Polysomnographic Study of the Prevalence of Sleep Bruxism in a Population Sample

The goal of the current study was to estimate the prevalence of sleep bruxism (SB) in the general population using a representative sample of 1,042 individuals who answered questionnaires and underwent polysomnography (PSG) examinations. After PSG, the individuals were classified into 3 groups: absence of SB, low-frequency SB, and high-frequency SB. The results indicated that the prevalence of SB, indicated by questionnaires and confirmed by PSG, was 5.5%. With PSG used exclusively as the criterion for diagnosis, the prevalence was 7.4% regardless of SB self-reported complaints. With questionnaires alone, the prevalence was 12.5%. Of the 5.5% (n = 56) with confirmed SB, 26 were classified as low-frequency SB, and 30 as high-frequency. The episodes of SB were more frequent in stage 2 sleep, and the phasic bruxism events were more frequent than tonic or mixed events in all sleep stages in individuals with SB. A positive association was observed between SB and insomnia, higher degree of schooling, and a normal/overweight body mass index (BMI). These findings demonstrate the prevalence of SB in a population sampled by PSG, the gold standard methodology in the investigation of sleep disorders, combined with validated questionnaires (ClinicalTrials.gov, NCT00596713).

Gastroesophageal reflux episodes in asthmatic patients and their temporal relation with sleep architecture

Gastroesophageal reflux (GER) is common in asthma patients and can contribute to sleep disruption. The aim of the present study was to determine the time-related distribution of GER events together with their impact on sleep in asthmatic subjects with GER disease symptoms. The inclusion criteria were: 18-65 years, controlled moderate to severe asthma and GER-compatible clinical evidence. The exclusion criteria were: chronic obstructive lung disease, smoking, infections of the upper airways, use of oral corticosteroids, other co-morbidities, pregnancy, sleep-related disorders, night-time shift work, and the use of substances with impact on sleep. Asthmatic patients with nocturnal symptoms were excluded. All-night polysomnography and esophageal pH monitoring were recorded simultaneously. Of the 147 subjects selected, 31 patients and 31 controls were included. Seventeen patients were classified as DeMeester positive and 14 as DeMeester negative. Both groups displayed similar outcomes when general variables were considered. Sleep stage modification one minute prior to GER was observed in the DeMeester-positive group. Awakening was the most frequent occurrence at GER onset and during the 1-min period preceding 38% of the nocturnal GER. Sleep stage 2 was also prevalent and preceded 36% of GER events. In the DeMeester-negative group, awakening was the most frequent response before and during GER. Modifications in sleep stages, arousals or awakenings were associated with 75% of the total GER events analyzed during the period of one minute before and after the fall of esophageal pH below 4 in the DeMeester-positive group. These data provide evidence that sleep modifications precede the GER events in asthmatic patients.