Snoring occurs when turbulent airflow created by narrowing of one or more cross-sectional areas in the upper airway causes soft tissues to vibrate. It usually is considered of little clinical importance, although it is known to coexist with obstructive sleep apnea syndrome (OSAS). Physicians typically regard it as a symptom of OSAS or a signal of its development sometime in the future.

However, snoring itself can have a significant health impact, research shows.

Measuring Snoring

There is no universal standard for measuring snoring, and the official definition -- “loud upper airway breathing sounds in sleep, without episodes of apnea or hyperventilation” -- is misleading. Snoring does occur during obstructive breathing.

“Primary snoring” is the term used when it occurs without obstructive events, while “secondary snoring” refers to a component of upper airway resistance syndrome.

Individuals have a poor sense of how loud or how long they snore, and observers' perceptions are only a little better, studies have shown. Therefore, researchers set out to develop an objective method of measuring snoring, incorporating a new unattended home sleep-study device.

Darrell H. Hunsaker MD FACS and Robert H. Riffenburgh PhD FASA, both from the Naval Medical Center in San Diego, began by defining snoring as excessively loud breathing sounds, louder than 50 decibels (dB), measured near the source (upper lip), which interferes with the sleep of a bed partner.

Home Sleep Studies Analyzed

They used a database containing anonymous records of 4,858 patients for whom snoring was measured by unattended home sleep studies. The sample included 4,151 males and 707 females with an average age of 54, ranging in age from 13 to 95 years.

The average body mass index, recorded in 3,778 records, was 34, with a range from 14 to 87.

Three measures of snoring were recorded:

Snoring was a component of the chief complaint in 2,624 records.

Sleepiness, Obesity, Chronic Fatigue

The researchers found a strong relationship between history of snoring and complaints of daytime sleepiness (80 percent), obesity (73 percent) and chronic fatigue (78 percent).

Only 42-48 percent of patients without those symptoms complained of snoring.

In three multiple regression analyses, snoring time, average loudness and peak loudness were predicted to a significant degree by AHI (Apnea Hypopnea Index), BMI and age.

Daytime sleepiness was strongly predicted by snoring time, weakly by average loudness and not at all by peak loudness.

The present study demonstrates that a patient's snoring history, as reported in the consultation referrals, is highly related to obesity, excessive daytime sleepiness and chronic fatigue symptoms, report the researchers.

Snoring Duration and Loudness

There ia a highly significant and independent association between the duration and loudness of snoring with Apnea Hypopnea Index and Body Mass Index.

Average sustained loudness increased almost 20 dB between normal and severe AHI.

Duration of sleep time spent snoring increased from 73 percent for normal AHI (in patients referred for sleep study) to 98 percent for severe AHI. It increased from 70 percent for normal BMI (in patients referred for sleep study) to 94 percent for morbidly obese BMI.

The team also noted a strong relationship between average sustained snoring loudness and the Epworth Sleepiness Scale.