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ORIGINAL CONTRIBUTIONS
Year : 2001  |  Volume : 55  |  Issue : 6  |  Page : 309--312

Plasma lipid peroxidation and vitamin E levels in smokers

S Kharb, V Singh, PS Ghalaut, A Sharma, GP Singh 
 Department of Medicine and Biochemistry, Pt. B. D. Sharma PGIMS, Rohtak,

Correspondence Address:
S Kharb
Department of Medicine and Biochemistry, Pt. B. D. Sharma PGIMS, Rohtak




How to cite this article:
Kharb S, Singh V, Ghalaut P S, Sharma A, Singh G P. Plasma lipid peroxidation and vitamin E levels in smokers.Indian J Med Sci 2001;55:309-312


How to cite this URL:
Kharb S, Singh V, Ghalaut P S, Sharma A, Singh G P. Plasma lipid peroxidation and vitamin E levels in smokers. Indian J Med Sci [serial online] 2001 [cited 2013 May 21 ];55:309-312
Available from: http://www.indianjmedsci.org/text.asp?2001/55/6/309/12059


Full Text

Chronic cigarette smoking represents a major risk factor for the development of atheroscle­rosis associated with coronary and peripheral vascular disease[1]. Cigarette smoking increases the concentration of triglycerides and lowers the concentration of high density lipoprotein cholesterol (HDL-C)[1]. Cigarette smoke contains abundant amount of oxidants which may promote oxidative modification of low density lipoprotein (LDL) and contribute to the pathogenesis of atherosclerosis. There is strong evidence that lipid peroxidation - and further oxidative modifica­tion of LDL increases its atherogenecity[2]. Alpha tocopherol is lipid soluble antioxidant carried in LDL. It inhibits lipid peroxidation and may play an important role in preventing atherogenic modifi­cation of LDL[3]. The present study is aimed at evaluating lipid peroxidation, vitamin E status and lipid profile in healthy smokers.

We studied thirty healthy smokers and 25 non smoking healthy adults in the age group 30 - 50 years ( employees and medical students of Pt. B. D. Sharma PGIMS, Rohtak ). Subjects were excluded from the screening if they had known endocrinologic disorders, diabetes mellitus, renal insufficiency, hepatic disease, illnesses characterized by an acute phase response or history of taking lipid owering drugs or vitamin E supplements. Entrance criteria for smoker group included subjects who smoked atleast 8 cigarettes per day for 8-15 years. After overnight fasting peripheral venous blood was drawn. Serum was seperated by centrifugation and biochemical studies were performed. The lipid profile was estimated enzy­matically and serum malonaldehyde ( MDA ) was estimated by thiobarbituric reac­tion[4]. Serum vitamin E was assayed spectrofluorometricaily[5].

 RESULTS



Smokers had higher values of MDA as compared to non­smokers (p -2) anion from cigarette smoke may reach the vascular endothelium and can then react with nitric oxide (NO -) to form peroxynitnte anion, a highly reactive intermediate with strong cytotoxic potency[6]. Thus, the damaging free radicals in cigarette smoke may cause ei­ther direct arterial wall injury or may initiate and/or accelerate secondary processes including depletion of antioxidants ( such as vitamin E), protein peroxidation and activation of phagocyte - platelet-endothelial cell interac­tion[7],[8]. In the present study, low levels of vitamin E were observed amongst the smokers as compared to non-smokers. Also, an inverse relationship between MDA and vitamin E was observed. An imbalance between proxidant and antioxidants within the vasculature may also be operative in smokers since plasma levels of vitamin E are in general lower in smokers as compared to non smoker control subjects, a phenomenon that appears to reflect increased metabolism as the result of oxidant load rather than decreased intake. Frei[9] reported that invitro exposure of blood plasma to gas phase of cigarette smoke did not influence lipid peroxidation until the endogenous ascorbic acid had been completely oxidized, in contrast, alpha - tocopherol was not consumed at a significant rate in those studies. This suggests that cigarette smoking might deplete hydro­philic antioxidants much earlier than lipophilic ones. Demonstr­ation of low level of antioxidant vitamin E in chronic smokers suggests that antioxidant therapy with vitamin E may limit the cardiovascular consequences of chronic smokers.

References

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