CPAP therapy does not decrease carotid IMT in patients with obstructive sleep apnoea
Continuous positive airway pressure (CPAP) does not significantly improve carotid intima-media thickness (IMT) in patients with obstructive sleep apnoea (OSA), according to a new meta-analysis.
“However, carotid IMT was significantly decreased after CPAP treatment in more severe OSA patients and patients with longer CPAP usage,” said researchers.
Pooled data from seven studies, corresponding to 167 cases, showed that there was no significant difference in IMT in OSA patients before and after CPAP (weighted mean difference [WMD], 0.052; 95 percent CI, -0.002 to 0.105; p=0.057). There was significant heterogeneity among studies (p=0.033).
Similarly, a meta-analysis of two included randomized controlled trials (RCTs) showed that CPAP treatment did not significantly change IMT compared with controls (WMD, 0.002; -0.125 to 0.129; p=0.976). No significant publication bias existed among the studies, according to Begg’s and Egger’s tests.
Subgroup analysis showed that those with severe OSA experienced significantly reduced IMT after CPAP treatment (WMD, 0.073; 0.022 to 0.124; p=0.021). Those who received CPAP therapy for at least 6 months also had significantly improved IMT (WMD, 0.121; 0.019 to 0.223; p=0.021).
The meta-analysis involved English articles that measured IMT by ultrasound in adult OSA patients who were receiving CPAP. Case reports, editorials, letters, review articles and animal studies were excluded. Information extracted from the studies included experimental design, CPAP duration, IMT measurements and sample characteristics.
Of the seven eligible studies, two were RCTs while the remaining five were observational studies. Two observational studies did not report the gender distribution in the sample while one did not detail carotid IMT thickness measurement.