Relationship between sleep apnoea syndrome,snoring and headaches

There is still a controversy regarding the relationship between sleep apnoea syndrome and headaches, especially morning headaches. Our objectives were: (i) to compare the prevalence and the clinical data of headaches in sleep apnoea syndrome (SAS) and control (snorers) groups defined by polysomnographic recording; (ii) to analyse the clinical improvement of headaches with appropriate treatment; and (iii) to correlate headaches with mood disorders, and nocturnal respiratory and architectural sleep parameters in order to understand the underlying pathophysiological mechanisms. This is a prospective study of 324 consecutive patients referred to our sleep centre for snoring. Of these, 312 patients who underwent sleep polysomnography were finally included. Patients and controls were interviewed about their medical past, headache history and clinical characteristics, their daytime sleepiness (Epworth's sleepiness scale) and their mood disorders (Zerssen's scale). Follow-up of patients with headaches (SAS and control groups), treated or not, was also assessed. According to our definition of SAS, patients were dissociated in SAS (n=164) and snorers (n=148). Fifty-three SAS patients had headaches, of whom 58.5% (n=30) suffered from morning headaches. However, there was no statistical difference between the two groups concerning the prevalence and the clinical characteristics of headaches. In addition, headaches and morning headaches were not correlated with nocturnal respiratory and architectural sleep parameters, nor with excessive daytime sleepiness, but were strongly correlated with mood disorders. In 36 SAS patients, headaches improved under treatment, but this was not statistically different from what was found among untreated snorers. Headaches and morning headaches are common in patients with SAS but may be considered as a non-specific symptom. The underlying mechanisms are not fully elucidated but depression could play an important role. Despite this absence of specificity, the treatment of SAS, especially nasal continuous positive airway pressure, leads to an improvement in headaches in several cases.     

Upright body position and weight loss improve respiratory mechanics and daytime oxygenation in obese patients with obstructive sleep apnoea

To determine whether upright body position and weight loss would improve daytime gas exchange in moderately obese patients with obstructive sleep apnoea (OSAS), 13 patients with mild or moderate OSAS were studied before and after weight loss. Pulmonary function tests, arterial blood gases and respiratory gas analysis were measured prior to and after a very low calorie diet (VLCD) period of six weeks. Arterial blood gases were measured in supine and standing positions and closing volume in supine and sitting positions before and after weight loss. In the upright position, there was a significant increase in PaO₂ (P<0·005) accompanied by a significant decrease in alveolar–arterial PO₂ difference (P<0·005) and closing volume (P<0·05). The median weight loss was 11 kg (range 5–18). The number of desaturation episodes (four percentage units or more per hour during sleep) (ODI₄) decreased (P<0·01) after weight loss. The change in PaO₂ with weight loss correlated with the decrease in ODI₄ (r=0·73, P<0·01). The increase in expiratory reserve volume (ERV) was closely related to the amount of weight lost (r=0·895, P<0·01). The results indicate that weight loss and upright body position improved daytime respiratory mechanics and gas exchange in obese patients with OSAS. The findings suggest that obesity plays an important role in the pathogenesis of daytime gas exchange disturbances in obese OSAS patients. The adoption of a more upright sleep posture might improve nocturnal oxygenation in obese patients with OSAS.     

Lung aeration during sleep in patients with obstructive sleep apnoea

Background: Previous studies have indicated that patients with obstructive sleep apnoea (OSA) have altered ventilation and lung volumes awake and the results suggest that this may be a determinant of severity of desaturations during sleep. However, little is known about regional lung aeration during sleep in patients with OSA. Methods: Twelve patients with OSA were included in the study. Computed tomography was used to study regional lung aeration during wakefulness and sleep. Lung aeration was calculated in ml gas/g lung tissue in four different regions of interest (ROI_1–4), along the border of the lung from ventral to dorsal. Results: Lung aeration in the dorsal (dependent) lung region (ROI₄) was lower during sleep compared to wakefulness 0·78 ± 0·19 versus 0·88 ± 0·19 (mean ± SD) ml gas/g lung tissue (P = 0·005). Associations were found between awake expiratory reserve volume and change in lung aeration from wakefulness to sleep in ROI₄ (r = ?0·69; P = 0·012). In addition, the change in lung aeration in the dorsal region correlated to sleep time (r = 0·69; P = 0·014) but not to time in supine position. The difference in lung aeration between inspiration and expiration (i.e. ventilation), was larger in the ventral lung region when expressed as ml gas per g lung tissue. In two patients it was noted that, during on‐going obstructive apnoea, lung aeration tended to be increased rather than decreased. Conclusions: Aeration in the dorsal lung region is reduced during sleep in patients with OSA. The decrease is related to lung volume awake and to sleep time.     

Predictors of health-related quality of life in patients with obstructive sleep apnoea

Title. Predictors of health-related quality of life in patients with obstructive sleep apnoea Aim. This paper is a report of a study to identify the common symptoms and demographic and physiological factors of obstructive sleep apnoea that are predictive of health-related quality of life in a Chinese population. Background. Health-related quality of life impairment in obstructive sleep apnoea is an increasingly important consideration, but little is known about the factors that influence quality of life in this population. Method. A total of 108 Chinese patients with newly diagnosed obstructive sleep apnoea were recruited in 2003 and assessed for health-related quality of life, daytime sleepiness, depression and anxiety. Associations between symptoms, demographic and physiological factors and quality of life were examined by Pearson linear correlation. Hierarchical multiple regression were used to determine predictors of overall quality of life and its dimensions. Results. Forty-six patients (42·6%) had depressed mood and 21 (19·4%) were anxious. Fifty-nine (54·6%) were hypersomnolent. The severity of symptoms of sleepiness, depression, and anxiety was statistically significantly inversely correlated with each domain and the total score for health-related quality of life. No statistically significant correlation was observed between disease severity and quality of life. Controlling for age and gender, anxiety and sleepiness predicted 45·2% of the variance of overall quality of life (R² = 0·452, P < 0·001). Anxiety was the strongest predictor of overall and each domain of health-related quality of life. Conclusion. Assessment of mood in patients with obstructive sleep apnoea should be an essential part of nursing practice. Comprehensive evaluation of symptoms, especially mood disturbance, is important for improving quality of life for these patients.     

Refractory chronic headache associated with obstructive sleep apnoea syndrome

The aim was to investigate the comorbidity of chronic refractory headache with obstructive sleep apnoea syndrome (OSAs). Seventy-two patients (51 women and 21 men) with chronic and refractory headaches, whose headache occurred during sleep or whose sleep was accompanied by snoring, were submitted to polysomnography. Patients diagnosed with OSAs (respiratory disturbance index > 10) began continuous positive airway pressure (C-PAP) treatment and were followed up for ≥ 6 months. Twenty-one cases of OSAs were identified (29.2% of the total investigated, 13.7% of the women and 66.6% of the men). Headaches were classified into several headache disorders, medication overuse headache and cluster headache being the most prevalent (nine and six of the 21 cases, respectively). In one case (1.4% of the total sample, 4.7% of all the men), the criteria for hypnic headache were fulfilled. Multivariate regression analysis revealed that age, male gender and body mass index were associated with OSAs. C-PAP treatment improved both sleep apnoea and headache in only a third of the cases. Patients suffering from chronic refractory headache associated with sleep or snoring, in particular those who are also middle-aged, overweight men, should be considered for polysomnography. C-PAP treatment alone does not seem to improve headache, but further investigation is needed.     

Severe obstructive sleep apnoea exacerbates the microvascular impairment in very mild hypertensives

Background Different studies have shown that obstructive sleep apnoea syndrome (OSAS), frequently associated with hypertension, represents a harmful and independent risk for cardiovascular diseases. The aim of our study was to ascertain whether the occurrence of OSAS could worsen microcirculatory impairment in very mild hypertensives. Materials and methods One hundred untreated very mild hypertensives underwent polysomnography and subdivided into 32 non‐OSAS, 33 mild OSAS and 35 severe OSAS patients on standardized criteria. They underwent routine blood chemistry, ambulatory blood pressure monitoring and anthropometric analysis. Skin capillary density (n mm^?2) of forearm (FAC) and periungueal (PUC) fields was obtained through videocapillaroscopy. By a venous congestion manoeuvre, PUC was maximized (CVC) and secondary capillary recruitment (GAIN) was calculated. These measurements served as indices of structural and functional capillary rarefaction, respectively. Results Severe OSAS hypertensives showed reduced FAC (P < 0·001) and PUC (P < 0·001) as compared to those with mild OSAS and non‐OSAS, but a greater CVC (P < 0·01) and GAIN (P < 0·001). Multiple regression analysis showed that PUC was inversely related to total sleep time with oxyhaemoglobin saturation at < 90% (TST90) (P < 0·001) and FAC to the apnoea‐hypopnoea index (AHI) (P < 0·001) and to the sleep propensity (P < 0·01). CVC was positively associated to AHI (P < 0·001) and GAIN to TST90 (P < 0·05). Conclusions The findings suggest that OSAS, by means of reduced basal and functional capillarity rarefaction, might pose an additional risk of impaired peripheral perfusion in very mild hypertensives. A microcirculation studytherefore should be a part of the clinical approach in patients at high cerebro‐cardiovascular risk such as hypertensives and patients with OSAS.     

Heart rate variability during sleep and sleep apnoea in a population based study of 387 women

Increased sympathetic activity during sleep has been suggested as a link between obstructive sleep apnoea syndrome and cardiovascular disease. Heart rate variability (HRV) is a measure of autonomic effect on the heart. Different parameters have been associated with sympathetic and parasympathetic activity. We have studied HRV in different sleep stages and related the HRV‐pattern to sleep apnoea in a population‐based sample of 387 women. We investigated the HRV‐parameters standard deviation of all R‐R intervals (SDNN), root of the averaged square of successive differences (RMSSD), low frequency component (LF), high frequency component (HF), ratio of low frequency component to high frequency component LF/HF and VSAI [variation in sympathetic activity between rapid eye movement (REM) and slow wave sleep, defined as LF_REM?LF_SWS]. The HRV‐parameters were compared with the results of a full‐night polysomnography. Hourly incidence of obstructive episodes was used for classifying the subjects into four apnoea‐hypopnoea index (AHI)‐groups (<5, ≥5 and <15, 15–30 and >30 events). Individual sleep stages were analysed by pooling all recordings. Women with high AHI had higher heart rate and LF/HF ratio. In subjects with AHI >30, LF/HF ratio however dropped to same level as with AHI <5. Subjects with high AHI had low VSAI. Levels of SDNN, LF and LF/HF ratio during REM and light sleep were similar to wakefulness. In slow wave sleep the parameters decreased. In conclusion, moderately increased prevalence of obstructive apnoeas was associated with signs of higher sympathetic activity. High AHI was however associated with a HRV‐pattern suggestive of depressed sympathetic drive and lowered ability to increase it during REM.     

Comparison of invasive intubation and noninvasive mechanical ventilation in patients with chronic obstructive pulmonary disease and obstructive sleep apnoea syndrome

ObjectiveThe concurrence of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnoea syndrome (OSAS) is defined as overlap syndrome (OS), but investigations into predictors of OS in patients with COPD remain limited. Here, potential markers of OS in patients with COPD were investigated, and results of intubation were compared between patients with COPD only or OS.MethodsThis retrospective study included patients with COPD who were divided according to OS diagnosis: COPD only (COPD group) or OS (OS group).ResultsAmong 206 patients with COPD, 120 were diagnosed with OS. Mean body mass index (BMI) was significantly higher in the OS versus COPD group (28.95 ± 2.96 versus 23.84 ± 4.06, respectively). Receiver operating characteristic curve analyses revealed that BMI was associated with OS (area under the curve, 0.835). The rate of invasive intubation within 48 h was lower in the OS versus COPD group (9.2% versus 20.9%, respectively), and the duration of noninvasive ventilation was longer in the OS versus COPD group.ConclusionsBMI may be a predictor of OS in patients with COPD. The duration of noninvasive ventilation was longer in patients with OS than in patients with COPD alone.     

Reproducibility of oximetry with a static charge-sensitive bed in evaluation of obstructive sleep apnoea

The reproducibility of overnight polygraphic recording with oximetry, the use of a static charge-sensitive bed (SCSB), thermistors and a body position sensor was assessed in diagnosing obstructive sleep apnoea syndrome (OSAS). Forty-six patients with a clinical suspicion of OSAS underwent a repeat recording. No treatment for OSAS and no change in patient characteristics was allowed between duplicate nights. Between repeated recordings significant correlations were found for ODI₄, time spent at Sa O ₂ < 90% and the mean nadir Sa O ₂. Good agreement was found in concordance of classification of ODI_4, time spent at Sa O ₂ < 90% and body movements. The combination of oximetry, thermistors, SCSB and body position sensor has a good reproducibility as an affordable screening method in the evaluation of OSAS.     

Simultaneous midline laser glossectomy with palatopharyngeal surgery for obstructive sleep apnoea syndrome

We investigate the outcome of performing tongue base reduction surgery and palatopharyngeal surgery in a single stage to determine whether the same-stage midline laser glossectomy (MLG) with extended uvulopalatal flap (EUPF) for obstructive sleep apnoea syndrome (OSAS) is a safe and effective procedure. Six male patients with a history of severe OSAS were recruited into the retrospective study. They were the first patients to undergo the MLG with EUPF procedure. Patients were identified to have retropalatal and hypopharyngeal sites of obstruction on the basis of fiberoptic endoscopy with Muller's manoeuvre and three-dimensional computerised tomography. No significant adverse events occurred. The follow-up polysomnography (6-month follow-up) revealed that the mean respiratory disturbance index from 50.7 to 11.6, snoring index from 230.9 to 137.3 and the minimal oxygen saturation from 76.3 to 88.8. This study confirms that the same-stage MLG with EUPF for OSAS is a safe and effective procedure.     

Abnormal respiratory-related evoked potentials in untreated awake patients with severe obstructive sleep apnoea syndrome

Aim: Obstructive sleep apnoeas generate an intense afferent traffic leading to arousal and apnoea termination. Yet a decrease in the sensitivity of the afferents has been described in patients with obstructive sleep apnoea, and could be a determinant of disease severity. How mechanical changes within the respiratory system are processed in the brain can be studied through the analysis of airway occlusion‐related respiratory‐related evoked potentials. Respiratory‐related evoked potentials have been found altered during sleep in mild and moderate obstructive sleep apnoea syndrome, with contradictory results during wake. We hypothesized that respiratory‐related evoked potentials’ alterations during wake, if indeed a feature of the obstructive sleep apnoea syndrome, should be present in untreated severe patients. Methods: Ten untreated patients with severe obstructive sleep apnoea syndrome and eight matched controls were studied. Respiratory‐related evoked potentials were recorded in Cz‐C3 and Cz‐C4, and described in terms of the amplitudes and latencies of their components P1, N1, P2 and N2. Results: Components amplitudes were similar in both groups. There was no significant difference in P1 latencies. This was also the case for N1 in Cz‐C3. In contrast, N1 latencies in Cz‐C4 were significantly longer in patients with obstructive sleep apnoea syndrome [median 98 ms (interquartile range 16·00) versus 79·5 ms (5·98), P = 0·015]. P2 and N2 were also significantly delayed, on both sides. Conclusions: The cortical processing of airway occlusion‐related afferents seems abnormal in untreated patients with severe obstructive sleep apnoea syndrome. This could be either a severity marker and/or an aggravating factor.