Abstract 5088: Exercise Training Increases Endothelial Progenitor Cells and Decreases Asymmetrical Dimethylarginine in Patients With Intermittent Claudication
Background - Exercise training is a well-established, non-invasive method to improve peripheral arterial perfusion and walking capacity in PAD patients.
Hypothesis - We designed a prospective randomized controlled trial to test the effect of training on laboratory markers of angiogenesis.
Methods - Thirty patients with intermittent claudication were randomized to supervised training twice a week for 6 months or standard medical therapy. Endothelial progenitor cells (EPC) were assessed by whole-blood flow cytometry (co-expression of CD34+CD133+KDR+) and cell culture assays (colony forming units/CFU and circulating angiogenic cells/CAC) at baseline, 3-months and 6-months after training as well as 12-months after study begin. Plasma ADMA was determined by immunoassay. In addition, changes in maximum walking distance were recorded.
Results - EPC measured by flow cytometry increased significantly three and six months after training paralleled by a significant decrease of ADMA (asymmetric dimethylarginine), a major endogenous inhibitor of NO synthase (see table⇓). The number of CFUs and CACs were significantly higher after 6-months compared to baseline upon exercise (P<0.05). No differences were observed in the standard group in timecourse. However, 6-months after training cessation the number of EPC and ADMA levels were similar to baseline. Exercise training showed a benefit on treadmill maximum walking distance with a trendwise increase at 6-months (training: baseline 116.6m±12.8 (mean±SEM) vs. 6-months 149.1m±17.8, P=0.08; standard: baseline 125.2m±23.9 vs. 6-months 108m±19.9, P=0.3). The benefit was sustained 6 months after training cessation in the exercise group (training: 12-months 157.5m±18.4, P=0.07; standard: 12-months 129.5m±26.9).
Conclusions - The beneficial effect of exercise training in PAD patients might partly be due to EPC mobilization mediated by improved NO synthesis as we observed reduced ADMA levels.