Trial Outcomes & Findings for Effect of Weight Loss on Myocardial Metabolism and Cardiac Relaxation in Obese Adults (NCT NCT00572624)

NCT ID: NCT00572624

Last Updated: 2017-05-15

Results Overview

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.

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 51 participants
• Primary outcome timeframe: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss
• Results posted on: 2017-05-15

Participant Flow

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.

Participant milestones

Measure	Diet Participants who received counseling and instruction about weight loss through diet and exercise	Gastric Bypass Surgery Participants who received gastric bypass surgery
Overall Study STARTED	37	14
Overall Study COMPLETED	20	10
Overall Study NOT COMPLETED	17	4

Reasons for withdrawal

Measure	Diet Participants who received counseling and instruction about weight loss through diet and exercise	Gastric Bypass Surgery Participants who received gastric bypass surgery
Overall Study Lost to Follow-up	10	4
Overall Study Wanted to do a different diet program	1	0
Overall Study Medication change	1	0
Overall Study Started a new job-- no time for study	1	0
Overall Study Admitted to being a smoker	1	0
Overall Study Refused to do the stress test	1	0
Overall Study Problem with vascular access	1	0
Overall Study Health issues unrelated to the study	1	0

Baseline Characteristics

Effect of Weight Loss on Myocardial Metabolism and Cardiac Relaxation in Obese Adults

Baseline characteristics by cohort

Measure	Diet n=20 Participants Participants who received counseling and instruction about weight loss through diet and exercise	Gastric Bypass Surgery n=10 Participants Participants who received gastric bypass surgery	Total n=30 Participants Total of all reporting groups
Age, Customized ≥ 21 and ≤ 50 years of age	20 Participants n=5 Participants	10 Participants n=7 Participants	30 Participants n=5 Participants
Sex: Female, Male Female	12 Participants n=5 Participants	10 Participants n=7 Participants	22 Participants n=5 Participants
Sex: Female, Male Male	8 Participants n=5 Participants	0 Participants n=7 Participants	8 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	20 Participants n=5 Participants	10 Participants n=7 Participants	30 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	5 Participants n=5 Participants	0 Participants n=7 Participants	5 Participants n=5 Participants
Race (NIH/OMB) White	15 Participants n=5 Participants	10 Participants n=7 Participants	25 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Region of Enrollment United States	20 participants n=5 Participants	10 participants n=7 Participants	30 participants n=5 Participants

PRIMARY outcome

Timeframe: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss

Population: Participants who lost 5% of their body weight during the study

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.

Outcome measures

Measure	Diet n=20 Participants Participants who received counseling and instruction about weight loss through diet and exercise	Gastric Bypass Surgery n=10 Participants Participants who received gastric bypass surgery
Total Myocardial Oxygen Consumption (MVO2) Baseline	1064 µmol/min Standard Deviation 318	1202 µmol/min Standard Deviation 373
Total Myocardial Oxygen Consumption (MVO2) Post-intervention	947 µmol/min Standard Deviation 309	835 µmol/min Standard Deviation 232

PRIMARY outcome

Timeframe: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss

Population: Participants who lost 5% of their body weight during the study and for whom data are available

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.

Outcome measures

Measure	Diet n=20 Participants Participants who received counseling and instruction about weight loss through diet and exercise	Gastric Bypass Surgery n=9 Participants Participants who received gastric bypass surgery
Total Myocardial Fatty Acid (FA) Utilization Baseline	148 nmol/g/min Standard Deviation 38	166 nmol/g/min Standard Deviation 48
Total Myocardial Fatty Acid (FA) Utilization Post-intervention	144 nmol/g/min Standard Deviation 36	148 nmol/g/min Standard Deviation 79

PRIMARY outcome

Timeframe: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss

Population: Participants who lost 5% of their body weight during the study and for whom data are available

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.

Outcome measures

Measure	Diet n=20 Participants Participants who received counseling and instruction about weight loss through diet and exercise	Gastric Bypass Surgery n=9 Participants Participants who received gastric bypass surgery
Total Myocardial Fatty Acid (FA) Oxidation Baseline	134 nmol/g/min Standard Deviation 37	141 nmol/g/min Standard Deviation 47
Total Myocardial Fatty Acid (FA) Oxidation Post-intervention	128 nmol/g/min Standard Deviation 37	127 nmol/g/min Standard Deviation 50

SECONDARY outcome

Timeframe: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss

Population: Participants who lost 5% of their body weight during the study and for whom data are available

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.

Outcome measures

Measure	Diet n=20 Participants Participants who received counseling and instruction about weight loss through diet and exercise	Gastric Bypass Surgery n=9 Participants Participants who received gastric bypass surgery
Left Ventricular (LV) Relaxation (E') Baseline	14.0 cm/second Standard Deviation 2.7	8.2 cm/second Standard Deviation 1.2
Left Ventricular (LV) Relaxation (E') Post-intervention	14.1 cm/second Standard Deviation 2.2	10.4 cm/second Standard Deviation 1.8

SECONDARY outcome

Timeframe: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss

Population: Participants who lost 5% of their body weight during the study and for whom data are available

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.

Outcome measures

Measure	Diet n=18 Participants Participants who received counseling and instruction about weight loss through diet and exercise	Gastric Bypass Surgery n=7 Participants Participants who received gastric bypass surgery
Septal Ratio (E/E') Post-intervention	6.1 ratio Standard Deviation 1.1	8.1 ratio Standard Deviation 0.9
Septal Ratio (E/E') Baseline	5.9 ratio Standard Deviation 1.1	12.5 ratio Standard Deviation 2.1

SECONDARY outcome

Timeframe: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss

Population: Participants who lost 5% of their body weight during the study and for whom data are available

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.

Outcome measures

Measure	Diet n=20 Participants Participants who received counseling and instruction about weight loss through diet and exercise	Gastric Bypass Surgery n=9 Participants Participants who received gastric bypass surgery
Left Ventricular (LV) Mass Post-intervention	186 grams Standard Deviation 32	141 grams Standard Deviation 20
Left Ventricular (LV) Mass Baseline	186 grams Standard Deviation 34	180 grams Standard Deviation 24

SECONDARY outcome

Timeframe: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss

Population: Participants who lost 5% of their body weight during the study

Heart rate was measured at scheduled physical examinations.

Outcome measures

Measure	Diet n=20 Participants Participants who received counseling and instruction about weight loss through diet and exercise	Gastric Bypass Surgery n=10 Participants Participants who received gastric bypass surgery
Mean Heart Rate Baseline	69 beats per minute Standard Deviation 11	72 beats per minute Standard Deviation 13
Mean Heart Rate Post-intervention	61 beats per minute Standard Deviation 12	65 beats per minute Standard Deviation 17

SECONDARY outcome

Timeframe: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss

Population: Participants who lost 5% of their body weight during the study

Mean arterial pressure was measured at scheduled physical examinations.

Outcome measures

Measure	Diet n=20 Participants Participants who received counseling and instruction about weight loss through diet and exercise	Gastric Bypass Surgery n=10 Participants Participants who received gastric bypass surgery
Mean Arterial Pressure Baseline	89 mm Hg Standard Deviation 9	89 mm Hg Standard Deviation 6
Mean Arterial Pressure Post-intervention	89 mm Hg Standard Deviation 10	86 mm Hg Standard Deviation 9

SECONDARY outcome

Timeframe: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss

Population: Participants who lost 5% of their body weight during the study

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.

Outcome measures

Measure	Diet n=20 Participants Participants who received counseling and instruction about weight loss through diet and exercise	Gastric Bypass Surgery n=10 Participants Participants who received gastric bypass surgery
Mean Body Mass Index Post-intervention	36 kg/m^2 Standard Deviation 7	29 kg/m^2 Standard Deviation 5
Mean Body Mass Index Baseline	39 kg/m^2 Standard Deviation 6	44 kg/m^2 Standard Deviation 7

SECONDARY outcome

Timeframe: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss

Population: Participants who lost 5% of their body weight during the study

Blood testing was conducted at scheduled times during the study. Serum cholesterol and triglycerides were measured by the enzymatic method (Roche Diagnostics).

Outcome measures

Measure	Diet n=20 Participants Participants who received counseling and instruction about weight loss through diet and exercise	Gastric Bypass Surgery n=10 Participants Participants who received gastric bypass surgery
Mean Total Serum Cholesterol and Triglycerides Total serum cholesterol, baseline	182 mg/dl Standard Deviation 38	167 mg/dl Standard Deviation 33
Mean Total Serum Cholesterol and Triglycerides Total serum cholesterol, post-intervention	153 mg/dl Standard Deviation 35	136 mg/dl Standard Deviation 27
Mean Total Serum Cholesterol and Triglycerides Serum triglycerides, baseline	153 mg/dl Standard Deviation 112	168 mg/dl Standard Deviation 90
Mean Total Serum Cholesterol and Triglycerides Serum triglycerides, post-intervention	118 mg/dl Standard Deviation 73	72 mg/dl Standard Deviation 21

SECONDARY outcome

Timeframe: Measured at baseline, 16 months after gastric bypass surgery-induced weight loss, and 8 months after diet-induced weight loss

Population: Participants who lost 5% of their body weight during the study

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.

Outcome measures

Measure	Diet n=20 Participants Participants who received counseling and instruction about weight loss through diet and exercise	Gastric Bypass Surgery n=10 Participants Participants who received gastric bypass surgery
Mean Homeostasis Model Assessment of Insulin Resistance Baseline	3.8 units on a scale Standard Deviation 2.0	5.5 units on a scale Standard Deviation 5.3
Mean Homeostasis Model Assessment of Insulin Resistance Post-intervention	2.7 units on a scale Standard Deviation 1.5	0.9 units on a scale Standard Deviation 0.4

Adverse Events

Diet

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Gastric Bypass Surgery

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Linda Peterson, M.D.

Washington University School of Medicine

Phone: 314-362-4577

Email: lpeterso@dom.wustl.edu

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place