Prevalence of sleep disturbances among young adults in three European countries.

The aim of this investigation was to study the geographic variation in sleep complaints and to identify risk factors for sleep disturbances in three European countries: Iceland (Reykjavik), Sweden (Uppsala and Göteborg) and Belgium (Antwerp). The study involved a random population of 2,202 subjects (age 20-45 years) who participated in the European Community Respiratory Health Survey. The subjects answered a questionnaire on sleep disturbances. Participants in Iceland and Sweden also estimated their sleep habits and sleep times during a period of 1 week in a sleep diary. Habitual (> or = 3/week) difficulties inducing sleep (DIS) were reported by 6-9% and early morning awakenings by 5-6% of the subjects. The estimated number of awakenings and the prevalence of nightmares was significantly lower in Reykjavik. Participants in Reykjavik went to bed at night and woke in the morning approximately 1 hour later than participants at the Swedish centers (p < 0.001). Symptoms of gastroesophageal reflux (GER) were associated with DIS (odds ratio [OR] = 2.7), nightmares (OR = 4.4), longer sleep latency and frequent nocturnal awakenings. Smoking correlated positively to DIS (OR = 1.8) and estimated sleep latency. We conclude that the prevalence of DIS was fairly similar at these four European centers but that there was a variation in the prevalence of nightmares and nocturnal awakenings. The significant correlation between reported GER and subjective quality of sleep should be followed up in studies using objective measurements.

Daytime sleepiness, snoring and gastro-oesophageal reflux amongst young adults in three European countries.

OBJECTIVES: To study the geographical variation in daytime sleepiness, snoring and disrupted breathing during sleep and to identify and compare risk factors using the same method in four European cities. DESIGN: A cross-sectional, multicentre epidemiological survey. SETTING: Reykjavik in Iceland, Uppsala and Göteborg in Sweden and Antwerp in Belgium. PARTICIPANTS: A random population sample of 2202 subjects who participated in the European Community Respiratory Health Survey. MAIN OUTCOME MEASURES: Sleep disturbances and daytime symptoms. RESULTS: At all the centres, 5% of the men and 2-3% of the women reported snoring every night. Daytime sleepiness (DS) was more often reported in Uppsala [odds ratio (OR) and 95% confidence interval: 1.6 (1.2-2.1)] than in the other centres, whilst daytime tiredness (DT) was most common in Reykjavik [ OR 1.8 (1.4-2.1)]. Snoring was positively correlated with age, male gender and body-mass index in all areas. Symptoms of gastro-oesophageal reflux were associated with DS: OR 2.6 (1.5 4.4) and DT: OR 4.5 (2.7-7.6) and disrupted breathing: OR 3.8 (1.4-10). DS and DT were reported more often by women than by men. CONCLUSION: The prevalence of snoring was about the same in all four areas, whilst there was a geographical variation in daytime sleepiness and tiredness. As complaints of DS and DT and disrupted breathing were more common in subjects who reported symptoms of gastro-oesophageal reflux, we suggest that polysomnographic studies comparing sleep patterns in adult patients with and without reflux should be conducted.