NIDDK Labs Archive Bariatric surgery information & the LABS study archive

Archived material from the LABS study participant website (via web.archive.org, snapshot of 2012-08-25). Historical document — links and contacts may be outdated.

Ancillary Studies

In addition to the main LABS study, other on-going studies use LABS participants. These studies will help to supplement the data, research and findings of the LABS study. They vary from investigations of behavior, sexual function and genetics. For this page, the principal investigator of each study has written a description of their research project. Be sure to check back for updates on enrollment and new research opportunities that may be available at your local site.

  1. Psychosocial Changes after Bariatric Surgery

    Principal Investigator: Dr. David Sarwer, MD (University of Pennsylvania)

    Participating LABS Centers: Neuropsychiatric Research Institute, University of Pittsburgh Medical Center

The LABS ancillary study Psychosocial Changes Associated with Weight Loss, investigates changes in sexual functioning and marital satisfaction in persons who undergo bariatric surgery and compares them to extremely obese individuals who are trying to lose weight with diet and exercise.

Obesity and physical inactivity are independently related to the likelihood of developing sexual dysfunction over time. For example, men with a BMI greater than 29 kg/m2 have a 30% greater risk of developing erectile dysfunction (ED). Up to 50 % of ED cases can be attributed to hypertension and cardiovascular disease, both commonly associated with obesity. Many treatments for hypertension can interfere with sexual functioning.

Obesity has also been associated with decreases in testosterone and sex hormone binding globulin for men and increases in testosterone and estrogen for women. Sex hormones typically improve with weight loss, but few researchers have looked at changes following bariatric surgery. Similarly, there have been few studies of changes in marital satisfaction following bariatric surgery.

Over the past two years, we have enrolled 149 LABS participants in this study: 64 from the North Dakota Medical School/Neuropsychiatric Research Institute (NRI) and 85 from the University of Pittsburgh School of Medicine. Before surgery and up to four years after surgery, study participants complete questionnaires covering topics related to marital and sexual functioning, quality of life and body image. They also provide a blood sample in order to assess changes in sex hormones. The results of this research will be compared to a sample of 59 individuals at the University of Pennsylvania who are losing weight with diet and exercise. As of January 2008, 23 LABS participants and 18 individuals from the University of Pennsylvania have reached their 1-year follow-up.

We are extremely grateful for the hard work of our research colleagues at NRI and the University of Pittsburgh. Most importantly, we also appreciate the LABS participants who are willing to be a part of the study. We believe that the study will provide us with important information on changes in marital and sexual functioning following bariatric surgery and we look forward to sharing those results with you in the future.

  1. **Cognitive Effects of Bariatric Surgery

    Principal Investigator: John Gunstad, PhD (Kent State University)

    Participating LABS Centers: Neuropsychiatric Research Institute, Columbia University Medical Center, Cornell University Medical Center**

Bariatric surgery provides significant health benefits to patients. In addition to substantial weight loss, many individuals experience an improvement or even a complete resolution of medical problems like Type 2 diabetes, high blood pressure, and sleep apnea. Our study wants to clarify whether bariatric surgery might actually improve memory and other thinking skills in patients.

Scientists have known for a long time that obese individuals are at higher risk for brain dysfunction, including conditions such as Alzheimer?s disease and stroke. New research shows that even obese individuals without these conditions show subtle problems with their memory, focusing their attention, and problem solving. But, there is reason to think that the weight loss following bariatric surgery might reverse these problems. Our research project is directly examining whether the weight loss following bariatric surgery might improve memory and other types of thinking skills.

As of July 2008, we have enrolled 125 participants from the Neuropsychiatric Research Institute and Columbia/Cornell University. Participants include bariatric surgery patients and individuals with similar demographic/medical characteristics that do not undergo surgery. All participants are asked to complete computerized tests of memory and other thinking skills at four timepoints: before surgery, 12-weeks after surgery, 12-months after surgery, and 24-months after surgery. By analyzing changes in test performance over time, we will be determine whether weight loss (and improvements in many medical conditions) improves memory and other thinking skills.

We are thankful for all the individuals that have agreed to participate in our research project. We believe that the study will provide important new information on the relationship between obesity and brain function and will share this information with you in future newsletters.

  1. Non-exercise Activity Thermogenesis and the LABS Participant

    Principal Investigator: Dr. James Levine (Mayo Clinic)

    Participating LABS Center: Oregon Health and Science University

There is an international epidemic of obesity with 1 to 2 billion people worldwide struggling to achieve normal body weight. In its wake, there has followed a similar global epidemic of the metabolic diseases, such as diabetes, hypertension and high cholesterol. Furthermore, there are millions of people around the world suffering from disordered sleep and joint problems as a result of their obesity. One of the few ways of achieving significant weight loss in those with medically complicated and substantial obesity is to undergo surgical procedures. Bariatric surgery has enabled many patients with medically complicated severe obesity to achieve sustained weight loss and improvement in their metabolic complications, as well as improved joint and sleep problems, plus an enhanced quality of life. There are several unexplained and major issues, however, with respect to how patients who go through bariatric surgery respond.

One key question is to ask whether the substantial improvements in health that follow bariatric surgery are in part, a consequence of improved and increased levels of day-long physical activity. The calories expended in association with day-long physical activity is called NEAT (non-exercise activity thermogenesis).

Low levels of NEAT have been associated with obesity and are thought now to be an important part of its cause. Therefore, there is a fundamental issue that needs to be addressed whether patients who successfully go through bariatric surgery and lose weight improve their NEAT after these surgical procedures. A second and perplexing issue is that many patients after bariatric surgery, despite tremendous personal commitment still regain weight that they have lost. This is understandably devastating for many patients in whom this occurs, and the cause of it is unclear. One hypothesis is that these patients are those who do not decrease their NEAT after bariatric surgery.

The goal of this program therefore, is to understand the role of NEAT adaptation after bariatric surgery in order to help understand first the role of NEAT in medically complicated obesity; second, the role of bariatric surgery in ameliorating low NEAT and improving it; and third the potential role of low NEAT in weight regain after bariatric surgery. In order to achieve these goals we will employ cutting edge electronic and non radioactive technologies to understand the role of NEAT in patents undergoing bariatric surgery for medically complicated obesity.

  1. **Body Composition & Resting Energy Expenditure Responses to Bariatric Surgeries

    Principal Investigator: Dr. Dympna Gallagher (St. Luke?s Roosevelt Hospital)

    Participating LABS Centers: Columbia University Medical Center, Cornell University Medical Center, University of Pittsburgh Medical Center**

    Weight loss magnitude and maintenance following surgical procedures surpasses that of conventional methods (eg, low-calorie diet, exercise, behavior modification). Little is known about the effects of these surgical operations on body composition and energy expenditure, and there are no direct comparisons among the different procedures. An important basic biological question remains as to whether body composition becomes normalized after substantial and sustained weight loss by extremely obese patients. This study proposes to analyze the composition of weight loss initially and at subsequent follow-up in a comprehensively characterized group of extremely obese persons undergoing rapid and large changes in weight using a 3-compartment body composition measurement approach that measures hydration and body density. A second major thrust derives from our work using magnetic resonance imaging to describe body composition changes at the tissue/organ level of analysis. Such analyses allow us to address additional questions of biological and clinical importance. For example, if metabolic rate is disproportionately low at reduced body weights, this may contribute in part to the high rate of weight regain (relapse). Specifically, resting energy expenditure, whole-body skeletal muscle and adipose tissue mass, and specific organs will be measured to establish if resting energy expenditure changes after weight loss can be accounted for by changes in body composition at the organ-tissue level.

    The LABS trial presents a population exceptionally suited for the study of these questions: 1) They are of a degree of fatness rarely studied, which allows us to test and extend the range of applicability of current knowledge, 2) They will undergo substantial weight loss, in contrast to the usual magnitude of weight change, 3) The weight loss is likely to be sustained over a long period of time thereby allowing for adaptations of organ/tissue mass and fat redistribution to occur. The surgical interventions achieve their effects by different degrees of restriction and malabsorption, providing an opportunity to determine whether and how this dimension affects body composition and thermogenesis. The principal research questions relate to the composition and nature of weight loss and how the former relates to changes in REE during the trial, and how weight change is influenced by type of surgery.

    Thus far we have enrolled 49 participants into this study (17 New York: Weill Cornell Medical Center referrals and 32 from the University of Pittsburgh). Prior to surgery and again at 1 year and 2 years post-surgery, participants undergo tests to measures resting energy expenditure, total body fat, hip bone density, total amount of water in body, a psychological questionnaire that assesses eating behavior, fasting blood measure for glucose and the hormones insulin, ghrelin, and leptin. As of September 30th, 2008, 19 participants have completed the 1 year follow-up.

    We acknowledge the efforts of our colleagues at Weill Cornell Medical Center and at the University of Pittsburgh in helping us conduct a successful study. We are greatly appreciative of the LABS participants who have enrolled in this study.

    • **Bariatric Surgery for Morbid Obesity: Clinical & Pathophysiologic Consequences

      Principal Investigator: Dr. Paul Berk (Columbia University Medical Center)

      Participating LABS Centers: Columbia University Medical Center, Cornell University Medical Center**

    Description Coming Soon

    • **Teen LABS

      Principal Investigator: Dr. Thomas Inge (Cincinnati Children?s Hospital)

      Participating LABS Centers: East Carolina University, Neuropsychiatric Research Institute, University of Pittsburgh Medical Center, Oregon Health and Science University**

    About 4 percent of children and adolescents are considered morbidly obese, and as a result they’re at significantly increased risk of serious health conditions such as diabetes and heart disease. Doctors want to know whether stomach surgery can help children avoid serious weight-related problems. Teen-LABS, sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases, will study 160 teens before, during and after the weight loss surgery.

    The study is directed by Dr. Thomas Inge, a pediatric surgeon and researcher at Cincinnati Children’s Hospital Medical Center in Ohio.
    The goal of Teen-LABS is to facilitate coordinated clinical, epidemiological and behavioral research in the field of adolescent bariatric surgery, through the cooperative development of common clinical protocols and a bariatric surgery database that will collect information from participating clinical centers performing bariatric surgery on teenagers.

    Teen-LABS will help pool the necessary clinical expertise and administrative resources to facilitate the conduct of multiple clinical studies in a timely, efficient manner. Also, the use of standardized definitions, shared clinical protocols and data-collection instruments will enhance investigators’ ability to provide meaningful evidence-based recommendations for patient evaluation, selection and follow-up care.
    In addition to investigating surgical outcomes, another broader goal of Teen-LABS is to better understand the etiology, pathophysiology, and behavioral aspects of severe obesity in youth and how this condition affects human beings over time. Finally, these researchers will work with investigators within the LABS consortium to compare the progress of teens who undergo stomach surgery, also called bariatric surgery, with 160 adults who have had the procedure.

    The Teen-LABS consortium members include: Cincinnati Children’s Hospital Medical Center, Texas Children’s Hospital, Children’s Hospital of Alabama, University of Pittsburgh, and Nationwide Children’s Hospital in Columbus, OH.

    • **Melanocortine-4 Receptor Mutations & Bariatric Surgery Outcome

      Principal Investigator: Dr. Christian Vaisse (University of California, San Francisco)

      Participating LABS Centers: Oregon Health and Science University**

    Description Coming Soon

    • **Psychological Issues in Bariatric Surgery

      Principal Investigator: Dr. Katherine Elder (Oregon Health and Science University)

      Participating LABS Centers: Oregon Health and Science University**

    Description Coming Soon

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