Abstract
Waterpipe tobacco (WPT) smoking is a public health problem with similar or even stronger effects than cigarette smoking. Although it appears to be associated with extensive oxidative stress, there is a limited number of studies on the oxidative effects of WPT smoking in stressful conditions. We, therefore, compared the responses of salivary flow rate (SFR), uric acid (UA) concentration, and peroxidase (POX) and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) activities between WPT smokers and non-smokers following a bout of exhaustive aerobic exercise (AE). Twenty-three sedentary young women (age: 22.95 ± 2.83 years) participated in this study, including 11 smokers (7.00 ± 1.41 uses/week) and 12 non-smokers. All participants were required to perform the Bruce protocol treadmill test at an initial gradient of 10% at 1.7 mph, with increases of these parameters every 3 min until exhaustion. Unstimulated saliva samples were collected before, immediately after, and 1 hour after AE. WPT smokers showed lower SFR compared with non-smokers at all time points (p < 0.05). In comparison to WPT smokers, a larger increase in POX activity (approximately 23% vs. 14%; p = 0.009) and a smaller decline in DPPH activity (approximately -8% vs. -15%; p = 0.004) were found in non-smokers compared with WPT smokers. While these changes were slowly compensated within 1 hour after exhaustion, the activity of both markers was different from the pre-exercise values (p < 0.001). There was also a trend for UA concentration in non-smokers to be higher during the recovery period, with no significant difference between the groups (p > 0.05). It seems that WPT smoking is associated with negative effects on important human antioxidants and a diminished antioxidative response following acute exercise.