Jose M. Montserrat

Long-term effect of continuous positive airway pressure in hypertensive patients with sleep apnea.

RATIONALE Continuous positive airway pressure (CPAP) is the current treatment for patients with symptomatic obstructive sleep apnea (OSA). Its use for all subjects with sleep-disordered breathing, regardless of daytime symptoms, is unclear. OBJECTIVES This multicenter controlled trial assesses the effects of 1 year of CPAP treatment on blood pressure (BP) in nonsymptomatic, hypertensive patients with OSA. METHODS We evaluated 359 patients with OSA. Inclusion criteria consisted of an apnea-hypopnea index (AHI) greater than 19 hour(-1), an Epworth Sleepiness Scale score less than 11, and one of the following: under antihypertensive treatment or systolic blood pressure greater than 140 or diastolic blood pressure greater than 90 mm Hg. Patients were randomized to CPAP (n = 178) or to conservative treatment (n = 181). BP was evaluated at baseline and at 3, 6, and 12 months of follow-up. MEASUREMENTS AND MAIN RESULTS Mean (SD) values were as follows: age, 56 +/- 10 years; body mass index (BMI), 32 +/- 5 kg x m(-2); AHI, 45 +/- 20 hour(-1); and Epworth Sleepiness Scale score, 7 +/- 3. After adjusting for follow-up time, baseline blood pressure values, AHI, time with arterial oxygen saturation less than 90%, and BMI, together with the change in BMI at follow-up, CPAP treatment decreased systolic blood pressure by 1.89 mm Hg (95% confidence interval: -3.90, 0.11 mm Hg; P = 0.0654), and diastolic blood pressure by 2.19 mm Hg (95% confidence interval: -3.46, -0.93 mm Hg; P = 0.0008). The most significant reduction in BP was in patients who used CPAP for more than 5.6 hours per night. CPAP compliance was related to AHI and the decrease in Epworth Sleepiness Scale score. CONCLUSIONS In nonsleepy hypertensive patients with OSA, CPAP treatment for 1 year is associated with a small decrease in BP. This effect is evident only in patients who use CPAP for more than 5.6 hours per night. Clinical trial registered with www.clinicaltrials.gov (NCT00127348).

Association between Obstructive Sleep Apnea and Cancer Incidence in a Large Multicenter Spanish Cohort

RATIONALE Obstructive sleep apnea (OSA) has been associated with increased cancer mortality, but whether it is also associated with cancer incidence is unknown. OBJECTIVES To investigate whether OSA is associated with increased cancer incidence in a large clinical cohort. METHODS A multicenter, clinical cohort study including consecutive patients investigated for suspected OSA between 2003 and 2007 in seven Spanish teaching hospitals. Apnea-hypopnea index (AHI) and percent nighttime with oxygen saturation less than 90% (TSat(90)) were used as surrogates of OSA severity, both as continuous variables and categorized by tertiles. Cox proportional hazards regression analyses were used to calculate hazard ratio (HR) and 95% confidence interval (CI) for cancer incidence after adjusting for confounding variables. MEASUREMENTS AND MAIN RESULTS A total of 4,910 patients were analyzed (median follow-up, 4.5 yr; interquartile range, 3.4-5.2). Compared with the lower TSat(90) category (<1.2%), the adjusted hazards (95% CI) of cancer incidence for increasing categories were 1.58 (1.07-2.34) for TSat(90) 1.2-12% and 2.33 (1.57-3.46) for TSat(90) greater than 12%. Continuous TSat(90) was also associated with cancer incidence (adjusted HR, 1.07 [1.02-1.13] per 10-unit increase in TSat(90)). In stratified analyses, TSat(90) was associated with cancer incidence in patients younger than 65 years (adjusted HR, 1.13 [95% CI, 1.06-1.21] per 10-unit increase in TSat(90)) and males (adjusted HR, 1.11 [95% CI, 1.04-1.17] per 10-unit increase in TSat(90)). AHI was not associated with cancer incidence in the adjusted analyses, except for patients younger than 65 years (adjusted HR for AHI >43 vs. <18.7, 1.66; 95% CI, 1.04-2.64). CONCLUSIONS Increased overnight hypoxia as a surrogate of OSA severity was associated with increased cancer incidence. This association seems to be limited to men and patients younger than 65 years of age.

Obstructive sleep apnea is associated with cancer mortality in younger patients.

OBJECTIVE The association between obstructive sleep apnea (OSA) and cancer mortality has scarcely been studied. The objective of this study was to investigate whether OSA is associated with increased cancer mortality in a large cohort of patients with OSA suspicion. METHODS This was a multicenter study in consecutive patients investigated for suspected OSA. OSA severity was measured by the apnea-hypopnea index (AHI) and the hypoxemia index (% night-time spent with oxygen saturation <90%, TSat90). The association between OSA severity and cancer mortality was assessed using Coxs proportional regression analyses after adjusting for relevant confounders. RESULTS In all, 5427 patients with median follow-up of 4.5 years were included. Of these, 527 (9.7%) were diagnosed with cancer. Log-transformed TSat90 was independently associated with increased cancer mortality in the entire cohort (hazard ratio [HR], 1.21; 95% confidence interval [CI], 1.03-1.42), as well as in the group of patients with cancer (HR, 1.19; 95% CI, 1.02-1.41). The closest association was shown in patients <65years in both the AHI (continuous log-transformed AHI: HR, 1.87; 95% CI, 1.1-3.2; upper vs lower AHI tertile: HR, 3.98; 95% CI, 1.14-3.64) and the TSat90 (continuous log-transformed TSat90: HR, 1.73; 95% CI, 1.23-2.4; upper vs. lower TSat90 tertile: HR, 14.4; 95% CI, 1.85-111.6). CONCLUSIONS OSA severity was associated with increased cancer mortality, particularly in patients aged <65 years.

Effectiveness of sequential automatic-manual home respiratory polygraphy scoring

Automatic home respiratory polygraphy (HRP) scoring functions can potentially confirm the diagnosis of sleep apnoea-hypopnoea syndrome (SAHS) (obviating technician scoring) in a substantial number of patients. The result would have important management and cost implications. The aim of this study was to determine the diagnostic cost-effectiveness of a sequential HRP scoring protocol (automatic and then manual for residual cases) compared with manual HRP scoring, and with in-hospital polysomnography. We included suspected SAHS patients in a multicentre study and assigned them to home and hospital protocols at random. We constructed receiver operating characteristic (ROC) curves for manual and automatic scoring. Diagnostic agreement for several cut-off points was explored and costs for two equally effective alternatives were calculated. Of 366 randomised patients, 348 completed the protocol. Manual scoring produced better ROC curves than automatic scoring. There was no sensitive automatic or subsequent manual HRP apnoea–hypopnoea index (AHI) cut-off point. The specific cut-off points for automatic and subsequent manual HRP scorings (AHI >25 and >20, respectively) had a specificity of 93% for automatic and 94% for manual scorings. The costs of manual protocol were 9% higher than sequential HRP protocol; these were 69% and 64%, respectively, of the cost of the polysomnography. A sequential HRP scoring protocol is a cost-effective alternative to polysomnography, although with limited cost savings compared to HRP manual scoring.

El síndrome de apneas-hipopneas durante el sueño en edades avanzadas

The population pyramid is changing due to the increasing longevity of the population, making it a priority to have better knowledge of those diseases that have an increasingly major impact in advanced age. Sleep apnea-hypopnea syndrome (SAHS) affects 15-20% of individuals over 65 years. However, despite this high prevalence and that one in four sleep studies are conducted on the elderly in this country and that more 60% of these were treated with CPAP, there are few specific studies in this age group on the diagnosis and management of this syndrome. The physiological increase of the number of sleep respiratory disorders with the passing of time may be the biggest obstacle when defining, diagnosing and treating SAHS in the elderly. In any case and while more solid scientific evidence is obtained, the National SAHS Consensus, as well as the Guidelines on the diagnosis and treatment of SAHS, recommend that, within logical limits, age itself should not be an obstacle to offering the elderly diagnostic help and treatment similar to that offered to the rest of the population.

[Sleep apnea-hypopnea syndrome in the elderly].

The population pyramid is changing due to the increasing longevity of the population, making it a priority to have better knowledge of those diseases that have an increasingly major impact in advanced age. Sleep apnea-hypopnea syndrome (SAHS) affects 15-20% of individuals over 65 years. However, despite this high prevalence and that one in four sleep studies are conducted on the elderly in this country and that more 60% of these were treated with CPAP, there are few specific studies in this age group on the diagnosis and management of this syndrome. The physiological increase of the number of sleep respiratory disorders with the passing of time may be the biggest obstacle when defining, diagnosing and treating SAHS in the elderly. In any case and while more solid scientific evidence is obtained, the National SAHS Consensus, as well as the Guidelines on the diagnosis and treatment of SAHS, recommend that, within logical limits, age itself should not be an obstacle to offering the elderly diagnostic help and treatment similar to that offered to the rest of the population.

Significance of Including a Surrogate Arousal for Sleep Apnea-Hypopnea Syndrome Diagnosis by Respiratory Polygraphy

RATIONALE Respiratory polygraphy is an accepted alternative to polysomnography (PSG) for sleep apnea/hypopnea syndrome (SAHS) diagnosis, although it underestimates the apnea-hypopnea index (AHI) because respiratory polygraphy cannot identify arousals. OBJECTIVES We performed a multicentric, randomized, blinded crossover study to determine the agreement between home respiratory polygraphy (HRP) and PSG, and between simultaneous respiratory polygraphy (respiratory polygraphy with PSG) (SimultRP) and PSG by means of 2 AHI scoring protocols with or without hyperventilation following flow reduction considered as a surrogate arousal. METHODS We included suspected SAHS patients from 8 hospitals. They were assigned to home and hospital protocols at random. We determined the agreement between respiratory polygraphy AHI and PSG AHI scorings using Bland and Altman plots and diagnostic agreement using receiver operating characteristic (ROC) curves. The agreement in therapeutic decisions (continuous positive airway pressure treatment or not) between HRP and PSG scorings was done with likelihood ratios and post-test probability calculations. RESULTS Of 366 randomized patients, 342 completed the protocol. AHI from HRP scorings (with and without surrogate arousal) had similar agreement with PSG. AHI from SimultRP with surrogate arousal scoring had better agreement with PSG than AHI from SimultRP without surrogate arousal. HRP with surrogate arousal scoring had slightly worse ROC curves than HRP without surrogate arousal, and the opposite was true for SimultRP scorings. HRP with surrogate arousal showed slightly better agreement with PSG in therapeutic decisions than for HRP without surrogate arousal. CONCLUSION Incorporating a surrogate arousal measure into HRP did not substantially increase its agreement with PSG when compared with the usual procedure (HRP without surrogate arousal).

Some Reflections on Intermittent Hypoxia. Does it Constitute the Translational Niche for Carotid Body Chemoreceptor Researchers

The views presented in this article are the fruit of reflections and discussion with my colleagues at Valladolid and with the members of the Sleep Apnea Hypopnea Syndrome Group of the CIBERES (Spain). We have assembled the article in three sections. In the first one we provide a mechanistic description of obstructive sleep apnea (OSA) and all of its components, including the repetitive episodes of upper airways (UA) obstruction and accompanying hypoxic hypoxia, the respiratory efforts to fight and overcome the obstruction, and the sleep fragmentation due to the hypoxia-triggered arousal reactions, all events occurring during sleep hours with frequencies that might reach up >40-50 episodes/sleep hour. When OSA is accompanied by some of the elements of a big cohort of associated pathologies (vascular, metabolic, and neuropsychiatric) it conforms the obstructive sleep apnea syndrome (OSAS). The high frequency of OSAS in adults (>35 years old) and the costs in every regard of the treatment makes the syndrome a primary importance socio-sanitary problem. In the second section, we describe the experimental models of OSAS, basically the episodic repetitive hypoxic model described by Fletcher and coworkers in 1992, today named in short intermittent hypoxia (IH). From these lines, we want to call for some kind of consensus among researchers to lessen the dispersion of IH protocols. Finally, in the last section we intend to share our optimism with all ISAC members. The optimism is based on the recognition that carotid body (CB) chemoreceptors are critical elements of one of the main pathophysiologic loops in the genesis of OSAS. Therefore, we believe that all of us, as ISAC members, are well qualified to contribute in multidisciplinary research teams with well defined translational interests.

2006: Año de la Apnea del Sueño. Análisis de las publicaciones en Archivos de Bronconeumología

El síndrome de apneas e hipopneas durante el sueño (SAHS) se caracteriza por episodios repetidos de colapso en la vía aérea superior. Estos colapsos pueden ser totales (apneas) o parciales (hipopneas). Las consecuencias de estos eventos son caídas en la saturación de oxígeno y despertares cerebrales transitorios, los cuales a su vez se suponen responsables de la somnolencia diurna excesiva y de trastornos neuropsiquiátricos1,2. La prevalencia del SAHS se ha cifrado en torno al 4-6% de los varones y el 2-4% de las mujeres3,4. El infradiagnóstico es un fenómeno universal5. En España se estima que menos del 10% de los casos están diagnosticados y, en consecuencia, tratados6. El diagnóstico del SAHS se realiza mediante polisomnografía, aunque en pacientes seleccionados puede efectuarse mediante poligrafía respiratoria (PR)5,7-9. Diversos estudios han demostrado que existe una asociación entre apneas del sueño e hipertensión arterial4,10-14, enfermedad cardiovascular y cerebrovascular15-18, y accidentes de tráfico19-22. La presión positiva continua en la vía aérea (CPAP) se considera el tratamiento de elección de los casos más sintomáticos23,24, pues ha demostrado mejorar los síntomas clínicos (especialmente la somnolencia diurna), la calidad de vida y el índice de apneas-hipopneas (IAH)25-29, así como disminuir los accidentes de tráfico30, los eventos cardiovasculares e incluso la mortalidad18. Por lo mencionado, el SAHS se considera un problema de salud pública de primera magnitud8,31.

Apnea del sueño y conducción de vehículos. Recomendaciones para la interpretación del nuevo Reglamento General de Conductores en España

Road traffic accidents are one of the main causes of death worldwide and are clearly associated with sleepiness. Individuals with undiagnosed sleep apnea-hypopnea syndrome (SAHS) are among the population with a high risk of experiencing sleepiness at the wheel and, consequently, road traffic accidents. Treatment with continuous positive airway pressure (CPAP) has been shown to reduce the risk of accidents among drivers with SAHS. For this reason, the European Union has included this disease in the psychological and physical criteria for obtaining or renewing a driving license. To comply with this European Directive, Spain has updated its driving laws accordingly. To facilitate the implementation of the new regulations, a group of experts from various medical societies and institutions has prepared these guidelines that include questionnaires to screen for SAHS, diagnostic and therapeutic criteria, and physicians report templates.