGROUND
Formation of nitric oxide-derived oxidants may serve as a mechanism linking inflammation to development of atherosclerosis. Nitrotyrosine, a specific marker for protein modification by nitric oxide-derived oxidants, is enriched in human atherosclerotic lesions and low-density lipoprotein (LDL) recovered from human atheroma.


OBJECTIVE
To determine whether systemic levels of nitrotyrosine are associated with the prevalence of coronary artery disease (CAD) and are modulated by hydroxymethylglutaryl coenzyme-A reductase inhibitor (statin) therapy.


METHODS
A case-control and interventional study at 2 urban tertiary-care referral centers; recruitment for each was from June 1, 2001, until January 1, 2002. For the case-control study, 100 case-patients with established CAD and 108 patients with no clinically evident CAD were recruited consecutively. In the interventional study, participants aged 21 years or older with hypercholesterolemia (LDL cholesterol > or =130 mg/dL [> or =3.5 mmol/L]) underwent nutrition and exercise counseling. Those whose levels did not decrease with 6 to 8 weeks were enrolled in the study (n = 35). For 12 weeks, they received 10 mg/d of oral atorvastatin therapy.


METHODS
In the case-control study, the association between systemic levels of protein-bound nitrotyrosine, CAD risk, and presence of CAD. In the interventional study, the change in nitrotyrosine, lipoprotein, and C-reactive protein (CRP) levels.


RESULTS
Nitrotyrosine levels were significantly higher among patients with CAD (median 9.1 micromol/mol [interquartile range, 4.8-13.8 micromol/mol] tyrosine vs 5.2 micromol/mol [interquartile range, 2.2-8.4 micromol/mol]; P<.001). Patients in the upper quartile of nitrotyrosine (29%; P<.001) had a higher odds of CAD compared with those in the lowest quartile (unadjusted odds ratio, 6.1; 95% confidence interval, 2.6-14.0; P<.001). In multivariate models adjusting for Framingham Global Risk Score and CRP, upper quartiles of nitrotyrosine remained associated with CAD (odds ratio, 4.4; 95% confidence interval, 1.8-10.6; P<.001). Statin therapy reduced nitrotyrosine levels significantly (25%; P<.02) with a magnitude similar to reductions in total cholesterol levels (25%; P<.001) and LDL particle number (29%; P<.001) yet were independent of alterations in lipoproteins and inflammatory markers like CRP.


CONCLUSIONS
The findings from this preliminary study indicate that nitrotyrosine levels are associated with the presence of CAD and appear to be modulated by statin therapy. These results suggest a potential role for nitric oxide-derived oxidants as inflammatory mediators in CAD and may have implications for atherosclerosis risk assessment and monitoring of anti-inflammatory actions of statins.
Shishehbor
Mehdi H
MH
Department of Cell Biology, and the Center for Cardiovascular Diagnostics and Prevention, the Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
Aviles
Ronnier J
RJ
Brennan
Marie-Luise
ML
Fu
Xiaoming
X
Goormastic
Marlene
M
Pearce
Gregory L
GL
Gokce
Noyan
N
Keaney
John F
JF
Penn
Marc S
MS
Sprecher
Dennis L
DL
Vita
Joseph A
JA
Hazen
Stanley L
SL
D000328:Adult; D000368:Aged; D000924:Anticholesteremic Agents / Q000627:therapeutic use*; D000069059:Atorvastatin; D002097:C-Reactive Protein / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000097:blood / Q000188:drug therapy; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000097:blood* / Q000517:prevention & control*; D005260:Female; D006538:Heptanoic Acids / Q000627:therapeutic use; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D006937:Hypercholesterolemia / Q000097:blood / Q000188:drug therapy; D008074:Lipoproteins / Q000097:blood; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011758:Pyrroles / Q000627:therapeutic use; D012307:Risk Factors; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000097:blood*
D000924:Anticholesteremic Agents; D006538:Heptanoic Acids; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D008074:Lipoproteins; D011758:Pyrroles; C002744:3-nitrotyrosine; D014443:Tyrosine; D002097:C-Reactive Protein; D000069059:Atorvastatin