Rheologic changes in venous blood during prolonged sitting

We examined blood rheologic changes, mainly blood viscosity, during long-te rm quiet sitting. Samples of blood were obtained from the arm and foot vein s of the healthy adult male volunteers before and after 2 h of quiet sittin g. Blood viscosity, was immediately determined with an oscillation viscomet er, and blood count and blood chemistry were analyzed. We found that the vi scosity in blood from a foot vein but not from an arm vein increased signif icantly after 2 h of sitting. Our results show that 2 h of quiet sitting ca n increase thrombotic tendency locally in the leg but not systemically and suggests the importance of measuring focal venous blood viscosity. (C) 2000 Elsevier Science Ltd. All rights reserved.