Glycemia (hemoglobin A1c) and incident venous thromboembolism in the Atherosclerosis Risk in Communities cohort study.

Diabetes has been inconsistently associated with increased risk of venous thromboembolism (VTE) and there is little direct evidence on the associations of glycemia levels with VTE. We used data from the Atherosclerosis Risk in Communities study to test the hypothesis that glycemia, as measured by hemoglobin A1c (A1c), is positively associated with VTE. Participants aged 45-64 years (n = 12,298) had A1c measured in 1990 and were followed for incident VTE (n = 345) through 2005. Because A1c is affected by diabetes treatment, analyses were stratified by history of diagnosed diabetes. Owing to evidence of non-linearity, we categorized A1c according to clinical cut-points: