Abstract MP57: Coagulation Factor IX and Incident Diabetes Risk: The REasons for Geographic and Racial Differences in Stroke (REGARDS) Study

Introduction: A prothrombotic state is implicated in the vascular complications of type 2 diabetes (DM), and such complications disproportionately affect Black compared to White adults. However, it is not known if this is due to DM or whether coagulation factor levels are related to DM incidence. Higher coagulation factor IX (FIX) was related to increased risk of CHD and stroke among Black but not White participants in the REGARDS cohort. We hypothesized higher FIX antigen would be associated with incident DM risk, with stronger relationships in Black versus White adults. Methods: REGARDS enrolled 30,239 Black and White adults from across the contiguous US from 2003-2006 with a second in-home visit from 2013-2016. The Biomarkers as MEDiators of Racial Disparities in Risk Factors (BioMedioR) nested cohort study included 4,400 participants who completed both visits, balanced on race and sex. Modified Poisson regression models estimated the RR of incident DM per 1-SD increment log FIX. We tested for a FIX-by-race interaction a priori due to differential associations of FIX with CHD and stroke by race in REGARDS. Results: Among 3,381 participants without baseline DM (mean age 63 years, 44% Black race, 51% women), 456 (13.5%) developed incident DM over 9.5-years. Adjusting for age, sex, and race, there was a significant difference in the association of FIX with DM by race (p-interaction<0.01). As shown in the Figure, adjusted for age and sex (Model 1), the RR (95% CI) for incident DM was 1.19 (1.05, 1.34) for Black adults and 1.49 (1.23, 1.81) for White adults. Adjusting for clinical risk factors (Model 2) fully attenuated this association for Black adults, and further adjusting for behavioral factors (Model 3) fully attenuated this association for Black and White adults. Conclusions: Higher FIX levels were associated with incident DM risk. Relationships between FIX and incident DM were stronger for White than Black adults. The FIX-DM association may be due to adverse clinical and behavioral risk factors.