Relation of Sleepiness to Respiratory Disturbance Index

Abstract

Obstructive sleep apnea syndrome is a well recognized cause of excessive sleepiness; however, the relation of sleepiness to mild sleep-disordered breathing (SDB), which affects as much as half the adult population, is uncertain. In order to explore this relation, we conducted a cross-sectional cohort study of community-dwelling adults participating in the Sleep Heart Health Study, a longitudinal study of the cardiovascular consequences of SDB. The study sample comprises 886 men and 938 women, with a mean age of 65 (SD 11) yr. Sleepiness was quantified using the Epworth Sleepiness Scale (ESS). Sleep-disordered breathing was quantified by the respiratory disturbance index (RDI), defined as the number of apneas plus hypopneas per hour of sleep, measured during in-home polysomnography. When RDI was categorized into four groups (< 5, 5 to < 15, 15 to < 30, >/= 30), a significantly progressive increase in mean ESS score was seen across all four levels of SDB, from 7.2 (4.3) in subjects with RDI < 5 to 9.3 (4.9) in subjects with RDI >/= 30 (p < 0.001). There was no significant modification of this effect by age, sex, body mass index, or evidence of chronic restriction of sleep time or periodic limb movement disorder. The percentage of subjects with excessive sleepiness, defined as an ESS score >/= 11, increased from 21% in subjects with RDI < 5 to 35% in those with RDI >/= 30 (p < 0. 001). We conclude that SDB is associated with excess sleepiness in community-dwelling, middle-aged and older adults, not limited to those with clinically apparent sleep apnea.

Excessive Daytime Sleepiness Increases the Risk of Motor Vehicle Crash in Obstructive Sleep Apnea

“…2 It has long been recognized that there is a poor relationship between the AHI-defined severity of OSA and the degree of daytime sleepiness. [24][25][26][27] It remains unclear why one individual with an AHI of 15 may be sleepy whereas another may be asymptomatic. 28 This poor correlation between AHI and ESS is reflected in our WASHS cohort data (r = 0.18).…”

Associations between weight change since 20 years of age and sleep-disordered breathing among male truck drivers

“…6 In Japan, the prevalence of BMI X30 in 2004 was much lower at 3% among adults aged 15 years or older. 7 The prevalence of SDB (apnea-hypopnea index (AHI), X15) was 9-14% for western adult men [8][9][10] and 5-10% for their Asian counterparts. 11,12 We previously reported that SDB was positively associated with overweight and excessive daytime sleepiness among Japanese adults.…”

Rehabilitation of Cardiovascular Disorders and Sleep Apnea

“…61,62 All of the studies discussed earlier showed that lower ESS scores and BMI in patients with stroke or HF and OSA cannot be explained by differences in the severity of OSA or other confounding factors and that those are not sensitive independent predictors of the presence of OSA. 63 Therefore, regardless of the underlying mechanisms, lower ESS scores and BMI may make the diagnosis of OSA less likely in the rehabilitation period, and as a result may have a negative impact on clinical course and outcome.…”