title: Lymphocyte Apoptosis in Smokers and Non-Smokers Following Different Intensity of Exercises and Relation with Lactate.
abstract: Purposes of this study were 1) to examine the exercise intensity where lymphocyte apoptosis index (AI) is significantly increased in smokers and non-smokers, 2) to find out whether AI is associated with level of lactate (L). Fourteen healthy untrained smokers (≤ 1 pack year,n=7) and non-smokers (n=7) aged 18 to 26 were recruited. Each subject conducted three treadmill runs at different intensities randomly. Running distance for all three runs was equivalent to 30 minute run at 70% VO2max. AI and L were analyzed at rest (Pre), immediately after (Post), and 1 h following (1 h post) each run. Data was analyzed using two way repeated measures ANOVA. Smokers showed higher AI than non-smokers at Post in 60% (12.5±0.62% vs. 9.97±0.51,p<.008) and 70% VO2maxrunning trials (17.53±0.57% vs. 15.6±0.41,p<.018). All L values at post showed significantly higher than Pre and 1 h post, but there was no significant difference between smokers and non-smokers. The strong positive relationship between AI and L was detected (r=.739, smokers vs.r=.793, non-smokers). Smokers tend to have higher AI than non-smokers following runs at 60% and 70% VO2max,but not following a run at 80% VO2max. An increase in AI following a run at 60% VO2maxindicates that lymphocyte apoptosis can be increased following moderate intensity exercise. Since L and AI at post were increased in dose-dependent manner to exercise intensity, it is suggested that an increase in lactate production during exercise might contribute to the increase in lymphocyte apoptosis.
authors.affiliation: Fitness and Sports program, Texas A&M International University, Laredo, TX, USA.
authors.forename: Kyung-Shin
authors.initials: KS
authors.lastname: Park
authors.affiliation: Department of Health and Kinesiology, Texas A&M University, College station, TX, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Lee
keywords: Lymphocyte apoptosis; exercise intensity; lactate; smoker