Prognostic Impact of Serum Transthyretin and Sarcopenia on 3-Year Mortality and Respiratory-Related Hospitalizations in Idiopathic Pulmonary Fibrosis: A Prospective Cohort Study.

内容摘要

Prognostic markers reflecting nutritional vulnerability in idiopathic pulmonary fibrosis (IPF) remain poorly defined. In this prospective cohort study, 63 stable outpatients with IPF were followed for 3 years. Sarcopenia was defined according to the 2019 Asian Working Group for Sarcopenia criteria. Serum transthyretin levels were measured concurrently. Cox proportional hazards regression, binary logistic regression, and Kaplan-Meier survival analyses were performed. During follow-up, 18 patients (29%) died and 21 (33%) experienced respiratory-related hospitalization. Serum transthyretin was an independent predictor of both 3-year mortality and respiratory-related hospitalization, even after adjusting for the Gender-Age-Physiology index. Conversely, sarcopenia and low appendicular skeletal muscle mass index (ASMI) were not independently associated with either outcome. Kaplan-Meier analysis demonstrated significant differences in both mortality and hospitalization according to serum transthyretin levels. Low ASMI evaluated using sex-specific cutoffs was associated with higher mortality in the unadjusted analysis, but not with hospitalization; sarcopenia was not significantly associated with either endpoint. Serum transthyretin may serve as a practical biomarker of nutritional vulnerability, providing complementary prognostic information beyond muscle mass-based assessment in IPF.