Effects of resistance training on endothelial progenitor cells in young smokers: a pilot study
BACKGROUND: Research has shown that cigarette smoking is linked to endothelial dysfunction, which represents a key early step in the development of atherosclerosis. This association between endothelial dysfunction and atherosclerosis also suggests that the status of an individual's endothelial function can be a potential indicator of a cardiovascular health. To better understand endothelial dysfunction, researchers have started to quantify peripheral circulating endothelial progenitor cells as effective biomarkers for cardiovascular risks. Many cardiovascular disease risk factors are immutable; however, recent studies have recognized resistance training as a viable strategy for cardiovascular disease prevention. Furthermore, there are only a few studies that focus on endothelial progenitor cells as a biomarker to investigate the effects of resistance training on cardiovascular health. This pilot study explored the effects of resistance intervention on circulating endothelial progenitor cells in both women and men smokers. METHODS: A group of 12 healthy young smokers were randomized into a 12-week RT or control group. Measurements were taken once at the beginning of the study and once again at the end of the study (week 13). Participants were assessed for any changes from baseline in endothelial progenitor cell count, nicotine dependence and relative strength. RESULTS: Average endothelial progenitor cell count decreased in both RT and control from baseline. However, RT saw a larger decrease in CD34+, CD133+, and KDR when compared to control. We observed a decrease in the mean Fargerstrom Test for Nicotine Dependence score for RT, while control saw an increase from the average baseline score. We also noted an increase in average relative strength from RT participants, while relative strength slightly decreased in control. There were no significant changes in body weight or body mass index in both groups. CONCLUSION: This is the first study to investigate the effects of RT on EPC count in young smokers. The findings from this study do not suggest a positive relationship between RT intervention and EPC count. Results did indicate that RT had a lower nicotine dependence compared with control following intervention, which provides more evidence for RT as an adjunctive strategy for smoke cessation. However, due to the low sample number in this study, an adequately powered experimental design is warranted.