Trial Outcomes & Findings for Effect of Dietary Glycemic Index on Beta-cell Function (NCT NCT01386645)
NCT ID: NCT01386645
Last Updated: 2020-08-12
Results Overview
The disposition index generated from an intravenous glucose tolerance test (insulin sensitivity x the acute insulin response to intravenous glucose) is a measure of beta-cell function.
Recruitment status
COMPLETED
Study phase
NA
Target enrollment
56 participants
Primary outcome timeframe
4 weeks
Results posted on
2020-08-12
Participant Flow
Participant milestones
| Measure |
Low GI Diet
low glycemic index diet
low glycemic index diet: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable low glycemic index diet (glycemic index \<35) for 4 weeks with all food provided by the Human Nutrition Lab
|
High GI Diet Placebo
high glycemic index diet plus placebo
high glycemic index diet plus placebo: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable high glycemic index diet (glycemic index \>70) for 4 weeks, all food provided by the Human Nutrition Lab. They will take placebo capsules (matching for active N-acetylcysteine (NAC) in arm 3) twice daily for the 4 weeks on the high GI diet. The NAC vs. placebo arms (arms 2 and 3) will be double-blinded.
|
High GI Diet NAC
high glycemic index diet plus N-acetylcysteine
high glycemic index diet plus N-acetylcysteine: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable high glycemic index diet (glycemic index \>70) for 4 weeks, all food provided by the Human Nutrition Lab. They will take N-acetylcysteine (NAC) two 600 mg capsules twice daily for the 4 weeks on the high GI diet. The NAC vs. placebo arms (arms 2 and 3) will be double-blinded.
|
|---|---|---|---|
|
Overall Study
STARTED
|
18
|
19
|
19
|
|
Overall Study
COMPLETED
|
18
|
18
|
17
|
|
Overall Study
NOT COMPLETED
|
0
|
1
|
2
|
Reasons for withdrawal
| Measure |
Low GI Diet
low glycemic index diet
low glycemic index diet: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable low glycemic index diet (glycemic index \<35) for 4 weeks with all food provided by the Human Nutrition Lab
|
High GI Diet Placebo
high glycemic index diet plus placebo
high glycemic index diet plus placebo: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable high glycemic index diet (glycemic index \>70) for 4 weeks, all food provided by the Human Nutrition Lab. They will take placebo capsules (matching for active N-acetylcysteine (NAC) in arm 3) twice daily for the 4 weeks on the high GI diet. The NAC vs. placebo arms (arms 2 and 3) will be double-blinded.
|
High GI Diet NAC
high glycemic index diet plus N-acetylcysteine
high glycemic index diet plus N-acetylcysteine: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable high glycemic index diet (glycemic index \>70) for 4 weeks, all food provided by the Human Nutrition Lab. They will take N-acetylcysteine (NAC) two 600 mg capsules twice daily for the 4 weeks on the high GI diet. The NAC vs. placebo arms (arms 2 and 3) will be double-blinded.
|
|---|---|---|---|
|
Overall Study
Physician Decision
|
0
|
0
|
1
|
|
Overall Study
Withdrawal by Subject
|
0
|
1
|
1
|
Baseline Characteristics
Effect of Dietary Glycemic Index on Beta-cell Function
Baseline characteristics by cohort
| Measure |
Low GI Diet
n=18 Participants
low glycemic index diet
low glycemic index diet: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable low glycemic index diet (glycemic index \<35) for 4 weeks with all food provided by the Human Nutrition Lab
|
High GI Diet Placebo
n=18 Participants
high glycemic index diet plus placebo
high glycemic index diet plus placebo: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable high glycemic index diet (glycemic index \>70) for 4 weeks, all food provided by the Human Nutrition Lab. They will take placebo capsules (matching for active N-acetylcysteine (NAC) in arm 3) twice daily for the 4 weeks on the high GI diet. The NAC vs. placebo arms (arms 2 and 3) will be double-blinded.
|
High GI Diet NAC
n=17 Participants
high glycemic index diet plus N-acetylcysteine
high glycemic index diet plus N-acetylcysteine: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable high glycemic index diet (glycemic index \>70) for 4 weeks, all food provided by the Human Nutrition Lab. They will take N-acetylcysteine (NAC) two 600 mg capsules twice daily for the 4 weeks on the high GI diet. The NAC vs. placebo arms (arms 2 and 3) will be double-blinded.
|
Total
n=53 Participants
Total of all reporting groups
|
|---|---|---|---|---|
|
Age, Continuous
|
57.2 years
STANDARD_DEVIATION 7.0 • n=5 Participants
|
50.6 years
STANDARD_DEVIATION 10.3 • n=7 Participants
|
51.2 years
STANDARD_DEVIATION 11.0 • n=5 Participants
|
53.0 years
STANDARD_DEVIATION 9.9 • n=4 Participants
|
|
Sex: Female, Male
Female
|
8 Participants
n=5 Participants
|
9 Participants
n=7 Participants
|
10 Participants
n=5 Participants
|
27 Participants
n=4 Participants
|
|
Sex: Female, Male
Male
|
10 Participants
n=5 Participants
|
9 Participants
n=7 Participants
|
7 Participants
n=5 Participants
|
26 Participants
n=4 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
0 Participants
n=4 Participants
|
|
Race (NIH/OMB)
Asian
|
3 Participants
n=5 Participants
|
3 Participants
n=7 Participants
|
2 Participants
n=5 Participants
|
8 Participants
n=4 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
|
0 Participants
n=4 Participants
|
|
Race (NIH/OMB)
Black or African American
|
2 Participants
n=5 Participants
|
4 Participants
n=7 Participants
|
8 Participants
n=5 Participants
|
14 Participants
n=4 Participants
|
|
Race (NIH/OMB)
White
|
13 Participants
n=5 Participants
|
11 Participants
n=7 Participants
|
7 Participants
n=5 Participants
|
31 Participants
n=4 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
0 Participants
n=4 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
0 Participants
n=4 Participants
|
|
Region of Enrollment
United States
|
18 participants
n=5 Participants
|
18 participants
n=7 Participants
|
17 participants
n=5 Participants
|
53 participants
n=4 Participants
|
|
BMI
|
32.5 kg/m^2
STANDARD_DEVIATION 4.7 • n=5 Participants
|
32.4 kg/m^2
STANDARD_DEVIATION 6.4 • n=7 Participants
|
32.7 kg/m^2
STANDARD_DEVIATION 8.0 • n=5 Participants
|
32.5 kg/m^2
STANDARD_DEVIATION 6.3 • n=4 Participants
|
PRIMARY outcome
Timeframe: 4 weeksPopulation: 1 participant in the LGI group ate before the second IVGTT and was excluded. One participant in the HGI/PLAC group could not get a second IV and we were unable to perform the IVGTT.
The disposition index generated from an intravenous glucose tolerance test (insulin sensitivity x the acute insulin response to intravenous glucose) is a measure of beta-cell function.
Outcome measures
| Measure |
Low GI Diet
n=17 Participants
low glycemic index diet
low glycemic index diet: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable low glycemic index diet (glycemic index \<35) for 4 weeks with all food provided by the Human Nutrition Lab
|
High GI Diet Placebo
n=17 Participants
high glycemic index diet plus placebo
high glycemic index diet plus placebo: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable high glycemic index diet (glycemic index \>70) for 4 weeks, all food provided by the Human Nutrition Lab. They will take placebo capsules (matching for active N-acetylcysteine (NAC) in arm 3) twice daily for the 4 weeks on the high GI diet. The NAC vs. placebo arms (arms 2 and 3) will be double-blinded.
|
High GI Diet NAC
n=17 Participants
high glycemic index diet plus N-acetylcysteine
high glycemic index diet plus N-acetylcysteine: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable high glycemic index diet (glycemic index \>70) for 4 weeks, all food provided by the Human Nutrition Lab. They will take N-acetylcysteine (NAC) two 600 mg capsules twice daily for the 4 weeks on the high GI diet. The NAC vs. placebo arms (arms 2 and 3) will be double-blinded.
|
|---|---|---|---|
|
Disposition Index
|
708 unitless
Interval 618.0 to 1244.0
|
793 unitless
Interval 594.0 to 1257.0
|
791 unitless
Interval 689.0 to 1215.0
|
SECONDARY outcome
Timeframe: 4 weeksPopulation: Adults with prediabetes after 4 weeks on study interventions.
Fasting urine F2alpha isoprostane/Cr ratio. Urine isoprostanes were measured by ELISA (Oxford Biomedical Research).
Outcome measures
| Measure |
Low GI Diet
n=18 Participants
low glycemic index diet
low glycemic index diet: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable low glycemic index diet (glycemic index \<35) for 4 weeks with all food provided by the Human Nutrition Lab
|
High GI Diet Placebo
n=18 Participants
high glycemic index diet plus placebo
high glycemic index diet plus placebo: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable high glycemic index diet (glycemic index \>70) for 4 weeks, all food provided by the Human Nutrition Lab. They will take placebo capsules (matching for active N-acetylcysteine (NAC) in arm 3) twice daily for the 4 weeks on the high GI diet. The NAC vs. placebo arms (arms 2 and 3) will be double-blinded.
|
High GI Diet NAC
n=17 Participants
high glycemic index diet plus N-acetylcysteine
high glycemic index diet plus N-acetylcysteine: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable high glycemic index diet (glycemic index \>70) for 4 weeks, all food provided by the Human Nutrition Lab. They will take N-acetylcysteine (NAC) two 600 mg capsules twice daily for the 4 weeks on the high GI diet. The NAC vs. placebo arms (arms 2 and 3) will be double-blinded.
|
|---|---|---|---|
|
Urine F2alpha Isoprostanes
|
2.51 ng/mg
Interval 1.94 to 3.81
|
3.35 ng/mg
Interval 2.35 to 6.4
|
3.43 ng/mg
Interval 2.53 to 6.67
|
SECONDARY outcome
Timeframe: 4 weeksPopulation: Adults with prediabetes with useable iPro CGMS data after the 4 week intervention.
Glycemic variability as measured by the standard deviation (SD) of the glucose levels from the iPro continuous glucose monitoring system (CGMS)
Outcome measures
| Measure |
Low GI Diet
n=16 Participants
low glycemic index diet
low glycemic index diet: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable low glycemic index diet (glycemic index \<35) for 4 weeks with all food provided by the Human Nutrition Lab
|
High GI Diet Placebo
n=17 Participants
high glycemic index diet plus placebo
high glycemic index diet plus placebo: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable high glycemic index diet (glycemic index \>70) for 4 weeks, all food provided by the Human Nutrition Lab. They will take placebo capsules (matching for active N-acetylcysteine (NAC) in arm 3) twice daily for the 4 weeks on the high GI diet. The NAC vs. placebo arms (arms 2 and 3) will be double-blinded.
|
High GI Diet NAC
n=16 Participants
high glycemic index diet plus N-acetylcysteine
high glycemic index diet plus N-acetylcysteine: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable high glycemic index diet (glycemic index \>70) for 4 weeks, all food provided by the Human Nutrition Lab. They will take N-acetylcysteine (NAC) two 600 mg capsules twice daily for the 4 weeks on the high GI diet. The NAC vs. placebo arms (arms 2 and 3) will be double-blinded.
|
|---|---|---|---|
|
Glycemic Variability
|
14.20 mg/dl
Standard Error 1.03
|
19.67 mg/dl
Standard Error 1.57
|
17.69 mg/dl
Standard Error 1.56
|
Adverse Events
Low GI Diet
Serious events: 0 serious events
Other events: 1 other events
Deaths: 0 deaths
High GI Diet Placebo
Serious events: 0 serious events
Other events: 1 other events
Deaths: 0 deaths
High GI Diet NAC
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Serious adverse events
Adverse event data not reported
Other adverse events
| Measure |
Low GI Diet
n=18 participants at risk
low glycemic index diet
low glycemic index diet: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable low glycemic index diet (glycemic index \<35) for 4 weeks with all food provided by the Human Nutrition Lab
|
High GI Diet Placebo
n=18 participants at risk
high glycemic index diet plus placebo
high glycemic index diet plus placebo: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable high glycemic index diet (glycemic index \>70) for 4 weeks, all food provided by the Human Nutrition Lab. They will take placebo capsules (matching for active N-acetylcysteine (NAC) in arm 3) twice daily for the 4 weeks on the high GI diet. The NAC vs. placebo arms (arms 2 and 3) will be double-blinded.
|
High GI Diet NAC
n=17 participants at risk
high glycemic index diet plus N-acetylcysteine
high glycemic index diet plus N-acetylcysteine: Following a 2 week medium glycemic index control diet (glycemic index 50-55), subjects will be provided with a weight stable high glycemic index diet (glycemic index \>70) for 4 weeks, all food provided by the Human Nutrition Lab. They will take N-acetylcysteine (NAC) two 600 mg capsules twice daily for the 4 weeks on the high GI diet. The NAC vs. placebo arms (arms 2 and 3) will be double-blinded.
|
|---|---|---|---|
|
Gastrointestinal disorders
gastroenteritis
|
5.6%
1/18 • Number of events 1 • 6 weeks
Participants were asked about any problems related to their general health, heart, lungs, gastrointestinal system, neurologic system, urinary system and musculoskeletal system at the screening visit and at the end of the control and intervention diets using a systematic screening form. Adverse events were also reported by participants as they occurred.
|
0.00%
0/18 • 6 weeks
Participants were asked about any problems related to their general health, heart, lungs, gastrointestinal system, neurologic system, urinary system and musculoskeletal system at the screening visit and at the end of the control and intervention diets using a systematic screening form. Adverse events were also reported by participants as they occurred.
|
0.00%
0/17 • 6 weeks
Participants were asked about any problems related to their general health, heart, lungs, gastrointestinal system, neurologic system, urinary system and musculoskeletal system at the screening visit and at the end of the control and intervention diets using a systematic screening form. Adverse events were also reported by participants as they occurred.
|
|
Musculoskeletal and connective tissue disorders
cracked tooth
|
0.00%
0/18 • 6 weeks
Participants were asked about any problems related to their general health, heart, lungs, gastrointestinal system, neurologic system, urinary system and musculoskeletal system at the screening visit and at the end of the control and intervention diets using a systematic screening form. Adverse events were also reported by participants as they occurred.
|
5.6%
1/18 • Number of events 1 • 6 weeks
Participants were asked about any problems related to their general health, heart, lungs, gastrointestinal system, neurologic system, urinary system and musculoskeletal system at the screening visit and at the end of the control and intervention diets using a systematic screening form. Adverse events were also reported by participants as they occurred.
|
0.00%
0/17 • 6 weeks
Participants were asked about any problems related to their general health, heart, lungs, gastrointestinal system, neurologic system, urinary system and musculoskeletal system at the screening visit and at the end of the control and intervention diets using a systematic screening form. Adverse events were also reported by participants as they occurred.
|
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place