Bernard Fleury

Chronic liver injury during obstructive sleep apnea

Patients with obstructive sleep apnea (OSA) are at risk for the development of fatty liver as a result of being overweight. Several data suggest that OSA per se could be a risk factor of liver injury; ischemic hepatitis during OSA has been reported, and OSA is an independent risk factor for insulin resistance. Therefore, we investigated liver damage and potential mechanisms in 163 consecutive nondrinking patients with nocturnal polysomnographic recording for clinical suspicion of OSA. Serum levels of liver enzymes were measured in all patients. Liver biopsy was offered to patients with elevated liver enzymes. Intrahepatic hypoxia was assessed by the expression of vascular endothelial growth factor (VEGF) on liver biopsy specimens. Severe OSA (apnea‐hypopnea index [AHI] > 50/hr) was seen in 27% of patients; 52% had moderate OSA (AHI 10‐50/hr), and 21% had no OSA. Overall, 20% had elevated liver enzymes. Independent parameters associated with elevated liver enzymes were body mass index (BMI) (OR: 1.13; CI: 1.03‐1.2) and severe OSA (OR: 5.9; CI: 1.2‐29). Liver biopsy was performed in 18 of 32 patients with elevated liver enzymes and showed steatohepatitis in 12 cases, associated with fibrosis in 7 cases. Patients with severe OSA were more insulin‐resistant according to homeostasis model assessment, had higher percentage of steatosis as well as scores of necrosis and fibrosis, despite similar BMI. Hepatic immunostaining used as an indirect marker of hypoxia was not different between patients with or without severe OSA. In conclusion, severe OSA is a risk factor for elevated liver enzymes and steatohepatitis independent of body weight. Promotion of insulin resistance is probably involved. Further studies are needed to determine whether hypoxia contributes directly to liver injury. (HEPATOLOGY 2005;41:1290–1296.)

Titrated mandibular advancement versus positive airway pressure for sleep apnoea

The aim of this study was to compare mandibular advancement device (MAd) therapy and continuous positive airway pressure (CPAP) for obstructive sleep apnoea/hypopnoea syndrome (OSAHS) after one-night polysomnographic (PSG) titration of both treatments. 59 OSAHS patients (apnoea/hypopnoea index (AHI): 34±13 events·h−1; Epworth scale: 10.6±4.5) were included in a crossover trial of 8 weeks of MAd and 8 weeks of CPAP after effective titration. Outcome measurements included home sleep study, sleepiness, health-related quality of life (HRQoL), cognitive tests, side-effects, compliance and preference. The median (interquartile range) AHI was 2 (1–8) events·h−1 with CPAP and 6 (3–14) events·h−1 with MAd (p<0.001). Positive and negative predictive values of MAd titration PSG for treatment success were 85% and 45%, respectively. Both treatments significantly improved subjective and objective sleepiness, cognitive tests and HRQoL. The reported compliance was higher for MAd (p<0.001) with >70% of patients preferring this treatment. These results support titrated MAd as an effective therapy in moderately sleepy and overweight OSAHS patients. Although less effective than CPAP, successfully titrated MAd was very effective at reducing the AHI and was associated with a higher reported compliance. Both treatments improved functional outcomes to a similar degree. One-night titration of MAd had a low negative predictive value for treatment success.

The age and other factors in the evaluation of compliance with nasal continuous positive airway pressure for obstructive sleep apnea syndrome. A Cox's proportional hazard analysis.

Objective: To elucidate the predictive role of age and other pre-treatment, putative confounding factors on compliance with nasal continuous positive airway pressure (nCPAP) therapy.Patients and methods: This study was designed as a prospective cohort study in the setting of a sleep laboratory in a teaching hospital at Saint Antoine, Paris. One hundred and sixty-three patients referred to the sleep laboratory with complaints of snoring and excessive daytime sleepiness for whom nCPAP had been prescribed for obstructive sleep apnea syndrome (OSAS; defined as an apnea-hypopnea index (AHI) of >15/h of sleep during a polysomnographic recording) were followed for a median period of 887 days. The main outcome measure was the risk ratio for elderly patients associated with nCPAP compliance.Results: Four patients, who remained under treatment, died before the end of the study, and 50 patients stopped their nCPAP therapy for reasons other than death (insomnia, equipment too noisy, etc.). When compliance curves were compared by univariate analysis (log-rank test), the oldest group (57/163 patients, >60 years old) was significantly less compliant with nCPAP than the youngest (P=0.01). However, in the Coxs proportional hazards model, age did not exert any independent effect on compliance with nCPAP after controlling for confounding factors (adjusted relative risk, 1.09, 0.5-2; P=0.70). On the other hand, female sex (adjusted relative risk, 2.8, 1.4-5.4; P=0.002), a body mass index (BMI) of </=30 kg/m(2) (adjusted relative risk, 2.2, 1.2-4; P=0.006), an Epworth sleepiness scale (ESS) score of </=15 (adjusted relative risk, 3.2, 1.1-8.9; P=0.025), an AHI of </=30/h (adjusted relative risk, 2.2, 1.2-4; P=0.01) and a nCPAP of >/=12 cmH(2)O (adjusted relative risk, 2.3, 1.2-4.4; P=0.011) were predictive factors for non-compliance.Conclusion: This study suggests that there is no independent effect of age on compliance with nCPAP therapy.

Radiofrequency Ablation for the Treatment of Mild to Moderate Obstructive Sleep Apnea

Objectives/Hypothesis Obstructive sleep apnea syndrome is due to pharyngeal obstructions, which can take place at the level of the soft palate. Temperature‐controlled radiofrequency ablation has been introduced as being capable of reducing soft tissue volume and excessive compliance. The aim of the study was to evaluate prospectively the possible efficacy of temperature‐controlled radiofrequency ablation applied to the soft palate in subjects with mild to moderate obstructive sleep apnea syndrome.

Economic arguments for the immediate management of moderate-to-severe obstructive sleep apnoea syndrome

The objective of this study was to measure the impact of a 6‐month delay in the diagnosis and treatment of patients with moderate obstructive sleep apnoea syndrome (OSAS) (apnoea/hypopnoea index (AHI) <30) or severe OSAS (AHI ≥30) on daytime sleepiness, cognitive functions, quality of life and healthcare expenditure (hospitalisations, medical visits, complementary tests, biological tests and drug prescriptions). In addition, this study aimed to analyse the incremental cost effectiveness ratios related to daytime sleepiness or quality of life following immediate introduction of treatment in these two populations. This study was conducted as a multicentre randomised controlled trial and carried out at two teaching hospitals in France. A total of 171 patients were followed for 6 months, with 82 patients randomised to group 1 “immediate polysomnography” and 89 in group 2 “polysomnography within 6 months”. Patients with severe OSAS were deprived of a significant improvement of their daytime sleepiness (5.1±5.0 at the Epworth Sleepiness Scale score in group 1 versus 0.2±3.4 in group 2) and quality of life (12.4±13.3 at the Nottingham Health Profile score in group 1 versus 0.7±10.1 in group 2) during the waiting time. The impact of delayed management in subjects with less severe OSAS only concerned daytime sleepiness (1.9±3.3 in group 1 versus 0.3±4.3 in group 2). Delayed treatment did not affect cognitive functions or healthcare expenditure regardless of the severity of the disease. Incremental cost effectiveness ratios related to rapid introduction of treatment were significantly lower in the patients with more severe OSAS. These results provide fairly clear medical and economic arguments in favour of early management of patients with more severe forms of obstructive sleep apnoea syndrome.

Symptoms of sleep apnea syndrome: High prevalence and underdiagnosis in the French population

OBJECTIVE To determine the prevalence of symptoms evocative of obstructive sleep apnea (SE-OSA) and the magnitude of obstructive sleep apnea (OSA) underdiagnosis. METHODS We used data from a cross-sectional survey conducted in 2008 in a representative sample of the French general population. Data were collected through interviews and self-administrated questionnaires and were complete for 12,203 adults (≥16 years old). SE-OSA was defined by snoring almost every night plus witnessed apneas or excessive daytime sleepiness (Epworth sleepiness scale score>10). RESULTS The prevalence of SE-OSA was 4.9% (95% CI: 4.5-5.3), and that of self-reported OSA diagnosis was 2.4% (2.1-2.7). The prevalence of SE-OSA was 8% among people with hypertension and 11% among obese people. A previous sleep monitoring session was reported by 2.7% (2.4-3.0) of the participants and by 15.1% of people with SE-OSA. This latter proportion increased with age (24% in people with SE-OSA aged 60 years or over) and was higher in obese people (26%) and in those with chronic diseases (27% among people with hypertension). CONCLUSION The prevalence of SE-OSA is high in France and OSA remains underdiagnosed, even in people with obesity or hypertension. Further efforts are needed to improve the diagnosis of OSA.

Objective patient compliance in long-term use of nCPAP

Concerns remain regarding patient compliance with nasal continuous positive airway pressure (nCPAP). Poor objective compliance during the first months of treatment has been reported, but no data are available among chronically treated patients. Use of nCPAP, in 17 chronically treated obstructive sleep apnoea patients (820+/-262 days) was evaluated objectively using a pressure monitor (MC+; Sefam, France). Two consecutive recording periods of 30 sessions of treatment were scheduled at the patients home. To minimize the potential bias caused by the introduction of the monitor, only the pressure data obtained at the end of the second period of recording (T2) were analysed. During the 28.1+/-2.6 monitored days, the mean effective daily rate of use was 7.1+/-1.1 h, 97% of the rate indicated by the standard in-built time counter. The prescribed pressure was observed during 95% of the machine run time. The nCPAP system was used for 94% of the monitored days. Sixty percent of the patients used their device every day. These preliminary results suggest that, contrary to reported compliance during the early period of the treatment, objective use of nasal continuous positive airway pressure therapy in chronically treated patients is satisfactory.

Economic studies and 'technical' evaluation of telemedicine: the case of telemonitored polysomnography.

Information and communication technology (ICT) is not yet integrated into current medical practice and frequently, organizational patterns of health care production are held responsible for this situation. However, and quite paradoxically, measures recently taken in France indicate that a preferential role is granted to ICT in order to promote the development of healthcare networks. In this context, one should carefully examine which factors, other than organizational ones, can explain the very slow diffusion of telemedicine. Actually, medical assessment of telemedicine is very seldom and the medical community is unable to appreciate the extent that this technology would modify the quality of care provided. Furthermore, and as a consequence of the former, there is no economic evaluation of telemedicine applications and its effects, in terms of productivity, remain virtual. In this article, based on an early evaluation of telemonitored polysomnography to diagnose sleep apnea syndrome, we show that it is possible, even at an experimental stage, to produce appropriate and convincing clinical results stating the true technological effectiveness (choice of an adequate clinical trial, selection of appropriate endpoints). Specific attention is given to the technical conditions in which the technology is assessed, we also provide most of the data that should be taken into account to foresee the major organizational transformations of the production processes. Our results show that early clinical ad hoc evaluations of telemedicine applications can be conducted promptly, providing strong clinical results and useful data for any forthcoming economic evaluation.

Wrist-actigraphic estimation of sleep time under nCPAP treatment in sleep apnoea patients

The aim of this study was to correlate daily use of nasal continuous positive airway pressure (nCPAP) with total sleep time (TST) evaluated by home actigraphy. Actigraphy was validated by comparing TST determined by actigraphy (aTST) and polysomnography (pTST) in 24 untreated patients with suspected sleep apnoea. The % sleep time spent under nCPAP was estimated on 3 consecutive days in 28 patients receiving long-term nCPAP, by comparing machine-use periods with sleep periods identified by home actigraphy. The mean difference between pTST and aTST was 2.5 min. The correlation coefficient between aTST and pTST was 0.90. Daily use of nCPAP over the 3 study days was 388±114 min. nCPAP was used 41–100% (82±17% (mean±sd)) of sleep time detected by actigraphy. Some patients used nCPAP during nonsleep periods. In conclusion, comparison of nasal continuous positive airway pressure use with sleep time estimated by home actigraphy shows marked individual differences in the % sleep time under nasal continuous positive airway pressure. These results suggest that actigraphic estimation of sleep time under nasal continuous positive airway pressure could provide a better index than simple daily use of the device to evaluate the impact of treatment in sleep apnoea.

Traitement du syndrome d’apnées obstructives du sommeil de l’adulte par orthèse d’avancée mandibulaire : actualisation des connaissances

Resume Le syndrome d’apnees obstructives du sommeil constitue un risque de sante non negligeable qui merite une prise en charge de la part des specialistes des voies aeriennes superieures. Lorsque le diagnostic de SAHOS est fonde, il convient de le traiter et differents moyens sont repertories. Differents traitements sont envisages : ventilation par pression positive (VPPC), ortheses d’avancee mandibulaire (OAM), interventions chirurgicales (tissus mous et tissus durs). Les auteurs developpent particulierement les traitements par OAM en decrivant leurs repercussions positives et negatives sur la ventilation, sur les ATM, les bases osseuses et les relations interarcades.