Oxidative stress biomarkers of sLOX-1, nitric oxide and 8-hydroxy-2?-deoxyguanosine (8-OHdG) associated with heart rate variability (HRV) and pulmonary dysfunction in chronic smokers

Cigarette smoking is associated with cardiovascular mortality, lung diseases and cancers. Smoking causes of sympathovagal change, which can be evaluated by the heart rate variability (HRV) technique and smoking also important risk factor for peripheral vessel injury and DNA damage, that can be used endothelial nitric oxide (NO), sLOX-1 and 8-OHdG markers, respectively, for assessment. The purpose of this study was to inquire changes that occur in HRV and NO in acute effect of smoking and including with sLOX-1 and 8-OHdG overproduction in chronic smokers. 60 males of smokers and nonsmokers equally were study. Time domain (RRI, SDNN, RMSSD and pNN50), frequency domain (HF, LF, LF/HF and Total power), nonlinear (SD1, SD2, alpha1, alpha2, ApEn and SampEn) parameters of HRV were obtained from all subjects and for 5-min and 15-min ongoing for smokers after completing a cigarette smoking simultaneously with blood collection in each segment of three phases of before smoking and then 5 minutes over to 15 minutes after completing of the smoking for NO and sLOX-1 measurement and urine collection for 8-OHdG evaluation. The spirometric measurement (FVC, FEV1, and FEV1/FVC) parameters of pulmonary function test were obtained from all subjects. We found the significantly lower of HRV (RRI, SDNN, RMSSD, pNN50, Total power, SD1, SD2, and ApEn) in smokers than nonsmokers and elevated of urinary 8-OHdG and serum sLOX-1 in smokers. Within 5 min after acute smoking showed significant evidence for adverse effect with autonomic function (decreased in RRI, HF, ApEn, SampEn and obviously less value of SD1/SD2 geometrical pattern but increased in LF, LF/HF, SD2 and alpha1) and in particular, lower NO, vasodilator immediately. In addition, from this state NO was significant correlation with HF, LF/HF, SD2 and SampEn. The pulmonary function, FEV1 significantly decreased in smokers, meanwhile FVC and FEV1/FVC (%) were not significantly different in both groups. Moreover, there was a significant correlation between FEV1/FVC (%) and LF/HF ratio (r = -0.62, p-value < 0.001). The HRV analysis on acute smoking can represent the autonomic modulation and which characterize the sympathetic increasing and vagal blunt for heart control, particularly after 5-min smoking. The dysfunction of autonomic system contributes to endothelial NO, mediated endothelium-dependent vasodilator. Then, the HRV of acute smokers can be used to predict the risk of cardiac diseases.