High-dose supplementation of selenium in left ventricular assist device implant surgery: A double-blinded, randomized controlled pilot trial.

BACKGROUND: Systemic inflammation and oxidative stress remain the main causes of complications in patients with heart failure receiving a left ventricular assist device (LVAD). Selenoproteins are a cornerstone of antioxidant defense mechanisms for improving inflammatory conditions. METHODS: In a monocentric, double-blinded pilot trial patients scheduled for LVAD implantation were randomized to receive 300 mcg of selenium orally the evening before surgery, followed by a high-dose of intravenous selenium supplementation (3000 mcg after anesthesia induction, 1000 mcg upon intensive care unit [ICU] admission, and 1000 mcg daily in the ICU for a maximum of 14 days) or placebo. The main outcomes were feasibility and effectiveness in restoring serum selenium concentrations. RESULTS: Twenty patients were included in the analysis. The average duration of study intervention was 12.6 days (7-14), with 97.7% dose compliance. No patient received open-label selenium. The supplementation strategy was effective in compensating low serum selenium concentrations (before surgery: control, 63.5 ± 11.9 mcg/L vs intervention, 65.8 ± 16.5 mcg/L; ICU admission: control, 49.0 ± 9.8 mcg/L vs intervention, 144.2 ± 45.4 mcg/L). Serum selenium concentrations in the intervention group were significantly higher during the observation period (baseline: mean of placebo (MoP), 63.1 vs mean of selenium (MoS), 64.0; ICU admission: MoP, 49.0 vs MoS, 144.6; day 1-13: MoP, 43.6-48.5 vs MoS, 100.4-131.0). CONCLUSION: Selenium supplementation in patients receiving LVAD implantation is feasible and effective to compensate a selenium deficiency.

Selenoprotein P as Biomarker of Selenium Status in Clinical Trials with Therapeutic Dosages of Selenite.

Selenoprotein P (SELENOP) is an established biomarker of selenium (Se) status. Serum SELENOP becomes saturated with increasing Se intake, reaching maximal concentrations of 5-7 mg SELENOP/L at intakes of ca. 100-150 µg Se/d. A biomarker for higher Se intake is missing. We hypothesized that SELENOP may also reflect Se status in clinical applications of therapeutic dosages of selenite. To this end, blood samples from two supplementation studies employing intravenous application of selenite at dosages >1 mg/d were analyzed. Total Se was quantified by spectroscopy, and SELENOP by a validated ELISA. The high dosage selenite infusions increased SELENOP in parallel to elevated Se concentrations relatively fast to final values partly exceeding 10 mg SELENOP/L. Age or sex were not related to the SELENOP increase. Western blot analyses of SELENOP verified the results obtained by ELISA, and indicated an unchanged pattern of immunoreactive protein isoforms. We conclude that the saturation of SELENOP concentrations observed in prior studies with moderate Se dosages (<400 µg/d) may reflect an intermediate plateau of expression, rather than an absolute upper limit. Circulating SELENOP seems to be a suitable biomarker for therapeutic applications of selenite exceeding the recommended upper intake levels. Whether SELENOP is also capable of reflecting other supplemental selenocompounds in high dosage therapeutic applications remains to be investigated.