The association between decreased ALPS index and emphysema as well as cognitive function in patients with COPD.

BACKGROUND

We evaluated the changes in ALPS index and related factors in patients with chronic obstructive pulmonary disease (COPD) through diffusion tensor imaging along the perivascular space (DTI-ALPS).

METHODS

This prospective study enrolled 41 patients with COPD and 38 healthy volunteers. All participants completed magnetic resonance imaging scans, pulmonary function tests, and COPD severity assessment, stroke risk, and cognitive function. Also, included 33 patients with COPD whose complete chest computed tomography (CT) images were available. We used DTI data to construct an index of diffusivity along the perivascular space (ALPS index) and calculated the percentages (%) of low-attenuation areas below -950 HU (LAA%--950) from CT images. We compared the ALPS index between patients with COPD and healthy controls and assessed the correlation of the ALPS index with clinical traits, cognitive function, and LAA%-950.

RESULTS

The ALPS index was significantly lower in patients with COPD than healthy controls (P = 0.003). Mini-Mental State Examination score (r = 0.445, P = 0.004), disease duration (r = -0.555, P < 0.001), and lgLAA%-950 (r = -0.356, P = 0.042) were correlated with ALPS index in patients with COPD. After adjusting for factors impacting the GS function, the above correlations remained significant (β = 0.04, P = 0.005; β = 0.02, P < 0.001; β = 0.06, P = 0.043, respectively).

CONCLUSIONS

Patients with COPD have a lower ALPS index, which is correlated with the cognitive impairment, emphysema and disease duration. This new understanding provides new insights into the potential processes of brain injury associated with COPD.