Increased microcirculatory heterogeneity in patients with obstructive sleep apnea

Abstract

IntroductionObstructive sleep apnea (OSA) is the most common form of sleep disordered breathing and has been associated with major cardiovascular comorbidities. We hypothesized that the microcirculation is impaired in patients with OSA and that the magnitude of impairment correlates to OSA severity.MethodsSubjects were consecutive patients scheduled for routine diagnostic polysomnography (PSG). OSA was defined by paradoxical rib cage movements together with abdominal excursions and by the apnea-hypopnea index (AHI) (events/hour; no apnea AHI<5; mild apnea 5≤AHI<15; moderate apnea 15≤AHI<30; severe apnea AHI ≥30). Sidestream darkfield imaging was used to assess the sublingual microcirculation. Recordings of sublingual microcirculation (5 random sites) were performed before and after overnight PSG. Data are summarized as mean (±SD); p values <0.05 were considered statistically significant.ResultsThirty-three consecutive patients were included. OSA was diagnosed in 16 subjects (4 moderate, 12 severe). There was no significant difference in microcirculation between subjects with moderate OSA and without OSA. However, compared to subjects without OSA, subjects with severe OSA (AHI≥30) showed a significant decrease of microvascular flow index (-0.07±0.17 vs. 0.08±0.14; p = 0.02) and increase of microvascular flow index heterogeneity (0.06±0.15 vs. -0.06±0.11; p = 0.02) overnight. Multiple regression analysis (adjusted for age and gender) showed both decrease of flow and increase of flow heterogeneity associated with AHI (b = -0.41; F = 1.8; p = 0.04 and b = 0.43; F = 1.9; p = 0.03, respectively).ConclusionAcute overnight microcirculatory changes are observed in subjects with severe OSA characterized by decreased flow and increased flow heterogeneity.

Association of Serum Total Testosterone Levels with Obstructive Sleep Apnea Severity

“…In a study, patients with severe OSA had significantly longer stage N1(%TST) sleep, shorter N3(%TST), and shorter REM sleep than the control group. [28] In our study, REM did not differ in severe OSA, but N3 was shorter, supporting this study. [28] Furthermore, N2 (%TST), NREM AHI, REM AHI parameters, and the ratio of patients with SpO₂<90% were significantly higher, mean SpO 2 , and minimum SpO 2 parameters were significantly lower in the severe OSA.…”

The Assessment of Endothelial Dysfunction among OSA Patients after CPAP Treatment

“…There were no statistically significant differences in flow or heterogeneity between patients with moderate OSA and non-OSA patients. On the other hand, patients with severe OSA presented decreased flow and increased heterogeneity in microcirculation during the night compared with patients without OSA [ 18 ].…”