Relationship between enuresis and obstructive sleep apnea–hypopnea syndrome in children

ObjectiveWe explored the relationship between enuresis and obstructive sleep apnea–hypopnea syndrome (OSAHS) in children and influencing factors of enuresis with OSAHS.MethodsWe recruited 196 children ≥5 years old from the otolaryngology outpatient department, who experienced snoring and underwent nasopharynx lateral radiography and in-laboratory polysomnography. We analyzed correlations between the apnea–hypopnea index (AHI) and lowest oxygen saturation (L-SaO2) with age, body mass index (BMI), tonsil size, and adenoidal–nasopharyngeal (A/N) ratio using the Pearson correlation test. Differences in severe OSAHS prevalence, age, AHI, L-SaO2, tonsil size, and A/N ratio between children with and without enuresis were assessed using the chi-square test and t-test. Risk factors of enuresis were analyzed using logistic regression. Follow-up was conducted to assess remission in children with enuresis after adenotonsillectomy.ResultsBMI, tonsil size, and A/N ratio were correlated with AHI and L-SaO2. Severe OSAHS prevalence, AHI, tonsil size, and A/N ratio were higher and L-SaO2 were lower in children with enuresis. Logistic regression showed that BMI, AHI, tonsil size, and sleep apnea were risk factors for enuresis.ConclusionsOur study findings showed that enuresis was associated with OSAHS in children. Adenotonsillectomy may improve the symptoms of enuresis.     

Detecting chronotype differences associated to latitude: a comparison between Horne--Östberg and Munich Chronotype questionnaires

Background: Chronotype, phase preference to perform activities during a 24-hour day, represents distinct circadian temporal organization of living organisms. Morning and evening types can be identified by questionnaires such as Horne and Östberg (HO) and Munich Chronotype Questionnaire (MCTQ). Environmental factors, such as different light–dark cycles experienced at different latitudes, interact with the organisms’ circadian timekeeping system. Therefore, chronotype is expected to vary as a result of different geographical locations.

Aim: To identify differences in chronotype distribution in populations of two Brazilian cities, Natal and Sao Paulo, located at different latitudes.

Subjects and methods: Two specific questionnaires, the Horne and Östberg Questionnaire (HO) and the Munich Chronotype Questionnaire (MCTQ), were used to identify chronotypes of undergraduate students from São Paulo and Natal.

Results: The comparison of the curve distributions of HO and MCTQ scores between both cities allowed one to observe that, while HO curves of São Paulo and Natal overlapped, MCTQ curves showed a clear shift towards eveningness in São Paulo.

Conclusion: This experiment confirmed results from previous studies that the farther away from the equator, the longer the delay of the sleep phase. It was also concluded that MCTQ is better at detecting this phenomenon.     

Cognitive impairment in obstructive sleep apnea

Obstructive sleep apnea (OSA) is characterised by repetitive cessation or reduction of airflow due to upper airway obstructions. These respiratory events lead to chronic sleep fragmentation and intermittent hypoxemia. Several studies have shown that OSA is associated with daytime sleepiness and cognitive dysfunctions, characterized by impairments of attention, episodic memory, working memory, and executive functions. This paper reviews the cognitive profile of adults with OSA and discusses the relative role of altered sleep and hypoxemia in the aetiology of these cognitive deficits. Markers of cognitive dysfunctions such as those measured with waking electroencephalography and neuroimaging are also presented. The effects of continuous positive airway pressure (CPAP) on cognitive functioning and the possibility of permanent brain damage associated with OSA are also discussed. Finally, this paper reviews the evidence suggesting that OSA is a risk factor for developing mild cognitive impairment and dementia in the aging population and stresses the importance of its early diagnosis and treatment.     

The Association between the Phenotype of Excessive Daytime Sleepiness and Blood Pressure in Patients with Obstructive Sleep Apnea-Hypopnea Syndrome

Objective Investigate the clinical features and the blood pressure (BP) pattern of the phenotype of excessive daytime sleepiness (EDS) in OSAHS.Methods A total of 508 Chinese adults with suspected OSAHS were referred to our sleep laboratory from October 2009 to May 2012. On the same night of polysomnography (PSG), the levels of blood pressure were measured before sleeping (bedtime BP) and immediately after waking up in the next morning (morning BP). EDS was recognized as Epworth Sleepiness Scale (ESS)≥9. Subjects were classified into four groups based on the apnea-hypopnea index (AHI) from PSG as follows: control (simple snoring) group (control, n=104) with AHI<5; mild group (mild, n=89) with AHI≥5 and <15; moderate group (moderate, n=70) with AHI≥15 and<30; and severe group (severe, n=245) with AHI ≥30. The differences and correlations between BP and PSG parameters in EDS and non-EDS group of OSAHS patients were analyzed.Results In all subjects, ESS was positively correlated with morning diastolic blood pressure (DBP), Mean arterial pressure (MAP) and bedtime DBP (r=0.144, 0.102 and 0.114, respectively, each P value<0.05). In OSAHS patients, ESS was only positively correlated with morning DBP (r=0.137, P<0.05). OSAHS patients with EDS phenotype were younger and were more likely to have the symptom of waking up feeling tired (36.1% vs. 23.2%, p=0.023), who had lower MSaO2, longer SIT90 (the ratio of time of SpO2 below 90% in total sleep time) and higher DBP (bedtime as well as morning). In patients with AHI≥15, ESS was correlated positively with both bedtime and morning DBP after controlling the confounding effects of age, sex, BMI, AHI and nadir nocturnal oxygen saturation( r=0.126,0.143, respectively, both P values<0.05). And in OSAHS patients of EDS phenotype, the bedtime DBP, bedtime MAP, morning DBP, and morning MAP were 3~5 mm Hg higher than that in patients of non-EDS phenotype(P<0.05). In the moderate and severe OSAHS group, patients with EDS phenotype were younger and had a lower mean blood oxygen saturation (MSaO2), longer time of SpO2 below 90% and higher SIT90 than patients with non-EDS phenotype (P<0.05). In hypertensive OSAHS patients, patients with EDS were also younger and had higher micro-arousal index (MiI), as well as higher morning DBP, morning MAP and bedtime DBP than that in non-EDS group (P<0.05).Conclusions EDS in OSAHS patients is a special phenotype, which was characterized by younger age, higher DBP and more severe hypoxic load. This feature is mainly manifested in moderate and severe OSAHS patients. It is very important to identify the phenotype of EDS in patients with OSAHS, who may meet more benefits from effective treatment of OSAHS by correcting the intermittent nocturnal hypoxia and sleep fragmentation.     

儿童阻塞性睡眠呼吸暂停低通气综合征与血压相关性研究

目的 探讨儿童阻塞性睡眠呼吸暂停低通气综合征(OSAHS)与血压的相关性。方法 纳入2012年7月至2013年7月以睡眠打鼾为主诉于上海儿童医学中心睡眠障碍诊治中心就诊的3~18岁儿童青少年,行整夜多导睡眠图(PSG)监测并测量睡前收缩压(SBP)和舒张压(DBP)。根据PSG监测结果分为非OSAHS组和OSAHS组,OSAHS组根据呼吸暂停低通气指数和最低血氧饱和度分为OSAHS轻、中和重度亚组。依据2010年中国儿童青少年血压参照标准诊断高血压。计算收缩压指数(SBPI)和舒张压指数(DBPI)。分析不同程度的OSAHS与血压的相关性。 结果 385例研究对象进入分析,平均年龄(5.5±2.3)岁,男262例,女123例。SBP (100.6 ±10.4) mmHg,DBP (63.2±8.5) mmHg,符合高血压诊断122例(31.7%),其中严重高血压42例(10.9%)。非OSAHS组261例(67.8%);OSAHS组124例,其中轻、中和重度亚组分别有54、43和27例。BMI、BMI-Z评分、颈围、超重及肥胖患病率指标OSAHS组显著高于非OSAHS组。①OSAHS组SBP显著高于非OSAHS组,但调整年龄、性别和BMI-Z评分后SBP的组间差异无统计学意义。OSAHS轻、中和重度亚组SBP和DBP差异有统计学意义 (SBP: F=3.46,P=0.034;DBP: F=4.27,P=0.016),在调整了年龄、性别和BMI-Z评分后SBP和DBP的组间差异仍有统计学意义(P<0.05)。②非OSAHS组和OSAHS组SBPI和DBPI差异无统计学意义;OSAHS轻、中和重度亚组SBPI和DBPI差异有统计学意义(SBPI:F=2.54,P=0.046; DBPI: F=3.25,P=0.042)。③OSAHS轻、中和重度亚组高血压检出率差异有统计学意义,调整了年龄、性别以及BMI-Z评分后,OSAHS重度亚组严重高血压的风险显著高于轻度亚组,OR=5.79 (95%CI: 1.45~23.11)。 结论 鼾症患儿高血压检出率显著高于正常人群,其中重度OSAHS患儿高血压及严重高血压的发生风险最高,提示应密切监测睡眠相关呼吸障碍患儿的血压。