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The article highlights that obstructive sleep apnoea (OSA) is a sleep disorder in which there are episodes of partial hypopnoea or complete obstruction apnoea of the upper airway during sleep. It also discusses that obstructive sleep apnoea is often underdiagnosed as it develops slowly and occurs predominantly during sleep or symptoms are misattributed to busy lives and chronic sleep deprivation.

The article presents information about a research conducted for determining the surgically induced weight loss effectiveness than with conventional weight loss therapy in the management of obstructive sleep apnea (OSA). The research employed a randomized controlled clinical trial of 60 obese patients with body mass index of greater than 35 and less than 55 with recently diagnosed OSA and an apnea-hypopnea index (AHI). These patients were prescribed continuous positive airway pressure (CPAP) therapy for managing OSA and were identified through accredited community sleep clinics. The trial has been conducted by university and teaching hospital-based clinical researchers in Melbourne, Victoria.

Objective: To assess whether severe gastroesophageal reflux (GER) is associated with abnormalities in lung function including measures of lung volume and gas diffusion. Methods: Data from 147 patients with obesity (body mass index [BMI] range, 31.7 to 70 kg/m[sup 2]) who presented for obesity surgery was analyzed retrospectively. A questionnaire was completed preoperatively that included a history of GER, frequency and severity of symptoms, investigations, and medications used. A history of lung disease, sleep-disordered breathing, and smoking also was obtained. A physician who was blinded to lung function graded GER severity prospectively by the results of pH monitoring and/or gastroscopy, and medication use. Spirometry, lung volumes, and gas transfer were measured preoperatively. Results: Patients with severe GER had reduced levels of the diffusing capacity of the lung for carbon monoxide (DLCO) [21.1 mL/min/mm Hg; 95% confidence interval (CI), 18.9 to 23.2], as measured by CO transfer, compared with those patients without GER (26.3 mL/min/mm Hg; 95% CI, 24.4 to 28.2; p = 0.001). This remained significant after adjusting for age, gender, BMI, and smoking history. Gas transfer corrected for lung volume also was reduced in the group with severe GER (4.6 mL/min/mm Hg per L; 95% CI, 4.3 to 4.9) compared to the group without GER (5.3 mL/min/mm Hg per L; 95% CI, 5.1 to 5.5; p = 0.001). There was no significant difference in other measures of lung function. Conclusions: Severe GER is associated with an impairment of gas exchange. This may be due to microaspiration of gastric acid or fluid into the airways. [ABSTRACT FROM AUTHOR]

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[sub Ic] (r² = 0.42). Neck circumference (the best single measure) could replace BMI and sex in the analysis (r² = 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 ≥ 3 provides a sensitivity and specificity of 89% and 81%, and 96% and 71% for AHIs of ≥ 15 and ≥ 30, respectively. None of the 31 subjects with scores of 0 or 1 were found to have an AHI ≥ 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. [ABSTRACT FROM AUTHOR]

Studies sleep disturbance in obese individuals. Percent prevalence of sleep disturbance in women versus men; Link of waist circumference and sleep apnea; Improvement of obesity-related sleep disorder with weight loss.

There is an increasing prevalence of obesity worldwide and its impact on respiratory health is of significant concern. Obesity affects the respiratory system by several mechanisms, including by direct mechanical changes due to fat deposition in the chest wall, abdomen and upper airway, as well as via systemic inflammation. The increased mechanical load in obese individuals leads to reduced chest wall and lung compliance and increased work of breathing. While there is generally minimal effect on spirometric values, as body mass index increases, the expiratory reserve volume, and hence functional residual capacity, reduces, often approaching residual volume in more severe obesity. The majority of evidence however suggests that obese individuals free from lung disease have relatively normal gas exchange. The link between asthma and obesity, while initially unclear, is now recognized as being a distinct asthma phenotype. While studies investigating objective markers of asthma have shown that there is no association between obesity and airway hyper-responsiveness, a recent working group identified obesity as a major risk factor for the development of asthma in all demographic groups. Although the temptation may be to attribute obesity as the cause of dyspnoea in symptomatic obese patients, accurate respiratory assessment of these individuals is necessary. Lung function tests can confirm that any altered physiology are the known respiratory consequences of obesity. However, given that obesity causes minimal changes in lung function, significant abnormalities warrant further investigation. An important consideration is the knowledge that many of the respiratory physiology consequences of obesity are reversible by weight loss. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Context: Observational studies suggest that surgically induced loss of weight may be effective therapy for type 2 diabetes.Objective: To determine if surgically induced weight loss results in better glycemic control and less need for diabetes medications than conventional approaches to weight loss and diabetes control.Design, Setting, and Participants: Unblinded randomized controlled trial conducted from December 2002 through December 2006 at the University Obesity Research Center in Australia, with general community recruitment to established treatment programs. Participants were 60 obese patients (BMI >30 and <40) with recently diagnosed (<2 years) type 2 diabetes.Interventions: Conventional diabetes therapy with a focus on weight loss by lifestyle change vs laparoscopic adjustable gastric banding with conventional diabetes care.Main Outcome Measures: Remission of type 2 diabetes (fasting glucose level <126 mg/dL [7.0 mmol/L] and glycated hemoglobin [HbA1c] value <6.2% while taking no glycemic therapy). Secondary measures included weight and components of the metabolic syndrome. Analysis was by intention-to-treat.Results: Of the 60 patients enrolled, 55 (92%) completed the 2-year follow-up. Remission of type 2 diabetes was achieved by 22 (73%) in the surgical group and 4 (13%) in the conventional-therapy group. Relative risk of remission for the surgical group was 5.5 (95% confidence interval, 2.2-14.0). Surgical and conventional-therapy groups lost a mean (SD) of 20.7% (8.6%) and 1.7% (5.2%) of weight, respectively, at 2 years (P < .001). Remission of type 2 diabetes was related to weight loss (R2 = 0.46, P < .001) and lower baseline HbA1c levels (combined R2 = 0.52, P < .001). There were no serious complications in either group.Conclusions: Participants randomized to surgical therapy were more likely to achieve remission of type 2 diabetes through greater weight loss. These results need to be confirmed in a larger, more diverse population and have long-term efficacy assessed.Trial Registration: actr.org Identifier: ACTRN012605000159651. [ABSTRACT FROM AUTHOR]

This article reports on a clinical trial to determine if gastric banding surgery could be effective therapy for the treatment of type 2 diabetes. Obesity and type 2 diabetes are both on the rise in the U.S. and other developed countries. The conditions are linked and weight control may be the most important factor in reducing the incidence of diabetes. This study wanted to see if surgically induced weight loss offered better blood sugar control and less need for medications than the more traditional approaches of diet and exercise. The study found that patients given the surgical option were more likely to achieve remission of their diabetes. The authors caution that a larger study needs to confirm their findings.

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. [ABSTRACT FROM AUTHOR]

Background: Type-2 diabetes is strongly driven by obesity. Observational studies suggest that weight loss through bariatric surgery is more effective than conventional therapy for the management of type-2 diabetes, but no randomized controlled trial has been performed. Methods: We conducted a 2-year randomized controlled trial involving 60 obese (BMI > 30 and < 40 kg/m2) subjects with recently diagnosed (<2years) typo-2 diabetes. Subjects drawn from the general community were randomly allocated to either a program of conventional diabetes therapy with an intensive lifestyle change to induce weight loss or had substantial weight loss induced by the placement of a laparoscopic adjustable gastric band (LAGB; LAP-BAND®, Allergan Health) in addition to conventional care. The intensity of programs was similar. Key outcome measures were diabetes remission (fasting plasma glucose <7mmol/l, plus HbA1c <6.2% while taking no hypoglycaemic drug therapy or insulin), HbA1c levels, indirect measures of insulin resistance, and presence of metabolic syndrome. Results: At 2 years, the LAGB group and conventional groups had lost mean (SD) of 20.7 (8.6) % and 1.7 (5.2) % of weight respectively (P <0.001). Remission of diabetes was achieved by 22 of 29 (76%) the LAGB, and 4 of 26 (15%) of the conventional 2-year completers (p<0.001). Weight loss was the major driver of remission (R2 =0.46, p<0.001), with a 13% weight loss cutoff providing an 85% sensitivity and 86% specificity for remission. HbA1c levels fell 22.5 (11.6) % in the LAGB and 5.4 (15.2) % in the conventionally treated groups. The surgical group also had greater improvements in fasting plasma glucose, insulin, triglycerides and HDL-cholesterol. The metabolic syndrome was present in 29 of 30 in each group initially and in 8 of 29 LAGB and 22 of 26 conventional groups at 2 years. There were no serious complications in either treatment group. Conclusions: There is a direct relationship between weight loss and remission of type 2 diabetes in obese subjects. Substantial weight loss induced by LAGB is associated with a significantly better outcome than conventional therapy. LAGB placement should be considered when planning a treatment program for obese subjects diagnosed with type-2 diabetes. [ABSTRACT FROM AUTHOR]