The prognostic role of high-density lipoprotein cholesterol/C- reactive protein ratio in idiopathic pulmonary fibrosis

Abstract Background The prognosis of idiopathic pulmonary fibrosis (IPF) patients is highly heterogeneous. Abnormalities in lipids and their metabolism play an important role in the development of IPF. Aim To investigate the value of lipid parameters, C-reactive protein (CRP) and high-density lipoprotein cholesterol/C-reactive protein (HDL-C/CRP) ratio levels in the prognosis of IPF patients. Design An observational cohort study. Methods We collected baseline data of non-IPF controls and IPF patients, and IPF patients were followed up for 4 years. All-cause death or lung transplantation and IPF-related death were the outcome events. Receiver operating characteristic curves and Cox proportional hazards models were used to analyze the predictive effect of lipid parameters, CRP and HDL-C/CRP ratio on the prognosis of IPF patients. Results IPF patients had lower HDL-C, HDL-C/CRP ratio and higher CRP compared to non-IPF controls. IPF patients who died or underwent lung transplantation were older and had worse pulmonary function, lower HDL-C, HDL-C/CRP ratio and higher CRP compared with surviving patients. HDL-C/CRP ratio was better than HDL-C and CRP in predicting all-cause death or lung transplantation. IPF patients with low HDL-C/CRP ratio had shorter survival times. The HDL-C/CRP ratio and diffusing capacity for carbon monoxide(DLCO)% of predicted were independent protective factors for all-cause death or lung transplantation and IPF-related death in IPF patients, while age and gender-age-physiology (GAP) Stage ≥ 2 (HR = 4.927) were independent risk factors for all-cause death or lung transplantation. Age > 65 years (HR = 3.533) was an independent risk factor for IPF-related death. Conclusion HDL-C/CRP ratio was a valid predictor of clinical outcomes in IPF patients, including all-cause death or lung transplantation and IPF-related death.