Six-minute walk distance predicting the risk of mortality in lymphangioleiomyomatosis patients
摘要
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).
MethodsA 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.
Conclusions6-minute walk distance effectively reflects the physical condition and prognosis and can be utilized as an important tool for clinical assessment in LAM patients.