Clinical Research Directory

Mother and Offspring's Nutritional Status -Pregnancy After Maternal Bariatric Surgery

The goal of this observational study is to learn how pregnancy after bariatric surgery affects the nutritional status of mothers and their babies. The study will also look at pregnancy complications and the best time to get pregnant after surgery. It includes pregnant women who have had bariatric surgery and compares them to pregnant women who have not had surgery. The main questions it aims to answer are: Do women who have had bariatric surgery have more vitamin and mineral deficiencies during pregnancy? Are pregnancy complications like preterm birth or high blood pressure more common after bariatric surgery? Do babies born to mothers who had bariatric surgery have different growth or nutrient levels? Researchers will compare women with and without bariatric surgery to see if there are differences in: Nutrient levels in blood and urine Pregnancy outcomes like gestational diabetes or preeclampsia Baby's birth weight, length, and vitamin levels Participants will: Give blood and urine samples during pregnancy and after birth Answer questions about their diet and health Have their weight and body composition measured Use a glucose monitor during pregnancy This study will help improve care for women who become pregnant after bariatric surgery.

Qigong Breathing Exercise on Bariatric Outcomes After Bariatric Surgery: a Randomized Controlled Clinical Trial

Bariatric surgery has been reported to be the most effective treatment option for losing and maintaining body weight and improving comorbidities and mortality associated with morbid obesity. Nevertheless, even though physical activity is recommended to optimize bariatric surgery results. Very little is known, about whether engaging in an exercise program after surgery can provide additional improvement in health outcomes. While to date there are relatively few researches studied the effect of exercise in patients who have undergone bariatric surgery. This study was conducted to explore the influence of Modified Qigong Breathing Exercise on pulmonary function, endurance and fitness on post bariatric surgery patients. Qigong as ancient Chinese traditional medicine have been documented to be effective in treating obesity. Literature showing that the desire to eat and the feeling of hunger, along with prospective food consumption in patients with obesity.

Identification of Pre-surgical Phenotypic Indicators Predictive of Quality of Life Trajectories in Obese Patients Following Bariatric Surgery

This study aims to identify pre-operative phenotypic determinants predictive of quality of life trajectories in post-bariatric surgery patients. In addition, this study will have as a secondary objective the highlighting of a potential link between post-surgery quality of life trajectories and those of anxiety/depression scores, eating behaviors and body mass indices. This study will be conducted during the usual care of patients undergoing the GEROM73 program, lasting a total of 30 months. The GEROM73 program includes care for the six months preceding bariatric surgery and the 24 months following surgery. This program supports patients throughout their bariatric care.. Throughout the GEROM73 program, patients will complete questionnaires on anxiety, depression, eating disorders, Impact of Weight on Quality Of Life. Patients' weight, body mass index and body schema will also be measured throughout the GEROM program.

The PREBA Study: Effect of Preoperative Weight Loss With a 14-day Low-calorie Diet on Surgical Procedure and Outcomes in Patients Undergoing RYGB Surgery

Bariatric guidelines recommend preoperative weight loss of 5% to reduce the risk of surgical complications. However, results in the literature on the improvement of surgical procedure and outcomes are still conflicting. This study aims to evaluate the effect of preoperative weight loss by means of a 14-day low-calorie diet in bariatric patients on operative time, the ease of the Roux-en-Y gastric bypass (RYGB) procedure and long-term weight loss in a real-life experimental setting.

Transition to Ambulatory Bariatric Surgery (TABS) Trial

This study will compare same day discharge and at least one night stay in the hospital after bariatric surgery. Patients undergoing bariatric surgery will be randomized (i.e. have an equal chance of either plan) to either group. The study's primary outcome is the frequency patients in the study require a visit to the emergency room within 7 days of their surgery.

Post-Prandial Carbohydrate Metabolism in Individuals With and Without Post-Bariatric Surgery Hypoglycemia (PBH)

In this study, the investigators will determine (a) whether metabolism (secretion and turnover) of glucagon is altered in patients with PBH, (b) whether this is affected by a meal, (c) whether PBH affects the ability of the body to produce glucose (endogenous glucose production), and (d) whether PBH affects the amount of glycogen in the liver (storage form of glucose) when fasting and after a meal. The investigators will determine the effect of glucagon to raise glucose levels after a meal. To answer these questions, participants will receive an infusion of a stable (nonradioactive) isotope of glucose and glucagon, and a meal containing a stable isotope of glucose. Glycogen will be measured by magnetic resonance imaging (MRI) of the liver before and after the meal. This information will be used to develop computer models for the glucagon pump system.

Tailored Stapled SADI-S: Initial Report and Preliminary Results

Obesity is a serious health problem worldwide and can lead to many diseases such as diabetes, high blood pressure, heart disease, and sleep apnea. When lifestyle changes and medications are not enough, metabolic and bariatric surgery (MBS) is currently the most effective and long-lasting treatment option. This study focuses on one of the newer types of bariatric surgery called Single Anastomosis Duodeno-Ileal Bypass with Sleeve Gastrectomy (SADI-S). This procedure combines two parts: Sleeve gastrectomy, which reduces the size of the stomach so the patient feels full after eating a small amount. Duodeno-ileal bypass, which shortens the path food takes through the small intestine to reduce calorie absorption. Our hospital's surgical team is studying a tailored version of this operation, where the length of the bypassed intestine is adjusted to each patient's anatomy. We believe this personalized approach may improve weight loss results while lowering the risk of vitamin and nutrient deficiencies. The study will include 40 adult patients with obesity who are undergoing SADI-S surgery, either as their first weight loss operation or as a revision surgery after an earlier sleeve gastrectomy. During the operation, surgeons will measure the total length of each patient's small intestine and use a formula to decide how much of it should be bypassed. The duodeno-ileal connection will be made using a stapled technique, which is expected to be safe and efficient. After surgery, patients will be followed regularly at 1, 3, 6, 9, and 12 months, and then once per year. At each visit, the study team will monitor weight loss, body mass index (BMI), resolution of diabetes and other obesity-related conditions, nutritional status (including vitamins and minerals), and any side effects such as diarrhea, reflux, or nutritional problems. The goal of this study is to learn whether this tailored SADI-S technique can provide strong, sustained weight loss and health improvement with fewer long-term complications. The results will help improve surgical planning for future patients by showing whether measuring and customizing the bypass length is safer and more effective than using a fixed length. All data collected will be kept confidential. Patients' participation in the study will not change their regular care or follow-up, and they can withdraw at any time without affecting their treatment.

Circulating Muscle-specific microRNAs and Renal, Nutritional and Inflammatory Biomarkers of Skeletal Muscle Loss During the First 18 Months After Laparoscopic Sleeve Gastrectomy

Metabolic and bariatric surgery produces substantial and durable weight loss, but a considerable proportion of that loss is not adipose tissue. Pooled estimates indicate approximately 8 kg of fat-free mass and 3 kg of skeletal muscle mass are lost within twelve months, with more than half occurring in the first three months. No validated circulating biomarker of skeletal muscle loss exists for this population, and body composition can currently be assessed only intermittently. Muscle-specific microRNAs (myomiRs) are mechanistically plausible candidates but have never been measured in patients undergoing metabolic and bariatric surgery. This study will characterise the trajectory of skeletal muscle loss over eighteen months after laparoscopic sleeve gastrectomy and evaluate, as exploratory analyses, whether circulating myomiRs and routinely accessible renal, nutritional and inflammatory measures track that trajectory.

Collagen Supplements and Post-MBS Muscle Mass/Body Image

This prospective, observational cohort study aims to evaluate whether the use of collagen-containing supplements is associated with differences in muscle mass, body composition, and body image among patients who have undergone sleeve gastrectomy (SG). The study will be conducted at the General Surgery outpatient clinic of a private hospital in Bursa, Türkiye, between May 2026 and March 2027, and will enroll adult patients (aged 18-65 years) who meet current ASMBS/IFSO eligibility criteria for metabolic and bariatric surgery. Participants will be naturally allocated into two observational groups based on their own choice to use or not use collagen-containing supplements; no supplement will be provided or recommended by the study team, and no intervention will be made to participants' standard clinical care. All patients will be followed according to routine clinical practice preoperatively and at 2 weeks, 1 month, 3 months, and 6 months postoperatively. Primary outcome measures include anthropometric parameters (body weight, BMI, fat mass, fat mass percentage, fat-free mass, muscle mass, percentage of weight loss, percentage of excess weight loss, waist and hip circumference) assessed via bioelectrical impedance analysis (Tanita MC-780 MA), and body image assessed using the Turkish-validated Body Shape Questionnaire (BSQ). Secondary outcomes include biochemical parameters, comorbidities, and macronutrient intake data obtained from 3-day dietary records analyzed using the BEBİS nutrition software. The study hypothesizes that patients using collagen-containing supplements will show significant differences in muscle mass and body composition parameters compared with non-users, and that supplement use will be significantly associated with BSQ scores. A sample size of approximately 52 participants per group was calculated using G\*Power 3.1 (one-way ANOVA, Cohen's f = 0.25, α = 0.05, power = 0.80).

Postoperative Nausea, Vomiting and Pain After Bariatric Surgery - a National Registry Study

Around 4,000-5,000 bariatric (weight-loss) operations are performed in Sweden every year. Nausea, vomiting and pain are common immediately after these operations, cause considerable suffering and increase the intensity and length of hospital care. Bariatric surgery is one of the procedures with the highest risk of postoperative nausea and vomiting (PONV): about one third of patients experience PONV already in the recovery unit, and registry data indicate that around 40% report severe pain at the same stage. This study links two national quality registries - the Swedish Perioperative Register (SPOR) and the Scandinavian Obesity Surgery Registry (SOReg) - to describe how often adult patients experience nausea, vomiting and pain in the post-anaesthesia care unit after primary bariatric surgery, and to identify patient, anaesthetic and surgical factors associated with these outcomes. The study tests whether total intravenous anaesthesia, the addition of a regional nerve block, and preoperative health-related quality of life are associated with PONV and pain, and whether early PONV or pain is associated with complications, unplanned hospital care or reoperation up to one year after surgery. The results are intended to show how well current evidence on preventing PONV and pain is applied in everyday practice and where care can be improved.

Oral Acetaminophen for Post-Op Pain Management in Bariatric Surgery Patients

Adult patients with morbid obesity who have had Roux-en-Y gastric bypass (RYGB) or laparoscopic sleeve gastrectomy (LSG) surgery have impaired drug metabolism. There is a paucity of information available on how these patients metabolize acetaminophen post operatively and if drug preparation has any effect on achieving adequate pain control. The surgery may alter the stomach pH, reduce surface area of the stomach, affect transit time, and alter anatomic and physiologic standard absorption of medications. Due to these anatomic and physiologic changes, we seek to understand the potential effects of liquid versus pill formulations of acetaminophen on pain control in this patient population. The purpose of this study is to assess for subjective and objective measures of optimized pain control between formulations of acetaminophen including oral pills and oral liquid.

FABP4 Response After Roux-en-Y Gastric Bypass

This retrospective observational cohort study examined serum fatty acid-binding protein 4 (FABP4) dynamics in 28 adults who underwent Roux-en-Y gastric bypass (RYGB), followed at baseline, 3 months, and 6 months. Anthropometric, metabolic, and inflammatory parameters were assessed alongside FABP4, fasting GLP-1, and PYY. Patients were classified as FABP4 responders (decrease from baseline to 6 months) or rebound/non-responders. The study investigated whether FABP4 trajectory after RYGB is associated with the magnitude of weight loss, systemic inflammation, and fasting incretin change.

New Imaging Tools to Explore Impact of Bariatric Surgery on Pancreatic Lesions: PACHIBA- Bariatric Surg

The investigators propose an exploratory study aiming at assessing the impact of surgical bariatric treatment on the improvement of pancreatic lesions detected by MRI. Pancreatic MRI will be performed in severe-obese patients with a planned bariatric surgery, before and 6 months after bariatric surgery. To assess the impact of bariatric surgery on pancreatic Magnetic Resonance Imaging (MRI) parameters in severe-obese patients

Metabolic Flux Analysis in Metabolic Dysfunction-Associated Steatotic Liver Disease

This prospective, single-center pilot study will evaluate metabolic flux dysregulation in adults with obesity and suspected or confirmed metabolic dysfunction-associated steatotic liver disease (MASLD) who are scheduled for protocol-eligible bariatric surgery at Vanderbilt University Medical Center. Participants will undergo research assessments before surgery, during the planned bariatric surgery encounter, and approximately 6 months after surgery. The study uses non-radioactive stable isotope tracer infusions, serial blood sampling, abdominal MRI/MRE, and research tissue specimens collected only during clinically planned bariatric surgery to quantify hepatic and extrahepatic metabolic fluxes. The primary objective is to determine how hepatic citric acid cycle flux and related metabolic pathways change after bariatric surgery and how these metabolic measures relate to liver fat, liver stiffness, and biopsy-graded MASLD/MASH severity.

Opportunistic Salpingectomy During Bariatric Surgery for Ovarian Cancer Prevention

Ovarian cancer is a deadly disease that is hard to detect early and difficult to treat. Research shows that most ovarian cancers actually start in the fallopian tubes, not the ovaries. Removing the fallopian tubes (a procedure called salpingectomy) can lower the risk of ovarian cancer by about 80%. This procedure has no added risk to the patient, but does lead to sterilization and thus it is only offered to individuals who have completed child-bearing. Adding salpingectomy to another surgery that a patient is undergoing is called opportunistic salpingectomy and is already standard of practice in many gynecologic surgeries, such as hysterectomy. However, it is not yet commonly offered during weight-loss (bariatric) surgery, even though many patients having this surgery could benefit. This study will test whether it is practical and safe to offer fallopian tube removal during bariatric surgery at three hospitals in Canada. Patients who are eligible and interested will be invited to have their fallopian tubes removed at the same time as their planned weight-loss surgery. The research team will track whether the procedure can be completed successfully, whether there are any added complications, and how much extra time or resources are needed. The goal is to help make this cancer-prevention option available to more people.

Protein Supplementation and Resistance Training to Prevent Fat-Free Mass Loss Following Metabolic-Bariatric Surgery

The goal of this clinical trial is to investigate the effects of daily protein supplementation and participation in a weekly supervised resistance training program on the prevention of excessive muscle mass loss following bariatric surgery. Patients treated at one of the participating centers will be invited to participate and will be randomly assigned to one of two groups. Participants in group 1 will receive standard postoperative care as currently provided. Participants in group 2 will also receive standard care, but in addition, they will be asked to consume extra protein daily and take part in a supervised resistance training session once a week. Previous research has shown that approximately one in five patients undergoing bariatric surgery experiences excessive muscle loss after the surgery. It is known that resistance training and protein intake can help maintain and even improve muscle mass. However, limited research has been conducted on the combined effects of protein supplementation and resistance training in patients after bariatric surgery. Therefore, the aim of this trial is to determine whether participants receiving the additional intervention experience less muscle mass loss compared to those receiving standard care alone.

Comparison of Hormonal Response to a Mixed-Meal Tolerance Test After Laparoscopic Roux-en-Y Gastric Bypass Versus Laparoscopic Sleeve Gastrectomy With Duodenojejunal Bypass in Patients With Super Morbid Obesity

Obesity is a major global health problem. Bariatric surgery is the most effective treatment, leading to substantial weight loss and improvement in obesity-related comorbidities. The most commonly performed procedures are Laparoscopic Roux-en-Y gastric bypass (LRYGB) and Laparoscopic sleeve gastrectomy (LSG). LRYGB is typically selected for patients with a BMI exceeding 50 kg/m2. Recently, LSG with duodenojejunal bypass (LSG-DJB) has been introduced. To date, no randomized controlled trial has compared LRYGB and LSG-DJB in patients with super morbid obesity, particularly regarding postoperative hormonal responses. This study aims to address this gap. If LSG-DJB results in a lower incidence of post-bariatric hypoglycemia than LRYGB, it would support its clinical benefit. Evaluation of GLP-1, GIP, glucagon, and insulin responses will clarify mechanisms underlying weight loss and postprandial glycemic changes.

Protein Need and Interest of " Quick Proteins " to the Obese Subject Operated by Bariatric Surgery (BIBOP)

The main objective of the study is to evaluate the protein requirement associated with postoperative weight loss caused by by-pass (shunt which leads to a certain degree of malabsorption) or sleeve gastrectomy (more technically conservative with less malabsorption), through the study of nitrogen balance. The benefit of protein supply easily absorbed and with high essential amino acids content (proteins "fast" soluble milk) on protein metabolism and muscle function will also be studied. Endotoxemia and intestinal flora variations were measured before and after bariatric surgery.

Rosuvastatin and Losartan Pharmacokinetics After Bariatric Surgery

This prospective, open-label, non-randomized pharmacokinetic study will evaluate how Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy affect systemic exposure to single oral test doses of rosuvastatin and losartan. Sixty adults scheduled for bariatric surgery will enter one of two parallel groups according to the clinically selected operation (30 RYGB and 30 sleeve gastrectomy). Each participant will receive rosuvastatin 10 mg and losartan 25 mg once within 30 days before surgery and again approximately 12 weeks after surgery. Plasma samples collected before dosing and at 1.5 and 4 hours after dosing will be used with maximum a posteriori Bayesian estimation to estimate individual pharmacokinetic parameters. In the 30-participant RYGB group only, paired stool samples will be used to explore gut microbiota and untargeted fecal metabolomic changes. The primary objective is to compare within-participant changes and between-procedure differences in drug exposure after bariatric surgery.

Swap Anesthetic Versus Continuous Desflurane in Adults Undergoing Bariatric Surgery

This randomized, parallel-group, non-inferiority clinical trial aims to evaluate whether an anesthetic swap strategy consisting of sevoflurane followed by desflurane 30 minutes before the end of surgery is non-inferior to continuous desflurane anesthesia with respect to extubation time in adults undergoing elective laparoscopic bariatric surgery. Secondary outcomes include time to achieve a Patient State Index (PSi) greater than 80, time to achieve an Aldrete score of at least 8, incidence of postoperative nausea and vomiting, post-anesthesia care unit length of stay, and desflurane-related costs.

Transit Bipartition After Sleeve Gastrectomy

This prospective, single-center study will evaluate adults undergoing revisional conversion from sleeve gastrectomy to intestinal transit bipartition. Forty participants will complete clinical, endoscopic, physiological, metabolic, hormonal, imaging, and stool assessments before surgery and during follow-up. The primary outcome is the within-participant change in solid-meal gastric emptying half-time (T½), measured by standardized scintigraphy from baseline to 6 months. Secondary and exploratory outcomes include reflux symptoms, DeMeester score and acid exposure, route-specific gastric transit, GLP-1 and ghrelin responses, glucose metabolism, fecal elastase, gut microbiota, body-weight trajectory, comorbidities, gastroileal anastomotic caliber, and safety.

Digital Follow-Up and Nursing Education in Bariatric Surgery Patients

This randomized controlled experimental study aims to evaluate the effect of a PHP-MySQL database-based digital follow-up system combined with structured nursing education on quality of life, body mass index (BMI), and exercise habits in patients undergoing bariatric surgery. Although bariatric surgery is an effective treatment for morbid obesity, long-term success depends largely on adherence to lifestyle modifications, including regular physical activity and sustained behavioral change. Participants will be randomly assigned to either an intervention group or a control group. The intervention group will receive structured nursing education along with an 8-week digitally monitored exercise program starting at postoperative month four. The control group will receive standard postoperative care. Outcomes will be assessed using the Moorehead-Ardelt Quality of Life Questionnaire II (MA-II), BMI measurements, and the International Physical Activity Questionnaire (IPAQ). The study aims to provide evidence for integrating digital health technologies and structured nursing interventions into postoperative bariatric care.

ABCG8, UGT1A1 and Gallstone Disease After Bariatric Surgery

The goal of this observational genetic case-control study is to learn whether two specific genetic variants in ABCG8 and UGT1A1 are associated with gallstone disease after bariatric surgery. The study includes adults who have previously undergone bariatric surgery. The main questions it aims to answer are whether the ABCG8 D19H variant and the UGT1A1 rs6742078 variant are associated with an increased risk of gallstone disease requiring cholecystectomy after bariatric surgery. Researchers will compare patients who underwent bariatric surgery and later had their gallbladder removed because of gallstone disease with patients who underwent bariatric surgery but did not develop gallstone disease or undergo cholecystectomy during follow-up. Participants will provide one blood sample for targeted genetic analysis and complete questionnaires about health, previous surgery, medication use, family history, and gastrointestinal quality of life. Relevant clinical information will also be collected from medical records.

Physiologic Response to Bariatric Surgery and the Impact of Adjunct Semaglutide in Adolescents

The study plans to learn more about what happens to the body after bariatric surgery in people 12 to 24 years old. The study aims to understand why people respond differently to bariatric surgery and how to define success beyond weight loss alone. The study also plans to learn more about whether a medication (semaglutide or tirzepatide) can help people 12 to 24 years old who, between 6 and 24 months after bariatric surgery, have not lost as much weight as expected.