The inconsistent nature of heart rate variability during sleep in normal children and adolescents

Introduction: Cardiac function is modulated by multiple factors including exogenous (circadian rhythm) and endogenous (ultradian 90-110 min sleep cycle) factors. By evaluating heart rate variability (HRV) during sleep, we will better understand their influence on cardiac activity. The aim of this study was to evaluate HRV in the dark phase of the circadian rhythm during sleep in healthy children and adolescents. Methods: One 3 min segment of pre-sleep electrocardiography (EEG) and 3, 6 min segments of electrocardiography recorded during polysomnography from 75 healthy children and adolescents were sampled during progressive cycles of slow wave sleep (SWS1, SWS2, SWS3). Three, 3 min segments of rapid eye movement sleep (REM) were also assessed, with REM1 marked at the last REM period before awakening. Studies that recorded REM3 prior to SWS3 were used for assessment. HRV variables include the following time domain values: mean NN (average RR intervals over given time), SDNN (Standard Deviation of RR intervals), and RMSSD (root Mean Square of beat-to-beat Differences). Frequency domain values include: low frequency (LF), high frequency (HF), and LF:HF. Results: Mixed linear effects model analysis revealed a significant difference in time and frequency domain values between sleep cycles and stages. Mean NN was lowest (highest heart rate) during pre-sleep then significantly increased across SWS1-3. Mean NN in SWS1 was similar to all REM periods which was significantly lower than both SWS2 and SWS3. SDNN remained at pre-sleep levels until SWS3, and then significantly increased in REM1&2. There was a large drop in LF from pre-sleep to SWS1. As cycles progressed through the night, LF remains lower than awake but increases to awake like levels by REM2. RMSSD and HF were lowest in pre-sleep and increased significantly by SWS1 and remain high and stable across stages and cycles except during the REM3 period where RMSSD decreased. Conclusion: Our results demonstrate that there are considerable changes in the spectral analysis of cardiac function occurring during different sleep stages and between sleep cycles across the night. Hence, time of night and sleep stage need to be considered when reporting any HRV differences.Anna Kontos, Mathias Baumert, Kurt Lushington, Declan Kennedy, Mark Kohler, Diana Cicua-Navarro, Yvonne Pamula, and James Marti

Baixa percepção de risco entre adolescentes espanhóis em relação ao consumo de álcool

Según los estudios recientes, los adolescentes españoles muestran una baja percepción del riesgo asociado al consumo de alcohol. El objetivo de la presente investigación es analizar los factores que favorecen esta baja percepción a partir de la opinión de un grupo de 32 profesionales/expertos en adolescencia, familia, escuela, medios de comunicación y políticas locales. Se utilizó una metodología cualitativa, fundamentada en Grounded Theory, a partir de la información obtenida mediante 5 grupos de discusión guiados por entrevistas semiestructuradas. Se identificaron 12 factores o subcategorías agrupados en 4 categorías generales: riesgo a corto plazo, inmediatez y percepción de invulnerabilidad (categoría ¿pensamiento adolescente¿); concepción benévola del alcohol, normalización del consumo y binomio alcohol-diversión (categoría ¿normas sociales¿); consumo habitual en los padres, inconsistencia verbal-no verbal en el modelado parental, consumo sin riesgo en los medios, consumo con resultados positivos en los medios (categoría ¿modelos sociales¿); excesivo contenido sanitario, riesgo a largo plazo (categoría ¿discurso preventivo¿). Tras discutir los resultados en el contexto de la literatura científica actual, se realizan varias propuestas con el objetivo de aumentar la percepción del riesgo en los adolescentes: incidir con mayor fuerza en contenidos sobre los riesgos a corto plazo del alcohol; orientar las estrategias educativas dirigidas al adolescente, también hacia los agentes de socialización, especialmente los padres; incidir en políticas centradas en la sustancia y en reducir la oferta.According to recent studies, Spanish adolescents show low perception of risk in alcohol consumption. The current study aims to analyze the factors that favor this low perception based on the opinion of a group of 32 professional experts on adolescence, family, school, mass media, and local policies. A qualitative methodology was used, based on Grounded Theory, using information from 5 focus groups guided by semi-structured interviews. Twelve factors or subcategories were identified, grouped in 4 general categories: short-term risk, immediacy, and perception of invulnerability (¿adolescent thinking¿ category); benevolent view of alcohol, normalization of consumption, and alcohol-entertainment binomial (¿social norms¿ category); parents¿ habitual consumption, verbal/non-verbal inconsistency in parental model, risk-free consumption depicted in the mass media, consumption with positive results in the media (¿social models¿ category); and excessive health content, long-term risk (¿preventive discourse¿ category). After discussing the results in the context of the current scientific literature, the article offers various proposals for increasing risk perception in adolescents: stronger impact of contents on short-term risks of alcohol; educational strategies targeted to adolescents to include agents of socialization, especially parents; and policies centered on the substance and reduction of supply.De acordo com estudos recentes, os adolescentes espanhóis mostram baixa percepção de risco em relação ao consumo de álcool. O estudo tem como objetivo analisar os fatores associados com a baixa percepção de risco, com base nas opiniões de um grupo de 32 especialistas em adolescência, família, escola, mídia e políticas locais. Foi utilizada uma metodologia qualitativa, baseada na Teoria Fundamentada, usando informações de cinco grupos focais orientados por entrevistas semi-estruturadas. Foram identificados 12 fatores ou subcategorias, agrupados em quatro categorias gerais: risco no curto prazo, imediatismo e percepção de invulnerabilidade (categoria de ¿pensamento adolescente¿); visão benevolente em relação ao álcool, normalização do consumo e binômio álcool-entretenimento (categoria de ¿normas sociais¿); consumo habitual pelos pais, inconsistência na comunicação verbal versus não verbal no modelo representado pelos pais, consumo isento de risco retratado pela mídia, consumo com resultados positivos na mídia (categoria de ¿modelos sociais¿) e excesso de conteúdo relacionado à saúde, risco no longo prazo (categoria de ¿discurso preventivo¿). Depois de discutir os resultados no contexto da literatura científica atual, o artigo oferece várias propostas para aumentar a percepção de risco entre os adolescentes: impacto mais forte de conteúdos sobre os riscos do álcool no curto prazo; estratégias educativas orientadas aos adolescentes para incluir os agentes da socialização, especialmente os pais, além de políticas centradas na substância e na redução da oferta.Departamento de Educación y Psicología SocialVersión del edito

The evidence that cyclic alternating pattern subtypes affect cognitive functioning is very weak

In their recent paper, Ferri et al. [1] examined the relationships between cognitive functioning and three subtypes of the cyclic alternating pattern (CAP) in non-REM sleep. They concluded that ‘‘CAP A1 subtypes are associated with higher [i.e., better] cognitive functioning, whereas CAP A3 subtypes are associated with lower [i.e., poorer] cognitive functioning” (p. 378). For the reasons summarised below, we contend that In their recent paper, Ferri et al. [1] examined the relationships between cognitive functioning and three subtypes of the cyclic alternating pattern (CAP) in non-REM sleep. They concluded that ‘‘CAP A1 subtypes are associated with higher [i.e., better] cognitive functioning, whereas CAP A3 subtypes are associated with lower [i.e., poorer] cognitive functioning” (p. 378). For the reasons summarised below, we contend that this conclusion is not warranted based on the data presented

Pediatric Sleep Survey Instrument - a screening tool for sleep disordered breathing

Purpose: The aim of this study was to assess the construct validity and clinical application of the Pediatric Sleep Survey Instrument (PSSI) as a tool to screen for sleep disordered breathing (SDB) in children. Methods: Polysomnography (PSG) outcomes and PSSI subscale scores were compared between a clinical cohort (N = 87, 5–10 years, 62 M/25 F) and a nonsnoring community sample (N = 55, 5–10 years, 28 M/27 F). Group comparisons assessed the ability of the PSSI subscales to discriminate between the clinical and community cohorts. Receiver operating characteristic (ROC) curves assessed construct validity, with the Apnea/Hypopnea Index (AHI) >5 events/h, OSA-18 score >60, and Pediatric Daytime Sleepiness Scale (PDSS) above the 70th percentile as the target references. Results: The clinical group had more respiratory events, respiratory-related arousals, fragmented sleep, and lower oxygen saturation nadir than the community group (p  5 events/h (area under the curve (AUC) = 0.7), an OSA-18 score >60 (AUC = 0.7), and a PDSS score in the 70th percentile (AUC = 0.8). The Morning Tiredness subscale accurately predicted a PDSS score in the 70th percentile (AUC = 0.8). A cutoff score of 5 on the SDB subscale showed a sensitivity of 0.94 and a specificity of 0.76, correctly identifying 77 and 100 % of the clinical and community cohorts, respectively. Conclusion: The PSSI Sleep Disordered Breathing subscale is a valid tool for screening SDB and daytime sleepiness in children aged 5–10 years.Sarah N. Biggs, Gillian M. Nixon, Margot J. Davey, Diana C. Cicua Navarro, J. Declan Kennedy, Kurt Lushington, Rosemary S. C. Horn