The obstructive sleep apnea syndrome is typically associated with conditions known to increase insulin resistance as hypertension, obesity, and diabetes. We investigated whether obstructive sleep apnea itself is an independent risk factor for increased insulin resistance and whether continuous positive airway pressure (CPAP) treatment improves insulin sensitivity. Forty patients (apnea–hypopnea index > 20) were treated with CPAP. Before, 2 days after, and after 3 months of effective CPAP treatment, hyperinsulinemic euglycemic clamp studies were performed. Insulin sensitivity significantly increased after 2 days (5.75 ± 4.20 baseline versus 6.79 ± 4.91 μmol/kg · min; p = 0.003) and remained stable after 3 months of treatment. The improvement in insulin sensitivity after 2 days was much greater in patients with a body mass index less than 30 kg/m2 than in more obese patients. The improved insulin sensitivity after 2 nights of treatment may reflect a decreasing sympathetic activity, indicating that sleep apnea is an independent risk factor for increased insulin resistance. The effect of CPAP on insulin sensitivity is smaller in obese patients than in nonobese patients, suggesting that in obese individuals insulin sensitivity is mainly determined by obesity and, to a smaller extent, by sleep apnea.

Rationale: Endobronchial valves (EBVs) have been successfully used in patients with severe heterogeneous emphysema to improve lung physiology. Limited available data suggest that EBVs are also effective in homogeneous emphysema. Objectives: To evaluate the efficacy and safety of EBVs in patients with homogeneous emphysema with absence of collateral ventilation assessed with the Chartis system. Methods: Prospective, multicenter, 1:1 randomized controlled trial of EBV plus standard of care (SoC) or SoC alone. Primary outcome was the percentage change in FEV₁ (liters) at 3 months relative to baseline in the EBV group versus the SoC group. Secondary outcomes included changes in FEV₁, St. George’s Respiratory Questionnaire (SGRQ), 6-minute-walk distance (6MWD), and target lobe volume reduction. Measurements and Main Results: Ninety-three subjects (age, 63.7 ± 6.1 yr [mean ± SD]; FEV₁, % predicted, 29.3 ± 6.5; residual volume, % predicted, 275.4 ± 59.4) were allocated to either the EBV group (n = 43) or the SoC group (n = 50). In the intention-to-treat population, at 3 months postprocedure, improvement in FEV₁ from baseline was 13.7 ± 28.2% in the EBV group and −3.2 ± 13.0% in the SoC group (mean between-group difference, 17.0%; P = 0.0002). Other variables demonstrated statistically and clinically significant changes from baseline to 3 months (EBV vs. SoC, respectively: SGRQ, −8.63 ± 11.25 vs. 1.01 ± 9.36; and 6MWD, 22.63 ± 66.63 m vs. −17.34 ± 52.8 m). Target lobe volume reduction at 3 months was −1,195 ± 683 ml (P < 0.0001). Of the EBV subjects, 97.2% achieved volume reduction in the target lobe (P < 0.0001). Procedure-related pneumothoraces occurred in 11 subjects (25.6%). Five subjects required removal/replacement of one or more valves. One subject experienced two valve migration events requiring removal/replacement of valves. Conclusions: EBV in patients with homogeneous emphysema without collateral ventilation results in clinically meaningful benefits of improved lung function, exercise tolerance, and quality of life.

The Endobronchial Valve for Emphysema Palliation Trial (VENT) was a multi-centre, prospective, randomised, controlled trial conducted to evaluate the safety and effectiveness of unilateral endobronchial valve (EBV) treatment. The purpose of this analysis was to assess outcomes in the previously unreported European VENT study cohort.Patients with advanced emphysema were randomly assigned (2:1) to receive Zephyr® (Pulmonx Inc., Redwood City, CA, USA) EBV treatment (n=111) or medical management (n=60).At 6 months, EBV patients demonstrated a significant improvement compared with the controls for mean±sdchange in forced expiratory volume in 1 s (7±20%versus0.5±19%; p=0.067), cycle ergometry (2±14 Wversus-3±10 W; p=0.04) and St George’s Respiratory Questionnaire (-5±14 pointsversus0.3±13 points; p=0.047). At 12 months, the magnitude of the difference between groups for change from baseline was of similar magnitude to the differences seen at 6 months. Rates for complications did not differ significantly. EBV patients with computed tomography (CT) scans suggestive of complete fissure and lobar occlusion had a mean±sdlobar volume reduction of -80±30% and >50% met minimal clinical difference thresholds. The degree of emphysema heterogeneity did not preclude excellent outcomes.Unilateral lobar volume reduction using EBV treatment is safe and superior clinical results correlated with CT suggestive of complete fissures and successful lobar occlusion. Emphysema heterogeneity was not critical for determining positive outcomes.

One-way endobronchial valves (EBVs) have been shown to relieve symptoms of emphysema, particularly in patients without collateral ventilation (CV) between the target and adjacent lobes. In this study, we investigated the ability of the bronchoscopic Chartis™ Pulmonary Assessment System to predict treatment response by determining the presence of CV.80 EBV patients underwent a pre-treatment Chartis assessment. Before and 30 days after implantation, high-resolution computed tomography scans were taken to determine target lobe volume reduction (TLVR). A pre- to post-treatment reduction of ≥350 mL was defined as significant. In addition, clinical outcomes (forced expiratory volume in 1 s (FEV₁), 6-min walk test and St George’s Respiratory Questionnaire) were compared over the same time period.Of the 51 patients classified as having an absence of CV according to their Chartis reading, 36 showed a TLVR ≥350 mL. 29 patients were classified as having CV, and of these 24 did not meet this TLVR cut-off. Chartis showed an accuracy level of 75% in predicting whether or not the TLVR cut-off would be reached. Those predicted to respond showed significantly greater TLVR (p<0.0001) and FEV₁improvement (p=0.0013) than those predicted not to respond.Chartis is a safe and effective method of predicting response to EBV treatment.

Serum leptin and ghrelin levels were investigated in patients with obstructive sleep apnoea (OSA) syndrome before and during continuous positive airways pressure (CPAP) treatment and compared with body mass index (BMI)-matched controls without OSA.Male patients (n=30) with OSA (apnoea/hypopnoea index=58±16, BMI=32.6±5.3 kg·m⁻²) underwent CPAP treatment. Fasting leptin and ghrelin were measured atbaseline and 2 days, and in the case of leptin 2 months after initiation of treatment.Baseline plasma ghrelin levels were significantly higher in OSA patients than in controls. After 2 days of CPAP treatment, plasma ghrelin decreased in almost all OSA patients (n=9) to levels that were only slightly higher than those of controls (n=9). Leptin levels did not change significantly from baseline after 2 days of CPAP treatment, but were higher than in the control group. After 8 weeks, leptin levels decreased significantly, although the BMI of the patients showed no change. The decrease in leptin levels was more pronounced in patients with a BMI <30 kg·m⁻².These data indicate that the elevated leptin and ghrelin levels are not determined by obesity alone, since they rapidly decreased during continuous positive airways pressure therapy.