Assessment of cognitive function and sleep-wake rhythms in community-dwelling older adults.

Disruption of the circadian rhythm and sleep-wake cycles is a consequence of aging and is associated with the cognitive decline and many neurodegenerative conditions. We investigated the bedtime, wake-up time, sleep timing (midpoint between bedtime and wake-up time), and sleep timing standard deviation (SD) using the actigraphy among 80 consecutive volunteers aged ≥ 60 years. Global cognitive function and executive function of detailed cognitive domains were evaluated using the mini-mental state examination (MMSE) and Wisconsin card sorting test (WCST) and subjective daytime sleepiness was assessed using the Epworth Sleepiness Scale (ESS). The category achievement (CA), total errors (TE), perseverative errors of Nelson (PEN), non-perseverative errors (NPE), and difficulties in maintaining set (DMS) on the WCST were significantly correlated with sleep timing SD (CA: r = - 0.276, p = 0.013, TE: r = 0.311, p = 0.005, PEN: r = 0.241, p = 0.032, NPE: r = 0.250, p = 0.025, DMS: r = 0.235, p = 0.036), but not with the MMSE score. Multiple regression analyses with the stepwise forward selection method including age, ESS score, bedtime, sleep timing, and sleep timing SD, revealed that the ESS score, and sleep timing SD were significant factors related to CA on the WCST (ESS score: ß = - 0.322, p = 0.004; sleep timing SD: ß = - 0.250, p = 0.022). Assessment of sleep-wake rhythms, daytime sleepiness, and cognitive function using the MMSE and WCST is valuable for the prediction of cognitive decline in the geriatric population.

Insomnia and obstructive sleep apnea as potential triggers of dementia: is personalized prediction and prevention of the pathological cascade applicable?

INTRODUCTION: Sleep disorders ultimately result in sleep deficiency and poor-quality adversely impacts the immune system, glucose metabolism, body weight control, cardiovascular and cerebrovascular function, cognitive function, psychological stability, work productivity, quality of life, and social safety. Sleep disorders are very common among the elderly and are often comorbid with other diseases such as dementia, and further accelerating the underlying neurodegenerative processes. Initial studies have not clearly revealed the relationship between sleep disorders and dementia. Nonetheless, recent findings have suggested that insomnia and obstructive sleep apnea (OSA) are closely associated with dementia and perhaps they could be good predictors of occurrence of dementia and optimal treatments for sleep deficiencies may prevent or delay the onset dementia. METHODS: Here, we conducted a systematic review based on the criteria of predictive, preventive, and personalized medicine on the association of dementia in elderlies with sleep disorder, namely insomnia and OSA. We included 7432 studies and analyzed a total of 14 publications after applying appropriate exclusion criteria. RESULTS: We found that OSA patients had a large tendency to develop and/or experience accelerations of both Alzheimer's disease (AD) and also vascular dementia, whereas insomnia patients only develop and/or experience accelerations of AD. This may be reflected in the fact that AD and vascular dementia have similar and at the same time also different mechanisms of action. Several studies have also revealed that treating sleep disorders in elderly patients prevented or delayed the onset of dementia, mitigating the progression of symptoms in patients who already manifested dementic symptoms and even reversing neurodegeneration in particular brain areas. DISCUSSION: Currently, the general medical consensus has poorly addressed the role of sleep disorders in exacerbating the risk of dementia. Critically, studies such as the present one emphasizes that the treatment of sleep disorders could be one the preventive measures to evade or to improve dementia symptoms. Additionally, elderly individuals often manifest different sleep deficiency symptoms than younger ones. Given this, an improved age-specific categorization and evaluation methods for sleep deficiency need to be implemented in diagnosing dementia in order to enable personalized assessments and treatments. Collectively, these findings may also assist to improve efforts in predictively detecting and eventually treating dementia.

Effects of sleep-disordered breathing and hypertension on cognitive function in elderly adults.

Purpose: The prevalence of sleep-disordered breathing (SDB) increases with aging. SDB is a risk of hypertension, and both might lead to cognitive decline. However, the role of SDB and hypertension on the pathogenesis of age-related cognitive decline remains unclear. We examined the effects of these two diseases on cognitive function in elderly adults.Methods: Fifty-two elderly individuals (mean age, 69.6 ± 4.0 years) free from impairment in daily living activities participated in this study. Apnea/hypopnea index (AHI) and minimum oxygen saturation (SpO2) were assessed using a portable home monitoring device. We evaluated excessive daytime sleepiness with the Epworth sleepiness scale (ESS). Cognitive performance was assessed using the Wisconsin card sorting test (WCST), continuous performance test-Identical pairs (CPT-IP), and N-back task. Hypertension and diabetes mellitus were evaluated via questionnaire and blood pressure value.Results: The WCST category achievement was significantly lower in participants with minimum SpO2 <90% than those with minimum SpO2 ≥90%. The percentage of correct answer on the 0- and 1-back tasks was significantly lower in the hypertensives than normotensives. Minimum SpO2 was correlated with category achievement on the WCST. Multiple regression analysis including age, sex, body mass index, AHI, minimum SpO2, ESS, hypertension, and diabetes mellitus revealed that hypertension was the most significant factor for percentage correct answers on the 0- and 1-back tasks. There were no significant correlations between body mass index, ESS or diabetes mellitus and the parameters of WCST, CPT-IP, or N-back tasks.Conclusion: In elderly adults, nocturnal hypoxia and hypertension had a negative effect on cognitive function.

Non-REM sleep-disordered breathing affects performance on the psychomotor vigilance task.

PURPOSE: Although many studies have investigated the clinical importance of sleep apnea on rapid eye movement (REM) and non-REM (NREM) sleep, the relationship between behavioral performance and apneic events during different sleep phases remains unclear. In the present study, we sought to investigate the effect of sleep phase fragmentation due to sleep-disordered breathing (SDB) during REM and NREM on the vigilance and sustainability of attention based on psychomotor vigilance task (PVT) performance. METHODS: From a pool of subjects who underwent consecutive diagnostic polysomnography (PSG) for obstructive sleep apnea, 163 adult subjects with both REM and NREM sleep ≥ 30 min were enrolled for our study and performed a standardized 10-min PVT. The main outcome variables of the PVT were mean reaction time (RT), PVT Lapse count, and the slope of the reciprocal RT. Subjective sleepiness was measured using the Epworth Sleepiness Scale (ESS). RESULTS: After multivariate linear regression analysis with adjustment for age, sex, body mass index, and the apnea-hypopnea index (AHI) of the counterpart sleep phase, we found that AHI during NREM (AHINREM) compared to AHI during REM (AHIREM) was significantly associated with PVT lapses. CONCLUSIONS: Our results suggest that SDB during NREM has a significant impact on vigilance lapses compared to that of REM.

Self-reported Sleep Duration and Subclinical Atherosclerosis in a General Population of Japanese Men.

AIM: There are few data regarding associations between sleep duration and subclinical atherosclerosis in Japan. The aim of this study was to evaluate associations of self-reported sleep duration with calcification in the coronary arteries (CAC) and carotid intima media thickness (IMT) in Japanese men. METHODS: This was a cross-sectional survey of 1093 randomly selected men from Kusatsu City, Japan. Average sleep duration on weekdays was estimated through questionnaire; CAC by computed tomography; and carotid IMT by ultrasonography. RESULTS: The prevalence of CAC was 50.0% for participants with sleep duration ＜5.5 h, 43.9% with 5.5-6.4 h, 50.0% with 6.5-7.4 h, 49.3% with 7.5-8.4 h, and 62.5% with ≥8.5 h. In univariate analysis, participants with sleep duration ≥8.5 h had significantly higher prevalence of CAC than those with 6.5-7.4 h (p=0.043). After adjustment for age and other risk factors, however, the association was not significant (p=0.776). The average IMT was 0.85 mm for participants with sleep duration ＜5.5 h, 0.83 mm with 5.5-6.4 h, 0.85 mm with 6.5-7.4 h, 0.88 mm with 7.5-8.4 h, and 0.90 mm with ≥8.5 h. None of the differences in IMT observed in crude or multivariable-adjusted analyses was significant (all p＞0.1). CONCLUSION: Self-reported sleep duration was not associated with increased CAC or carotid IMT in a general population of Japanese men.

Obstructive sleep apnea in preschool-aged Japanese children - efficiency of screening using lateral neck radiography.

Conclusions The prevalence of obstructive sleep apnea (OSA) in preschool-aged children diagnosed by the International Classification of Sleep Disorders (ICSD) version 3 criteria was relatively higher than that diagnosed by ICSD-2. Although the assessment of the upper airway by lateral neck radiography was effective for detecting OSA in this age group, this assessment is not recommended for all children as a screening method because of parental concern related to radiation exposure. Objective This study investigated the prevalence of OSA and the screening capacity of lateral neck radiography in community-based preschool-aged children. Methods Parents of 211 children aged 3-6 years were requested to complete the sleep-related questionnaire. Subjects who agreed to further investigations were invited to undergo home type 3 portable monitoring and clinical examination, including radiography. We estimated the prevalence of OSA and evaluated the detection power of radiography for predicting OSA. Results One hundred and eighty-eight (89.1%) subjects completed the questionnaire and 67 (31.8%) agreed to further examinations. The weighted prevalence was 7.3% and 12.8% by ICSD-2 and 3, respectively. Area under the receiver operator curve for the adenoidal/nasopharyngeal and tonsil/pharyngeal ratios measured using radiography was slightly larger than that for tonsil size graded by visual inspection.

[Sleep health education for elderly people].

Successful aging is characterized by minimal age-associated loss of the physiological functions of sleep and circadian clock. Sleep health education is necessary to have normal, quality nighttime sleep and full daytime alertness. Elderly people show changes of sleep parameters, accompanied by increased napping. Many studies have reported that daytime sleepiness or napping in elderly people could have potentially serious effects such as dementia and life-style related diseases. The main topics of sleep health education for elderly people are as follows: Right knowledge of sleep mechanism, understanding the bad influence of excessive napping, the effects of light on the circadian rhythm and negative effects of caffeine, alcohol and television.

Evaluation of adenotonsillectomy and tonsillectomy for pediatric obstructive sleep apnea by rhinomanometry and the OSA-18 questionnaire.

CONCLUSION: Nasal resistance and the OSA-18 score were useful for evaluating surgical treatments. The sleep disturbance score may also be useful for predicting the severity of obstructive sleep apnea (OSA) in children. OBJECTIVE: We evaluated the effect of surgery on children with OSA using polysomnography (PSG) parameters, nasal resistance, and the OSA-18 questionnaire, and also investigated the cut-off OSA-18 score to screen for pediatric OSA. METHODS: This was a retrospective study in which PSG parameters and nasal resistance were measured using a rhinomanometer and the OSA-18 score was obtained from the OSA-18 questionnaire before and after surgery in 45 children with OSA. RESULTS: The mean age of the 45 patients was 5.7 ± 2.0 years. The mean value of the obstructive apnea hypopnea index (O-AHI) improved from 16.2 ± 14.3/h before surgery to 1.1 ± 1.7/h after surgery, the mean nasal resistance improved from 0.44 ± 0.19 to 0.32 ± 0.10 Pa/cm(3)/s, and the mean OSA-18 score improved from 61.1 ± 13.7 to 30.4 ± 5.8, and all these improvements were significant. The O-AHI value was lower than 1/h after surgery in 64.4% of patients (29/45). The O-AHI value was significantly correlated with the sleep disturbance score (r = 0.352, p = 0.018). When the cut-off OSA-18 score for screening was set at 40, sensitivity was 100%.

Type I Chiari malformation presenting central sleep apnea.

Sleep apnea is a rare but a well-known clinical feature of type I Chiari malformation. It may be obstructive or central in nature. Sleep apnea in patients with type I Chiari malformation rarely presents without accompanying neurological signs or symptoms. We here report a case of a 10-year-old girl who presented with central sleep apnea without any other neurological signs but was ultimately diagnosed with type I Chiari malformation. The patient initially showed mild improvement in symptoms after administration of an acetazolamide. Finally, posterior fossa decompression dramatically improved her respiratory status during sleep, both clinically and on polysomnography. This case suggests that type I Chiari malformation should be considered in the differential diagnoses of central apneas in children, even if there are no other neurological signs and symptoms. Furthermore, sagittal craniocervical magnetic resonance imaging may be necessary for a definitive diagnosis.

Prevalence of obstructive sleep apnea syndrome in Japanese elementary school children aged 6-8 years.

PURPOSE: We aimed to determine the prevalence of and the risk factors for obstructive sleep apnea syndrome (OSAS) in Japanese children aged 6-8 years. METHODS: The parents of 202 children aged 6-8 years who attended a single elementary school in Shiga, Japan, were requested to complete the Child and Adolescent Sleep Checklist (CASC) and perform home Type 3 portable monitoring of their children. By using the CASC data and monitor recordings, we estimated the prevalence of pediatric OSAS with the help of different diagnostic criteria and identified the risk factors associated with OSAS. RESULTS: Complete data were obtained from 170 of the 194 children whose parents participated in the study. The mean total apnea-hypopnea index and obstructive apnea hypopnea index were 1.4 ± 1.3 and 0.4 ± 0.6 h(-1), respectively, and central apnea was the most prevalent type of respiratory event, accounting for 70.4% of all events. The overall prevalence of OSAS ranged from 0.6% to 43.5%, depending on the cutoff value used, and was 3.5% when using International Criteria of Sleep Disorders version II (ICSD II) diagnostic criteria. The presence of tonsillar hypertrophy was the only parameter whose prevalence was significantly elevated in children with OSAS across all diagnostic criteria. CONCLUSIONS: The prevalence of pediatric OSAS varies according to the diagnostic criteria used, indicating the need for further research focusing on outcomes to define a clinically significant diagnostic threshold. The presence of tonsillar hypertrophy is an important risk factor in the development of pediatric OSAS.

Obstructive sleep apnea in Asian primary school children.

PURPOSE: The objectives of this study were to examine the prevalence of obstructive sleep apnea (OSA) in primary school children, relationships between OSA and tonsillar hypertrophy, adenoid, and patency of the nasal cavity, and the effects of the tonsillar hypertrophy and adenoid on the nasal patency. METHODS: An examination of the palatine tonsils and anterior rhinoscopy, completion of a questionnaire survey, a measurement of nasal resistance, an examination for sleep apnea at home using portable polysomnography device, and radiography of pharyngeal tonsil were performed in 152 primary school children. RESULTS: The obstructive apnea hypopnea index (O-AHI) increased with enlargements in the palatine tonsils. The adenoidal nasopharyngeal ratio (A/N ratio) decreased with advances in grade. A significant difference was observed in the O-AHI between those with and without adenoid. The median value of the O-AHI increased with advances in grade. The nasal resistance was significantly higher in the group with adenoid compared as in the group without. It was also higher in the nasal disease group with OSA than in the group without. Full polysomnography(PSG) was recommended in 16 (10.5%) of 152 who underwent the examination using the portable polysomnography device, and of the eight who underwent PSG, six (75%) were confirmed to have OSA, while its prevalence in all subjects was estimated as 7.9%. CONCLUSIONS: Disturbances in nasal respiration as well as tonsillar hypertrophy and adenoid were found to be a risk factor of OSA in primary school children.

Pilot study on the effects of a 1-day sleep education program: influence on sleep of stopping alcohol intake at bedtime.

The aim of this pilot study was to evaluate whether sleep was improved by a 1-day sleep education program in an occupational setting and whether stopping alcohol intake at bedtime might influence sleep. Subjects were 40 high school employees. The sleep education program lasted 4.5 hours and consisted of sleep science information, and sleep hygiene education including the risk of sleep related breathing disorder resulting from alcohol intake. Sleep conditions were evaluated by self-administered questionnaires at baseline and approximately 1 month later. The mean the Epworth Sleepiness Scale (ESS) score was significantly decreased by 1.2 points (P = 0.04), while the mean sleep duration was significantly decreased by 10 minutes (P = 0.02). Shortened sleep duration coincided with a decrease in sleepiness. This may indicate an improvement in sleep quality. The percentage of habitual alcohol intake at bedtime was significantly decreased (from 38.5% (15/39) to 20.5% (8/39), P = 0.04). Subjects who stopped alcohol intake at bedtime (n = 8) received the most benefit, with decreased scores of ESS and Insomnia Severity Index (ISI), although the reductions were not significant. This education program offers the possibility of improving sleep conditions among the general population, especially in those who cease habitual alcohol intake at bedtime. Further larger, randomized, controlled studies are warranted.

Relationship between adenoid size and severity of obstructive sleep apnea in preschool children.

OBJECTIVE: To investigate the contributions of adenoid and tonsil sizes to obstructive sleep apnea syndrome (OSAS) in normal-weight children in two age categories: preschool and schoolchildren. METHODS: Fifty-eight normal-weight (body mass index z-score<2) symptomatic children with OSAS (apnea-hypopnea index ≥ 2) were evaluated. The patients were divided into two age categories: preschool (age<6; n=33) and schoolchildren (age ≥ 6; n=25). Polysomnographic findings and adenoid and tonsil sizes were compared. The relative contributions of body mass index and adenoid and tonsil sizes were also investigated with a regression analysis. RESULTS: Adenoid grade and apnea index correlated significantly in preschool children (r=0.45, p<0.01). On regression analysis, adenoid grade was a significant predictor of the apnea index in preschool children. The influence of adenoid hypertrophy decreased from preschool to schoolchildren. Tonsil size had little influence on the apnea index in either group. CONCLUSION: Adenoid hypertrophy was a major contributor to OSAS in normal-weight preschool children. The upper airway morphology of younger children with OSAS differed from that of older children with OSAS.

Children with severe or moderate obstructive sleep apnoea syndrome show a high incidence of persistence after adenotonsillectomy.

CONCLUSION: Persistent obstructive sleep apnoea syndrome (OSAS) occurs in approximately 20% of normal-weight children after adenotonsillectomy (T&A) and, in nearly 70% of them, it is caused by adenoid regrowth. Patients with severe or moderate OSAS showed a high incidence of persistent disease even after T&A. Allergic disease, severity and large adenoid size are associated with adenoid regrowth and persistent disease. OBJECTIVES: To investigate factors contributing to persistent OSAS and adenoid regrowth after T&A in normal-weight children. METHODS: This was a prospective, observational study at a single institute and involved 49 normal-weight children with severe or moderate OSAS (apnoea-hypopnoea index, AHI, ≥ 5) who underwent T&A. Background information, nasal endoscopic data and pre- and postoperative polysomnographic data were collected. A third polysomnography (PSG) was performed 1.5 year postoperatively in children who subsequently developed symptoms of sleep disturbance. RESULTS: Thirteen children (27%, 13/49) were symptomatic 1.5 years after T&A. Allergic rhinitis (38.5% vs 11.1%, p = 0.03) and allergic disease (69.2% vs 30.6%, p = 0.02) were seen more frequently in these children. A third PSG confirmed persistent disease (AHI ≥ 5) in nine children (18.4%, 9/49). Six children (12.2%, 6/49) were diagnosed as having adenoid regrowth and three (6.1%, 3/49) underwent revision adenoidectomy.

A Prospective Population-based Study of Total Nasal Resistance in Korean Subjects.

OBJECTIVES: Rhinomanometry is a widely accepted method for objective assessment of nasal patency. However, few studies have reported the values of otherwise healthy population for nasal resistance in East Asians. The purpose of this study was to measure normal total nasal resistance (TNR) values in a large sample of Korean adults and to reveal parameters contributing to TNR values. METHODS: Subjects were enrolled from a cohort of the Korean Genome and Epidemiology Study. They were evaluated by anthropometry, questionnaire, and active anterior rhinomanometry at transnasal pressures of 100 and 150 Pascal (Pa). RESULTS: The study sample consisted of 2,538 healthy subjects (1,298 women and 1,240 men) aged 20 to 80 years. Normal reference TNR values were 0.19±0.08 Pa/cm(3)/second at 100 Pa and 0.22±0.09 Pa/cm(3)/second at 150 Pa. The TNR of women was significantly higher than that of men (P<0.0001). TNR decreased with increasing age in both genders (P<0.05). In women, lower body weight was related to increasing TNR. In men, current smokers had higher TNR than ex-smokers and never smokers. CONCLUSION: The results of the present study provide information regarding the values of otherwise healthy population of TNR and parameters associated with TNR in Korean adults.

A new modification of uvulopalatopharyngoplasty for the treatment of obstructive sleep apnea syndrome.

OBJECTIVE: To evaluate objective and subjective improvement after applying a new surgical technique, two-piece palatopharyngoplasty (Two-P4), to the treatment of obstructive sleep apnea syndrome (OSAS). METHODS: Twenty-four patients with mild to severe OSAS underwent Two-P4 between January 2002 and November 2007. Polysomnography and Epworth Sleepiness Scale (ESS) score were used to evaluate surgical results. RESULTS: Mean apnea-hypopnea index (AHI) improved from 50.9 to 10.7 after Two-P4. Mean ESS score decreased significantly from 13.0 to 7.7. Body mass index was unchanged after surgery. Objective success as evaluated by a 50% reduction in AHI and by AHI <20 was obtained in 22 of 24 patients (91.7%). Mean reduction in AHI was 76.9% for all 24 patients, 86.2% for patients with Friedman's anatomical stage I, 78.9% for stage II, and 54.5% for stage III. CONCLUSION: Two-P4 is a novel surgical treatment for OSAS patients with a high success rate (91.7%) as evaluated by reductions in AHI. Two-P4 keeps the middle soft palate intact to form independent scars on both sides, which constrict to stretch the soft palate and widen the pharyngeal space.

Nasal resistance in Japanese elementary schoolchildren: determination of normal value.

CONCLUSION: Rhinomanometry is a useful method for evaluating nasal airway patency in schoolchildren, and we could confirm the validity of the results it produces. OBJECTIVE: Our purpose was to assess the validity nasal resistance measurements produced using anterior active rhinomanometry by comparing the results with those of our previous study and to determine a normal value of the nasal resistance. METHODS: Nasal resistance was measured by rhinomanometry in 852 children using the active anterior method. RESULTS: Mean nasal resistance was 0.45 ± 0.70 Pa/cm(3)/s. Nasal diseases were noted in 358 (42%) children, and nasal condition was normal (the normal group) in 494 (58%) children. Nasal resistance was 0.57 ± 1.05 Pa/cm(3)/s in the nasal disease group and 0.35 ± 0.16 Pa/cm(3)/s in the normal group, showing that resistance was significantly higher in the nasal disease group. In the normal nasal groups, nasal resistance tended to be lower in the children in higher grades (first grade, 0.44 ± 0.17 Pa/cm(3)/s; second grade, 0.37 ± 0.11 Pa/cm(3)/s; third grade, 0.36 ± 0.23 Pa/cm(3)/s; fourth grade, 0.36 ± 0.14 Pa/cm(3)/s; fifth grade, 0.30 ± 0.08 Pa/cm(3)/s; sixth grade, 0.29 ± 0.11 Pa/cm(3)/s), and taller groups (<120 cm, 0.43 ± 0.16 Pa/cm(3)/s; 120-130 cm, 0.37 ± 0.19 Pa/cm(3)/s; 130-140 cm, 0.34 ± 0.12 Pa/cm(3)/s; >140 cm, 0.28 ± 0.09 Pa/cm(3)/s). Results similar to those seen in our previous study were obtained in each group.

A before and after comparison of the effects of forest walking on the sleep of a community-based sample of people with sleep complaints.

BACKGROUND: Sleep disturbance is a major health issue in Japan. This before-after study aimed to evaluate the immediate effects of forest walking in a community-based population with sleep complaints. METHODS: Participants were 71 healthy volunteers (43 men and 28 women). Two-hour forest-walking sessions were conducted on 8 different weekend days from September through December 2005. Sleep conditions were compared between the nights before and after walking in a forest by self-administered questionnaire and actigraphy data. RESULTS: Two hours of forest walking improved sleep characteristics; impacting actual sleep time, immobile minutes, self-rated depth of sleep, and sleep quality. Mean actual sleep time estimated by actigraphy on the night after forest walking was 419.8 ± 128.7 (S.D.) minutes whereas that the night before was 365.9 ± 89.4 minutes (n = 42). Forest walking in the afternoon improved actual sleep time and immobile minutes compared with forest walking in the forenoon. Mean actual sleep times did not increase after forenoon walks (n = 26) (the night before and after forenoon walks, 380.0 ± 99.6 and 385.6 ± 101.7 minutes, respectively), whereas afternoon walks (n = 16) increased mean actual sleep times from 342.9 ± 66.2 to 475.4 ± 150.5 minutes. The trend of mean immobile minutes was similar to the abovementioned trend of mean actual sleep times. CONCLUSIONS: Forest walking improved nocturnal sleep conditions for individuals with sleep complaints, possibly as a result of exercise and emotional improvement. Furthermore, extension of sleep duration was greater after an afternoon walk compared to a forenoon walk. Further study of a forest-walking program in a randomized controlled trial is warranted to clarify its effect on people with insomnia.

Clinical implications of mandible and neck measurements in non-obese asian snorers: ansan city general population-based study.

OBJECTIVES: Anthropometric abnormalities of the mandible and neck may contribute to snoring in non-obese Asians. The study evaluated the clinical implications of mandible and neck measurements in non-obese Asian snorers. METHODS: The external mandible and neck measurements (neck circumference, two lengths of neck, mandibular body angle, and lengths of mandibular ramus and body) were compared between snorers and non-snorers in a sample of 2,778 non-obese Koreans (1,389 males, 1,389 females) aged 40 to 69 years (mean, 48.47±7.72 years). RESULTS: The overall prevalence of snoring was 64.7% (899/1,389) and 48.3% (671/1,389) in non-obese male and female subjects, respectively. In non-obese males, snorers had significantly a greater neck circumference (P<0.0001) and shorter mandibular body length (P=0.0126) than non-snorers. In non-obese females, snorers had significantly greater neck circumferences (P=0.0165), compared with non-snorers. However, there were no statistically significant differences in other variables between non-snorers and snorers. CONCLUSION: Anthropometric abnormalities of the mandible and neck, including thick neck circumference in both genders and small mandible size in males, may be relevant contributing factors to snoring in non-obese Asian snorers.