DVT, often referred to as “economy class syndrome,” occurs in the lower extremities and can be life-threatening when clots leave the lower extremities and migrate to the brain and lungs, according to new research. Professor Frits Rosendaal of Leiden University Hospital in the Netherlands and his research team compared blood clotting factor concentrations in 71 healthy individuals after an eight-hour flight with those of another group of volunteers after watching an eight-hour movie, concluding that “some individuals initiated clotting activity in their bodies after the eight-hour flight, suggesting that our air travel initiated some kind of clotting mechanism, which led to a clotting effect. some sort of clotting mechanism, which leads to thrombosis.” Possible mechanism: Another collaborator involved in this project, Suzanne Cannegieter, PhD, says the study sheds light on a possible mechanism between DVT and long flights. ”There has been a question in the medical community: if a person stays in a car instead of in the cabin, and both spend the same amount of time toward the same time, does that also increase the incidence of DVT?” In an interview with Reuters, she said, “This study tells us that this is not the case. There are specific factors in the cabin that contribute to the higher incidence, and it’s never just about sitting still for long periods of time.” Bob Preston of BATA (British Air Travel Association) said: There is a small group of people who are more inclined to develop DVT and they should get a doctor’s opinion before a long-haul flight. Scientists found that passengers after long-haul flights had higher blood concentrations of clotting factors than those who sat still for long periods after a movie theater, especially those who also had other DVT risk factors. Professor Ronsendaal said that about 40 percent of the people had a significantly higher risk of developing DVT because of a genetic mutation. In addition, female passengers flying after taking oral contraceptives also had an increase in clotting factors. In a commentary on the study, Dr. Hans Stricker of Locarno, Switzerland, said the results provide strong evidence for the existence of “travel-mediated thrombosis. He suggests that to reduce the risk of DVT, air travelers should avoid sedative medications prior to flying and avoid excessive alcohol consumption. Compression stockings can also have a positive effect on improving blood flow.