Background: Paraoxonase is a high-density lipoprotein (HDL)-associated enzyme that protects lipoproteins from oxidative modifications and from becoming atherogenic in nature. Smoking is a well-known major cardiovascular risk factor that promotes lipid peroxidation (LP). The present study examined the hypothesis that smoking modulates the activity of paraoxonase and depletes antioxidants.
Aim: The present study evaluated paraoxonase activity, antioxidant status and LP in smoking and non-smoking normolipidaemic acute myocardial infarct (AMI) patients, and results were compared with controls.
Settings and design: The serum paraoxonase activities, antioxidants and LP were determined in 86 normolipidaemic patients diagnosed of AMI, and 86 age-sex-matched healthy volunteers served as control.
Material and methods: Serum paraoxonase activities were measured by enzymatic kit. The glutathione peroxidase, superoxide dismutase and catalase activity was determined by standard methods. Malondialdehyde was measured by the thiobarbituric acid reaction, and conjugated diene levels by the Recknagel and Glende method. Serum uric acid, total bilirubin, serum albumin and lipid profiles were analysed by standard methods.
Statistics: The values were expressed as mean±SD, and data from the patients and control were compared using the Student t test.
Results and conclusion: The total cholesterol/HDL cholesterol ratio, triglycerides, low-density lipoprotein cholesterol, low-density lipoprotein/HDL cholesterol ratio and triglyceride/HDL cholesterol ratio were significantly higher, and HDL cholesterol significantly lower in smokers compared with non-smoking AMI patients. Superoxide dismutase, glutathione peroxidase and catalase were significantly higher in non-smokers compared with smokers. Serum albumin, uric acid and bilirubin were higher in the control compared with smoking AMI patients. The malondialdehyde and conjugated dienes were significantly higher, and paraoxonase activities were significantly lower in smokers compared with non-smokers.
Keywords: Smoker; acute myocardial infarction; antioxidants; cardiac function; lipid trials; lipids; normolipidaemia; oxidative stress; paraoxonase.