A prospective study of anticardiolipin antibodies as a risk factor for venous thrombosis in a general population (the HUNT study)

Summary. We prospectively examined whether there is an association between elevated anticardiolipin antibody levels and the risk for a future first venous thrombosis (VT) in a general population. We studied this in a large population‐based nested case‐cohort study of 508 VT cases and 1464 matched control subjects from a cohort of 66 140 participants in the Health Study of Nord‐Trøndelag in Norway. Venous thrombosis was validated using standardized criteria for venous thrombosis and pulmonary embolism. Prethrombotic serum anticardiolipin antibodies were measured by an enzyme‐linked immunoassay. There was no association between elevated anticardiolipin antibody levels and subsequent venous thrombosis, overall or after stratification by sex, different age groups or idiopathic vs. secondary thrombosis. The overall odds ratio was 1.11 (95% CI: 0.71–1.74) for greater than vs. less than the 95th percentile of anticardiolipin antibody levels. In conclusion, in this general population sample elevated anticardiolipin antibody levels was not a risk factor for subsequent venous thrombosis.