Measures of Kidney Disease and the Association of Venous Thromboembolism in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) Study

Abstract

Background

Kidney disease has been associated with venous thromboembolism (VTE) risk, but results conflict and there is little information regarding blacks.

Study Design

Prospective cohort study

Setting & Participants

30,239 black and white adults aged 45 years or older enrolled in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) study 2003–2007.

Predictors

Estimated glomerular filtration rate (eGFR) using the combined creatinine-cystatin C (eGFR _cr-cysC) equation and urinary albumin-creatinine ratio (ACR).

Outcomes

The primary outcome was adjudicated VTE, and secondary outcomes were provoked and unprovoked VTE separately. Mortality was a competing risk event.

Results

Over 4.6 years’ follow-up, 239 incident VTE events occurred over 124,624 person-years. Cause-specific HRs of VTE were calculated using proportional hazards regression adjusted for age, sex, race, region of residence and body mass index. The adjusted VTE HRs for eGFR _cr-cysC 60–<90, 45–<60 and <45 versus ≥90 ml/min/1.73m ² were 1.28 (95% CI, 0.94–1.76), 1.30 (95% CI, 0.77–2.18) and 2.13 (95% CI, 1.21–3.76). The adjusted VTE HRs for ACR 10–<30, 30–<300, ≥300 versus <10 mg/g were 1.14 (95% CI, 0.84–1.56), 1.15 (95% CI, 0.79–1.69) and 0.64 (95% CI, 0.25–1.62). Associations were similar for provoked and unprovoked VTE.

Limitations

Single measurement of eGFR and ACR may have led to misclassification. Smaller numbers of events may have limited power.

Conclusions

There was an independent association of low eGFR (<45 vs ≥90 mL/min/1.73 m2) with VTE risk, but no association of ACR and VTE.