Research Paper|Volume 12, Issue 5|pp 4371—4378

Vitamin D levels are prognostic factors for connective tissue disease associated interstitial lung disease (CTD-ILD)

Yujuan Gao¹, Qi Zhao¹, Xiaohua Qiu¹, Yi Zhuang¹, Min Yu¹, Jinghong Dai¹, Hourong Cai¹, Xin Yan¹

¹Department of Respiratory and Critical Care Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing 210008, Jiangsu, China

* Equal contribution

Received: October 11, 2019Accepted: February 25, 2020Published: March 12, 2020

Copyright © 2020 Gao et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

Objective: Vitamin D deficiency was associated with CTD-ILD and reduced lung function. We sought to confirm that lower Vitamin D level would be related to shorter survival times.

Results: The CTD-ILD patients had lower Vitamin D level(P<0.05). Among patients with CTD-ILD who have improved lung function after treatment, elevation of Vitamin D level was positively associated with ΔFVC (%), ΔFEV1(%) and ΔDLCO-SB (%). The median survival time of patients with high serum 25(OH)D level was significantly longer than the patients with low 25(OH)D level group (16.5 months vs14.0 months, P=0.007). The Vitamin D was identified as an independent prognostic factor with a hazard ratio of 0.869 (95% CI 0.772-0.977, P =0.019).

Conclusions: Vitamin D level was lower in patients with CTD-ILD and associated with poor prognosis. Continuous levels of Vitamin D may be an important serum biomarker of prognosis.

Methods: 85 CTD-ILD patients, 71 Idiopathic pulmonary fibrosis (IPF) patients and 78 healthy control patients were included in the study. In the subgroup analysis, the CTD-ILD patients were divided into anti-MDA5 antibody-positive group and anti-MDA5 antibody-negative group according to the serum autoantibodies results. The survival analysis evaluated effect of Vitamin D level on disease prognosis.