Evaluation of the structural organization of sleep in obstructive apnea syndrome from the perspective of modern pathophysiology

Abstract

To evaluate the features of structural organization of sleep in men 35-55 years of age with varying degrees of severity and duration of clinical manifestations of obstructive sleep apnea syndrome (OSAS) from the perspective of modern pathophysiology. The study included 49 male patients, aged 35-55 years (average age was 43.4±9.2 years), with a body mass index (BMI) of 33.64±1.2 kg/m2 with complaints of snoring of varying degrees of intensity, daytime sleepiness, arrest of breathing during sleep (according to others). The control group consisted of 15 healthy men who did not have complaints of sleep disorders and clinical manifestations of OSAS. The Pittsburgh sleep quality index (PSQI) questionnaire and polysomnographic monitoring study (PSG) were used. According to the results of the polysomnographic study, all patients were divided into 2 subgroups: 12 men of group 1with moderate OSAS (duration of clinical manifestations 4.5±1.0 years) and 37 men of group 2 with severe OSAS (duration 1.5±1.5 years). A decrease in the sleep quality was detected in 61.9% of patients in the group 1 and 89.2% of patients in the group 2. Significantly higher scores for the components of «sleep disturbance» and «daytime dysfunction» in patients with a longer duration of clinical manifestations were detected. Changes in the structure of sleep were identified in patients compared with controls. A statistically significant increase in WASO led to the reduction of sleep efficiency. In patients of group 2, a deficiency of the deep stages and REM-sleep was determined. There was a significant increase in the number of arousals in patients of both groups relative to the controls. Moreover, significant between-group differences were found. The short duration of OSAS symptoms causes a restructuring of the physiological system of sleep homeostasis to a different level of functioning with compensatory hyperfunction of the structures responsible for REM sleep and a decrease (economization) in the activity of anabolic processes during sleep due to a decrease in SWS, which is a characteristic feature of long-term adaptation. Severe course of OSAS leads to the appearance of specific phenomena of gross structural disorganization of sleep - «alpha-delta sleep» and disruption of its segmental organization, which shows the depletion and disruption of compensatory-adaptive mechanisms in the system of sleep homeostasis, disintegration and transformation of functional physiological system in the pathological condition.