# Six-minute walk distance predicting the risk of mortality in lymphangioleiomyomatosis patients

## TL;DR

This study shows that the six-minute walk test can predict mortality risk in lymphangioleiomyomatosis patients, helping doctors assess their prognosis.

## Contribution

The study identifies a specific 6MWD cut-off value (425.5 m) as a novel predictor of mortality risk in LAM patients.

## Key findings

- A 6MWD of less than 425.5 meters is strongly associated with higher mortality risk in LAM patients.
- 6MWD correlates with pulmonary function and quality of life indicators in LAM patients.
- Sirolimus treatment is linked to improved survival in LAM patients.

## Abstract

The study aims to explore the value of the six-minute walk test (6MWT) in assessing the severity and prognosis of patients with lymphangioleiomyomatosis (LAM).

A retrospective analysis was conducted on 403 LAM patients from the LAM registry study at the Peking Union Medical College Hospital (PUMCH). Survival and progression datasets were constructed. Results: ROC curve analysis established the optimal cut-off value for the six-minute walk distance (6MWD) to predict increased risk of mortality was 425.5 m. The 6MWD low group (6MWD < 425.5 m) exhibited lower SpO₂, higher rates of desaturation, higher post-6MWT Borg dyspnea scale scores, worse pulmonary function indicators (FEV1%pred and DLCO%pred), and poorer quality of life assessments (SGRQ) (P < 0.001). Furthermore, the 6MWD showed a significant positive correlation with baseline FEV1%pred (P < 0.001). Multivariate regression analysis indicated that 6MWD, age, desaturation, and post-6MWT Borg dyspnea scale scores were independently correlated with baseline FEV1%pred (P < 0.001). Progression dataset analysis demonstrated no significant correlation between 6MWT parameters and the annual decline in FEV1. Kaplan-Meier survival curves showed a significantly reduced survival probability for patients with 6MWD < 425.5 m, desaturation, or post-6MWT Borg dyspnea scale≥2. Multivariate Cox regression indicated that 6MWD < 425.5 m (HR = 3.759, P = 0.0375), FEV1%pred < 70% (HR = 12.48, P = 0.0045), and sirolimus (HR = 0.1194, P < 0.001) were independent factors affecting survival in patients.

6-minute walk distance effectively reflects the physical condition and prognosis and can be utilized as an important tool for clinical assessment in LAM patients.

The online version contains supplementary material available at 10.1186/s13023-026-04194-9.