Assessment of daytime symptoms in snoring subjects and obstructive sleep apnea patients

• Autores: Ana Isabel Sánchez, Gualberto Buela Casal
• Localización: Salud mental, ISSN 0185-3325, Vol. 30, Nº. 1, 2007, págs. 9-15
• Idioma: inglés
• Títulos paralelos:
  • Evaluación de los síntomas diurnos en pacientes roncadores y pacientes con apnea obstructiva del sueño
• Enlaces
  • Texto completo (pdf)
• Dialnet Métricas: 2 Citas
• Resumen
  • español

    El síndrome de apnea obstructiva del sueño (SAOS) es un trastorno de la respiración que se produce durante el sueño, caracterizado por episodios repetidos de apnea (cese total del flujo aéreo) o hipopnea (cese parcial) con una duración mínima de 10 segundos.

    La sintomatología asociada al trastorno es muy variada. La mayoría de los pacientes se queja de problemas cognitivos, dificultades de concentración, excesiva somnolencia diurna, despertares frecuentes y aumento de la actividad motora durante el sueño, así como de cambios en el estado de humor y en el carácter. De todos los síntomas observados en el trastorno, el ronquido es el rasgo más universal de la apnea del sueño y una de las causas más comunes de referencia para la evaluación del trastorno. Hoy en día se estima que aproximadamente 70% de los pacientes que acude a los laboratorios de sueño padece ronquido, siendo en este grupo además bastante alta la sospecha de un posible diagnóstico de SAOS.

    Algunos estudios han centrado su interés en evaluar si las personas que manifiestan ronquido crónico muestran algún tipo de sintomatología que pueda utilizarse como medida preventiva para el posterior desarrollo de la apnea del sueño. Aunque los resultados de estos estudios no son muy concluyentes, lo que sí parece confirmarse es que en muchos casos el ronquido puede llegar a producir consecuencias clínicas importantes. Por ello, y con base en la bibliografía revisada, el objetivo de la presente investigación es evaluar si hay o no diferencias en somnolencia diurna, tiempo de reacción, memoria a corto plazo, depresión, ansiedad estado-rasgo y neuroticismo entre un grupo de pacientes con SAOS y un grupo de pacientes roncadores crónicos.

    Material y método: Se utilizó una muestra compuesta por 11 roncadores crónicos (tres mujeres y ocho hombres), con un rango de edad que oscilaba entre los 29 y 58 años (X = 43,82 y DT = 8,67), y 14 pacientes con SAOS (dos mujeres y 12 hombres), cuyo rango de edad se encontraba entre los 30 y 65 años (X = 49.64 y DT = 10,67). Todos los sujetos fueron seleccionados en un centro hospitalario. Como puede observarse, en los datos se ponen de manifiesto las diferencias en cuanto a la distribución por sexos del trastorno, informadas en la bibliografía revisada.

    La poligrafía cardiorrespiratoria fue la técnica utilizada para establecer el diagnóstico de SAOS. El procedimiento incluye un registro del electrocardiograma, movimientos torácicos y abdominales, flujo aéreo a través de nariz y boca, y nivel de saturación de oxígeno en la sangre. El ronquido se midió mediante un micrófono traqueal. Como medida de la somnolencia diurna, se utilizó la Escala de Somnolencia de Epworth. Se utilizó un programa en leguaje BASIC para evaluar el tiempo de reacción perceptivo motor simple. Para evaluar la sintomatología depresiva, se utilizó la adaptación al castellano del Inventario de Depresión de Beck (BDI). El Cuestionario de Ansiedad Estado/Rasgo (STAI) fue utilizado para evaluar los dos niveles de ansiedad. Las puntuaciones en neuroticismo se obtuvieron por medio del Inventario de Personalidad de Eysenck. La prueba de dígitos del WAIS en orden directo e inverso se utilizó para evaluar la memoria a corto plazo.

    Todos los pacientes con SAOS seleccionados tenían un índice de apneas-hipopneas mayor a 10 (IAH > 10), en tanto que los sujetos roncadores crónicos, que no entraban dentro de esta patología del sueño, tenían un IAH < 10. Los sujetos eran remitidos por el médico de cabecera al centro hospitalario por sospecha clínica de SAOS, aunque también era necesario descartar otras patologías respiratorias, como síndrome de hipoventilación-obesidad o enfermedad pulmonar obstructiva crónica (EPOC).

    A todos los pacientes se les realizaron una exploración y una entrevista medica para recabar todos los datos útiles para establecer el diagnóstico. Concluida la exploración, se citaba al paciente para dormir esa noche en la unidad de sueño, donde se realizaba la poligrafía cardiorrespiratoria de todas las horas de sueño. Así se obtenía, para cada uno de los pacientes, la siguiente información: a) número total de apneas obstructivas, duración mínima y máxima e índice de apneas; b) número total de hipopneas, duración mínima y máxima e índice de hipopneas; c) número de desaturaciones a lo largo de la noche y la caída media; d) nivel medio y mínimo de SAO2%, y e) índice de apneas-hipopneas.

    Finalizada la noche de sueño, se analizaban los resultados obtenidos en la poligrafía respiratoria para decidir si el paciente presentaba o no apnea de sueño. Una vez realizado el diagnóstico, se procedía a la evaluación psicológica de cada uno de ellos. Todas las pruebas psicológicas se realizaron en el mismo lugar y en las mismas condiciones para cada uno de los sujetos. Las pruebas se aplicaron de forma individual.

    Resultados: Como técnica para el análisis de los resultados, se utilizó una técnica no paramétrica; concretamente la prueba U de Mann-Whitney. Los resultados de este estudio indican que existen diferencias estadísticamente significativas en somnolencia diurna (p < 0,05) y en sintomatología depresiva (p < 0,01) entre ambos grupos de sujetos. Por otra parte, no se observaron diferencias entre ambos grupos en el resto de variables evaluadas.

    Conclusiones: Los resultados obtenidos en el estudio muestran que los pacientes con SAOS presentan mayores niveles de somnolencia diurna así como puntuaciones más elevadas en depresión en comparación con el grupo de roncadores crónicos. En el resto de variables evaluadas las diferencias entre ambos grupos de sujetos no fueron estadísticamente significativas.

  • English

    The obstructive sleep apnea syndrome (OSAS) is a type of sleep disorder that has called the attention of many researchers because of its widespread distribution among middle-aged subjects. The OSAS is a respiratory problem characterized by the existence of apneas, defined as 10 second minimum intervals during which no aerial flux exchange takes place through the upper airways and the hypopneas not characterized by an arrest, but by a reduction of aerial flux through the upper airways.

    The most widespread index used in the diagnosis of the OSAS severity has been the apnea/hypopnea index (AHI). There is little consensus based on the apnea/hypopnea index regarding the clinical definition of the sleep apnea syndrome, as there is not a single criterion for the categorization of sleep apnea patients into severity levels.

    Nowadays, it is estimated that about 70% of the patients referred to sleep laboratories suffer from snoring, and it is suspected that they might also suffer from sleep apnea. Obstructive sleep apnea patients may suffer from memory and cognitive problems, excessive daytime sleepiness, as well as mood disturbance, among other symptoms. Additionally, this disorder has severe medical and social consequences.

    One of the most characteristic symptoms in sleep apnea is snoring. Although snoring is one of the symptoms of sleep apnea, it should be remembered it is a typical phenomenon among population in general. There is a primary kind of snoring, the most frequent type in less severe cases, which even occurs among the normal population. In this case, the noise accompanying inspiration is made with almost every breath. Secondly, there is another kind of snoring that is either intermittent or cyclic, and snoring does not come with every breath but silent periods are also frequent. The latter indicates apnea.

    A considerable number of epidemiological studies regarding snoring have been produced of late. Several of them have concluded that snoring may have severe clinical consequences. Most patients suffering from obstructive sleep apnea start having simple snores. In the last decade there has been a marked increase of patients who manifest respiratory disorders related to sleep who do not fall into the category of apnea patients. Nevertheless, the morbidity of these clinical disorders is not yet known, a circumstance that makes treatment more difficult.

    Only a reduced number of studies have tried to find out whether snorers show any kind of symptoms that could be used as a preventive measure against the development of sleep apnea.

    For all the previous reasons, the aim of this study is to assess whether there are any differences in daytime sleepiness, reaction time, short-term memory, depression, trait anxiety, state anxiety and neuroticism between a group of patients with obstructive sleep apnea and a group of snoring individuals who had not been diagnosed as suffering from OSAS.

    Material and method:

    The sample was made up of 11 snorers (two women and nine men), in an age range between 29 and 58 (X= 43.82 and SD= 8.67), and 14 patients with OSAS (two women and 12 men), in the age range between 30 and 65 (X= 49.64 and SD= 10.67), who were selected from a clinical population. The AHI used for establishing an OSAS diagnostic was of 10 apneas/hypopneas per sleeping hour. The patients were diagnosed to be snorers if they showed an apnea/hypopnea index <10.

    The following instruments were used in the evaluation of snoring subjects and obstructive sleep apnea patients: 1. Cardio-respiratory polygraph of every hour of sleep for each one of the patients. The procedure consists in night-time monitoring of the following parameters: a) electrocardiogram; b) respiratory movements (expansion and relaxation of the thorax and abdomen), which evaluate the respiratory force; c) oronasal flow and d) oxygen saturation. The snoring was measured through a tracheal microphone. 2. To measure the subjective daytime sleepiness, the Epworth Sleepiness Scale was used. 3. A BASIC software program was used to measure the simple perceptual reaction times in milliseconds. 4. The digits test of WAIS was used in straight and inverse order to evaluate the capacity of short term memory. 5. To evaluate the depressive symptoms, the Beck’s Depression Inventory was employed. 6. The State/Trait Anxiety Inventory was used as a measurement of the state and trait anxiety levels. 7. As an index of neuroticism levels, the Eysenck Personality Inventory was used.

    Subjects under clinical risk of an OSAS diagnosis were referred to a sleep unit by primary care physicians. Respiratory pathologies other than OSAS were ruled out before the subjects’ inclusion. Among these were, in particular, obesity hypoventilation syndrome, and chronic obstructive pulmonary disease. All the patients underwent a medical examination and a medical interview in which a detailed clinical history of each patient was compiled. Once the medical examination was over, each patient was given an appointment to sleep one night in hospital. Subsequently, cardio-respiratory poligraphy, registering height hours of sleep, was administered to each patient with the objective to establish a diagnosis. The morning after, a manual analysis was made of the following parameters which indicate the presence or absence of the disturbance and its severity: total number of nocturnal obstructive apneas, total number of hypopneas, value of saturation during the night, mean and minimum levels of SaO2% and apnea/hypopnea index.

    Afterwards, the sleep apnea diagnosis was established for those patients who showed an apnea/hypopnea index higher than 10. Snoring subjects with a lesser apnea/hypopnea index than 10 did not fit into the pathology of sleep apnea. Obstructive apneas were defined as the arrest of air flux during sleep along with the occurrence of respiratory movements lasting more than 10 seconds. Hypopnea was defined as an episode during which the partial obstruction of the upper airways produced a significant reduction of the air flux.

    The following morning, the psychological variables were evaluated (daytime sleepiness, short-term memory, reaction time, depression, neuroticism, state and trait anxiety). This process was carried out in the same place and under the same conditions for every subject. The tests were completed between 8:30 and 11:30 in the morning. Additionally, an exclusion criterion was established as the suffering from any psychiatric illness past or present in any way that could influence the psychological functioning of the patient.

    As a method of analysis of the results, a non-parametric analysis technique was used: the U Mann-Whitney test. All statistical analyses were made with the statistics package SPSS, 8.0, Spanish version.

    Results:

    Results from this study show that there are statistically significant differences between daytime sleepiness (p<0.05) and depressive symptoms (p<0.01) between both groups of subjects, whereas no statistically significant differences were found in terms of short term memory, reaction time, state anxiety levels, trait anxiety and neuroticism.

    Conclusions:

    The analysis of the results obtained reveals that the levels of daytime sleepiness are much higher in patients with OSAS than those in the snoring group. Some studies note that the fragmentation of sleep is responsible for excessive sleepiness during the day. Nevertheless, in this study we observed greater levels of obesity in patients with OSAS than in snoring patients, which could also explain the greater levels of sleepiness. In relation to the depression variable, the average scores show that depression levels are higher in apnea patients than in the snoring group. One of the possible explanations of this result is that the majority of apnea patients, due to the severity of the pathology, consequently present higher deficits in their daily social functioning, etc. Probably, the conditions previously described tend to influence an increase of depression levels.