An interventional study of Diet and Gastric bypass surgery in Obesity, sponsored by Washington University School of Medicine. Completed at 1 site in United States. Open to participants aged 21 Years to 50 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2017-05-15.
Sponsored by Washington University School of Medicine · Not applicable, Interventional, and Basic science
Obesity adversely affects myocardial (muscular heart tissue) metabolism, efficiency, and diastolic function. The objective of this study was to determine if weight loss could improve obesity-related myocardial metabolism and efficiency and if these improvements were directly related to improved diastolic function.
This was a prospective, interventional study in obese adults ages 21 to 50 years of age to determine whether weight loss could improve obesity-related myocardial metabolism and efficiency. Two different mechanisms of weight loss were studied: diet and exercise and gastric bypass surgery. Positron emission tomography (PET) was used to quantitate myocardial oxygen consumption (MVO2) and myocardial fatty acid (FA) metabolism. Echocardiography with tissue Doppler imaging was used to quantify cardiac structure, systolic and diastolic function (left ventricular (LV) relaxation (E') and septal ratio (E/E')).
1,766 studies on the registry are indexed under Weight Loss; 277 are open to participants now.
This study's enrollment of 51 is below the median of 73 across 1,496 interventional studies indexed under Weight Loss.
Browse Weight Loss studies →Washington University School of Medicine is the lead sponsor of 1,764 studies on the registry; 270 are open to participants now.
Of its 325 completed or terminated interventional studies of FDA-regulated products, 212 (65%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Participants who received counseling and instruction about weight loss through diet and exercise
Behavioral: Diet
Participants who received gastric bypass surgery
Procedure: Gastric bypass surgery
Participants attended 20 group behavioral modification sessions led by a behaviorist, a registered dietician, and a physical therapist. The meal plans ranged from 1200 to 1500 kilocalories per day, depending on subject sex and BMI, and were designed to achieve ≤1% body weight loss/week. Participants completed daily food records, and were taught a variety of weight management skills. The exercise component included strength, flexibility, balance, and endurance instruction, gradually increasing to 30 minutes of exercise 5 days/week.
The same surgeon performed all bypass procedures using standard techniques. A small (\~20 ml) proximal gastric pouch was created by stapling the stomach, and a 75-cm Roux-en-Y limb was constructed by transecting the jejunum distal to the ligament of Treitz, and creating a jejunojejunostomy 75 cm distal to the transection.
Total Myocardial Oxygen Consumption (MVO2)
The evening before an imaging study, all participants were given a meal containing 12 kcal/kg adjusted body weight (=ideal body weight + ((actual body weight-ideal body weight) x 0.25)). Participants fasted until their imaging studies were completed. Myocardial oxygen consumption (MVO2) was measured using positron emission tomography (PET) following injection of 1-\^11C-acetate. Total MVO2 was calculated by multiplying the MVO2 measure by left ventricular weight.
Time frame: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss
Total Myocardial Fatty Acid (FA) Utilization
The evening before an imaging study, all participants were given a meal containing 12 kcal/kg adjusted body weight (=ideal body weight + ((actual body weight-ideal body weight) x 0.25)). Participants fasted until their imaging studies were completed. Myocardial blood flow was measured using positron emission tomography (PET) following injection of \^30O-water. Myocardial fatty acid (FA) utilization was measured using PET after injection of 1-\^11C-palmitate. The calculations that describe the relationship between the different measures of myocardial FA metabolism are: FA utilization/gram = blood flow/gram × FA uptake/gram × \[average plasma free FA at the time of the 1-11C-palmitate injection\]; FA utilization/gram = FA oxidation/gram + esterification/gram. Total fatty acid utilization was calculated by multiplying the fatty acid utilization rate by left ventricular weight.
Time frame: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss
Total Myocardial Fatty Acid (FA) Oxidation
The evening before an imaging study, all participants were given a meal containing 12 kcal/kg adjusted body weight (=ideal body weight + ((actual body weight-ideal body weight) x 0.25)). Participants fasted until their imaging studies were completed. Myocardial fatty acid utilization was measured using positron emission tomography (PET) after injecting 1-\^11C-palmitate. Total fatty acid oxidation was calculated by multiplying the fatty acid oxidation rate by left ventricular weight.
Time frame: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss
Left Ventricular (LV) Relaxation (E')
Immediately following MVO2 measurement, complete two-dimensional, M-mode, and Doppler echocardiographic studies were performed using second harmonic imaging. Left ventricular relaxation (E') was measured at the lateral annulus. All reported measurements represent the average of three consecutive cardiac cycles. A single investigator blinded to all clinical parameters evaluated all echocardiograms.
Time frame: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss
Septal Ratio (E/E')
Immediately following MVO2 measurement, complete two-dimensional, M-mode, and Doppler echocardiographic studies were performed using second harmonic imaging. The early diastolic (E) velocity was measured, left ventricular relaxation (E') was measured at the lateral mitral annulus, and the E/E'(septal) ratio was calculated. All reported measurements represent the average of three consecutive cardiac cycles. A single investigator blinded to all clinical parameters evaluated all echocardiograms. The normal septal ratio from the lateral mitral annulus is \<5, a ratio from 5 to 10 is indeterminate, and a ratio of \>10 indicates elevated left atrial pressure.
Time frame: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss
Left Ventricular (LV) Mass
Immediately following MVO2 measurement, complete two-dimensional, M-mode, and Doppler echocardiographic study were performed using second harmonic imaging. Left ventricular (LV) mass was measured using the area-length method. All reported measurements represent the average of three consecutive cardiac cycles. A single investigator blinded to all clinical parameters evaluated all echocardiograms.
Time frame: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss
Mean Heart Rate
Heart rate was measured at scheduled physical examinations.
Time frame: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss
Mean Arterial Pressure
Mean arterial pressure was measured at scheduled physical examinations.
Time frame: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss
Mean Body Mass Index
Participant weight and height was measured at scheduled physical examinations. Body mass index was calculated as participant body weight in kilograms divided by their height in meters squared.
Time frame: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss
Mean Total Serum Cholesterol and Triglycerides
Blood testing was conducted at scheduled times during the study. Serum cholesterol and triglycerides were measured by the enzymatic method (Roche Diagnostics).
Time frame: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss
Mean Homeostasis Model Assessment of Insulin Resistance
The homeostasis model assessment of insulin resistance (HOMA) was used to calculate insulin resistance using the first AM, fasting glucose and insulin levels. Plasma insulin levels were measured by radioimmunoassay, and glucose levels were measured by automated hexokinase assay. A HOMA score of \<3 represents normal insulin resistance, a score between 3 and 5 moderate insulin resistance, and a score of 5 or higher represents severe insulin resistance.
Time frame: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss
Gastric bypass surgery participants were recruited from the Barnes-Jewish Hospital bariatric surgery center. Diet and exercise participants were recruited from the Volunteer for Health office of Washington University School of Medicine.
| Milestone | Diet | Gastric Bypass Surgery |
|---|---|---|
| Started | 37 | 14 |
| Completed | 20 | 10 |
| Not completed | 17 | 4 |
| Withdrew: Lost to follow-up | 10 | 4 |
| Withdrew: Wanted to do a different diet program | 1 | 0 |
| Withdrew: Medication change | 1 | 0 |
| Withdrew: Started a new job-- no time for study | 1 | 0 |
| Withdrew: Admitted to being a smoker | 1 | 0 |
| Withdrew: Refused to do the stress test | 1 | 0 |
| Withdrew: Problem with vascular access | 1 | 0 |
| Withdrew: Health issues unrelated to the study | 1 | 0 |
The evening before an imaging study, all participants were given a meal containing 12 kcal/kg adjusted body weight (=ideal body weight + ((actual body weight-ideal body weight) x 0.25)). Participants fasted until their imaging studies were completed. Myocardial oxygen consumption (MVO2) was measured using positron emission tomography (PET) following injection of 1-\^11C-acetate. Total MVO2 was calculated by multiplying the MVO2 measure by left ventricular weight.
| µmol/min | Diet | Gastric Bypass Surgery |
|---|---|---|
| Baseline | 1064 ± 318 | 1202 ± 373 |
| Post-intervention | 947 ± 309 | 835 ± 232 |
The evening before an imaging study, all participants were given a meal containing 12 kcal/kg adjusted body weight (=ideal body weight + ((actual body weight-ideal body weight) x 0.25)). Participants fasted until their imaging studies were completed. Myocardial blood flow was measured using positron emission tomography (PET) following injection of \^30O-water. Myocardial fatty acid (FA) utilization was measured using PET after injection of 1-\^11C-palmitate. The calculations that describe the relationship between the different measures of myocardial FA metabolism are: FA utilization/gram = blood flow/gram × FA uptake/gram × \[average plasma free FA at the time of the 1-11C-palmitate injection\]; FA utilization/gram = FA oxidation/gram + esterification/gram. Total fatty acid utilization was calculated by multiplying the fatty acid utilization rate by left ventricular weight.
| nmol/g/min | Diet | Gastric Bypass Surgery |
|---|---|---|
| Baseline | 148 ± 38 | 166 ± 48 |
| Post-intervention | 144 ± 36 | 148 ± 79 |
The evening before an imaging study, all participants were given a meal containing 12 kcal/kg adjusted body weight (=ideal body weight + ((actual body weight-ideal body weight) x 0.25)). Participants fasted until their imaging studies were completed. Myocardial fatty acid utilization was measured using positron emission tomography (PET) after injecting 1-\^11C-palmitate. Total fatty acid oxidation was calculated by multiplying the fatty acid oxidation rate by left ventricular weight.
| nmol/g/min | Diet | Gastric Bypass Surgery |
|---|---|---|
| Baseline | 134 ± 37 | 141 ± 47 |
| Post-intervention | 128 ± 37 | 127 ± 50 |
Immediately following MVO2 measurement, complete two-dimensional, M-mode, and Doppler echocardiographic studies were performed using second harmonic imaging. Left ventricular relaxation (E') was measured at the lateral annulus. All reported measurements represent the average of three consecutive cardiac cycles. A single investigator blinded to all clinical parameters evaluated all echocardiograms.
| cm/second | Diet | Gastric Bypass Surgery |
|---|---|---|
| Baseline | 14.0 ± 2.7 | 8.2 ± 1.2 |
| Post-intervention | 14.1 ± 2.2 | 10.4 ± 1.8 |
Immediately following MVO2 measurement, complete two-dimensional, M-mode, and Doppler echocardiographic studies were performed using second harmonic imaging. The early diastolic (E) velocity was measured, left ventricular relaxation (E') was measured at the lateral mitral annulus, and the E/E'(septal) ratio was calculated. All reported measurements represent the average of three consecutive cardiac cycles. A single investigator blinded to all clinical parameters evaluated all echocardiograms. The normal septal ratio from the lateral mitral annulus is \<5, a ratio from 5 to 10 is indeterminate, and a ratio of \>10 indicates elevated left atrial pressure.
| ratio | Diet | Gastric Bypass Surgery |
|---|---|---|
| Baseline | 5.9 ± 1.1 | 12.5 ± 2.1 |
| Post-intervention | 6.1 ± 1.1 | 8.1 ± 0.9 |
Immediately following MVO2 measurement, complete two-dimensional, M-mode, and Doppler echocardiographic study were performed using second harmonic imaging. Left ventricular (LV) mass was measured using the area-length method. All reported measurements represent the average of three consecutive cardiac cycles. A single investigator blinded to all clinical parameters evaluated all echocardiograms.
| grams | Diet | Gastric Bypass Surgery |
|---|---|---|
| Baseline | 186 ± 34 | 180 ± 24 |
| Post-intervention | 186 ± 32 | 141 ± 20 |
Heart rate was measured at scheduled physical examinations.
| beats per minute | Diet | Gastric Bypass Surgery |
|---|---|---|
| Baseline | 69 ± 11 | 72 ± 13 |
| Post-intervention | 61 ± 12 | 65 ± 17 |
Mean arterial pressure was measured at scheduled physical examinations.
| mm Hg | Diet | Gastric Bypass Surgery |
|---|---|---|
| Baseline | 89 ± 9 | 89 ± 6 |
| Post-intervention | 89 ± 10 | 86 ± 9 |
Participant weight and height was measured at scheduled physical examinations. Body mass index was calculated as participant body weight in kilograms divided by their height in meters squared.
| kg/m^2 | Diet | Gastric Bypass Surgery |
|---|---|---|
| Baseline | 39 ± 6 | 44 ± 7 |
| Post-intervention | 36 ± 7 | 29 ± 5 |
Blood testing was conducted at scheduled times during the study. Serum cholesterol and triglycerides were measured by the enzymatic method (Roche Diagnostics).
| mg/dl | Diet | Gastric Bypass Surgery |
|---|---|---|
| Total serum cholesterol, baseline | 182 ± 38 | 167 ± 33 |
| Total serum cholesterol, post-intervention | 153 ± 35 | 136 ± 27 |
| Serum triglycerides, baseline | 153 ± 112 | 168 ± 90 |
| Serum triglycerides, post-intervention | 118 ± 73 | 72 ± 21 |
The homeostasis model assessment of insulin resistance (HOMA) was used to calculate insulin resistance using the first AM, fasting glucose and insulin levels. Plasma insulin levels were measured by radioimmunoassay, and glucose levels were measured by automated hexokinase assay. A HOMA score of \<3 represents normal insulin resistance, a score between 3 and 5 moderate insulin resistance, and a score of 5 or higher represents severe insulin resistance.
| units on a scale | Diet | Gastric Bypass Surgery |
|---|---|---|
| Baseline | 3.8 ± 2.0 | 5.5 ± 5.3 |
| Post-intervention | 2.7 ± 1.5 | 0.9 ± 0.4 |
Collected over Adverse events were collected from the baseline visit through 8 months for the diet group and through 16 months for the gastric bypass surgery group.. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Diet | — | 0/37 (0%) | 0/37 (0%) |
| Gastric Bypass Surgery | — | 0/14 (0%) | 0/14 (0%) |
Participants who lost 5% of their total body weight following either the diet or gastric bypass surgery interventions
| Age, Customized(Participants) | Diet | Gastric Bypass Surgery | Total |
|---|---|---|---|
| ≥ 21 and ≤ 50 years of age | 20 | 10 | 30 |
| Sex: Female, Male(Participants) | Diet | Gastric Bypass Surgery | Total |
|---|---|---|---|
| Female | 12 | 10 | 22 |
| Male | 8 | 0 | 8 |
| Ethnicity (NIH/OMB)(Participants) | Diet | Gastric Bypass Surgery | Total |
|---|---|---|---|
| Hispanic or Latino | 0 | 0 | 0 |
| Not Hispanic or Latino | 20 | 10 | 30 |
| Unknown or Not Reported | 0 | 0 | 0 |
| Race (NIH/OMB)(Participants) | Diet | Gastric Bypass Surgery | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 0 | 0 | 0 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 |
| Black or African American | 5 | 0 | 5 |
| White | 15 | 10 | 25 |
| More than one race | 0 | 0 | 0 |
| Unknown or Not Reported | 0 | 0 | 0 |
| Region of Enrollment(participants) | Diet | Gastric Bypass Surgery | Total |
|---|---|---|---|
| United States | 20 | 10 | 30 |
Plan to share: No
This study is completed, as verified in May 2017. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Washington University School of Medicine