Association between body fat decrease during the first year after diagnosis and the prognosis of idiopathic pulmonary...

Area of Science:

• Pulmonology
• Radiology
• Body Composition Analysis

Background:

• The prognostic significance of body fat changes in idiopathic pulmonary fibrosis (IPF) is not well understood.
• Investigating the impact of body fat alterations in the first year post-diagnosis on IPF patient outcomes is crucial.

Purpose of the Study:

• To determine the association between changes in body fat area during the first year after IPF diagnosis and patient outcomes.
• To evaluate if body fat changes serve as an independent prognostic factor in IPF.

Main Methods:

• Retrospective analysis of 307 IPF patients with CT scans and pulmonary function tests at diagnosis and one-year follow-up.
• Deep learning software used to quantify fat and muscle areas at the T12-L1 level from CT images.
• Cox regression and log-rank tests analyzed the association between body composition changes and a composite outcome of death or lung transplantation.

Main Results:

• A decrease in fat area ≥ 52.3 cm² during the first year was associated with an increased risk of the composite outcome (HR 1.566, P=0.022).
• This association remained significant after adjusting for baseline and one-year clinical variables.
• Patients with significant fat area decrease had a higher incidence of the composite outcome (58.4% vs. 43.9%, P=0.007).

Conclusions:

• A decrease of ≥ 52.3 cm² in fat area at T12-L1 within one year post-diagnosis is an independent predictor of poor prognosis in IPF patients.
• Deep learning-based measurement of body composition changes offers valuable prognostic information in IPF.