Fibrinolytic Potential During Use Of Seated Vs Treadmill Workstation

INTRODUCTION: Approximately 2.7 million blood clot-induced events occur each year, including most heart attacks and strokes. Upright, seated positions reduce blood flow, promote blood pooling and viscosity, and are theorized to impact hemostasis. Thus, occupational environments that include prolonged periods of seated work may contribute to the formation of a thrombus. Use of a treadmill desk may enhance fibrinolytic capacity compared to a static, seated position and, thus, reduce thrombotic potential. PURPOSE: To observe the effects of low intensity walking at a treadmill workstation on changes in fibrinolytic potential compared to use of a traditional, sedentary workstation. METHODS: Eleven healthy adults (n = 9 men, 2 women; 22 ± 2 yrs; 26.3 ± 5.7 kg/m2) completed two trials, conducted in random order and separated by one week. Both trials consisted of performing a series of clerical and mental tasks lasting approximately 2 hours. One trial was completed while seated at a desk, and the 2nd trial was conducted while walking one mph at a treadmill workstation. Venous blood samples were collected at baseline and immediately after completion of the tasks, and analyzed for the following fibrinolytic markers: tissue plasminogen activator (tPA) activity and antigen, plasminogen activator inhibitor-1 (PAI-1) activity and antigen. RESULTS: A significant time x trial interaction (p < 0.05) was observed for PAI-1 activity, in which active PAI-1 decreased during the walking trial (67.1 ± 11.4 - 63.0 ± 12.4 AU/ml) and increased while sitting (61.7 ± 11.4 - 65.8 ± 12.0 AU/ml). PAI-1 antigen did not differ between trials or timepoints (walking 7.5 ± 6.1 - 7.8 ± 4.4 ng/ml, seated 9.2 ± 5.7 - 7.6 ± 5.7 ng/ml). No effects were observed for tPA activity or antigen. CONCLUSIONS: Low intensity walking at a treadmill workstation attenuates inhibition of fibrinolysis that is observed during seated desk work. These results indicate thrombotic potential is increased during seated desk work, and reduced while using a treadmill workstation.