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Abstract: TH-PO224

Ankle-Brachial Index Predicts Vascular Calcification in Hemodialysis Patients with Severe Hyperparathyroidism

Session Information

Category: Bone and Mineral Metabolism

  • 402 Bone and Mineral Metabolism: Clinical

Authors

  • Leite, Maurilo, Federal University of Rio de Janeiro, Niteroi, RJ, Brazil
  • Pichone, Alinie Da silva, Federal University of Rio de Janeiro, Niteroi, RJ, Brazil
  • Gomes, Carlos Perez, UFRJ, Rio de Janeiro, Brazil
Background

Vascular calcification, which is a common complication of secondary hyperparathyroidism (sHPT), is related with high mortality in chronic kidney disease (CKD) patients. Besides the increase of intact parathyroid hormone (iPTH), high levels of phosphorus induce phenotypic changes in vascular smooth muscle cells (VSMC) that differentiate on osteoblast-like cells causing calcification at the media of arterial wall. This study aims to correlate ankle-brachial index (ABI) with biochemical abnormalities and presence of vascular calcification on X-Ray exams.

Methods

We analyzed thirty hemodialysis (HD) patients over eighteen years of age and with iPTH higher than 1000pg/ml. All patients underwent an assessment of their clinical history, laboratory data and radiographic evaluation. ABI was measured by portable Doppler Medpej®DF 7001.

Results

The age was 44.8±8.7yo, 70% women, HD vintage 136.8±61.6 months, serum phosphorus 6.1±1.0mg/dl and iPTH 2883.7±1165.2pg/ml. 66% of patients had Adragão Score>3, 76% had arteriovenous fistula (AVF) calcification and 52% had lumbar aortic calcification. Adragão Score correlated with AVF calcification (r=0.5;p<0.01) and lumbar aorta (r=0.70;p<0.01). The ABI was 1.79±0.96 and correlated with Adragão score (r=0.54;p<0.01), AVF calcification (r=0.47;p<0,05) and phosphorus level (r=0.84;p<0.05). In sHPT evaluation, we routinely use a simple vascular calcification score on plain radiographic films of pelvis and hands (Adragão score). We verified significant correlation between this score compared to AVF and lumbar aortic calcifications. Moreover, ABI, a simple clinical tool performed at bedside, was strongly correlated with serum phosphorus, Adragão score and AVF calcification. All this findings corroborate with the role of phosphorus in osteoblastic differentiation of VSMC and vessel stiffness caused by media calcification.

Conclusion

We observed high prevalence of vascular calcification in hemodialysis patients with severe hyperparathyroidism using conventional image methods and the ABI was a practice tool for this diagnosis in this population.

Funding

  • Government Support - Non-U.S.