[Steady car engine noise does not affect the cognitive abilities of sleep apnea syndrome patients]. / El ruido monótono no afecta a las capacidades cognitivas en pacientes con síndrome de apnea del sueño.

Traffic accidents are more frequent for sleep apnea syndrome (SAS) patients than in the population at large. The mechanisms that underlie this observation are poorly defined. Our working hypothesis was that in SAS patients the steady noise of a car engine might alter cognitive capacities that may be involved in driving, thus increasing the risk of traffic accidents. To test this hypothesis we designed a prospective randomized controlled trial. Eighteen SAS patients (apnea-hypopnea index [SEM] 62 [6] h1) and 18 healthy controls were studied. All the participants were evaluated in random order both in basal conditions and after exposure to the steady noise of a car engine recorded on a compact disc. Their level of vigilance was evaluated (Steer-Clear) as well as their reaction time (PVT 192). Attention, coordination, and memory were measured using the following tests: Wechsler Memory Scale (digit span), the Wechsler Intelligence Scale (digit symbol), and Lezack's Trail Making tests A and B. The SAS patients were slightly younger than the control group (mean 50 [7] vs 57 [11] years, respectively; P=.05). The patients showed a lower level of vigilance than the controls both in basal and engine noise conditions (P<.05). No differences between groups were found for the other variables studied. Exposure to steady car engine noise had no effect on the tests of either group. In conclusion, the results of our study do not support the hypothesis that steady car engine noise significantly alters the cognitive ability of SAS patients.

El ruido monótono no afecta a las capacidades cognitivas en pacientes con síndrome de apnea del sueño / Steady car engine noise does not affect the cognitive abilities of sleep apnea syndrome patients

Los accidentes de tráfico son más frecuentes en pacientes con síndrome de apnea del sueño (SAS) que en la población general. Los mecanismos que subyacen a esta observación están poco definidos. Nuestra hipótesis de trabajo fue que en pacientes con SAS el ruido monótono generado por el motor de un coche puede alterar las capacidades cognitivas potencialmente relacionados con la conducción y, de esta forma, incrementar el riesgo de padecer accidentes de tráfico. Para probar esta hipótesis se diseñó un trabajo prospectivo, aleatorio y controlado. Se incluyó a 18 pacientes con SAS (índice de apnea-hipopnea 62 ñ 6 h-1) y 18 controles sanos. Todos los participantes fueron evaluados (de forma aleatoria) en condiciones basales y estando sometidos al ruido del motor de un coche que había sido previamente grabado en un disco compacto. Se evaluaron el nivel de vigilancia (Steer-Clear®) y el tiempo de reacción (PVT 192®). La atención, coordinación y memoria se exploraron mediante los siguientes tests: dígitos directos e inversos de la escala de memoria de Wechsler, clave de números de la escala de inteligencia de Wechsler y el trailmaking tests A y B de Lezack. Los pacientes fueron ligeramente más jóvenes que los controles (50 ñ 7 frente a 57 ñ 11 años; p = 0,05). Comparados con los controles, los pacientes mostraron un nivel de vigilancia inferior tanto en situación basal como con ruido (p < 0,05). El resto de las variables estudiadas no fueron diferentes entre los grupos. La exposición a un ruido monótono no modificó los tests realizados en ningún grupo. En conclusión, los resultados de nuestro estudio no apoyan la hipótesis de que el ruido monótono generado por el motor de un coche altere de forma significativa la capacidad cognitiva en pacientes con SAS (AU)

Effectiveness of continuous positive airway pressure in mild sleep apnea-hypopnea syndrome.

The aim of this trial was to evaluate the effectiveness of continuous positive airway pressure (CPAP) in patients with mild sleep apnea- hypopnea syndrome (SAHS). One hundred forty-two consecutive patients with mild SAHS (apnea-hypopnea index 10-30, without severe sleepiness) were randomly assigned to receive conservative treatment (CT)-sleep hygiene and weight loss-(65 patients) or CT plus CPAP (77 patients), and 125 patients (86% males, age: 54 +/- 9 yr, BMI: 29 +/- 4 kg/m(2), AHI: 20 +/- 6, ESS: 12 +/- 4) completed the follow-up. The following outcomes were assessed at inclusion and after 3 and 6 mo of treatment: sleepiness (Epworth scale, multiple sleep latency test [MSLT]), other symptoms related to SAHS, cognitive function, and perceived health status (Functional Outcomes of Sleep Questionnaire [FOSQ], Nottingham Health profile). The relief of SAHS-related clinical symptoms was significantly greater in the CPAP group than in the CT group; the Epworth scale and FOSQ also showed more improvement in the CPAP group but did not reach significance. There were no significant differences in the other tests performed probably because the baseline values were normal. CPAP compliance was 4.8 +/- 2.2 h and treatment continuation was accepted by 62% of the patients at the end of the study. These results suggest that CPAP can be considered in treating patients with mild SAHS on the basis of an improvement in symptoms.

Treatment with continuous positive airway pressure is not effective in patients with sleep apnea but no daytime sleepiness. a randomized, controlled trial.

BACKGROUND: The sleep apnea-hypopnea syndrome is defined by a pathologic number of respiratory events during sleep (the apnea-hypopnea index, defined as the number of apnea and hypopnea episodes per hour) and daytime symptoms (mostly, excessive sleepiness). In patients with the sleep apnea syndrome, treatment with continuous positive airway pressure (CPAP) normalizes both the apnea-hypopnea index and diurnal symptoms. However, the effect of CPAP in persons with a pathologic apnea-hypopnea index without daytime sleepiness is unclear. OBJECTIVE: To investigate the short-term effects of CPAP on quality of life, objective sleepiness, cognitive function, and arterial blood pressure in nonsleepy patients with a pathologic apnea-hypopnea index. DESIGN: Multicenter randomized, placebo-controlled, parallel-group study. SETTING: Six teaching hospitals in Spain. PATIENTS: 55 patients with an apnea-hypopnea index of 30 or greater who did not have daytime sleepiness (Epworth Sleepiness Scale score

Angiotensin converting enzyme in patients with sleep apnoea syndrome: plasma activity and gene polymorphisms.

The prevalence of several cardiovascular diseases is increased with obstructive sleep apnoea syndrome (OSAS), due to, as yet, unclear reasons. Angiotensin converting enzyme (ACE) abnormalities have been implicated in the pathogenesis of various cardiovascular diseases. In this study, plasma ACE activity and the distribution of an insertion (I)/deletion (D) polymorphism of the ACE gene were determined in OSAS patients and in healthy controls. A total of 63 patients with OSAS (mean+/-SEM 54.5+/-2.5 apnoea/hypopnoeas.h(-1)) and 32 healthy subjects were studied. To avoid potential confounding factors, patients treated with ACE inhibitors or continuous positive airway pressure were excluded, as well as controls in whom a blood sample was not obtained early in the morning. ACE activity was determined spectrophotometrically in 46 OSAS patients and 25 controls. The I/D ACE polymorphism was determined by polymerase chain reaction in 44 patients and 32 controls. ACE activity was higher in OSAS patients (53.9+/-2.5 IU.L(-1)) than in healthy controls (42.4+/-3.1 IU.L(-1), p<0.01). This was independent of the presence of arterial hypertension. The frequency distribution of the DD, II and ID genotypes in OSAS patients (30%, 16%, 54%, respectively) was not significantly different from that seen in healthy subjects (31%, 28%, 41%, respectively, p=0.356). These results indicate that ACE plasma activity is increased in untreated OSAS patients. This increased activity may contribute to the pathogenesis of the cardiovascular disease in these patients.

Long-term effects of CPAP on daytime functioning in patients with sleep apnoea syndrome.

Daytime sleepiness, impaired cognitive performance and dysphoric mood are often present in patients with obstructive sleep apnoea syndrome (SAS). This prospective controlled study evaluates the effects of treatment with continuous positive airway pressure (CPAP) during 1 yr on daytime functioning in a large group of patients with SAS. The authors studied 80 patients (mean+/-sem 49+/-1 yrs) with SAS with a mean apnoea-hypopnoea index of 60+/-2 h-1, and 80 healthy control subjects matched for sex and age (46+/-1 yrs.). Measurements were obtained at the beginning of the study and 12+/-1 months later, and included: daytime sleepiness (Epworth scale), depression and anxiety (Beck tests), vigilance (Steer-Clear) and reaction time (Psychometer Vigilance Test 192). Drug, coffee and alcohol intake, as well as the sleep schedule, were also recorded. Results showed that, before treatment, patients were more somnolent (p<0.001), anxious (p<0.01) and depressed (p<0.001) than control subjects. Also, they had a longer reaction time (p<0.05) and poorer vigilance (p<0.01). The use of CPAP improved significantly the levels of somnolence (p<0.0001) and vigilance (p<0.01), but failed to modify anxiety and depression. Reaction time changes were minor. Variables with a potential confounding effect did not change during the study. These results provide firm evidence to substantiate the use of continuous positive airway pressure in patients with sleep apnoea syndrome.