Metabolic syndrome increases dietary α-tocopherol requirements as assessed using urinary and plasma vitamin E catabolites: a double-blind, crossover clinical trial

Am J Clin Nutr. 2017 Mar;105(3):571-579. doi: 10.3945/ajcn.116.138495. Epub 2017 Jan 11.

Abstract

Background: Vitamin E supplementation improves liver histology in patients with nonalcoholic steatohepatitis, which is a manifestation of the metabolic syndrome (MetS). We reported previously that α-tocopherol bioavailability in healthy adults is higher than in those with MetS, thereby suggesting that the latter group has increased requirements.Objective: We hypothesized that α-tocopherol catabolites α-carboxyethyl hydroxychromanol (α-CEHC) and α-carboxymethylbutyl hydroxychromanol (α-CMBHC) are useful biomarkers of α-tocopherol status.Design: Adults (healthy or with MetS; n = 10/group) completed a double-blind, crossover clinical trial with four 72-h interventions during which they co-ingested 15 mg hexadeuterium-labeled RRR-α-tocopherol (d6-α-T) with nonfat, reduced-fat, whole, or soy milk. During each intervention, we measured α-CEHC and α-CMBHC excretions in three 8-h urine collections (0-24 h) and plasma α-tocopherol, α-CEHC, and α-CMBHC concentrations at various times ≤72 h.Results: During the first 24 h, participants with MetS compared with healthy adults excreted 41% less α-CEHC (all values are least-squares means ± SEMs: 0.6 ± 0.1 compared with 1.0 ± 0.1 μmol/g creatinine, respectively; P = 0.002), 63% less hexadeuterium-labeled (d6)-α-CEHC (0.04 ± 0.02 compared with 0.13 ± 0.02 μmol/g creatinine, respectively; P = 0.002), and 58% less d6-α-CMBHC (0.017 ± 0.004 compared with 0.041 ± 0.004 μmol/g creatinine, respectively; P = 0.0009) and had 52% lower plasma d6-α-CEHC areas under the concentration curves [area under the curve from 0 to 24 h (AUC0-24h): 27.7 ± 7.9 compared with 58.4 ± 7.9 nmol/L × h, respectively; P = 0.01]. d6-α-CEHC peaked before d6-α-T in 77 of 80 paired plasma concentration curves. Urinary d6-α-CEHC 24-h concentrations were associated with the plasma AUC0-24 h of d6-α-T (r = 0.53, P = 0.02) and d6-α-CEHC (r = 0.72, P = 0.0003), and with urinary d6-α-CMBHC (r = 0.88, P < 0.0001), and inversely with the plasma inflammation biomarkers C-reactive protein (r = -0.70, P = 0.0006), interleukin-10 (r = -0.59, P = 0.007), and interleukin-6 (r = -0.54, P = 0.01).Conclusion: Urinary α-CEHC and α-CMBHC are useful biomarkers to noninvasively assess α-tocopherol adequacy, especially in populations with MetS-associated hepatic dysfunction that likely impairs α-tocopherol trafficking. This trial was registered at clinicaltrials.gov as NCT01787591.

Keywords: bioavailability; metabolic syndrome; nutrient requirements; vitamin E; α-CEHC; α-carboxyethyl hydroxychromanol; α-carboxymethylbutyl hydroxychromanol.

Publication types

  • Clinical Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Area Under Curve
  • Biomarkers / blood
  • Biomarkers / urine
  • C-Reactive Protein / metabolism
  • Chromans / blood
  • Chromans / metabolism*
  • Chromans / urine
  • Creatinine / urine
  • Cross-Over Studies
  • Double-Blind Method
  • Female
  • Humans
  • Inflammation / blood
  • Interleukin-10 / blood
  • Interleukin-6 / blood
  • Liver / pathology
  • Male
  • Metabolic Syndrome / metabolism*
  • Metabolic Syndrome / pathology
  • Nutritional Requirements*
  • Nutritional Status*
  • Pentanoic Acids / blood
  • Pentanoic Acids / metabolism*
  • Pentanoic Acids / urine
  • Young Adult
  • alpha-Tocopherol / metabolism*

Substances

  • 5-(6-hydroxy-2,5,7,8-tetramethyl-chroman-2-yl)-2-methyl-pentanoic acid
  • Biomarkers
  • Chromans
  • Interleukin-6
  • Pentanoic Acids
  • carboxyethyl-hydroxychroman
  • Interleukin-10
  • C-Reactive Protein
  • Creatinine
  • alpha-Tocopherol

Associated data

  • ClinicalTrials.gov/NCT01787591