Phylloquinone intake as a marker for coronary heart disease risk but not stroke in women

Objective: To examine the feasibility of using phylloquinone intake as a marker for coronary heart disease (CHD) and stroke risk in women. Design and setting: Nurses' Health Study, a prospective cohort study during 1984-2000. Dietary data were collected in 1984, 1986, 1990, and 1994 using a validated semiquantitative food frequency questionnaire. Subjects: A total of 72 874 female nurses, aged 38-65 y, without previously diagnosed angina, myocardial infarction (MI), stroke, or cancer at baseline. Main outcome measures: Incidence of nonfatal MI, CHD deaths, total CHD events, ischemic, and total strokes. Results: There were 1679 CHD events (1201 nonfatal) and 1009 strokes (567 ischemic). After adjustment for age and lifestyle factors associated with cardiovascular disease risk, the multivariate relative risks (RR) (95% CI) of total CHD from the lowest to the highest quintile category of phylloquinone intake were 1 (reference), 0.80 (0.69-0.94), 0.86 (0.74-1.00), 0.77 (0.66-0.99), and 0.79 (0.68-0.92), P for trend 0.01. Further adjustment for dietary intakes of saturated fat, polyunsaturated fat, trans fatty acids, eicosapentaenoic, and docosahexaenoic acids, cereal fiber, and folate attenuated the association (RR comparing extreme quintiles 0.84 [0.71-1.00], P for trend 0.12). Incidence rates of total or ischemic strokes were not associated with phylloquinone intake. Conclusion: The data suggest that high phylloquinone intake may be a marker for low CHD risk. Dietary and lifestyle patterns associated with phylloquinone intakes, rather than intake of the nutrient itself, might account for all or part of the weak association.