Abstract P272: Dietary Intake of Vitamin K and the Risk of Incident Pulmonary Embolism in the Nurses’ Health Study

Abstract

Introduction: Vitamin K, which is consumed as phylloquinone (K 1 ) and menaquinone (K 2 ), impacts some vitamin-K dependent proteins involved in hemostasis. It is unknown whether dietary intake of phylloquinone and menaquinone are associated with incident pulmonary embolism (PE) risk. Hypotheses: Dietary intake of phylloquinone and menaquinone will be positively associated with the risk of incident PE and, in secondary analyses, idiopathic PE. Methods: Eligible women were Nurses’ Health Study participants free of venous thromboembolism (VTE) at 1984 baseline (n=74,821). Participants completed a food frequency questionnaire every four years (1984-2010) and we calculated intake of phylloquinone and menaquinone. Eligible PE cases were confirmed via medical record review or participant reconfirmation, or self-reported among persons with prior cancer. Cases were defined as idiopathic in the absence of cancer, recent surgery, and trauma. Cox Proportional Hazards models estimated hazard ratios and 95% confidence intervals for PE associated with time-varying energy-adjusted quintiles of phylloquinone, and separately, menaquinone. Two models adjusted for time-varying covariates, first including lifestyle and medical factors and next adding energy-adjusted nutrients. Secondary analyses estimated idiopathic PE risk. Results: We identified 568 incident PE events during 1,328,669 person-years. In analyses adjusted for lifestyle and medical factors, there was no evidence of a linear association between incident PE risk and energy-adjusted quintiles of phylloquinone intake (linear p-trend across quintile medians = 0.37) or menaquinone intake (linear p-trend = 0.57). Results for idiopathic PE risk were similarly null, as were results after further adjustment for nutrients (Table). Conclusions: In this study of U.S. women, there was no evidence of a linear association between energy-adjusted quintiles of phylloquinone or menaquinone intake and incident PE risk, before or after adjustment for other nutrients.