Snoring: a source of noise pollution and sleep apnea predictor

Snoring is a highly prevalent condition associated with obstructive sleep apnea (OSA) and sleep disturbance in bed partners. Objective measurements of snoring in the community, however, are limited. The present study was designed to measure sound levels produced by self-reported habitual snorers in a single night. Snorers were excluded if they reported nocturnal gasping or had severe obesity (BMI > 35 kg/m2). Sound was measured by a monitor mounted 65 cm over the head of the bed on an overnight sleep study. Snoring was defined as sound ≥40 dB(A) during flow limited inspirations. The apnea hypopnea index (AHI) and breath-by-breath peak decibel levels were measured. Snore breaths were tallied to determine the frequency and intensity of snoring. Regression models were used to determine the relationship between objective measures of snoring and OSA (AHI ≥ 5 events/h). The area under the curve (AUC) for the receiver operating characteristic (ROC) was used to predict OSA. Snoring intensity exceeded 45 dB(A) in 66% of the 162 participants studied, with 14% surpassing the 53 dB(A) threshold for noise pollution. Snoring intensity and frequency were independent predictors of OSA. AUCs for snoring intensity and frequency were 77% and 81%, respectively, and increased to 87% and 89%, respectively, with the addition of age and sex as predictors. Snoring represents a source of noise pollution in the bedroom and constitutes an important target for mitigating sound and its adverse effects on bed partners. Precise breath-by-breath identification and quantification of snoring also offers a way to risk stratify otherwise healthy snorers for OSA.

Association between air pollution and sleep disordered breathing in children

BACKGROUND AND OBJECTIVE

Similar to other respiratory diseases, sleep disordered breathing (SDB) may be exacerbated by air contaminants. Air pollution may have an impact on incidence and severity of SDB in children. The aims of this study were to examine potential associations between the exposure to different air pollutants and SDB symptoms in children.

METHODS

In this cross-sectional study, parents from first grade children of elementary schools throughout Chile were included. Data about clinical and family-related SDB risk factors, and the pediatric sleep questionnaire (PSQ) were obtained. Air pollution and meteorological data were obtained from the Chilean online air quality database.

RESULTS

A total of 564 children (44.9% males) aged (median) 6 years (5-9 year) were included. Prevalence of SDB based on PSQ was 17.7%. When examining air pollutants and conditions, only higher humidity (β = 0.005, 95%CI 0.001-0.009, P = 0.011) was significantly associated with higher PSQ scores after adjusting for demographic and household variables. Higher ozone (O₃ ) levels (OR = 1.693, 95%CI 1.409-2.035, P < 0.001), higher humidity (OR = 1.161, 95%CI 1.041-2.035, P = 0.008) and higher dioxide sulfur (SO₂ ) levels (OR = 1.16, 95%CI 1.07-1.94, P < 0.001]) were associated with increased odds of wheezing-related sleep disturbances after adjusting for confounders. Lower temperature was a significant predictor of snoring at least >3 nights/week, following adjustment (OR = 0.865, 95%CI 0.751-0.997, P < 0.05).

CONCLUSION

Sleep respiratory symptoms (wheezing and snoring) are significantly associated with air pollutants such as O₃ and SO₂ . In addition, meteorological conditions such as humidity and low temperatures may be also associated with SDB-related symptoms.

Reduction in Parasympathetic Tone During Sleep in Children With Habitual Snoring

Introduction: Changes in the autonomic nervous system due to Obstructive Sleep Apnea (OSA) during the life span have been described. Some pediatric studies have shown cardiovascular effects in children who do not fit the criteria for OSA; namely children with mild sleep disordered breathing. Objective: We investigated heart rate variability (HRV) during sleep in children with chronic snoring and flow limitation events during sleep. Methods: Ten children and adolescents with chronic snoring and an apnea hypopnea index < 1, associated to high Respiratory Index, and 10 controls matched for age, gender, and Tanner stage were monitored following one night of habituation in the sleep laboratory. HRV was studied at each sleep stage. The time and frequency domains were calculated for each 5-min period. Results: All patients were chronic heavy snorers. They presented an apnea hypopnea index = 0.8, respiratory disturbance index = 10.2/h with lowest O2 saturation 96.1 ± 2.4%. The total power of HRV was decreased in all stages (p < 0.05). There was also a decrease in NN50 and pNN50 during all sleep stages compared to healthy controls (p = 0.0003 and p = 0.03, respectively). Conclusion: A reduction in parasympathetic tone was found in the patient group. This may represent an autonomic impairment during sleep in children with mild SDB. A reduction in HRV in children with habitual snoring could be associated with possible increases in cardiovascular risk in adulthood. Significance: The study indicates that children with habitual snoring have important parasympathetic tone changes during sleep.

Associations of snoring frequency and intensity in pregnancy with time-to-delivery

BACKGROUND

Sleep-disordered breathing (SDB) is linked to adverse pregnancy outcomes. However, little is known about the association of SDB with timing of delivery. We examined the association of snoring frequency, a key SDB marker, and snoring intensity, a correlate of SDB severity, with time-to-delivery among a cohort of pregnant women.

METHODS

In this prospective cohort study, 1483 third trimester pregnant women were recruited from the University of Michigan prenatal clinics. Women completed a questionnaire about their sleep, and demographic and pregnancy information was abstracted from medical charts. After exclusion of those with hypertension or diabetes, 954 women were classified into two groups by their snoring onset timing, chronic or pregnancy-onset. Within each of these groups, women were divided into four groups based on their snoring frequency and intensity: non-snorers; infrequent-quiet; frequent-quiet; or frequent-loud snorers. Cox proportional hazard regression models were used to investigate the association between snoring frequency and intensity and time-to-delivery, adjusting for maternal characteristics.

RESULTS

Chronic snoring was reported by half of the pregnant women, and of those, 7% were frequent-loud snorers. Deliveries before 38 weeks' gestation are completed occurred among 25% of women with chronic, frequent-loud snoring. Compared with pre-pregnancy non-snorers, women with chronic frequent-loud snoring had an increased hazard ratio for delivery (adjusted hazard ratio 1.60, 95% confidence interval 1.04, 2.45).

CONCLUSIONS

Snoring frequency and intensity is associated with time-to-delivery in women absent of hypertension or diabetes. Frequent-loud snoring may have a clinical utility to identify otherwise low-risk women who are likely to deliver earlier.

Increased risk for new-onset hypertension in midlife male snorers: The 14-year follow-up study

While the association between sleep-related breathing disorders such as snoring and hypertension has been well established, it still remains unclear whether the association differs by age and gender. Therefore, in this 14-year follow-up study, we examined the independent association between self-reported snoring and the incidence of hypertension by gender and age groups in a large cohort of Korean adults. A total of 4,954 adults, aged 40-69 years, free of hypertension at baseline were enrolled. Participants were divided into three groups based on a self-reported snoring frequency: never; occasional (snoring <4 nights per week); and habitual snorer (snoring ≥4 nights). At baseline and biennial follow-up visits, blood pressure was measured by trained examiners. Incident hypertension was defined as the first occurrence at any follow-up examination where the participants had blood pressure ≥140/90 mmHg or were being treated with antihypertensive medication. After adjusting for known cardiovascular risk factors, only in men aged ≤45 years was habitual snoring significantly associated with a 1.5 times higher risk for incident hypertension than never snoring. In this age group, habitual snoring was significantly associated with increased risk for the development of hypertension, regardless of the presence of excessive daytime sleepiness. In women, snoring was not significantly associated with hypertension incidence in any age group. The present study suggests that young male snorers may be at high risk for the future development of hypertension, which has important clinical implications for early detection and treatment of snoring to reduce the burden of cardiovascular disease.

Severe obstructive sleep apnea in children with elevated blood pressure

The objective was to determine the prevalence of habitual snoring and obstructive sleep apnea (OSA) in a cohort of children referred for elevated blood pressure (BP), and to determine the association between OSA and BP elevation, learning difficulties, and behavioral problems. We performed a retrospective review of 446 consecutive new patients referred for elevated BP. One hundred four (23%) had habitual snoring. Patients with habitual snoring were more likely to be obese (86.5 vs. 55.6%, P < .001) and to have Medicaid insurance (52.4 vs. 36%, P = .004). Seventy-four patients had polysomnography, of which 57 (77%) had OSA; 21 (37%) had severe OSA. Severe OSA was associated with higher office systolic BP index after adjusting for body mass index, age, sex, and socioeconomic status (β = 0.07, P = .014). Fifty-two percent of patients with severe OSA had office systolic BP in the Stage 2 hypertension range. Children with habitual snoring or OSA were not at increased risk of receiving school services for a learning disability or receiving medications for inattention or mood problems. In summary, habitual snoring is common in children referred for elevated BP, and those with severe OSA are at higher risk of significantly increased BP.

Sleep-disordered breathing and verbal skills in school-aged community children

Sleep-disordered breathing (SDB) has been repeatedly associated with neurocognitive deficits in children. However, impairments in verbal skills have been inconsistently reported. The effects of SDB on verbal skills of 76 age-, gender, ethnicity, and maternal education matched groups of children with habitual snoring, but normal overnight sleep studies (HS), and children with significant SDB were compared to non-snoring healthy controls. A multi-method assessment of verbal abilities, and language neurodevelopment was chosen to unravel verbal skills. Preschoolers' difficulties in processing verbal instructions of increasing linguistic complexity, and school-aged children's reduced ability of verbal concepts provide evidence of SDB effects on verbal abilities. Although overall cognitive performances of SBD children remain in normative range, their problematic verbal skills may ultimately adversely affect academic performances or socioemotional behaviors.