Evaluation of Vitamin D Storage in Adipose Tissue

Severely obese individuals commonly have very low vitamin D levels. This can be a serious problem because low vitamin D levels are associated with bone disease, including broken bones and other medical conditions such as diabetes, high blood pressure, and cancer which already affect the obese population. Weight loss, or bariatric surgery, is also associated with low vitamin D levels and patients who have low levels even before the operation may be at increased risk.

Investigation of Calcium/Calmodulin Dependent Protein Kinase II (CaMKII) activity in human liver tissue.

The goal of this research is to gain information whether a calcium sensing enzyme called "Calcium/Calmodulin Dependent Protein Kinase" is activated in obesity. This research will supplement additional information about the pathogenesis of insulin resistance associated with obesity.

Follow up on factors related to weight regain after bariatric surgery

The purpose of this study is to determine factors related to long-term weight regain after bariatric surgery. Any individual who ahs undergone bariatric surgery at least 5 years ago are eligible for the study. Individuals are asked to complete a short, online questionnaire.  After 100 patients complete the questionnaire, they are entered into a lottery to win a $20 gift card (1 in 4 odds). 

Mechanisms of Long Term Remission and Reemergence of Type 2 Diabetes Mellitus after Gastric Bypass Surgery

The purpose of this study is to determine the hormonal mechanisms of long term remission and reemergence of type 2 diabetes after gastric bypass surgery.  Individuals who had type 2 diabetes prior to gastric bypass surgery and underwent surgery at least two years prior are eligible for this study. Study participants will receive $100 for the study visit, which includes a meal test (approximately 3 hours), which is used to assess gut hormones during a meal simulation. 

Use of Endoscopically Delivered Radiofrequency Ablation for the Treatment of Patients Who Have Undergone Roux-en-Y Gastric Bypass and Have Failed to Achieve/ Maintain Satisfactory Excess Body Weight Loss

The purpose of this study is to determine the effectiveness of radiofrequency ablation, delivered via endoscopy, for the treatment of weight regain or inadequate weight loss after gastric bypass surgery. Individuals who have regained at least 25% of their lost weight or who did not lose at least 40% of their excess weight are eligible for this study.

Changes in Insulin Sensitivity, Appetite Hormones, Body Composition, and Energy Expenditure after Weight Loss induced by Bariatric Surgery

  • The purpose of these studies are to examine insulin sensitivity, appetite hormones, metabolic rate and body composition before and after weight loss induced by gastric bypass, gastric banding, or sleeve gastrectomy surgery.
  • Participation involves visits to Columbia Medical Center before and after surgery for blood tests and measurement of metabolism, body fat and muscle mass.