A PROSPECTIVE-STUDY OF RISK-FACTORS FOR PULMONARY-EMBOLISM IN WOMEN

Objective.-To investigate risk factors for pulmonary embolism in women . Design.-Prospective study based on biennial, mailed questionnaires. Setting.-Nurses' Health Study with 16 years of follow-up from 1976 to 1992. Patients.-A group of 112 822 women aged 30 to 55 years in 1976, free from diagnosed cardiovascular disease or cancer at baseline. Over all, there were 1 619 770 person-years of follow-up. Measurements.-Bas ed on self-report and medical records, we documented 280 cases of pulm onary embolism, of which 125 were primary (no identified antecedent ca ncer, trauma, surgery, or immobilization). information on height, weig ht, cigarette smoking, hypertension, diabetes, and hypercholesterolemi a was collected by questionnaire. Results.-In multivariate analysis, o besity, cigarette smoking, and hypertension were independent predictor s of pulmonary embolism. Specifically, obese women (body mass index gr eater than or equal to 29.0 kg/m(2)) had an increased risk of primary pulmonary embolism (multivariate relative risk=2.9; 95% confidence int erval [CI], 1.5-5.4). Heavy cigarette smokers also had an increased ri sk of primary pulmonary embolism. The relative risk (RR) of primary pu lmonary embolism was 1.9 (95% CI, 0.9-3.7) for women currently smoking 25 to 34 cigarettes per day and 3.3 (95% CI, 1.7-6.5) for those smoki ng 35 cigarettes or more daily as compared with never smokers. Hyperte nsion, even after adjustment for body mass index, was also associated with an increased risk of primary pulmonary embolism (RR=1,9; 95% CI, 1.2-2.8), High serum cholesterol levels (RR=1.1;95% CI, 0.62-1.8) and diabetes (RR=0.7; 95% CI, 0.3-1.9) did not appear to be related to pri mary pulmonary embolism. Conclusion.-These prospective data indicate t hat obesity, cigarette smoking, and hypertension are associated with i ncreased risk of pulmonary embolism in women. Control of these risk fa ctors will decrease risks of pulmonary embolism as well as coronary he art disease.