Sleep-disordered breathing and its concomitants in a subclinical population

In order to evaluate possible deficits accompanying sleep-disordered breathing (SDB) in a subclinical population, the nocturnal respiration, health status, and sleep/wake cycle of 46 healthy, heavy-snoring men were measured. Sixty-two percent of these subjects had at least one episode of apnea/hypopnea, while 13% had high levels of apnea/hypopnea [apnea/hypopnea index (AHI) greater than or equal to 5]. Most events occurred in stages 1 or 2 or in REM sleep. Strong relationships between weight and SDB were observed, as were more modest relationships between age and SDB. Correlational procedures indicated relationships between SDB and higher blood pressure, subjective sleepiness, and napping. Because similar, but stronger, relationships involving these variables are observed in patients with a sleep apnea syndrome (SAS), it appears that a continuum exists between heavy-snoring men and patients with SAS. When these subjects were grouped by level of SDB, subjects with high levels of SDB (AHI greater than or equal to 5) had significantly lower nocturnal oxygenation parameters than the remaining subjects. However, there were no between-group differences in health or sleep/wake variables. It is concluded that while apnea/hypopnea events in subclinical populations may not be completely benign events, the level at which they may be considered frankly pathological is presently unclear.