FP352COMBINED LOW STATUS OF VITAMIN D AND VITAMIN K IS ASSOCIATED WITH ALL-CAUSE MORTALITY AND PREMATURE GRAFT FAILURE IN STABLE KIDNEY TRANSPLANT RECIPIENTS

Abstract

Introduction and Aims: Kidney transplant recipients (KTR) are often low in micronutrient status, including vitamin D and K status. The long-term implications of combined low statusof vitamin D andKinKTR are unknown. Weinvestigated vitamin D and K status in relation to all-cause mortality and premature graft failure in stable outpatient KTR. Methods: We studied 461 KTR from a single-center after median 6.1 years (interquartile range 3.0-11.9) after transplantation. At baseline, vitamin D and K status were measured by 25-hydroxyvitamin D [25(OH)D] and dephosphorylated uncarboxylated matrix gla protein (dp-ucMGP) respectively. Vitamin D and vitamin K were categorized by 25(OH)D <50/>50 mmol/L and median dp-ucMGP <996/>996 pmol/L. We used Cox regression analyses to estimate hazard ratios (HR) and 95% confidence intervals. Results: At baseline, mean age was 526 12 years, and 122 KTR (26%) had combined low vitamin D and K status. During median 9.8 years (interquartile range 8.7-10.3) fol-low-up, 128 patients (28%) died and 48 (10%) developed graft failure. Combined low vitamin D and K status was associated with 2.46 (95% CI 1.30-4.63) greater risk of all cause-mortality and a 2.93 (95% CI 1.05-8.13) greater risk of graft failure. Of all KTR, 45 (10%) used vitamin D supplements, mainly alfacalcido (80%). Plasma dp-ucMGP was more strongly associated with all-cause mortality and graft failure in vitamin D supplement users compared to no vitamin D supplement users: HR per 500 pmol/L ducMGP 1.11 (1.04-1.19) and 1.41 (1.08-1.84), (see Figure 1,P-for interaction 0.06 and 0.108, respectively adjusted for age and sex). Conclusions: Combined low vitamin D and K status is highly prevalent in stable KTR. The joint association of low vitamin D and K status is associated with greater risk of premature mortality. Vitamin D supplement users with low vitamin K status have a strong risk of premature mortality and graft failure compared to non-users. Future studies should address whether combined vitamin D and K supplementation may lead to improved outcomes after kidney transplantation.