Continuous and Loud Snoring Only in the Supine Posture

Abstract

Snoring and suspected sleep apneas are the most frequent causes for referral for a sleep study. Snoring varies across night and is usually recorded in all body postures. Here we report a unique patient showing continuous and loud snoring only in the supine posture.

Citation:

Oksenberg A, Gadoth N. Continuous and loud snoring only in the supine posture. J Clin Sleep Med 2015;11(12):1463–1464.

Snoring and suspected sleep apneas are the most frequent causes for referral for a sleep study. Snoring varies across night and is usually recorded in all body postures. Here we report a unique patient showing continuous and loud snoring only in the supine posture.

REPORT OF CASE

A 61-year-old hypertensive man was referred to our sleep unit because of snoring and obstructive sleep apnea (OSA). According to his wife, he has been snoring intermittently for the last 30 years. He denied sleep apneas. He sleeps from 22:00–23:00 until 05:15 and during daytime only on Saturdays. He does not complain of daytime sleepiness. Epworth Sleepiness Scale (ESS) score is 7. Past medical history includes non-insulin dependent diabetes mellitus, corrected hypocalcaemia and unspecified renal failure. He does not smoke. His body mass index is 27.6.

His complete nocturnal polysomnographic (PSG) evaluation (Embla, S4500) revealed an apnea-hypopnea index (AHI) of 8.8. Apneas/hypopneas were present only in the supine posture and related to REM sleep; AHI supine = 15.1,

AHI lateral = 0, REM AHI = 18.1; NREM AHI = 5.2. Total sleep time (TST) = 367 minutes, TST supine = 214 minutes, TST lateral = 153 minutes.

A unique finding was that the patient snored loudly, continuously, and almost exclusively in the supine posture with maximum intensity of 62 dB. (Quest Sound Level Meter, model 2700 with a calibrated microphone placed 1 meter from his head). Only a few snores were recorded in the right posture (maximal intensity 46 dB). He did not sleep in the left or prone position (Figure 1)

Figure 1.

When sleeping in the supine posture, the snoring was loud and continuous, while in the right posture the snoring almost disappeared. During the 3rd REM period few apneas and desaturations were recorded parallel with continuous snoring which disappeared completely when he turned from the supine to the right side (arrow).

DISCUSSION

The worsening effect of the supine posture during sleep on snoring and in particular on OSA, has led to the development of positional therapy (PT), i.e., the avoidance of the supine position during sleep, as a beneficial behavioral therapy for many patients.¹ The vast majority of sleep apnea patients are positional (56% to 80% of all OSA patients and 65% to 87% of mild OSA patients). For them, the supine posture is the dominant aggravating factor, and thus PT could represent a simple effective mode of therapy.^2,3

One possible limitation of PT is that in spite of its ability to reduce and even eliminate supine sleep time and its related breathing disorders, PT cannot overcome snoring in the lateral postures. A modification of the typical PT, i.e., adopting a slightly elevated upright position (even as little as 15 degrees) decreases the number of snoring events⁴ and thus could represent an additive value to the classical PT for overcoming snoring.

We present a unique patient with loud and continuous snoring almost exclusively in the supine posture. In our experience, this snoring pattern seems to be rare. Indeed, we did not find a similar distinct pattern of supine snoring in 760 consecutive PSG recordings of adults seeking treatment for sleep problems who were evaluated in our unit.

The natural history of snoring is generally referred to snoring occurring at the early stage of this disorder in the supine posture. Snoring at this early stage is sporadic, mainly when the snorer is very tired, when suffering a severe cold or after alcohol consumption. With the passage of time, but mainly following weight gain, snoring appears also in the lateral/prone postures and even in the sitting sleep position.⁵ In most nonapneic snorers, snoring events occur more frequent in the supine posture but also in non-supine positions.⁶ Moreover, when snoring is present in all body postures, the patient usually suffers from different levels of OSA severity.

Unfortunately, the evaluation of the severity and intensity of snoring has not been standardized. We used a calibrated sound level meter for that purpose, but this is not the standard in every sleep unit and is usually not available in ambulatory systems. Moreover, the acoustic analyses of snoring which seems to be relatively accurate, is not sensitive enough for diagnosing OSA; therefore, there is much more work to be done.⁷ Recently, new applications have been offered in cellular phones claiming to measure accurately snoring intensity. Until a thoroughly validation and standardization of those methods is reached, their quality value remains questionable.

Loud and continuous snoring almost exclusively in the supine posture appears to be a rare condition. Even in a classical positional OSA patient, snoring is still present when sleeping on the left side.⁸

This patient had mild supine OSA worsening during REM sleep, but his breathing abnormalities during REM sleep were revealed only in the supine posture. When he turned on his right side, neither apneas/hypopneas nor snores were recorded (Figure 1, 3rd REM period). Nevertheless, when snoring was absent, a slight and insignificant airflow limitation was sporadically observed in the nasal pressure recording.

It could be of interest to share our experience with other investigators and find out if the presented unique snoring pattern is indeed rare as we have observed.

DISCLOSURE STATEMENT

This was not an industry supported study. The authors have indicated no financial conflicts of interest.