Improvement in proteinuria attenuates the occurrence of venous thromboembolism: A population-based cohort study.

Proteinuria contributes to venous thromboembolism (VTE), and its levels can change over time. This registry-based retrospective study investigated the association between changes in proteinuria status and VTE occurrence at the population level. We included participants (n = 1,712,507) who underwent two successive health checkups during the initial period (2003 or 2004) and the subsequent period (2005 or 2006). Outcomes were defined as the occurrence of VTE, including deep vein thrombosis, pulmonary thromboembolism, and other venous thromboses, according to the International Classification of Diseases-10 code. A multivariate Cox proportional hazards model was used to assess the occurrence of VTE based on changes in proteinuria. Over a median follow-up period of 14.5 years, 45,711 participants (event rate: 1.88%) experienced a VTE. Compared with the normal group, the incidence risk of VTE dose dependently increased with the severity of proteinuria in each of the persistent, progressed, and improved groups (p for trend < 0.001). In a pairwise comparison, the risk of occurrence of VTE in the improved (hazard ratio [HR]: 1.18, 95% confidence interval [CI]: 1.10-1.27), progressed (HR: 1.31, 95% CI: 1.23-1.40), and persistent groups (HR: 1.88, 95% CI: 1.61-2.19) were higher than that of the normal group. In addition, the improved group had a lower risk of VTE occurrence than that of the persistent group (HR: 0.69, 95% CI: 0.58-0.82, p < 0.001). Our study showed that the incidence risk of VTE was associated with change and severity of proteinuria status. Improvement in proteinuria may attenuate the occurrence of VTE.