TY - JOUR T1 - The effects of endogenous and exogenous vitamin D on the rate of mature elastin degradation in COPD patients JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2016.PA4015 VL - 48 IS - suppl 60 SP - PA4015 AU - Rob Janssen AU - Ruben Zaal AU - Michiel Spanbroek AU - Jody van den Ouweland AU - Pieter Zanen AU - Richard Dekhuijzen AU - Wim Janssens Y1 - 2016/09/01 UR - http://erj.ersjournals.com/content/48/suppl_60/PA4015.abstract N2 - Introduction: Two RCTs suggest that vitamin D supplementation lowers exacerbation frequency in vitamin D deficient COPD patients (Lehouck, A. et al. Ann Intern Med 2012; 156:105-14/Martineau, A.R. et al. Lancet Respir Med 2015; 3:e24-5). However, information regarding the effect of vitamin D on the rate of mature elastin degradation is lacking. We hypothesized that vitamin D supplementation in vitamin D deficient (serum 25-[OH]D<20 ng/mL) COPD patients reduces the rate of mature elastin degradation quantified by plasma desmosines levels (pDES).Methods: pDES was measured by LC-MS/MS in 142 COPD patients from the Leuven vitamin D intervention trial (100,000 IU vitamin D supplementation or placebo every 4 weeks for 1 year).Results: At baseline, no significant correlation was found between 25-[OH]D and pDES levels. No significant interaction between 25-[OH]D change and pDES change was found in the placebo arm. In the vitamin D supplementation arm, a significant negative association was found between pDES change and baseline 25-[OH]D levels (r=-0.44;p<0.001;n=56). Conclusions Endogenous vitamin D did not have an effect on the rate of mature elastin degradation. However, opposite to our hypothesis, exogenous high doses of vitamin D accelerated the rate of mature elastin degradation in vitamin D deficient COPD patients and decelerated this process in those who were vitamin D sufficient at baseline. ER -