The Interplay of Race/Ethnicity and Obesity on the Incidence of Venous Thromboembolism

INTRODUCTION: Factors predisposing asymptomatic individuals within the community to venous thromboembolism (VTE) are not fully understood. This study characterizes the incidence and determinants of VTE among the Multi-Ethnic Study of Atherosclerosis cohort with a focus on race/ethnicity and obesity. METHODS: This study (analyzed in 2020–2021) used the Multi-Ethnic Study of Atherosclerosis cohort (2000–2017), which includes participants with diverse ethnic/racial backgrounds aged 45–84 years without cardiovascular disease at baseline. The primary endpoint was time to diagnosis of VTE defined using ICD codes (415, 451, 453, 126, 180, and 182). Multivariable adjusted hazard ratios of the predictors of VTE were calculated with a focus on the interaction between obesity and race/ethnicity categories. RESULTS: Over a median follow-up period of 14 years, 233 individuals developed VTE. Incidence rates (per 1,000 person-years) varied across racial/ethnic groups with the highest incidence among Black (4.02) followed by White (2.98), Hispanic (2.08), and Chinese (0.79) participants. There was a stepwise increase in the incidence rate of VTE with increasing BMI regardless of race/ethnicity: normal (1.95), overweight (2.52), obese (3.63), and morbidly obese (4.55). The association between BMI and VTE was strongest among non-White women with the highest incidence rate for obese (4.8) compared with non-obese (1.6). The interaction for obesity, gender, and race was statistically significant (p=0.01) in non-White obese women. Risk of VTE increased with age for all race/ethnicities. Other significant predictors of VTE were cancer at baseline and follow-up, long-term warfarin use, smoking, and D-dimer levels, whereas statin use was associated with lower VTE events. CONCLUSIONS: This study finds that obesity may confer an increased risk for VTE among non-White women as compared with other groups—White men, White women, and non-White men.