Obstructive sleep apnea (OSA) is a clinical syndrome characterized by occlusion of upper airways during sleep. The occlusions results in shortly hypoxia, which awakes the patient. When the patient awakes, activity in the pharyngeal muscles results in opening of the upper airway again.~OSA is associated with overweight. Studies have shown high prevalence (60-94%) of obstructive sleep apnea (OSA) among patients undergoing gastric bypass (bariatric) surgery.~Fifteen studies have investigated the effect of bariatric surgery on OSA. All of them conclude a highly positive effect on OSA by bariatric surgery and the following weight loss. However, a huge number of dropouts biases these studies. The dropout rate in the studies are around 60 percent. No studies are from northern Europe.~The Investigators want to perform a study investigating the prevalence of OSA among over weighted patients undergoing bariatric surgery in Denmark.~The Investigators state that the prevalence of OSA among patients undergoing bariatric surgery in Denmark is high. The investigators state that the effect of bariatric surgery is significant on severity of OSA. The Investigators state that they can perform a study without a huge number of dropouts.~The investigators investigate patients by making sleep monitoring by embletta. During one night of sleep with this apparatus, the investigators will get information on number of wake-ups during sleep, the apnea-hypopnea index and saturation during sleep. All of this gives the investigators information whether the patient have OSA or not.~Patients will undergo sleep monitoring prior to surgery. The time interval from monitoring to day of surgery varies from 1 month to one day. the investigators repeat the sleep monitoring one year after date of surgery. Differences in primary endpoint and secondary endpoints is calculated.~Today all of the subjects have undergone surgery. From November 1.2013 the investigators invites all patients to sleep monitoring once again. The investigators were hot able to register this trial before this date because of the political situation in the US. This site was closed. The Investigators hope that the investigators still are able to register the study.
Studies have shown high prevalence (60-94%) of obstructive sleep apnoea (OSA) among patients undergoing bariatric surgery.~Fifteen studies are published investigating the effect of bariatric surgery on OSA. All of them conclude a highly positive effect on OSA by bariatric surgery and weight loss. However these studies are biased by a huge number of drop outs. The drop out rate in the studies are around 60 percent.~The Investigators state that the prevalence of OSA among patients undergoing bariatric surgery in Denmark is high. The Investigators state that the effect of bariatric surgery is significant on severity of OSA. The Investigators state that we can perform a study without a huge number of dropouts.