The role of mineral metabolism and inflammation on dialysis vascular access failure

Abstract

Thrombosis of arteriovenous fistula (AVF) is the leading cause of vascular access (VA) loss usually due to silent stenosis. Therefore, assessment of relevant risk factors of VA monitoring may provide insight into potential therapeutic targets for stenosis and thrombosis. The aim of this study was to evaluate the influence of cardiovascular risk factors (including inflammation and mineral metabolism dysfunctions) on the failure of internal AVF in HD patients. 128 HD patients with internal AVF were included in the study and followed up for two years. At baseline, VA morphology and function were followed by Doppler ultrasonography and serum albumin, prealbumine, C-reactive protein, orosomucoid, calcium, phosphorus, parathyroid hormone, bone-type alkaline phosphatase, osteoprotegerin and receptor activator of nuclear factor κB ligand were measured. At baseline, 50 stenoses were detected but none of them required any intervention. Age and biological parameters did not significantly differ between patients with or without VA stenosis. Over the two year- follow up, VA thrombosis occurred in 19 patients. Preexisting stenosis of VA was present in 9/19 patients (47.3% of cases) (chi-square = 3.708, p = 0.0538). Despite the low rate of events, phosphorus [1.75 (0.95–2.77) vs 1.42 (0.47–3.22) mmol/L, p = 0.0416], Calcium x Phosphorus product [4.00 (2.00–5.90) vs 3.40 (1.10–6.80) mmol2/L2, p = 0.0676] and parathyroid hormone [165.00 (1.00–944.00) vs 79.50 (1.00–846.60) ng/L, p = 0.0814) levels were higher in the 19 thrombotic patients whereas all other biological parameters did not significantly differ. These results, which confirm that VA thrombosis occurs more frequently upon preexisting stenosis, also demonstrate that mineral metabolism disorders, compared to inflammation, may contribute to VA dysfunction leading to thrombosis.

Vascular Access Care and Treatment Practices Associated with Outcomes of Arteriovenous Fistula: International Comparisons from the Dialysis Outcomes and Practice Patterns Study

“…The greater BFR variability in North America may be one reason why the AVF survival/facility median BFR relationship was stronger in North America than in Japan and EUR/ANZ. It is difficult to assess our results with those published previously which have been variable regarding patient-level BFR and AVF survival [22,23]. However, our study has provided the largest international sample for testing these relationships with detailed and extensive adjustments to allow greater generalizability and greater ability to account for treatment-by-indication bias.…”

PKA-induced Receptor Activator of NF-κB Ligand (RANKL) Expression in Vascular Cells Mediates Osteoclastogenesis but Not Matrix Calcification

“…Serum OPG levels correlate with the severity of coronary disease and rate of atherosclerosis progression (11)(12)(13)(14)(15)(16). OPG knock-out mice exhibit both arterial calcification and osteoporosis as well as accelerated progression of atherosclerotic lesions and calcification (17,18).…”

Treatment of vitamin D deficiency/insufficiency with ergocalciferol is associated with reduced vascular access dysfunction in chronic hemodialysis patients

“…We also evaluated the impact of treatment with ergocalciferol on the frequency of VAD. 11,21 Of note, 42% of our patients had vitamin D deficiency defined as 25OHD levels <15 ng/mL. 19,[22][23][24] This high prevalence is thought to be due to lack of exposure to sunlight, inadequate synthesis by the skin of uremic patients, and restricted diet.…”

“…Currently, there is no pharmacologic therapy for preventing VAD. 21 We hypothesized that VDDI may negatively impact vascular access in HD patients. [18][19][20] Previous studies, including our own, indicate that 50% to 90% of CKD population has vitamin D deficiency or insufficiency (VDDI).…”