Natural evolution of snoring: a 5-year follow-up study.

Abstract

The natural evolution of snoring was studied in a middle-aged population in Finland. A questionnaire was mailed to a stratified random sample of 1600 people aged 36-50 years in 1985 with a response rate of 75.2%; 53% of them completed also the 5-year-follow-up questionnaire. Clinical examinations (N = 36) and whole-night polygraphic recordings (N = 22) were made to habitual (every or almost every night) snorers and daily sleepy persons. A total of 626 persons completed the 5-year-follow-up questionnaire. The prevalence of habitual snoring among men was 28.3-43.8% and among women 6.3-18.8%, increasing with age. Sleepiness was common: doze-off at the wheel was reported by 23% of snorers and traffic accidents because of sleepiness by 4.5%. Hypertension was clearly more common (p = 0.002) among habitual snorers, but the self-reported rates of strokes and coronary heart disease were not increased in this study. None of the snorers had been investigated because of their snoring or sleepiness during the five years. In polygraphic recordings 11/22 showed an oxygen desaturation index (ODI4) more than 5/h; active treatment was started for 8 of them. The observed prevalence of sleep apnea syndrome with ODI4 > 10 was 1.1% in this study. Snorers, even with clear sleepiness, are passive in seeking help for their symptoms. Physicians should actively diagnose this treatable condition impairing the quality of life and increasing the risk of traffic accidents and vascular diseases.