Validity of a simple sleep monitor for diagnosing OSA in bariatric surgery patients

Background: One third of bariatric surgery patients have an apnea–hypopnea index (AHI)>15/hr, representing moderate and severe forms of obstructive sleep apnea (OSA). Treating these forms of OSA is recommended to reduce the risk of perioperative complications. The AHI derived from poly(somno)graphy [P(S)G] is the gold standard for OSA diagnosis. However, performing P(S)G in all patients scheduled for bariatric surgery is time consuming and expensive. An accurate and simple screening tool able to rule out moderate to severe OSA would reduce the number of patients needing mandatory P(S)Gs. Objectives: To assess the validity of a simple sleep monitor (Checkme Health Monitor) as a screening tool for OSA in bariatric surgery patients. Setting: Obesity Center Amsterdam, OLVG-West, Amsterdam, the Netherlands Methods: Patients scheduled for bariatric surgery were prospectively enrolled in this study. All patients underwent preoperative P(S)G and simultaneously used the Checkme to assess the oxygen desaturation index. The diagnostic performance of the Checkme for AHI ≥15/hr was assessed using receiver operating characteristic curve analysis. Results: A total of 50 patients were analyzed. Sensitivity and negative predictive value were 100% and 100%, respectively, specificity and positive predictive value were 69% and 64%, respectively, for the optimal cutoff value of Checkme-3% oxygen desaturation index ≥9/hr for P(S)G-AHI ≥15. The area under the curve value expressed by the receiver operating characteristic curve was.95. Conclusion: The Checkme is valid for exclusion of moderate and severe OSA in bariatric surgery patients. The Checkme enables bariatric clinics not to perform P(S)G in all patients scheduled for bariatric surgery

Do Complications Alter Postoperative Weight Loss 1 Year After Primary and Revisional Roux-en-Y Gastric Bypass?

Around 10 % of the bariatric surgery patients experience postoperative complications ( <30 days). It could be hypothesized that complications influence postoperative weight loss, which is one of the most important endpoints of bariatric surgery. Therefore, this study inventoried the effect of complications on postoperative weight loss. A consecutive database including patients who were operated from November 2007 onwards was retrospectively reviewed. All short-term complications were classified according to the Clavien-Dindo classification. Weight loss was assessed at 6 and 12 months postoperatively. A total of 1130 patients underwent either primary (n = 907, 80.3 %) or revisional (n = 233, 19.7 %) surgery till October 2013. Short-term complications occurred in 115 (10.2 %) patients, of whom 48 (41.7 %) had a severe (Clavien-Dindo ≥ 3) complication. One year post surgery, 184 patients (16.3 %) were lost to follow-up. Patients with a short-term complication had a higher percentage of excess weight loss (%EWL) at 6 months (58.6 (SD 16.6) versus 52.9 (SD 17.6), p = 0.003) and 1 year (71.9 (SD 22.3) versus 65.9 (SD 21.3), p = 0.017) of follow-up. Although a trend was seen toward higher BMI loss and total weight loss (TWL) after 6 months, no effect was seen 1 year postoperatively. In multivariable linear regression analysis, complications were not a significant predictor for 1-year %EWL. Although short-term complications alter 1-year %EWL, no effect was seen on BMI loss and TWL. In addition, complications were not a predictor in a multivariable linear regression model for 1-year %EWL. It can be concluded that short-term complications do not impair weight loss after Roux-en-Y gastric bypas

Influence of continuous positive airway pressure on postoperative leakage in bariatric surgery

Background: Obstructive sleep apnea (OSA) affects two third of morbidly obese individuals undergoing bariatric surgery. Perioperative usage of continuous positive airway pressure (CPAP) is advised for moderately and severe OSA to avoid respiratory failure and cardiac events. CPAP increases the air pressure in the upper airway, but also may elevate the air pressure in the esophagus and stomach. Concern exists that this predisposes to mechanical stress resulting in suture or staple line disruption (further referred to as suture line disruption). Objectives: To evaluate whether perioperative CPAP usage is associated with an increased risk of suture line disruption after bariatric surgery. Setting: Obesity Center Amsterdam, OLVG-west, Amsterdam, the Netherlands. Methods: All patients who underwent bariatric surgery including a suture line were eligible for inclusion. Only patients with information regarding OSA severity as defined by the apnea-hypopnea-index and postoperative CPAP usage were included. Results: From November 2007 to August 2016, postoperative CPAP status was documented in 2135 patients: 497 (23.3%) used CPAP postoperatively, whereas 1638 (76.7%) used no CPAP. Mean body mass index was 44.1 kg/m2 (standard deviation 6.6). Suture line disruption occurred in 25 patients (1.2%). The leakage rate was not associated with CPAP usage (8 [1.6%] in CPAP group versus 17 [1%] in non-CPAP group, P =.300). CPAP was no risk factor for suture line disruption in multivariable analysis as well. Conclusion: Postoperative CPAP does not appear to increase the risk of suture line disruption in bariatric surgery. CPAP is recommended in all patients with moderate or severe OSA who undergo bariatric surgery

Increased plasma ANGPTL7 levels with increased obstructive sleep apnea severity

Background: Weight-loss surgery is one of the recommended methods for treating obstructive sleep apnea (OSA) in obese patients. While weight reduction is critical to relieve symptoms of OSA, the biochemical factors involved in post-surgery improvement are still unknown. We aimed to explore the link between ANGPTL7 and OSA in patients with different OSA severity. Furthermore, we examined the effect of treating OSA with bariatric surgery on ANGPTL7 level. Methods: We quantified levels of circulating ANGPTL7 in fasting plasma and adipose tissue samples of 88 participants before and after bariatric surgery. Confocal microscopy analyses were also performed to assess the ANGPTL7 expression in subcutaneous white adipose tissue biopsies obtained from people with moderate-to-severe OSA compared to those with none or mild OSA. The study involved 57 individuals with none or mild OSA and 31 patients with moderate-to-severe OSA. Results: Levels of circulating ANGPTL7 were significantly higher in people with moderate-to-severe OSA (1440 ± 1310 pg/ml) compared to the none or mild OSA group (734 ± 904 pg/ml, p = 0.01). The increase in ANGPTL7 correlated significantly and positively with the apnea-hypopnea index (AHI, r =.226, p =.037), and AHI-supine (r =.266, p =.019) in participants with moderate-to-severe OSA. Multivariate logistic regression analysis demonstrated an association between ANGPTL7 and OSA severity (log2 ANGPTL7; OR =1.24, p = 0.024). ANGPTL7 levels exhibited significant positive correlations with the levels of TG and oxLDL (p-value = 0.002 and 0.01 respectively). Bariatric surgery reduced the levels of both ANGPTL7 and AHI significantly. Conclusion: Here we report significantly increased levels of ANGPTL7 both in the circulation and in adipose tissue of patients with OSA, which concurred with increased inflammation and OSA severity. Levels of ANGPTL7 decreased significantly as OSA showed a significant improvement post-surgery supporting a potential role for ANGPTL7 in either OSA progression or a role in an OSA-related mechanism