Weight change over 9 years and subsequent risk of venous thromboembolism in the ARIC cohort.

BACKGROUND/OBJECTIVES: Weight gain increases risk of cardiovascular disease, but has not been examined extensively in relationship to venous thromboembolism (VTE). The association between weight change over 9 years and subsequent VTE among participants in the Atherosclerosis Risk in Communities (ARIC) study was examined, with a hypothesis that excess weight gain is a risk factor for VTE, relative to no weight change. SUBJECTS/METHODS: Quintiles of 9-year weight change were calculated (visit 4 1996–1998 weight minus visit 1 1987–1989 weight in kg: Quintile 1: ≥ −1.81 kg; Quintile 2: <−1.81 to ≥ 1.36 kg; Quintile 3: >1.36 to ≤4.08 kg; Quintile 4: >4.08 to ≤7.71 kg; Quintile 5: > 7.71 kg). Incident VTEs from visit 4 (1996–1998) through 2015 were identified and adjudicated using medical records. Hazard ratios (HRs) were calculated using Cox models. RESULTS: 529 incident VTEs were identified during an average of 19 years of follow up. Compared to Quintile 2, participants in Quintile 5 of weight change had 1.46 times the rate of incident VTE (HR = 1.46 (95% CI 1.09, 1.95), adjusted for age, race, sex, income, physical activity, smoking and prevalent CVD). The HR for Quintile 5 was modestly attenuated to 1.38 (95% CI 1.03, 1.84) when visit 1 BMI was included in the model. When examined separately, results were significant for unprovoked VTE, but not for provoked VTE. Among those obese at visit 1, both weight gain (HR 1.86 95% CI 1.27,2.71) and weight loss (HR 2.11 95% CI 1.39, 3.19) were associated with incident VTE, compared with normal weight participants with no weight change. CONCLUSIONS: Weight gain later life was associated with increased risk for unprovoked VTE. Among those with obesity, both weight gain and weight loss were associated with increased risk for VTE.