Astaxanthin vs placebo on arterial stiffness, oxidative stress and inflammation in renal transplant patients (Xanthin): a randomised controlled trial.
BACKGROUND
There is evidence that renal transplant recipients have accelerated atherosclerosis 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 dietary supplement astaxanthin has shown promise as an antioxidant and anti-inflammatory therapeutic agent in cardiovascular disease. The aim of this trial is to investigate the effects of astaxanthin supplementation on arterial stiffness, oxidative stress and inflammation in renal transplant patients.


METHODS
This is a randomised, placebo controlled clinical trial. A total of 66 renal transplant recipients will be enrolled and allocated to receive either 12 mg/day of astaxanthin or an identical placebo for one-year. Patients will be stratified into four groups according to the type of immunosuppressant therapy they receive: 1) cyclosporine, 2) sirolimus, 3) tacrolimus or 4) prednisolone+/-azathioprine, mycophenolate mofetil or mycophenolate sodium. Primary outcome measures will be changes in 1) arterial stiffness measured by aortic pulse wave velocity (PWV), 2) oxidative stress assessed by plasma isoprostanes and 3) inflammation by plasma pentraxin 3. Secondary outcomes will include changes in vascular function assessed using the brachial artery reactivity (BAR) technique, carotid artery intimal medial thickness (CIMT), augmentation index (AIx), left ventricular afterload and additional measures of oxidative stress and inflammation. Patients will undergo these measures at baseline, six and 12 months.


CONCLUSIONS
The results of this study will help determine the efficacy of astaxanthin on vascular structure, oxidative stress and inflammation in renal transplant patients. This may lead to a larger intervention trial assessing cardiovascular morbidity and mortality.


BACKGROUND
ACTRN12608000159358.
Fassett
Robert G
RG
Renal Research, Royal Brisbane and Women's Hospital, Herston, Brisbane, Queensland, Australia. rfassett@mac.com
Healy
Helen
H
Driver
Ritza
R
Robertson
Iain K
IK
Geraghty
Dominic P
DP
Sharman
James E
JE
Coombes
Jeff S
JS
D001158:Arteries / Q000187:drug effects / Q000503:physiopathology*; D001167:Arteritis / Q000097:blood*; D002097:C-Reactive Protein / Q000378:metabolism; D004311:Double-Blind Method; D006801:Humans; D016030:Kidney Transplantation; D018384:Oxidative Stress / Q000187:drug effects*; D011184:Postoperative Period; D011673:Pulsatile Flow / Q000187:drug effects*; D012107:Research Design; D000683:Serum Amyloid P-Component / Q000378:metabolism; D024341:Xanthophylls / Q000627:therapeutic use; D000099153:Pentraxins
D002097:C-Reactive Protein; D000683:Serum Amyloid P-Component; D024341:Xanthophylls; D000099153:Pentraxins; C005948:astaxanthine