Pitfalls of AHI system of severity grading in obstructive sleep apnoea (original) (raw)
Related papers
Clinical and functional prediction of moderate to severe obstructive sleep apnoea
The Clinical Respiratory Journal, 2010
Introduction: Upper airway inflammation and narrowing are characteristics of obstructive sleep apnoea (OSA). Inflammatory markers have been found to be increased in exhaled breath and induced sputum of patients with OSA. Objectives: The aim of this study was to investigate if the measurement of exhaled nitric oxide (FENO), as marker of airway inflammation, together with the forced mid-expiratory/mid-inspiratory airflow ratio (FEF50/FIF50), as marker of upper airway narrowing, may help to predict OSA. Methods: Two hundred one consecutive outpatients with suspected OSA were prospectively studied between January 2004 and December 2005. All patients underwent clinical examination, spirometry with measurement of FEF50/FIF50, maximum inspiratory pressure, arterial blood gas analysis, exhaled nitric oxide (FENO) and overnight polysomnography. Linear regression models were used to evaluate the effect of measured variables on the apnoea-hypopnoea index (AHI). Models were cross-validated by bootstrapping. Results: Most of the patients were obese and had severe OSA. FEF50/FIF50, FENO and an interaction term between smoking and FENO contributed significantly to the predictive model for AHI, in addition to age, neck circumference, body mass index and carboxyhaemoglobin saturation. A nomogram to predict AHI was obtained, which converted the effect of each covariate in the model to a 0-100 scale. The nomogram showed a good predictive ability for AHI values between 25 and 64. Conclusions: The measurement of FENO and of FEF50/FIF50 improves the ability to predict OSA and may be used to identify patients who require a sleep study.
Co-morbidities associated with obstructive sleep apnea in non-obese patients
Introduction Obstructive sleep apnea (OSA) is characterized by partial or complete recurrent upper airway obstruction during sleep. OSA brings many adverse consequences, such as hypertension, obesity, diabetes mellitus, cardiac and encephalic alterations, behavioral, among others, resulting in a significant source of public health care by generating a high financial and social impact. The importance of this assessment proves to be useful, because the incidence of patients with comorbidities associated with AOS has been increasing consistently and presents significant influence in natural disease history. Objective The objective of this study is to assess major comorbidities associated with obstructive sleep apnea (OSA) and prevalence in a group of patients diagnosed clinically and polysomnographically with OSA. Methods This is a retrospective study of 100 charts from patients previously diagnosed with OSA in our service between October 2010 and January 2013. Results We evaluated 100 patients with OSA (84 men and 16 women) with a mean age of 50.05 years (range 19-75 years). The prevalence of comorbidities were hypertension (39%), obesity (34%), depression (19%), gastroesophageal reflux disease (GERD) (18%), diabetes mellitus (15%), hypercholesterolemia (10%), asthma (4%), and no comorbidities (33%). Comorbidities occurred in 56.2% patients diagnosed with mild OSA, 67.6% with moderate OSA, and 70% of patients with severe OSA. Conclusion According to the current literature data and the values obtained in our paper, we can correlate through expressive values obesity with OSA and their apnea hypopnea index (AHI) values. However, despite significant prevalence of OSA with other comorbidities, our study could not render expressive significance values able to justify their correlations.
Apnea-hypopnea index in sleep studies and the risk of over-simplification
Sleep Science, 2018
According to recent reports, sleep disorders affect 30% of the adult population and 5-10% of children. Obstructive Sleep Apnea Hypopnea Syndrome (OSA) has a considerable epidemiological impact and demand for consultation is growing in our community. Therefore, it is necessary to know the principles of interpretation of diagnostic methods. A suspicion of OSA requires confirmation. According to the guidelines of the Argentine Association of Respiratory Medicine, polysomnography (PSG) is the gold standard for OSA diagnosis, while home sleep testing (HST) can be accepted as a comparatively effective method depending on the clinical situation of the patient. This article questions the use of AHI (apnea-hypopnea index) as the only measurement needed to diagnose OSA and assess its severity. In fact, it is surprising that, despite the large mass of data analyzed during sleep studies, current practices only focus on AHI. More than four decades have passed since OSA was first described. Our tendency to oversimplify complex conditions may prevent us from gaining a deeper and more thorough understanding of OSA. The development and validation of OSA severity scoring systems based on multiple parameters is still a pending issue.
New steps forward for obstructive sleep apnoea in the era of precision medicine
European Respiratory Journal, 2018
]. Obstructive sleep apnoea (OSA) is a progressive disorder characterised by repeated upper-airway collapse during sleep that leads to intermittent hypoxia and hypercapnia, fragmented sleep, fluctuations in blood pressure and increased sympathetic nervous system activity [1]. Population studies in the early 1990s found OSA (defined by an apnoea-hypopnoea index (AHI) >5 events•h −1) in 9% of middle-aged women and 24% of middle-aged men [2]. Later studies have demonstrated a higher occurrence (in 17% of women and 34% of men), which was mainly attributed to increasing body mass index in the general population over time [3]. Notably, the HypnoLaus study, which is to date the largest European epidemiological study [4], demonstrated that 61% of women and 84% of men in an unselected general cohort of 2121 adults had OSA based on the polysomnographic AHI cutoff level of 5 events•h −1 and on the recent hypopnoea definitions of the American Academy of Sleep Medicine [5]. HEINZER et al. [4] concluded in the HypnoLaus study that the prevalence of OSA was highly dependent on technical procedures (i.e. nasal cannula recording subtle breathing variation for scoring hypopnoeas) as well as the hypopnoea definition (3% desaturations instead of 4% desaturations, and/or arousals) [5]. There have been significant changes in the definition of OSA over time, with research reports suggesting an independent association between OSA and metabolic and cardiovascular disease (CVD), especially in the sleep clinic cohorts with self-reported excessive daytime sleepiness (EDS) [6-8]. The first choice for treatment of OSA is positive airway pressure (PAP), which has been demonstrated to reduce EDS and improve the quality of life [9]. In patients with CVD who do not report EDS, adherence to PAP treatment has been challenging in the recent randomised controlled trials (RCTs) [10, 11]. It has been shown that OSA has different clinical phenotypes based on anatomical [12] or physiological [13] features, or a mixture of both [14]. The degree of EDS, sex differences in presentation of symptoms and comorbid conditions may vary substantially [15]. OSA during rapid eye movement sleep has been linked to hypertension among individuals who otherwise have normal total AHI values [16], suggesting that this subgroup of patients deserve attention with regard to CVD outcomes [17]. Despite increasing research evidence linking OSA with metabolic and cardiovascular outcomes, and the beneficial effect of PAP treatment in the observational studies [8, 18], there is still a lack of convincing data from the RCTs that treating this disorder reduces the cardiovascular risk. Ethical concerns regarding randomisation of symptomatic OSA patients to no treatment have influenced the design of long-term RCTs during the last decade, focusing on asymptomatic or minimally
Comorbidities Associated with Obstructive Sleep Apnea: a Retrospective Study
International Archives of Otorhinolaryngology, 2016
Introduction Obstructive sleep apnea (OSA) is characterized by partial or complete recurrent upper airway obstruction during sleep. OSA brings many adverse consequences, such as hypertension, obesity, diabetes mellitus, cardiac and encephalic alterations, behavioral, among others, resulting in a significant source of public health care by generating a high financial and social impact. The importance of this assessment proves to be useful, because the incidence of patients with comorbidities associated with AOS has been increasing consistently and presents significant influence in natural disease history. Objective The objective of this study is to assess major comorbidities associated with obstructive sleep apnea (OSA) and prevalence in a group of patients diagnosed clinically and polysomnographically with OSA. Methods This is a retrospective study of 100 charts from patients previously diagnosed with OSA in our service between October 2010 and January 2013. Results We evaluated 100 patients with OSA (84 men and 16 women) with a mean age of 50.05 years (range 19-75 years). The prevalence of comorbidities were hypertension (39%), obesity (34%), depression (19%), gastroesophageal reflux disease (GERD) (18%), diabetes mellitus (15%), hypercholesterolemia (10%), asthma (4%), and no comorbidities (33%). Comorbidities occurred in 56.2% patients diagnosed with mild OSA, 67.6% with moderate OSA, and 70% of patients with severe OSA. Conclusion According to the current literature data and the values obtained in our paper, we can correlate through expressive values obesity with OSA and their apnea hypopnea index (AHI) values. However, despite significant prevalence of OSA with other comorbidities, our study could not render expressive significance values able to justify their correlations.
A Clinical Prediction Formula for Apnea-Hypopnea Index
International Journal of Otolaryngology, 2014
Objectives. There are many studies regarding unnecessary polysomnography (PSG) when obstructive sleep apnea syndrome (OSAS) is suspected. In order to reduce unnecessary PSG, this study aims to predict the apnea-hypopnea index (AHI) via simple clinical data for patients who complain of OSAS symptoms. Method. Demographic, anthropometric, physical examination and laboratory data of a total of 390 patients (290 men, average age 50 ± 11) who were subject to diagnostic PSG were obtained and evaluated retrospectively. The relationship between these data and the PSG results was analyzed. A multivariate linear regression analysis was performed step by step to identify independent AHI predictors. Results. Useful parameters were found in this analysis in terms of body mass index (BMI), waist circumference (WC), neck circumference (NC), oxygen saturation measured by pulse oximetry (SpO 2 ), and tonsil size (TS) to predict the AHI. The formula derived from these parameters was the predicted AHI = (0.797 × BMI) + (2.286 × NC) − (1.272 × SpO 2 ) + (5.114 × TS) + (0.314 × WC). Conclusion. This study showed a strong correlation between AHI score and indicators of obesity. This formula, in terms of predicting the AHI for patients who complain about snoring, witnessed apneas, and excessive daytime sleepiness, may be used to predict OSAS prior to PSG and prevent unnecessary PSG.
Sleep And Breathing, 2004
A major problem in the discussion of sleep-disordered breathing is caused by the use of different criteria to define its terms. Hypopnea is a good example of this: there is no consensus about its definition yet. In our study, the diagnosis value of apnea-hypopnea indexes (AHIs) determined by different hypopnea definitions was evaluated. The 90 patients who had an AHI > 5, scored according to the hypopnea definition of the American Academy of Sleep Medicine (AASM), participated in our study. The records of these patients were scored three times more according to different hypopnea definitions (hypopnea-arousal, hypopneadesaturation, hypopnea-effort). AHI AASM , AHI arousal , AHI desat , and AHI effort were determined via new scorings. Patients' daytime sleepiness was evaluated by the Epworth Sleepiness Scale ( > 10). When all of three major symptoms (snoring, observed apnea, and daytime sleepiness) were found in a patient's history, the term ''clinical OSAS'' was applied. The Epworth value correlated with all of the indexes. In the scope of both the determination of daytime sleepiness and the verification of ''clinical OSAS'' diagnosis, the value AHI AASM ¼ 5 had the highest sensitivity (100%) and specificity (94%).
ERJ Open Research
New findings on pathophysiology, epidemiology, and outcome have raised concerns on the relevance of the apnoea–hypopnoea index (AHI) in the classification of obstructive sleep apnoea (OSA) severity. Recently, a multicomponent grading system decision integrating symptomatology and comorbidities (Baveno classification), was proposed to characterise OSA and to guide therapeutic decisions. We evaluated whether this system reflects the OSA population, whether it translates into differences in outcomes, and whether the addition of AHI improves the scheme. A total of 14 499 OSA patients from the European Sleep Apnoea Database cohort were analysed. The groups were homogeneously distributed and were found to clearly stratify the population with respect to baseline parameters. Differences in sleepiness and blood pressure between the groups were analysed in a subgroup of patients after 24–36 months of treatment. Group A (minor symptoms and comorbidities) did not demonstrate any effect of treat...
Thorax, 2012
Impaired insulin sensitivity (ISx), increased visceral abdominal fat (VAF) and liver fat are all central components of the metabolic syndrome and characteristics of men with obstructive sleep apnoea (OSA). The reversibility of these observed changes with continuous positive airway pressure (CPAP) treatment in men with OSA has not been systematically studied in a randomised sham-controlled fashion. 65 men without diabetes who were CPAP naïve and had moderate to severe OSA (age=49±12 years, apnoea hypopnoea index (AHI)=39.9±17.7 events/h, body mass index=31.3±5.2 kg/m(2)) were randomised to receive either real (n=34) or sham (n=31) CPAP for 12 weeks. At 12 weeks, all subjects received real CPAP for an additional 12 weeks. Main outcomes were the change at week 12 from baseline in VAF, ISx and liver fat. Other metabolic outcomes were changes in the disposition index, total fat, and blood leptin and adiponectin concentrations. The AHI was lower on CPAP compared with sham by 33 events/h (...