Effect of smoke and non-smoke tobacco on nitric oxide levels in diabetic patients

Objective: Diabetes mellitus confers an increased cardiometabolic risk in affected individuals. Several mechanisms underlie this equation, but endothelial dysfunction has been implicated as the final common pathway by several studies. Endogenous nitric oxide (NO) is one of the principal molecules mediating normal endothelial vasodilation. This study was aimed at ascertaining the effects of smoke and non-smoke tobacco, both of which are commonly used by Indians, on the serum NO levels. Materials and Methods: A total of 208 type 2 diabetic patients attending the diabetes clinic were enrolled in this study. Data on age, gender, smoking, and tobacco chewing were collected, and the serum levels of NO determined using nitrate reductase and Griess Reagent which converts nitrite to a deep purple azo compound. The amount of the azochromophore accurately reflected the amount of NO in the samples. Results: The mean value of serum NO in smokers was 54.92 μmol/L, as compared to 60.60 μmol/L in non-smokers. The mean value of serum NO in tobacco chewers was 57.32 μmol/L and in tobacco non-chewers was 60.61 μmol/L. In this study, a near-significant association was found between the low serum levels of NO in smokers as compared to nonsmokers. But there was no significant association of serum NO levels in tobacco chewers and non-tobacco chewers. Conclusion: In this study, the difference in effects of different forms of nicotine usage on the NO levels was assessed, as it provides an insight into the mechanism of the effects of oral versus inhaled forms of nicotine use. In conclusion, new facts have been elucidated in this study, and to the best of our knowledge, this is the first comparison of smoke and nonsmoke tobacco in relation to the serum levels of NO for estimating the burden of vascular risk with various forms of tobacco use in diabetes.