Assessment of serum cotinine and oxidative stress markers in tobacco users

Abstract

Augmented production of free radicals associated with smoking with decrease in antioxidant levels and increase in peroxidation of biomolecules have been shown in various studies. The studies with smokeless tobacco use having depictive data were lacking. To estimate serum cotinine (CTN) levels and oxidative stress markers in tobacco smokers and smokeless tobacco users and to compare them with tobacco nonusers. This cross sectional study was performed in 180 study subjects divided into 6 groups - tobacco smokers, tobacco chewers, tobacco mishri users, dual tobacco chewers and mishri users, dual smokers and smokeless tobacco users and tobacco nonusers. Serum CTN levels were estimated. Oxidative stress was estimated by Malondialdehyde (MDA) and enzymatic antioxidant Superoxide Dismutase (SOD). Serum MDA levels were significantly high and erythrocytic SOD levels were significantly low in tobacco users than tobacco nonusers (P<0.001). There was a significant negative relationship between cotinine and SOD, a significant positive relation between cotinine and MDA in tobacco users. There was a significant negative relationship between duration of tobacco use and SOD, a significant positive relation between duration of tobacco use and MDA. There was a significant negative relationship between amount of tobacco use and SOD. Tobacco users with longer duration of tobacco use with increased levels of serum cotinine have increased oxidative stress which can be a risk factor for many diseases. Tobacco chewing equally increases oxidative stress as that of smoking.