U-Shaped Relationship Between MSpO2 Levels and the Incidence of Frailty in Elderly OSA Patients: Findings from a Multicenter Cohort Study.

Abstract

Background: Previous studies have demonstrated a significant correlation between obstructive sleep apnea (OSA) and frailty. However, the association of mean pulse oxygen saturation (MSpO₂) with frailty among OSA patients remains unconfirmed. This study aimed to explore this potential association using data from a multicenter, prospective cohort.

Methods: A total of 1006 elderly patients diagnosed with OSA through polysomnography (PSG) from January 2015 to October 2017 were enrolled. Patients were stratified into four groups according to their MSpO₂ levels to assess differences in frailty onset. Multivariate Cox regression analysis, Kaplan-Meier curves, restricted cubic splines, and subgroup analyses were employed to evaluate variations in frailty onset across different MSpO₂ levels.

Results: Over a median follow-up period of 52 months, 275 patients developed frailty. Analysis using restricted cubic splines revealed a U-shaped trend between MSpO₂ and frailty risk (non-linear p-value = 0.028). Patients in the lowest quartile (MSpO₂ < 91.6%) exhibited a higher risk of frailty (hazard ratio [HR] = 1.43, 95% confidence interval [CI] 1.03-1.97, P = 0.029) compared to those in the third quartile (MSpO₂ 93-95%). Subgroup and sensitivity analyses confirmed the robustness of the U-shaped relationship.

Conclusion: There is a U-shaped association between MSpO₂ and frailty among patients with OSA. Enhancing MSpO₂ levels may mitigate the risk of frailty and improve prognosis in this population.