Search

Rationale: Obesity is a major risk factor towards the development of obstructive sleep apnea, while significant weight loss (both conservatively managed and surgically assisted) has a variable effect upon its severity. Differences in the effect of weight loss on obstructive sleep apnea may be due to underlying craniofacial characteristics., Objectives: To determine whether craniofacial characteristics can predict OSA treatment response to significant weight loss., Methods: We analyzed craniofacial measurements from lateral cephalograms performed at baseline on 57 patients enrolled in a previously reported 2-year randomized clinical weight loss trial (laparoscopic adjustable gastric band surgery versus conservatively [dietician and very low calorie diet] treated). Group mean weight loss was ∼ 13% (mean weight loss 131 to 114 kg), with corresponding reduction in mean apnea-hypopnea index (AHI) from 61 to 41 events/h. Computer assisted lateral cephalogram analysis was undertaken by three trained staff blinded to treatment. We analyzed lateral cephalogram and demographic data at baseline (cross-sectional) and change over two years (interventional) in 54 patients., Measurements and Main Results: Baseline cross-sectional analysis indicated no cephalometric measurement correlated significantly with baseline AHI when corrected for neck circumference. The percentage change in AHI over 2 years correlated with a shorter menton-gonion distance (i.e., mandibular body length). The % change in AHI correlated with the % weight change (R(2) = 0.25, p < 0.001) and mandibular body length (R(2) = 0.19, p = 0.002). The % change in AHI correlated with combined weight change and mandibular body length (combined R(2) = 0.31, p < 0.001)., Conclusions: Weight loss as a therapeutic option for severe OSA with severe obesity may be predicted by shorter mandibular body length as measured by lateral cephalometry., (© 2015 American Academy of Sleep Medicine.)

Objective: This study examined the impact of using two abbreviated signal montages on the accuracy, precision and inter-scorer reliability of polysomnography (PSG) sleep and arousal scoring, compared to a standard reference montage, in a cohort of patients investigated for obstructive sleep apnoea (OSA). One abbreviated montage incorporated two signals dedicated to sleep and arousal scoring, and the other incorporated a single signal., Methods: Four scorers from two laboratories each scored 15 PSGS four times in random order: once using each abbreviated montage and twice using the reference montage., Results: Use of the two-signal montage resulted in small changes in the distribution of sleep stages, a reduction in the arousal index and resultant reductions in sleep and arousal scoring agreement. For the one-signal montage, although similar magnitude sleep stage distribution changes were observed, there were larger reductions in the arousal index, and sleep and arousal scoring accuracy. Additionally, using the one-signal montage, there were statistically significant reductions in the precision of summary statistics including total sleep time (TST) and the amount of rapid eye movement (REM) sleep scored, and reductions in the inter-scorer reliability of REM sleep and arousal scoring., Conclusions: These findings demonstrate that abbreviated signal montages may result in underestimation of the arousal index and, depending on the montage, poorer precision in TST and REM sleep scoring, with potential consequences for apnoea-hypopnoea index (AHI) measures and OSA diagnosis. The results highlight the importance of careful evaluation of PSG results when using portable devices that have restricted signals, and they offer guidance for future PSG and portable monitoring standards., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Context: Obstructive sleep apnea (OSA) is strongly related to obesity. Weight loss is recommended as part of the overall management plan for obese patients diagnosed with OSA., Objective: To determine whether surgically induced weight loss is more effective than conventional weight loss therapy in the management of OSA., Design, Setting, and Patients: A randomized controlled trial of 60 obese patients (body mass index: >35 and <55) with recently diagnosed (<6 months) OSA and an apnea-hypopnea index (AHI) of 20 events/hour or more. These patients had been prescribed continuous positive airway pressure (CPAP) therapy to manage OSA and were identified via accredited community sleep clinics. The trial was conducted between September 2006 and March 2009 by university- and teaching hospital-based clinical researchers in Melbourne, Australia. Patients with obesity hypoventilation syndrome, previous bariatric surgery, contraindications to bariatric surgery, or significant cardiopulmonary, neurological, vascular, gastrointestinal, or neoplastic disease were excluded., Interventions: Patients were randomized to a conventional weight loss program that included regular consultations with a dietitian and physician, and the use of very low-calorie diets as necessary (n = 30) or to bariatric surgery (laparoscopic adjustable gastric banding; n = 30)., Main Outcome Measures: The primary outcome was baseline to 2-year change in AHI on diagnostic polysomnography scored by staff blinded to randomization. Secondary outcomes were changes in weight, CPAP adherence, and functional status., Results: Patients lost a mean of 5.1 kg (95% CI, 0.8 to 9.3 kg) in the conventional weight loss program compared with 27.8 kg (95% CI, 20.9 to 34.7 kg) in the bariatric surgery group (P < .001). The AHI decreased by 14.0 events/hour (95% CI, 3.3 to 24.6 events/hour) in the conventional weight loss group and by 25.5 events/hour (95% CI, 14.2 to 36.7 events/hour) in the bariatric surgery group. The between-group difference was -11.5 events/hour (95% CI, -28.3 to 5.3 events/hour; P = .18). CPAP adherence did not differ between the groups. The bariatric surgery group had greater improvement in the Short Form 36 physical component summary score (mean, 9.3 [95% CI, 0.5 to 18.0]; P = .04)., Conclusion: Among a group of obese patients with OSA, the use of bariatric surgery compared with conventional weight loss therapy did not result in a statistically greater reduction in AHI despite major differences in weight loss., Trial Registration: anzctr.org Identifier: 12605000161628.

Background: Obstructive sleep apnea (OSA) is common in severely obese subjects (body mass index [BMI] > 35). Overnight polysomnography (OPS) is the "gold standard" method of evaluating this condition; however, it is time-consuming, inconvenient, and expensive. Selection of patients for OPS would be enhanced if we could better predict those likely to have clinically significant OSA., Study Objective: To look for clinical and biochemical predictors of OSA in symptomatic patients presenting for obesity surgery., Design and Patients: Symptoms suggestive of OSA were sought in a structured interview. We report OPS results of 99 consecutive subjects in whom OSA was clinically suspected. Predictors of apnea-hypopnea index (AHI) were sought from an extensive preoperative data collection. Multivariate linear and logistic analysis was used to identify independent predictors of AHI., Results: Symptoms were poor predictors of AHI, with observed sleep apnea the only positive predictor. Four clinical and two biochemical factors independently predicted AHI: observed sleep apnea, male sex, higher BMI, age, fasting insulin, and glycosylated hemoglobin A(Ic) (r(2) = 0.42). Neck circumference (the best single measure) could replace BMI and sex in the analysis (r(2) = 0.43). With cutoffs selected, a simple scoring system using these six factors provides a method of predicting those with moderate or severe OSA. A score > or = 3 provides a sensitivity and specificity of 89% and 81%, and 96% and 71% for AHIs of > or = 15 and > or = 30, respectively. None of the 31 subjects with scores of 0 or 1 were found to have an AHI > or = 15., Conclusion: We explore sleep disturbance and report a simple method of predicting OSA in severely obese symptomatic subjects. This should assist in limiting the use of OPS to those with greater risk and provide a method of assessing risk in those not presenting primarily with a sleep problem.