Meta-analysis finds global glymphatic impairment in sleep disorders versus healthy controls

This meta-analysis synthesized evidence on glymphatic function, as measured by the DTI-ALPS index, in patients with sleep disorders compared to healthy controls. It included 2,315 participants, though the specific study settings and follow-up duration were not reported. The analysis pooled data to assess global glymphatic impairment and deficits in obstructive sleep apnea, without detailing individual interventions or comparators beyond the broad categories of sleep disorders and healthy controls.

Key findings indicate significant global glymphatic dysfunction in sleep disorders, with a standardized mean difference (SMD) of -1.60 (95% CI [-2.65, -0.54], p = 0.003). For obstructive sleep apnea specifically, the meta-analysis reported pronounced deficits, with an SMD of -0.92 (p = 0.003). These results suggest an association between sleep disorders and reduced glymphatic activity, but the analysis did not provide absolute numbers or details on adverse events, as safety data were not reported.

Limitations noted by the authors include extremely high heterogeneity (I2 = 94.7%), which reduces the reliability of the pooled estimates and complicates generalizability. The authors caution against inferring causation from the observational studies included, as the meta-analysis cannot establish causality. Practice relevance was not reported, so clinical implications remain uncertain, and the findings should be interpreted with caution due to the methodological constraints.