Dados do Trabalho

Título

Sleep quality in Upper Airway Resistance Syndrome indicated by cyclic alternating pattern analysis

Introdução

Upper Airway Resistance Syndrome (UARS) is suspected in individuals with excessive daytime sleepiness, fatigue, and sleep fragmentation associated with increased respiratory effort. UARS can negatively impact daytime function. Conventional polysomnography parameters do not demonstrate significant abnormalities in UARS patients but increase in RERAs. Sleep abnormalities may not be indicated by AASM current manual definition in UARS patients. Cyclic alternating pattern (CAP) is a periodic electroencephalogram activity of non-REM sleep that expresses a condition of sleep instability.

Objetivo

The objective of the study was to compare CAP components between UARS patients and health individuals.

Métodos

Fifteen subjects with UARS and 15 age- and sex- matched controls had their sleep study blinded analyzed. UARS criteria were the presence of sleepiness (Epworth Sleepiness Scale–ESS ≥10) and/or fatigue (Modified Fatigue Impact Scale≥38) associated with an apnea/hypopnea index (AHI)≤5 and a respiratory disturbance index (RDI)>5 events/hour of sleep, and/or flow limitation in more than 30% of total sleep time. Control group criteria were AHI<5 events/hour, RDI≤ 5 events/hour and < 30% of TST with flow limitation and ESS<10, without sleep, clinical, neurological, or psychiatric disorder. CAP electroencephalogram of both groups was analyzed.

Resultados

The number of CAP cycles in NREM 1 stage was significantly higher in UARS patients compared to controls (3.0 ± 1.1 vs 0.5 ± 0.2, respectively). Mean phase B duration in NREM 1 stage was significantly higher in UARS patients compared to control group (31.3 ± 8.1 vs 3.1 ± 1.4). Mean phase B duration in both NREM 2 and 3 were also significantly higher in UARS patients (28.3 ± 1.0 vs 25 ± 0.9, p = 0,02 and 25.3 ± 1.1 vs 21.7 ± 1.0, respectively). There was a significant positive correlation between number of CAP cycles in NREM 1 (r = 0.5) and mean phase B duration in NREM 1 (r = 0.6) and ESS. There was a significant positive correlation between number of CAP cycles in NREM 1 (r = 0.4), mean phase B duration in NREM 3 (r = 0.4) and mean phase B duration in NREM (r = 0.4) and Beck Depression Inventory score (BDI).

Conclusões

We found higher number of CAP cycles in NREM 1 and higher mean phase B duration in NREM 1, 2 and 3 stages in UARS compared to control, suggesting altered sleep regulation leading to sleep instability.

Palavras -chave

Upper Airway Resistance Syndrome, cyclic alternating pattern, sleep instability