Health
Air travel could cause thrombosis
NEWS IN BRIEF — Posted March 27, 2006
The low-pressure and low-oxygen environment during air travel might contribute to the development of deep vein thrombosis in susceptible individuals, according to a report in the March 9 The Lancet.
Studies have found a twofold to fourfold increased risk of thrombosis after air travel, with greater risk associated with longer rather than shorter flights. But the mechanism of clot formation during air travel is unclear, the researchers said. Some think immobilization for long periods could play a role, but flight-specific factors also could contribute.
Researchers measured the concentrations of markers of clotting activation in blood samples from 71 healthy volunteers before, during and immediately after an eight-hour flight. To separate the flight factors from immobilization alone, they compared concentrations in the same individuals at the same time points during eight hours of sitting in a cinema and eight hours of regular daily activities.
The authors found increased concentrations in clotting activation markers during flight compared with the other two situations, especially in participants who had additional risk factors for thrombosis, including those who were carriers of a mutation in the factor V gene or were taking oral contraceptives.
The finding led researchers to conclude that the activation of coagulation that occurs in some people during a long flight indicates that mechanisms in addition to immobilization are at work.
Note: This item originally appeared at http://www.ama-assn.org/amednews/2006/03/27/hlbf0327.htm.