Vitamin C Depletion and All-Cause Mortality in Renal Transplant Recipients

• Published in: Nutrients 2017-06, Vol.9 (6), p.568
• Main Authors: Sotomayor, Camilo G, Eisenga, Michele F, Gomes Neto, Antonio W, Ozyilmaz, Akin, Gans, Rijk O B, Jong, Wilhelmina H A de, Zelle, Dorien M, Berger, Stefan P, Gaillard, Carlo A J M, Navis, Gerjan J, Bakker, Stephan J L
• Format: Article
• Language: English
• Subjects: Adhesion; Adhesion tests; Adult; Ascorbic acid; Ascorbic Acid - blood; Ascorbic Acid Deficiency - complications; Biomarkers; Biomarkers - blood; Body Composition; Body Mass Index; C-reactive protein; C-Reactive Protein - metabolism; Cell adhesion; Cell adhesion & migration; Cell adhesion molecules; Confidence intervals; Creatinine - blood; Depletion; Dietary Supplements; Endpoint Determination; Female; Follow-Up Studies; Health risk assessment; Humans; Inflammation; Inflammation - blood; Inflammation - complications; Intercellular Adhesion Molecule-1 - blood; Kidney - physiopathology; Kidney Diseases - blood; Kidney Diseases - mortality; Kidney Diseases - surgery; Kidney Transplantation; Male; Middle Aged; Mortality; Proportional Hazards Models; Prospective Studies; Proteins; Proteinuria - blood; Proteinuria - diagnosis; Statistical analysis; Vascular cell adhesion molecule 1; Vascular Cell Adhesion Molecule-1 - blood; Vitamin C
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu9060568

Vitamin C may reduce inflammation and is inversely associated with mortality in the general population. We investigated the association of plasma vitamin C with all-cause mortality in renal transplant recipients (RTR); and whether this association would be mediated by inflammatory biomarkers. Vitamin C, high sensitive C-reactive protein (hs-CRP), soluble intercellular cell adhesion molecule 1 (sICAM-1), and soluble vascular cell adhesion molecule 1 (sVCAM-1) were measured in a cohort of 598 RTR. Cox regression analyses were used to analyze the association between vitamin C depletion (≤28 µmol/L; 22% of RTR) and mortality. Mediation analyses were performed according to Preacher and Hayes's procedure. At a median follow-up of 7.0 (6.2-7.5) years, 131 (21%) patients died. Vitamin C depletion was univariately associated with almost two-fold higher risk of mortality (Hazard ratio (HR) 1.95; 95% confidence interval (95%CI) 1.35-2.81, < 0.001). This association remained independent of potential confounders (HR 1.74; 95%CI 1.18-2.57, = 0.005). Hs-CRP, sICAM-1, sVCAM-1 and a composite score of inflammatory biomarkers mediated 16, 17, 15, and 32% of the association, respectively. Vitamin C depletion is frequent and independently associated with almost two-fold higher risk of mortality in RTR. It may be hypothesized that the beneficial effect of vitamin C at least partly occurs through decreasing inflammation.