London | Obese women who use oral contraceptives may have an increased risk for a rare type of stroke, a new study has found. Cerebral venous thrombosis (CVT) is a rare condition that mainly affects young adults and children. Risk factors for CVT overlap some with those for venous thromboembolism (VTE) and include cancer and oral contraceptives but there also are risk factors specific to CVT including local infections and head trauma.
Researchers from Academic Medical Centre in Netherlands studied patients with CVT from two hospitals. The study of men and women included 186 case patients with CVT and 6,134 healthy controls for comparison. Patients with CVT were more often younger (40 vs 48 years old), female, more often used oral contraceptives and more frequently had a history of cancer compared with control participants.
Researchers found obesity (a body mass index 30 or more) was associated with increased risk of CVT and that the association appeared due to the increased risk among women taking oral contraceptives. There was a nearly 30-fold increased risk of CVT among obese women taking oral contraceptives compared with women of normal weight not taking oral contraceptives.
There also was an increased risk of CVT in overweight women who used oral contraceptives. However, there was no association between obesity and CVT among men or women who did not use oral contraceptives.
The increased risk of VTE and CVT associated with oral contraceptives in the presence of obesity might make physicians reluctant to prescribe oral contraceptives to obese women, researchers said. The findings were published in JAMA Neurology.
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