Toxins (May 2020)

Sevelamer Use in End-Stage Kidney Disease (ESKD) Patients Associates with Poor Vitamin K Status and High Levels of Gut-Derived Uremic Toxins: A Drug–Bug Interaction?

  • Lu Dai,
  • Björn K. Meijers,
  • Bert Bammens,
  • Henriette de Loor,
  • Leon J. Schurgers,
  • Abdul Rashid Qureshi,
  • Peter Stenvinkel,
  • Pieter Evenepoel

DOI
https://doi.org/10.3390/toxins12060351
Journal volume & issue
Vol. 12, no. 6
p. 351

Abstract

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Gut microbial metabolism is not only an important source of uremic toxins but may also help to maintain the vitamin K stores of the host. We hypothesized that sevelamer therapy, a commonly used phosphate binder in patients with end-stage kidney disease (ESKD), associates with a disturbed gut microbial metabolism. Important representatives of gut-derived uremic toxins, including indoxyl sulfate (IndS), p-Cresyl sulfate (pCS), trimethylamine N-oxide (TMAO), phenylacetylglutamine (PAG) and non-phosphorylated, uncarboxylated matrix-Gla protein (dp-ucMGP; a marker of vitamin K status), were analyzed in blood samples from 423 patients (65% males, median age 54 years) with ESKD. Demographics and laboratory data were extracted from electronic files. Sevelamer users (n = 172, 41%) were characterized by higher phosphate, IndS, TMAO, PAG and dp-ucMGP levels compared to non-users. Sevelamer was significantly associated with increased IndS, PAG and dp-ucMGP levels, independent of age, sex, calcium-containing phosphate binder, cohort, phosphate, creatinine and dialysis vintage. High dp-ucMGP levels, reflecting vitamin K deficiency, were independently and positively associated with PAG and TMAO levels. Sevelamer therapy associates with an unfavorable gut microbial metabolism pattern. Although the observational design precludes causal inference, present findings implicate a disturbed microbial metabolism and vitamin K deficiency as potential trade-offs of sevelamer therapy.

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