Cancer Epidemiology Unit, University of Oxford, Oxford, United Kingdom.
Circulation. 2012 Apr 17;125(15):1897-904. doi: 10.1161/CIRCULATIONAHA.111.063354. Epub 2012 Mar 6.
Obesity and surgery are known risk factors for venous thromboembolism (VTE), but there is limited information about the independent effects of obesity on the incidence of postoperative VTE. We linked questionnaire data from the Million Women Study with hospital admission and death records to examine the risk of VTE in relation to body mass index (BMI) both in the absence of surgery and in the first 12 weeks following an operation.
Overall, 1 170 495 women (mean age, 56.1 years) recruited in 1996 to 2001 through the National Health Service Breast Screening Programme in England and Scotland were followed for an average of 6 years, during which time 6438 were admitted to hospital or died of VTE. The adjusted relative risks of VTE increased progressively with increasing BMI and women with a BMI ≥ 35 kg/m(2) were 3-4 times as likely to develop VTE as those with a BMI 22.5 to 24.9 (relative risk 3.45 [95% CI 3.09-3.86]). Overweight and obese women were more likely than lean women to be admitted for surgery and also to develop postoperative VTE. During a 12-week period without surgery, the incidence rates of VTE per 1000 women with a BMI < 25 and ≥ 25 were 0.10 (0.09-0.10) and 0.19 (0.18-0.20); the corresponding rates in the 12 weeks following day and inpatient surgery were, respectively, about 4 and 40 times higher.
VTE risk increases with increasing BMI and the associated excess risk is much greater after surgery than without surgery.
肥胖和手术是静脉血栓栓塞症（VTE）的已知危险因素，但关于肥胖对术后 VTE 发生率的独立影响的信息有限。我们将来自“百万妇女研究”的问卷调查数据与住院和死亡记录相关联，以检查与体重指数（BMI）相关的 VTE 风险，既包括无手术情况下的风险，也包括手术后 12 周内的风险。
总体而言，1996 年至 2001 年期间，通过英格兰和苏格兰国家卫生服务乳腺筛查计划招募的 1170495 名女性（平均年龄 56.1 岁）接受了平均 6 年的随访，在此期间，有 6438 名女性因 VTE 住院或死亡。VTE 的调整后相对风险随着 BMI 的增加而逐渐增加，BMI≥35kg/m2的女性发生 VTE 的可能性是 BMI 22.5-24.9 的女性的 3-4 倍（相对风险 3.45 [95%CI 3.09-3.86]）。超重和肥胖女性比瘦女性更有可能接受手术，也更有可能发生术后 VTE。在无手术的 12 周内，BMI<25 和≥25 的女性中每 1000 人发生 VTE 的发生率分别为 0.10（0.09-0.10）和 0.19（0.18-0.20）；在随后的 12 周内，日间手术和住院手术的发生率分别约为 4 倍和 40 倍。
VTE 风险随 BMI 增加而增加，手术后的相关风险比无手术时高得多。
