The risk of venous thromboembolism (VTE) appears to be higher as BMI increases and when surgery is required, according to an investigation of more than a million middle-aged women. Women with a BMI of 35 kg/m2 or higher were more than three times as likely to develop VTE than women with a BMI ranging between 22.5 kg/m2 and 24.9 kg/m2. Incidence rates of VTE per 1,000 women were four times higher for those with a BMI less than 25 kg/m2 and 40 times higher for those with a BMI of 25 kg/m2 or higher during the 12 weeks following surgery when compared with a 12-week period without surgery.

Abstract: Circulation, March 6, 2012.