Trial Outcomes & Findings for Nitrate Supplementation and Exercise Tolerance in Patients With Type 2 Diabetes (NCT NCT02804932)

NCT ID: NCT02804932

Last Updated: 2024-05-28

Results Overview

A 12-lead ECG, symptom limited cardiopulmonary exercise testing with gas exchange measurements will be performed on a cycle ergometer using a ramp protocol to determine maximal aerobic capacity (VO2max) and exercise efficiency.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

54 participants

Primary outcome timeframe

Pre and post 8 weeks of dietary nitrate supplementation

Results posted on

2024-05-28

Participant Flow

Participant milestones

Participant milestones
Measure
Beetroot Crystals (Nitrate)
Participants will receive a nitrate rich beetroot powder (10g/day) for 8 weeks. Super Beets: Nitrate rich beetroot powder (10g/day) for 8 weeks
Placebo (Beetroot Powder, no Nitrate)
Participants will receive a beetroot powder placebo (no nitrate) for 8 weeks. Super Beets Placebo: Nitrate deficient beetroot powder (10g/day) for 8 weeks
Nondiabetic Control Subjects
All pre supplementation measures and study visits will be performed in a group of 15 nondiabetic control subjects to allow us to 1) quantify the degree of impairment in T2D prior to intervention and 2) assess the effectiveness of the nitrate therapy in restoring the primary outcome measures back to 'normal'. Nondiabetic controls will not receive an 8-week beetroot supplementation.
Overall Study
STARTED
20
19
15
Overall Study
COMPLETED
19
18
15
Overall Study
NOT COMPLETED
1
1
0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Beetroot Crystals (Nitrate)
n=20 Participants
Participants will receive a nitrate rich beetroot powder (10g/day) for 8 weeks. Super Beets: Nitrate rich beetroot powder (10g/day) for 8 weeks
Placebo (Beetroot Powder, no Nitrate)
n=19 Participants
Participants will receive a beetroot powder placebo (no nitrate) for 8 weeks. Super Beets Placebo: Nitrate deficient beetroot powder (10g/day) for 8 weeks
Nondiabetic Control Subjects
n=15 Participants
All pre supplementation measures and study visits will be performed in a group of 15 nondiabetic control subjects to allow us to 1) quantify the degree of impairment in T2D prior to intervention and 2) assess the effectiveness of the nitrate therapy in restoring the primary outcome measures back to 'normal'. Nondiabetic controls will not receive an 8-week beetroot supplementation.
Total
n=54 Participants
Total of all reporting groups
Age, Categorical
>=65 years
8 Participants
n=20 Participants
5 Participants
n=19 Participants
4 Participants
n=15 Participants
17 Participants
n=54 Participants
Age, Categorical
<=18 years
0 Participants
n=20 Participants
0 Participants
n=19 Participants
0 Participants
n=15 Participants
0 Participants
n=54 Participants
Age, Categorical
Between 18 and 65 years
12 Participants
n=20 Participants
14 Participants
n=19 Participants
11 Participants
n=15 Participants
37 Participants
n=54 Participants
Age, Continuous
58.4 years
STANDARD_DEVIATION 9.7 • n=20 Participants
58.7 years
STANDARD_DEVIATION 8.8 • n=19 Participants
60.2 years
STANDARD_DEVIATION 9.2 • n=15 Participants
59.2 years
STANDARD_DEVIATION 9.1 • n=54 Participants
Sex: Female, Male
Female
5 Participants
n=20 Participants
5 Participants
n=19 Participants
5 Participants
n=15 Participants
15 Participants
n=54 Participants
Sex: Female, Male
Male
15 Participants
n=20 Participants
14 Participants
n=19 Participants
10 Participants
n=15 Participants
39 Participants
n=54 Participants
Race and Ethnicity Not Collected
0 Participants
Race and Ethnicity were not collected from any participant.
Region of Enrollment
United States
20 participants
n=20 Participants
19 participants
n=19 Participants
15 participants
n=15 Participants
54 participants
n=54 Participants

PRIMARY outcome

Timeframe: Pre and post 8 weeks of dietary nitrate supplementation

Population: One subject in the nitrate group did not reach maximal criteria during testing. Therefore, VO2max data was analyzed only in 18 participants in the nitrate group. Nondiabetic control subjects only completed VO2max testing once (same time point as pre measurements for T2D subjects).

A 12-lead ECG, symptom limited cardiopulmonary exercise testing with gas exchange measurements will be performed on a cycle ergometer using a ramp protocol to determine maximal aerobic capacity (VO2max) and exercise efficiency.

Outcome measures

Outcome measures
Measure
Beetroot Crystals (Nitrate)
n=18 Participants
Participants will receive a nitrate rich beetroot powder (10g/day) for 8 weeks. Super Beets: Nitrate rich beetroot powder (10g/day) for 8 weeks
Placebo (Beetroot Powder, no Nitrate)
n=18 Participants
Participants will receive a beetroot powder placebo (no nitrate) for 8 weeks. Super Beets Placebo: Nitrate deficient beetroot powder (10g/day) for 8 weeks
Nondiabetic Control Subjects
n=15 Participants
All pre supplementation measures and study visits will be performed in a group of 15 nondiabetic control subjects to allow us to 1) quantify the degree of impairment in T2D prior to intervention and 2) assess the effectiveness of the nitrate therapy in restoring the primary outcome measures back to 'normal'. Nondiabetic controls will not receive an 8-week beetroot supplementation.
Maximal Exercise Capacity (VO2max)
VO2max - Pre supplementation
20.7 mL/kg/min
Standard Deviation 7.0
20.0 mL/kg/min
Standard Deviation 4.2
27.6 mL/kg/min
Standard Deviation 8.7
Maximal Exercise Capacity (VO2max)
VO2max - Post supplementation
21.9 mL/kg/min
Standard Deviation 7.4
19.7 mL/kg/min
Standard Deviation 4.6

PRIMARY outcome

Timeframe: Pre and post 8 weeks of dietary nitrate supplementation

Population: Nondiabetic control subjects only completed rhythmic forearm exercise and forearm blood flow measurements at one study visit (same time point as pre measurements for T2D subjects).

Forearm blood flow will be determined using Doppler ultrasound during rhythmic forearm exercise.

Outcome measures

Outcome measures
Measure
Beetroot Crystals (Nitrate)
n=19 Participants
Participants will receive a nitrate rich beetroot powder (10g/day) for 8 weeks. Super Beets: Nitrate rich beetroot powder (10g/day) for 8 weeks
Placebo (Beetroot Powder, no Nitrate)
n=18 Participants
Participants will receive a beetroot powder placebo (no nitrate) for 8 weeks. Super Beets Placebo: Nitrate deficient beetroot powder (10g/day) for 8 weeks
Nondiabetic Control Subjects
n=15 Participants
All pre supplementation measures and study visits will be performed in a group of 15 nondiabetic control subjects to allow us to 1) quantify the degree of impairment in T2D prior to intervention and 2) assess the effectiveness of the nitrate therapy in restoring the primary outcome measures back to 'normal'. Nondiabetic controls will not receive an 8-week beetroot supplementation.
Change in Skeletal Muscle Perfusion During Exercise
Forearm Blood Flow - pre supplementation
156 ml/min
Standard Deviation 69
143 ml/min
Standard Deviation 69
200 ml/min
Standard Deviation 64
Change in Skeletal Muscle Perfusion During Exercise
Forearm Blood Flow - post supplementation
175 ml/min
Standard Deviation 73
143 ml/min
Standard Deviation 66

PRIMARY outcome

Timeframe: Pre and post 8 weeks of dietary nitrate supplementation

Population: Final number of participants studied with muscle biopsies was smaller than the total number of subjects enrolled in the study. The lower number was influenced by: (i) subjects not consenting to the muscle biopsy procedure; or (ii) technical problems (ex: not enough muscle tissue and/or extensive proportion of intramuscular fat obtained). Nondiabetic control subjects only had muscle biopsies performed at one time point (same time point as pre measurements for T2D subjects).

Muscle biopsies were obtained from the vastus lateralis using a Bergstrom needle with suction under local anesthesia, which will yield \~200-250mg of tissue. Mitochondrial function was assessed as follows: Fiber bundles were chemically permeabilized with saponin and mitochondrial respiration was analyzed by in situ high-resolution respirometry at 37°.

Outcome measures

Outcome measures
Measure
Beetroot Crystals (Nitrate)
n=12 Participants
Participants will receive a nitrate rich beetroot powder (10g/day) for 8 weeks. Super Beets: Nitrate rich beetroot powder (10g/day) for 8 weeks
Placebo (Beetroot Powder, no Nitrate)
n=6 Participants
Participants will receive a beetroot powder placebo (no nitrate) for 8 weeks. Super Beets Placebo: Nitrate deficient beetroot powder (10g/day) for 8 weeks
Nondiabetic Control Subjects
n=10 Participants
All pre supplementation measures and study visits will be performed in a group of 15 nondiabetic control subjects to allow us to 1) quantify the degree of impairment in T2D prior to intervention and 2) assess the effectiveness of the nitrate therapy in restoring the primary outcome measures back to 'normal'. Nondiabetic controls will not receive an 8-week beetroot supplementation.
Change in Skeletal Muscle Mitochondrial Function
CHO-supported respiration - Pre
64.6 Oxygen Flux, JO2 (pmol/(s*mg))
Standard Deviation 22.2
71.0 Oxygen Flux, JO2 (pmol/(s*mg))
Standard Deviation 20.5
87.5 Oxygen Flux, JO2 (pmol/(s*mg))
Standard Deviation 21.5
Change in Skeletal Muscle Mitochondrial Function
CHO-supported respiration - Post
75.4 Oxygen Flux, JO2 (pmol/(s*mg))
Standard Deviation 16.4
59.8 Oxygen Flux, JO2 (pmol/(s*mg))
Standard Deviation 11.1

Adverse Events

Beetroot Crystals (Nitrate)

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Placebo (Beetroot Powder, no Nitrate)

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Nondiabetic Control Subjects

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. Darren Casey

University of Iowa

Phone: 13193841009

Results disclosure agreements

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