Valor predictivo de la historia clínica y oximetría nocturna en la pesquisa de pacientes con apneas obstructivas del sueño / Predictive value of clinical features and nocturnal oximetry for the detection of obstructive sleep apnea syndrome

Background: Obstructive sleep apnea syndrome (OSA) is an important cause of morbidity and mortality in adults. Aim: To evaluate the diagnostic value of clinical features and oximetric data to screen for obstructive sleep apnea before performing polysomnograpy or respiratory polygraphy. Material and Methods: We studied 328 consecutive adult patients referred for snoring or excessive daytime sleepiness to a sleep clinic in whom a standardized questionnaire and the Sleepiness Epworth Scale were performed and body mass index (BMI), cervical circumference (CC), and nocturnal oximetry were measured. Results: Fifty three percent (n = 173) had evidence of clinically significant OSA (apnea/hypopnea index (AHI) > 15 events/h). Patients with OSA were more likely to be male, obese (BMI ≥ 26 kg/m²), smokers, to have a thick neck (CC > 41 cm), and to have a significant greater prevalence of relative reported apneas and excessive daytime sleepiness, as determined by Epworth scale. Male gender (Odds ratio (OR): 4.00; 95 percent confidence intervals (CI): 1.59-10.0, p = 0.003), BMI ≥ 26 kg/m² (OR: 3.68; 95 percentCI: 1.59-8.49, p = 0.002), smoking (OR: 2.29; 95 percent CI: 1.17-4.47, p = 0.015), Epworth index > 13 (OR: 2.65; 95 percent CI: 1.35-5.23, p = 0.005) and duration of symptoms over 2 years (OR: 2.35; 95 percent CI: 1.20-4.58, p = 0.012) were significant independent predictors of OSA. In nocturnal oximetry, the lowest SpO2 (SpO2 min) and the length of registries below 90 percent (CT-90) were independent predictors of OSA and both correlated significantly with AHI (r = -0.49 and r = 0.46 respectively, p < 0.001). Conclusions: No single factor was usefully predictive of obstructive sleep apnea. However, combining clinical features and oximetry data may be appropriate to detect clinically significant OSA patients.

Obstructive sleep apnoea: Definitions, epidemiology & natural history.

Obstructive sleep apnoea (OSA) is increasingly being recognized as an important health issue in the last two to three decades. It is characterized by frequent episodes of upper airway collapse during sleep, causing recurrent arousals, intermittent hypoxaemia, sleep fragmentation and poor sleep quality. There is accumulating evidence that OSA is being considered as an independent risk factor for hypertension, glucose intolerance / diabetes mellitus, cardiovascular diseases and stroke, leading to increased cardiometabolic morbidity and mortality. The prevalence rates of OSA have been estimated in the range of 2 to 10 per cent worldwide, and the risk factors for obstructive sleep apnoea include advanced age, male sex, obesity, family history, craniofacial abnormalities, smoking and alcohol consumption. The common clinical presenting symptoms are heavy snoring, witnessed apnoeas and daytime hypersomnolence, which would help to identify the affected individuals. With increasing awareness of this disease entity and associated complications in our society, there have been increased referrals to sleep physicians or expertise for further investigations and diagnostic evaluation. Early recognition and treatment of obstructive sleep apnoea may prevent from adverse health consequences. some of the epidemiological aspects of obstructive sleep apnoea in adults are reviewed.