The pilot study will assess the feasibility and efficacy of cryoablation procedure to freeze the vagus nerve in obese patients with type 2 diabetes. Aim 1 will focus on changes in glycemic control. Aim 2 will evaluate differences in body weight and anthropometric measurements. This study will provide much needed data for a novel therapeutic intervention to manage obese patients with type 2 diabetes.
Obesity is a growing epidemic, currently affecting over 1/3 of the adult US population and is a well-established risk factor for the development of diabetes and cardiovascular disease. Given that the majority of patients with type 2 diabetes (T2D) are obese, weight loss is the cornerstone of treatment, and has been shown to decrease risk of long term complications, lead to improvements in A1c and lipid levels, as well as decreased need for medications and improvements in quality of life. Unfortunately, lifestyle intervention is often ineffective at achieving long-term sustainable, clinically significant weight loss. Bariatric surgery is a successful intervention, leading to 20-30% weight loss with remission of diabetes in 30-65% of patients 1-5 years post surgery. However, this invasive procedure is associated with high rates of short- and long-term complications, including need for reoperations, vitamin/mineral deficiencies, anemia, and osteoporosis. It is clear that the current management options for obese patients, including lifestyle changes, medications and surgery, are suboptimal and innovative strategies are necessary to optimize diabetes control and weight management. Energy balance and glycemic control are mediated largely by the gut-brain axis, specifically the vagus nerve. The vagus nerve can stimulate or inhibit food intake depending on nutritional status. Vagal nerve signaling is disrupted in the setting of obesity and thought to contribute to overeating behaviors. Vagus nerve blockade has the potential to be a highly efficacious, minimally invasive intervention to address current obesity treatment limitations. Clinical studies evaluating the efficacy of an implantable electric vagus nerve blockade device found that subjects lost on average 8.8% of total body weight at 1 year; patients with T2D experienced improved glycemic control, with an average A1c improvement of 1.0% at 12 months. Unfortunately, nearly 40% of subjects experienced side effects related to the device. A recent pilot study from the researchers of this study reported weight loss efficacy of a minimally invasive computerized tomography (CT) guided cryoablation of the vagus nerve in obese, non-diabetic subjects. Patients lost 5.6% of total body weight and 22.7% excess body weight at 6 months with no significant side effects. The purpose of this current study is to evaluate the feasibility and efficacy of this procedure through a randomized control trial in obese patients with T2D. The researchers hypothesize that those patients undergoing the cryoablation procedure will experience improvement in glycemic control and enhanced weight loss at 6 months follow-up compared to the control group. Participants will be randomized to receive either CT guided cryoablation of the vagus nerve plus lifestyle intervention or lifestyle intervention alone. The lifestyle intervention lasts for 26 weeks and participants will be followed for 12 months in total.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
5
The Visual ICE Cryoablation System is a mobile console system intended for cryoablative tissue destruction using a minimally invasive procedure. The Visual-ICE System uses high-pressure argon gas that circulates through closed-tip cryoablation needles to induce tissue freezing. Active tissue thawing is achieved by circulating helium gas through the needles or, alternatively, by the use of Galil Medical i-Thaw technology. The procedure will be done under CT guidance and involves a 4-5 mm scalpel incision followed by percutaneous probe placement about the posterior gastroesophageal junction (the location of the posterior vagal trunk). The probe will create a zone of decreased temperature (-20 to -40 degrees Celsius) involving the posterior vagal nerve fibers/plexus. The cryoablation process will include a 3-minute freeze, followed by a 1-minute thaw, and a second 3-minute freeze and 1 minute thaw.
The lifestyle intervention structure will include three face-to-face counseling sessions at baseline, 3 and 6 months. Dietary counseling to follow a low carbohydrate diet will be provided by a registered dietitian. Focus will be on increasing fruits and vegetables and decreasing refined sugars and processed foods. It will also include motivational interviewing, goal setting and nutrition education. In addition, subjects will be encouraged by exercise physiologist to slowly increase physical activity to at least 150 minutes weekly. There will be weekly phone calls or texts (participants' choice) providing a total of 26 points of contact recommended by the United States Preventive Services Task Force.
Emory University Hospital Midtown
Atlanta, Georgia, United States
Emory University Hospital
Atlanta, Georgia, United States
Grady Health System
Atlanta, Georgia, United States
The Emory Clinic
Atlanta, Georgia, United States
Hemoglobin A1c
The hemoglobin A1c test result reflects average blood sugar level for the past two to three months. Specifically, the A1c test measures what percentage of hemoglobin is coated with sugar (glycated). The higher A1c level, the poorer blood sugar control and the higher risk of diabetes complications.
Time frame: Baseline, Month 3, Month 6, Month 12
Insulin Resistance Score Homeostatic Model Assessment of Insulin Resistance (HOMA-IR)
Insulin resistance score HOMA-IR is computed with the formula: fasting plasma glucose (mmol/l) times fasting serum insulin (mU/l) divided by 22.5. Low HOMA-IR values indicate high insulin sensitivity, whereas high HOMA-IR values indicate low insulin sensitivity (insulin resistance).
Time frame: Baseline, Month 3, Month 6, Month 12
Number of Deaths Among Recipients of the Cryoablation
Mortality among recipients of the cryoablation was documented.
Time frame: Up to Month 12
Number of Adverse Events Related to the Cryoablation
The count of procedure related complications, such as bleeding, infection, pneumothorax, hemothorax, pulmonary injury, complications of sedation, pain requiring hospital admission or treatment, dysphagia, gastroparesis, nausea and vomiting, and gastrointestinal ulceration was documented for the duration of the study.
Time frame: Up to Month 12
Body Mass Index (BMI)
Body Mass Index (BMI) is a person's weight in kilograms divided by the square of height in meters.
Time frame: Baseline, Month 3, Month 6
Waist Circumference
Waist circumference is a measurement taken around the abdomen at the level of the umbilicus (belly button). Waist circumference is measured in centimeters.
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Emory Johns Creek Hospital
Johns Creek, Georgia, United States
Time frame: Baseline, Month 3, Month 6
Waist-to-hip Ratio
A waist-to-hip ratio of greater than 1.0 indicates a higher risk of developing heart disease. For women, a healthy waist-to-hip ratio is less than 0.85 while under 0.9 is a healthy ratio for men.
Time frame: Baseline, Month 3, Month 6
Total Cholesterol
A healthy level of total cholesterol is 125 - 200 mg/dL.
Time frame: Baseline, Month 6
Low-Density Lipoprotein (LDL)
A healthy level of LDL is less than 100 mg/dL.
Time frame: Baseline, Month 6
Triglycerides
A healthy level of triglycerides is less than 150 mg/dL.
Time frame: Baseline, Month 6
Systolic Blood Pressure
A normal systolic blood pressure level is less than 120 millimeters of mercury (mmHg).
Time frame: Baseline, Month 3, Month 6
Diastolic Blood Pressure
A normal diastolic blood pressure level is less than 80 mmHg.
Time frame: Baseline, Month 3, Month 6
Daily Caloric Intake
Daily caloric intake is measured by 3-day food recall. Mean daily caloric intake is assessed as kilocalories (kcal) consumed per day.
Time frame: Baseline, Month 3, Month 6
Change in Anti-hyperglycemic Medication Regimen
Anti-hyperglycemic medications will be adjusted at visits under the direction of the endocrinologist, or as needed for clinically significant hypo- or hyperglycemic events. Changes in baseline medication regimen will be examined to determine if medication needs decrease or increase during the study.
Time frame: Month 3, Month 6
Appetite Visual Analog Scale Score for Hunger
The Appetite Visual Analog Scale includes 8 items which are scored on 100-mm visual analogue scales. The item for hunger asks participants how hungry they feel, where 0 = not at all and 100 = never been more hungry.
Time frame: Baseline, Week 1, Month 1, Month 3, Month 6
Appetite Visual Analog Scale Score for Satisfaction
The Appetite Visual Analog Scale includes 8 items which are scored on 100-mm visual analogue scales. The item for satisfaction asks participants how satisfied they feel, where 0 = completely empty and 100 = cannot eat another bite.
Time frame: Baseline, Week 1, Month 1, Month 3, Month 6
Appetite Visual Analog Scale Score for Fullness
The Appetite Visual Analog Scale includes 8 items which are scored on 100-mm visual analogue scales. The item for fullness asks participants how full they feel, where 0 = not full at all and 100 = totally full.
Time frame: Baseline, Week 1, Month 1, Month 3, Month 6
Appetite Visual Analog Scale Score for Eating Quantity
The Appetite Visual Analog Scale includes 8 items which are scored on 100-mm visual analogue scales. The item for eating quantity asks participants how much they think they can eat, where 0 = nothing at all and 100 = a lot.
Time frame: Baseline, Week 1, Month 1, Month 3, Month 6
Appetite Visual Analog Scale Score for Desire for Certain Foods
The Appetite Visual Analog Scale includes 8 items which are scored on 100-mm visual analogue scales. Four items of the questionnaire ask participants if they would like to eat something sweet, salty, savory, and fatty. Each item is scored as 0 = yes, very much and 100 = no, not at all.
Time frame: Baseline, Week 1, Month 1, Month 3, Month 6
International Physical Activity Questionnaire (IPAQ) Score
The IPAQ assesses physical activity during the past 7 days with 27 items. Based on the type, duration, and frequency of activity, respondents are categorized as having low activity, moderate activity, or high activity.
Time frame: Baseline, Month 3, Month 6
Fasting Glucose Level
A normal fasting blood sugar level is 99 mg/dL or lower, glucose levels of 100 - 125 mg/dL indicates prediabetes, and levels of 126 mg/dL and higher indicates diabetes.
Time frame: Baseline, Month 3, Month 6
Fasting Insulin Level
A normal fasting insulin level for the Emory Healthcare Laboratory is 1.9 to 23.0 milli-international units per liter (mIU/L). High levels of fasting insulin are associated with obesity and early stage type 2 diabetes (T2D). Type 1 diabetes and advanced T2D are associated with low levels of insulin.
Time frame: Baseline, Month 3, Month 6