BACKGROUND

Serum lipoproteins, such as high-density lipoproteins (HDL), may influence disease severity in idiopathic pulmonary fibrosis (IPF). Here, we investigated associations between serum lipids and lipoproteins and clinical end-points in IPF.

METHODS

Clinical data and serum lipids were analysed from a discovery cohort (59 IPF subjects, 56 healthy volunteers) and validated using an independent, multicentre cohort (207 IPF subjects) from the Pulmonary Fibrosis Foundation registry. Associations between lipids and clinical end-points (forced vital capacity, 6-min walk distance, gender age physiology (GAP) index, death or lung transplantation) were examined using Pearson's correlation and multivariable analyses.

RESULTS

Serum concentrations of small HDL particles measured using nuclear magnetic resonance spectroscopy (S-HDLP) correlated negatively with the GAP index in the discovery cohort of IPF subjects. The negative correlation of S-HDLP with GAP index was confirmed in the validation cohort of IPF subjects. Higher levels of S-HDLP were associated with lower odds of death or its competing outcome, lung transplantation (OR 0.9 for each 1-μmol·L increase in S-HDLP, p<0.05), at 1, 2 and 3 years from study entry in a combined cohort of all IPF subjects.

CONCLUSIONS

Higher serum levels of S-HDLP are negatively correlated with the GAP index, as well as with lower observed mortality or lung transplantation in IPF subjects. These findings support the hypothesis that S-HDLP may modify mortality risk in patients with IPF.