Sleep Evaluation Before and After Metabolic Surgery

Obesity is frequently associated with sleep disturbances, including poor sleep quality, insomnia symptoms, daytime sleepiness, and obstructive sleep apnea. Metabolic surgery is an effective treatment for obesity and may improve several sleep-related outcomes, but the long-term change in sleep quality after surgery is not well understood. Most previous studies have relied on questionnaires or single-night measurements, which may not fully reflect sleep patterns in daily life. The SLEEP-BAM study is an observational longitudinal cohort study in adults scheduled for primary metabolic surgery at Catharina Hospital Eindhoven, the Netherlands. Participants will complete two home-based sleep measurement periods: one before surgery and one approximately 1 year after surgery. During each period, participants will wear two wearable devices for 5 consecutive nights: a Garmin Index Sleep Monitor and a viQtor research device. Participants will also complete sleep questionnaires and a daily sleep diary. The main aim is to evaluate the change in objective sleep quality from before surgery to 1 year after surgery, measured using the Garmin Sleep Score. Secondary aims include evaluating changes in sleep duration, sleep efficiency, sleep timing, sleep regularity, oxygen saturation, heart rate variability, subjective sleep quality, daytime sleepiness, anxiety and depression symptoms, and quality of life. The study will also explore whether changes in sleep quality are associated with postoperative weight loss. The study does not change the standard surgical treatment. Participants undergo metabolic surgery as part of routine care, and the research procedures consist only of sleep monitoring, questionnaires, and sleep diaries.

Inclusion Criteria: * Age 18 years or older. * Body mass index (BMI) of 40 kg/m² or higher, or BMI of 35 kg/m² or higher with obesity-related comorbidities. * Scheduled for primary metabolic surgery, including Roux-en-Y gastric bypass, sleeve gastrectomy, or, if performed within standard care, one-anastomosis gastric bypass. * Willing and able to wear wearable devices for 5 consecutive nights during both study measurement periods. * Willing and able to complete sleep questionnaires and a daily sleep diary. * No shift-based or irregular night-shift work schedule that could interfere with sleep measurements. * Able and willing to provide written informed consent. Exclusion Criteria: * Revisional bariatric procedure. * Diagnosed obstructive sleep apnea currently treated with continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP). * High clinical suspicion of obstructive sleep apnea during the standard preoperative work-up requiring further diagnostic evaluation or treatment. * Chronic preoperative use of medications that may significantly alter sleep quality, including benzodiazepines, zolpidem, or other sedatives or sleep aids. * Unable to complete the study procedures or comply with wearable device use, questionnaires, or sleep diary completion.