The influence of gender on symptoms associated with obstructive sleep apnea.

BACKGROUND: It has been reported that the clinical expression of obstructive sleep apnea (OSA) may differ in women and men. OBJECTIVE: The objective of this study was to evaluate the influence of gender on reported OSA-related symptoms in a large clinical population of patients. METHODS: The database from the sleep laboratory of a tertiary care center was examined. Adult patients who had undergone a diagnostic polysomnography and completed the Berlin questionnaire, a sleep questionnaire, and the Epworth sleepiness scale were selected. Multiple logistic regression analysis was performed to assess the relationship between OSA-associated symptoms and different potential explanatory variables. RESULTS: The study sample included 1084 patients, median age was 53 years, 46.5% (504) were women, 72.7% (788) had OSA (apnea/hypopnea index ≥ 5), and 31.2% were obese. After adjusting for age, body mass index, and apnea/hypopnea index, men were more likely to report snoring (OR 4.06, p < 0.001), habitual or loud snoring (OR 2.34, p < 0.001; 2.14, p < 0.001, respectively) and apneas (OR 2.44, p < 0.001), than women. After controlling for multiple variables, female gender was an independent predictive factor for reported tiredness (OR 0.57, p 0.001), sleep onset insomnia (OR 0.59, p 0.0035), and morning headaches (OR 0.32, p < 0.001). Reports of excessive daytime sleepiness, nocturia, midnight insomnia, and subjective cognitive complaints were not significantly associated with gender. CONCLUSION: Women with OSA were more likely to report tiredness, initial insomnia, and morning headaches, and less likely to complain of typical OSA symptoms (snoring, apneas) than men.

Validation of ApneaLink Ox™ for the diagnosis of obstructive sleep apnea.

OBJECTIVE: The aim of the study was to validate the automatic and manual analysis of ApneaLink Ox™ (ALOX) in patients with suspected obstructive sleep apnea (OSA). METHODS: All patients with suspected OSA had a polysomnography (PSG) and an ALOX performed in the sleep laboratory. For automatic analysis, hypopnea was defined as a decrease in airflow ≥30 % of baseline for at least 10 s plus oxygen desaturation ≥3 or 4 %. While for the manual analysis, hypopnoea was considered when a reduction of airflow ≥30 % of ≥10 s plus oxygen desaturation ≥3 % or increase in cardiac rate ≥5 beats/min were identified or, when only a reduction of airflow ≥50 % was observed. OSA was defined as a respiratory disturbance index (RDI) ≥5. The apnea/hypopnea automatic index (AHI3-a, AHI4-a) and manual index were estimated. Receiver operating characteristics (ROC) analysis and the agreement between ALOX and PSG were performed. RESULTS: Fifty-five patients were included (38 men; mean age, 48.2; median, RDI 15.1; median BMI, 30 Kg/m(2)). The automatic analysis of ALOX under-estimated the RDI from PSG, mainly for the criterion of oxygen desaturation ≥4 % (AHI3-a-RDI, -3.6 ± 10.1; AHI4-a-RDI, -6.5 ± 10.9, p < 0.05). The autoscoring from ALOX device showed a better performance when it was set up to identify hypopneas with an oxygen desaturation criterion of ≥3 % than when it was configured with an oxygen desaturation criterion of ≥4 % (area under the receiver operator curves, 0.87 vs. 0.84). Also, the manual analysis was found to be better than the autoscoring set up with an oxygen desaturation of ≥3 % (0.923 vs. 0.87). The manual analysis showed a good interobserver agreement for the classification of patients with or without OSA (k = 0.81). CONCLUSION: The AHI obtained automatically from the ApneaLink Ox™ using oxygen desaturation ≥3 % as a criterion of hypopnea had a good performance to diagnose OSA. The manual scoring from ApneaLink Ox™ was better than the automatic scoring to discriminate patients with OSA.

How reliable is the manual correction of the autoscoring of a level IV sleep study (ApneaLink™) by an observer without experience in polysomnography?

OBJECTIVE: This study aims to compare the manual correction of the automatic analysis of ApneaLink™ between a skilled observer in the interpretation of sleep studies and a subject trained only in the scoring of ApneaLink™ device. METHODS: Ninety-six subjects performed the ApneaLink™ and polysomnography (PSG) simultaneously in the sleep laboratory. Two blind observers, who were independent from the results of the PSG, performed first the automatic scoring and then the hand correction from the ApneaLink™ device. The scorers of ApneaLink™ represented two physicians with different levels of training (scorer A: 20 years of experience in reading polysomnography plus 3 years of experience in the interpretation of ApneaLink™, scorer B: 1 year of experience in the analysis of ApneaLink™). The interobserver agreement was assessed with the intraclass correlation coefficient (ICC) and kappa statistics. The diagnostic accuracy of the manual analysis ApneaLink™ device was evaluated by the area under the receiver operator curve (AUC-ROC). RESULTS: Ninety patients were included (69 men; mean age, 49.6; median RDI, 13.9; median BMI, 29.3 Kg/m(2)). The ICC between the manual apnea/hypopnea index from ApneaLink™ and the respiratory disturbance index of the PSG for each observer was similar (scorer A, 0.902; CI 95% 0.80-0.95; vs. scorer B, 0.904; CI 95% 0.86-0.94; p = 0.9). The agreement between the observers on the presence or absence of obstructive sleep apnea syndrome (OSAS) was very good (kappa, 0.83; CI 95% 0.69-0.98). The AUC-ROC was similar between the observers (scorer A, 0.88; CI 95% 0.78-0.98; scorer B, 0.83; CI 95% 0.71-0.95; p = 0.5). CONCLUSIONS: The non-expert observer showed a very good agreement with the expert observer on the results of the manual correction of the ApneaLink™ autoscoring. Both observers had similar diagnostic accuracy to identify subjects with OSAS when compared with PSG.