Snoring Related to Obesity, Excessive Daytime Sleepiness, and Chronic Fatigue

Newswise — Snoring is due to vibration of soft tissues of the upper airway, which in turn is caused by turbulent airflow created by narrowing of one or more cross sectional areas in the upper airway. Most believe it is just noise and by itself, not harmful to your health. A new research study finds otherwise.

Snoring is considered of little clinical importance in many reports in the sleep literature. Although recognized to coexist with obstructive sleep apnea syndrome (OSAS), snoring is looked on more as a symptom or signal of development of OSAS sometime in the future. However, some studies do recognize that snoring can have an independent impact on health. Habitual snoring has been independently linked to obesity, poor academic performance and daytime sleepiness, hypertension, stroke, and ischemic heart disease. The majority of these studies identify snoring by history only. Very few studies classify snoring by objective measurements.

No universally accepted standard for measuring snoring has been developed. The official definition of snoring as “loud upper airway breathing sounds in sleep, without episodes of apnea or hyperventilation” falls short of recognizing that snoring occurs during obstructive breathing as well. Therefore, snoring has been subcategorized into “Primary Snoring”, which occurs without obstructive events, and “Secondary Snoring”, a component of upper airway resistance syndrome.

Many studies have clearly showed that self perception of snoring poorly correlated, and observer perception only moderately correlated, with mean, maximum loudness, and snoring index (SI). Accordingly, two researchers set out to introduce an objective method of measuring snoring incorporating a new unattended home sleep study device and to utilize it in assessing the relationship of a patient history of snoring to sleep complaints and demographic characteristics.

The authors of “Snoring Significance in Patients Undergoing Unattended Home Sleep Studies,” are Darrell H. Hunsaker MD FACS and Robert H. Riffenburgh PhD FASA, both from the Naval Medical Center San Diego, San Diego, CA. Their findings are to be presented at the 109th Annual Meeting & OTO EXPO of the American Academy of Otolaryngology—Head and Neck Surgery Foundation, being held September 25-28, 2005, at the Los Angeles Convention Center, Los Angeles, CA.

Methodology: The researchers defined 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. The database contained anonymous records of 4,858 patients for whom snoring was measured by the unattended home sleep studies. The sample contained 4,151 males and 707 females with an average age of 54, ranging 13 to 95 years. The average body mass index, recorded in 3,778 records, was 34, ranging from 14 to 87. Three measures of snoring were recorded: (1) sustained loudness, measured as average loudness in dB of sleep sounds when such loudness exceeds 50 dB, (2) peak loudness, measured as the loudest sleep sound in dB detected, and (3) duration, measured as the percent of time asleep in which snoring exceeded 50 dB. Snoring was a component of the chief complaint in 2,624 records.

Results: A strong relationship exists between a history of snoring and complaints of daytime sleepiness (80 percent), obesity (73 percent), and chronic fatigue (78 percent). By contrast, only 42-48 percent of patients without these symptoms complain of snoring. In three multiple regression analyses, percent of time snoring, average loudness, and peak loudness are all significantly predicted by AHI (Apnea Hypopnea Index), BMI, and age. Daytime sleepiness was strongly predicted by percent time snoring, weakly by average loudness, and not at all by peak loudness.

Conclusions: The present study demonstrates that the history of snoring on the consultation referral is highly related to obesity, excessive daytime sleepiness, and chronic fatigue symptoms. We also demonstrated highly significant and independent association between the duration of snoring, average sustained snoring loudness, and peak snoring loudness with Apnea Hypopnea Index and Body Mass Index, and sustained loudness with the Epworth Sleepiness Scale. 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 and increased from 70 percent for normal BMI (in patients referred for sleep study) to 94 percent for morbidly obese BMI.

This research highlights how this sleep disorder (snoring), not normally covered by insurers, can be debilitating to the patient’s health.