Upper airway resistance syndrome patients have worse sleep quality compared to mild obstructive sleep apnea

Abstract

Purpose: To compare sleep quality and sustained attention of patients with Upper Airway Resistance Syndrome (UARS), mild Obstructive Sleep Apnea (OSA) and normal individuals. Methods: UARS criteria were presence of excessive daytime sleepiness (Epworth Sleepiness Scale - ESS - ≥ 10) and/or fatigue (Modified Fatigue Impact Scale - MFIS - ≥ 38) associated to Apnea/hypopnea index (AHI) ≤ 5 and Respiratory Disturbance Index (RDI) > 5 events/hour of sleep or more than 30% of total sleep time with flow limitation. Mild OSA was considered if the presence of excessive daytime sleepiness (ESS ≥ 10) and/or fatigue (MFIS ≥ 38) associated to AHI ≥ 5 and ≤ 15 events/hour. "Control group" criteria were AHI < 5 events/hour and RDI ≤ 5 events/hour and ESS ≤ 9, without any sleep, clinical, neurological or psychiatric disorder. 115 individuals (34 UARS and 47 mild OSA patients and 34 individuals in "control group"), adjusted for age, gender, body mass index (BMI) and schooling years, performed sleep questionnaires and sustained attention evaluation. Psychomotor Vigilance Task (PVT) was performed five times (each two hours) from 8 a.m. to 4 p.m. Results: UARS patients had worse sleep quality (Functional Outcomes of Sleep Questionnaire - FOSQ - and Pittsburgh Sleep Quality Index - PSQI: p < 0.05) and more fatigue than mild OSA patients (p = 0.003) and scored significantly higher in both Beck inventories than "control group" (p < 0.02). UARS patients had more lapses early in the morning (in time 1) compared to the results in the afternoon (time 5) than mild OSA (p = 0.02). Mild OSA patients had more lapses in times 2 than in time 5 compared to "control group" (p = 0.04). Conclusions: UARS patients have a worse sleep quality, more fatigue and a worse early morning sustained attention compared to mild OSA. These last had a worse sustained attention than controls.