Association of low serum fetuin A levels with poor arteriovenous access patency in patients undergoing maintenance hemodialysis

Abstract

Background: Fetuin A, a predictor of mortality in dialysis patients, is associated with vascular calcification and atherosclerosis in hemodialysis (HD) patients. Whether it predicts arteriovenous (AV) access patency is unknown. This study aimed to investigate the association between fetuin A and AV access patency in HD patients.

Study design: Prospective observational study.

Setting & participants: 238 prevalent HD patients (127 women and 111 men; mean age, 60 ± 12 years) were followed up for AV access patency for 32 months.

Predictors: Tertiles of baseline circulating fetuin A levels, corresponding to 0.15-0.25, 0.26-0.32, and 0.33-0.51 g/L.

Outcome: The major outcome was loss of unassisted AV access patency, defined as AV access thrombosis or need for intervention.

Measurements: Fetuin A and other markers of inflammation.

Results: 100 patients had loss of AV access patency (42%) on follow-up. Patients in the lowest fetuin A tertile had the worst AV access patency (log-rank test, χ(2) = 8.68; P = 0.01). Using Cox proportional hazards regression with patients in the lowest fetuin A tertile as reference, patients in the intermediate tertile had an HR of 0.49 (95% CI, 0.29-0.82), whereas those in the highest fetuin A tertile had an HR of 0.43 (95% CI, 0.25-0.75) for loss of AV access patency. Similarly, considering patients using AV fistulas or grafts separately, patients in the highest fetuin A tertile had less risk of losing AV access patency than patients in the other tertiles (HR, 0.40 [95% CI, 0.19-0.84] for patients with AV fistulas and HR, 0.25 [95% CI, 0.10-0.65] for patients with AV grafts).

Limitations: Focus on the patency of prevalent rather than new AV access in maintenance hemodialysis patients.

Conclusions: Fetuin A deficiency is associated with a higher risk of loss of AV access patency in either native AV fistulas or AV grafts in HD patients.