Study of biochemical markers of oxidative stress in smokers versus nonsmokers with mixed anxious and depressive disorder

Introduction: Oxidative stress is induced by tobacco smoking and is also associated with anxiety and depression, two common psychiatric disorders, frequently associated with tobacco use. Aim: To correlate tobacco use and mixed anxious and depressive disorder (MADD) with oxidative stress markers useful in clinical practice. Methods: A study of Uric acid, Vitamin C and Malondialdehyde, as oxidative stress markers, was conducted in 31 +- smokers versus nonsmokers with MADD. Other useful parameters assessed were serum cholesterol, triglycerides and creatinine. Smoking profile was quantified by number of packs-years (PA) and Fagerstrom nicotine dependence score (FNDS) with exhaled carbon monoxide validation, while MADD was certified by The Hamilton Anxiety/Depression Scale (HAM-A/D.) Results: Malondialdehyde (MDA) serum concentration was significantly increased in 73% of smokers, while Vitamin C was lower in 90% of both smoking and no smoking MADD patients. Lower concentrations of uric acid were described in smokers, suggesting decreased endogenous production. Discriminant analysis of smokers with MADD, considering variables of PA, FNDS, cholesterol and MDA is shown in Fig.1. Conclusions: Smoking amplifies oxidative stress described in psychiatric disorders. Monitoring biomarkers of both tobacco exposure and oxidative stress can improve disease management.