The role of upper airway and facial skeleton anatomy in the evolution of obstructive sleep apnea: an 8-year follow-up.

PURPOSE: To evaluate the role of anatomic alterations of the upper airway and facial skeleton in the evolution of obstructive sleep apnea (OSA) in a prospective population-based study with an 8-year follow-up. METHODS: This was a population-based, longitudinal, prospective study, which took place from 2007 to 2015 at the Instituto do Sono, Sao Paulo, Brazil. In 2007, type I polysomnography (PSG), otorhinolaryngological examination, and collection of anthropometric measurements of all volunteers were performed. Volunteers were classified according to their anatomical features of the upper airway and facial skeleton. After 8 years, volunteers were invited for reevaluation. The relationship between anatomical characteristics and polysomnographic evolution was evaluated. RESULTS: The study included 554 patients. After 8 years of follow-up, there was an increase in neck circumference and body mass index of the participants. There was a worsening in all polysomnographic parameters analyzed, with an increase in the apnea-hypopnea index, a decrease in minimum saturation values, and an increase in the percentage of sleep time with peripheral oxyhemoglobin saturation <90%. There was no statistical relationship between the anatomical findings considered unfavorable and the worsening of polysomnographic parameters. CONCLUSIONS: In a sample of the general population, after 8 years, we did not find any relationship between upper airway and facial skeleton characteristics and the progression of OSA.

The reproducibility of clinical OSA subtypes: a population-based longitudinal study.

PURPOSE: The identification of subgroups of obstructive sleep apnea (OSA) is critical to understand disease outcome and treatment response and ultimately develop optimal care strategies customized for each subgroup. In this sense, we aimed to perform a cluster analysis to identify subgroups of individuals with OSA based on clinical parameters in the Epidemiological Sleep Study of São Paulo city (EPISONO). We aimed to analyze whether or not subgroups remain after 8 years, since there is not any evidence showing if these subtypes of clinical presentation of OSA in the same population can change overtime. METHODS: We used data derived from EPISONO cohort, which was followed over 8 years after baseline evaluation. All individuals underwent polysomnography, answered questionnaires, and had their blood collected for biochemical examinations. OSA was defined according to AHI ≥ 15 events/h. Cluster analysis was performed using latent class analysis (LCA). RESULTS: Of the 1042 individuals in the EPISONO cohort, 68% agreed to participate in the follow-up study (n = 712), and 704 were included in the analysis. We were able to replicate the OSA 3-cluster solution observed in previous studies: disturbed sleep, minimally symptomatic and excessively sleepy in both baseline (36%, 45% and 19%, respectively) and follow-up studies (42%, 43%, and 15%, respectively). The optimal cluster solution for our sample based on Bayesian information criterion (BIC) was 2 cluster for baseline (disturbed sleep and excessively sleepy) and 3 clusters for follow-up (disturbed sleep, minimally symptomatic, and excessively sleepy). A total of 45% of the participants migrated clusters between the two evaluations (and the factor associated with this was a greater delta-AHI (B = - 0.033, df = 1, p = 0.003). CONCLUSIONS: The results replicate and confirm previously identified clinical clusters in OSA which remain in the longitudinal analysis, with some percentage of migration between clusters.

Inter-examiner agreement of the systematic physical examination in patients with obstructive sleep disorders.

PURPOSE: The goal of this study was to investigate the agreement between examiners who were or were not trained in the physical examination of the upper airway (UA) and the craniofacial skeleton of individuals with obstructive sleep disorders (OSD). METHOD: A systematic assessment of the UA and craniofacial skeleton was performed on 55 individuals with OSD. The participants were consecutively assessed by three otorhinolaryngologists who specialized in sleep medicine for at least 1 year (trained examiners) and two doctors who were attending a residency program in otorhinolaryngology (untrained examiners). RESULTS: When analyzing all of the parameters assessed, the concordance was better in the trained group (k = 0.694, which is considered "good") compared to the untrained group (k = 0.475, "fair") (p < 0.001). The inter-examiner agreement was also better in the trained compared to the untrained group, as follows: craniofacial (k = 0.643 vs. 0.349), nasal (k = 0.657 vs. 0.614), and pharyngeal (k = 0.729 vs. 0.276) abnormalities (p < 0.05). CONCLUSION: The overall concordance of the physical examination of the UA and craniofacial skeleton was "good" among the trained specialists and "fair" among examiners without appropriate training, despite its subjectivity.

New insights on the pathophysiology of inspiratory flow limitation during sleep.

INTRODUCTION: Inspiratory flow limitation (IFL) is defined as a "flattened shape" of inspiratory airflow contour detected by nasal cannula pressure during sleep and can indicate increased upper airway resistance especially in mild sleep-related breathing disorders (SRBD). The objective of this study was to investigate the association between upper airway abnormalities and IFL in patients with mild SRBD. METHODS: This study was derived from a general population study consisting of selected individuals with apnea-hypopnea index (AHI) below 5 events/h of sleep, ("no obstructive sleep apnea" group) and individuals with AHI between 5 and 15 events/h ("mild obstructive sleep apnea" group). A total of 754 individuals were divided into four groups: group 1: AHI <5/h and <30 % of total sleep time (TST) with IFL (515 individuals), group 2: AHI <5/h and >30 % of TST with IFL (46 individuals), group 3: AHI: 5-15/h and <30 % of TST with IFL (168 individuals), and group 4: AHI: 5-15/h and >30 % of TST with IFL (25 individuals). RESULTS: Individuals with complains of oral breathing demonstrated a risk 2.7-fold larger of being group 4 compared with group 3. Abnormal nasal structure increased the chances of being in group 4 3.2-fold in comparison to group 1. Individuals with voluminous lateral wall demonstrated a risk 4.2-fold larger of being group 4 compared with group 3. CONCLUSION: More than 30 % of TST with IFL detected in sleep studies was associated with nasal and palatal anatomical abnormalities in mild SRBD patients.

Subjective, anatomical, and functional nasal evaluation of patients with obstructive sleep apnea syndrome.

BACKGROUND: Studies have shown a high occurrence of nasal alterations in patients with obstructive sleep apnea syndrome (OSAS), but no studies have used different methods to evaluate the nose of patients with OSAS. The objective of this study was to evaluate the nose of patients with OSAS, compare them to controls, and correlate the different methods used to evaluate the nose. METHODS: Forty-seven patients with moderate/severe OSAS and 20 controls who were matched for gender, age, and body mass index were included. Questionnaires regarding sleep and nasal symptoms, physical examination, rhinoscopy, nasofibroscopy, nasal inspiratory peak flow (NIPF), and acoustic rhinometry (AR) measurements were performed. RESULTS: In the OSAS group, 33 (70.2%) were male, with a mean age of 53.2 ± 9.1 years. In the control group, 13 (65%) were male, with a mean age of 53.7 ± 9.7 years. The OSAS group had a higher score on the nasal symptoms scale (p < 0.01) and a higher frequency of nasal alterations [presence of septal deviation, clinical complaints (p = 0.01) and hypertrophy of the inferior nasal turbinate (p < 0.01)]. The NIPF and AR parameters could not differentiate between the OSAS and control groups. There were no significant correlations among the different methods used to evaluate the nose. Lower NIPF values were capable of predicting higher apnea-hypopnea index scores (p = 0.007). CONCLUSION: Clinical complaints and nasal alterations as measured by rhinoscopy and nasofibroscopy were associated with the presence of OSAS, which was not the case for the NIPF and AR parameters. The results of different evaluation methods were not correlated with each other.