title: Astaxanthin has no effect on arterial stiffness, oxidative stress, or inflammation in renal transplant recipients: a randomized controlled trial (the XANTHIN trial).
abstract: BACKGROUND
  There is evidence that renal transplant recipients have accelerated atherosclerosis that is manifest by increased cardiovascular morbidity and mortality. The high incidence of atherosclerosis is, in part, related to increased arterial stiffness, vascular dysfunction, elevated oxidative stress, and inflammation associated with immunosuppressive therapy. The carotenoid astaxanthin has shown potent antioxidant and anti-inflammatory properties.
  
  
  OBJECTIVE
  The aim was to investigate the effects of oral astaxanthin on arterial stiffness, oxidative stress, and inflammation in renal transplant recipients.
  
  
  METHODS
  This trial used a randomized, placebo-controlled, double-blind design in which 61 patients received either 12 mg astaxanthin/d or an identical placebo orally for 1 y. Primary outcomes were 1) arterial stiffness measured by aortic pulse wave velocity (PWV), 2) oxidative stress assessed by total plasma F2-isoprostanes, and 3) inflammation assessed by plasma pentraxin-3. Secondary outcomes included vascular function, carotid artery intima-media thickness, augmentation index, central blood pressure, subendocardial viability ratio, and additional measures of oxidative stress and inflammation. Patients underwent assessments at baseline and at 6 and 12 mo.
  
  
  RESULTS
  Fifty-eight participants completed the study. There were no significant between-group differences in the changes in any of the primary outcome measures (PWV changed by +9.5% and +6.0%, F2-isoprostanes changed by -3.0% and -9.7%, and pentraxin-3 changed by +50.6% and -11.0% in the placebo and astaxanthin groups, respectively). There were no significant between-group differences in secondary outcome measures. Larger-than-expected variability decreased the power of the study and increased the possibility of a type 2 statistical error.
  
  
  CONCLUSIONS
  Astaxanthin (12 mg/d for 12 mo) had no effect on arterial stiffness, oxidative stress, or inflammation in renal transplant recipients. This trial was registered at the Australian New Zealand Clinical Trials Registry (http://www.anzctr.org.au/) as ACTRN12608000159358.
authors.affiliation: School of Human Movement and Nutrition Sciences, University of Queensland, St. Lucia, Australia; and jcoombes@uq.edu.au.
authors.forename: Jeff S
authors.identifier: http://orcid.org/0000-0002-6990-3596
authors.initials: JS
authors.lastname: Coombes
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Australia.
authors.forename: James E
authors.identifier: http://orcid.org/0000-0003-2792-0811
authors.initials: JE
authors.lastname: Sharman
authors.affiliation: School of Human Movement and Nutrition Sciences, University of Queensland, St. Lucia, Australia; and.
authors.forename: Robert G
authors.identifier: http://orcid.org/0000-0002-5318-6940
authors.initials: RG
authors.lastname: Fassett
mesh_terms: D000328:Adult; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D050197:Atherosclerosis / Q000209:etiology; D002097:C-Reactive Protein / Q000378:metabolism; D004311:Double-Blind Method; D028441:F2-Isoprostanes / Q000097:blood; D005260:Female; D006801:Humans; D007165:Immunosuppression Therapy / Q000009:adverse effects; D007249:Inflammation / Q000097:blood / Q000209:etiology; D007668:Kidney / Q000601:surgery*; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects*; D063177:Pulse Wave Analysis; D000683:Serum Amyloid P-Component / Q000378:metabolism; D059289:Vascular Stiffness / Q000187:drug effects*; D024341:Xanthophylls / Q000494:pharmacology; D000099153:Pentraxins
chemical_list: D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D002097:C-Reactive Protein; D028441:F2-Isoprostanes; D000683:Serum Amyloid P-Component; D024341:Xanthophylls; D000099153:Pentraxins; C005948:astaxanthine
keywords: F2-isoprostanes; carotid artery intima-media thickness; pentraxin-3; pulse wave velocity; vascular function