Trial Outcomes & Findings for Leucine for Depression Study (L-DEP) (NCT NCT03557684)

NCT ID: NCT03557684

Last Updated: 2023-06-08

Results Overview

Depression Subscale of the Short Form of the Profile of Mood States (POMS-SF): total score ranges from 0 to 32; higher values represent worse outcome, i.e., more severe depressed mood; the absolute values at each time point are presented here rather than change of values between time points; zero (0) in mean and standard deviation reflect measured data and not placeholder values.

Recruitment status

TERMINATED

Study phase

EARLY_PHASE1

Target enrollment

59 participants

Primary outcome timeframe

At baseline and then at 1, 1.5, 2, 3, 4, 5, and 6 hours after LPS (or saline) administration

Results posted on

2023-06-08

Participant Flow

A total of 88 subjects were interviewed, 73 eligible, and 70 randomized. Out of these 70, 11 did not participate in the actual study (7 declined; 3 tested positive in urine toxicology on the study day, which was a pre-set exclusion criterion; 1 reported using a drug given by another study on the study day). Thus, 59 were enrolled in and started the study, an experimental provocation trial involving LPS injection, which was a necessary step for a participant to be considered enrolled and started.

Participant milestones

Participant milestones
Measure
PO Leucine & IV LPS
Oral (PO) leucine 6 g twice a day for 2 weeks followed by a single intravenous (IV) bolus of lipopolysaccharide (LPS) 0.8 ng/kg of body weight leucine: amino acid leucine in powder lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Placebo & IV LPS
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of LPS 0.8 ng/kg of body weight PO placebo: maltodextrin lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Leucine & IV Placebo
PO leucine 6 g twice a day for 2 weeks followed by a single IV bolus of 0.9% saline leucine: amino acid leucine in powder IV placebo: 0.9% saline
PO Placebo & IV Placebo
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of 0.9% saline PO placebo: maltodextrin IV placebo: 0.9% saline
Overall Study
STARTED
23
18
8
10
Overall Study
COMPLETED
23
18
8
10
Overall Study
NOT COMPLETED
0
0
0
0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Leucine for Depression Study (L-DEP)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
PO Leucine & IV LPS
n=23 Participants
Oral (PO) leucine 6 g twice a day for 2 weeks followed by a single intravenous (IV) bolus of lipopolysaccharide (LPS) 0.8 ng/kg of body weight leucine: amino acid leucine in powder lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Placebo & IV LPS
n=18 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of LPS 0.8 ng/kg of body weight PO placebo: maltodextrin lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Leucine & IV Placebo
n=8 Participants
PO leucine 6 g twice a day for 2 weeks followed by a single IV bolus of 0.9% saline leucine: amino acid leucine in powder IV placebo: 0.9% saline
PO Placebo & IV Placebo
n=10 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of 0.9% saline PO placebo: maltodextrin IV placebo: 0.9% saline
Total
n=59 Participants
Total of all reporting groups
Age, Continuous
35.2 years
STANDARD_DEVIATION 16.3 • n=5 Participants
26.8 years
STANDARD_DEVIATION 12.7 • n=7 Participants
33.1 years
STANDARD_DEVIATION 12.6 • n=5 Participants
31.9 years
STANDARD_DEVIATION 14.9 • n=4 Participants
31.8 years
STANDARD_DEVIATION 14.6 • n=21 Participants
Sex: Female, Male
Female
10 Participants
n=5 Participants
8 Participants
n=7 Participants
2 Participants
n=5 Participants
4 Participants
n=4 Participants
24 Participants
n=21 Participants
Sex: Female, Male
Male
13 Participants
n=5 Participants
10 Participants
n=7 Participants
6 Participants
n=5 Participants
6 Participants
n=4 Participants
35 Participants
n=21 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
4 Participants
n=5 Participants
1 Participants
n=7 Participants
2 Participants
n=5 Participants
1 Participants
n=4 Participants
8 Participants
n=21 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
19 Participants
n=5 Participants
17 Participants
n=7 Participants
6 Participants
n=5 Participants
9 Participants
n=4 Participants
51 Participants
n=21 Participants
Ethnicity (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
0 Participants
n=21 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
0 Participants
n=21 Participants
Race (NIH/OMB)
Asian
8 Participants
n=5 Participants
9 Participants
n=7 Participants
1 Participants
n=5 Participants
3 Participants
n=4 Participants
21 Participants
n=21 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
0 Participants
n=21 Participants
Race (NIH/OMB)
Black or African American
2 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
0 Participants
n=4 Participants
2 Participants
n=21 Participants
Race (NIH/OMB)
White
10 Participants
n=5 Participants
8 Participants
n=7 Participants
6 Participants
n=5 Participants
7 Participants
n=4 Participants
31 Participants
n=21 Participants
Race (NIH/OMB)
More than one race
2 Participants
n=5 Participants
1 Participants
n=7 Participants
0 Participants
n=5 Participants
0 Participants
n=4 Participants
3 Participants
n=21 Participants
Race (NIH/OMB)
Unknown or Not Reported
1 Participants
n=5 Participants
0 Participants
n=7 Participants
1 Participants
n=5 Participants
0 Participants
n=4 Participants
2 Participants
n=21 Participants
Region of Enrollment
United States
23 participants
n=5 Participants
18 participants
n=7 Participants
8 participants
n=5 Participants
10 participants
n=4 Participants
59 participants
n=21 Participants
Body-mass index
24.3 kg/m^2
STANDARD_DEVIATION 4.0 • n=5 Participants
23.6 kg/m^2
STANDARD_DEVIATION 3.0 • n=7 Participants
26.3 kg/m^2
STANDARD_DEVIATION 2.9 • n=5 Participants
25.5 kg/m^2
STANDARD_DEVIATION 4.0 • n=4 Participants
24.6 kg/m^2
STANDARD_DEVIATION 3.6 • n=21 Participants

PRIMARY outcome

Timeframe: At baseline and then at 1, 1.5, 2, 3, 4, 5, and 6 hours after LPS (or saline) administration

Depression Subscale of the Short Form of the Profile of Mood States (POMS-SF): total score ranges from 0 to 32; higher values represent worse outcome, i.e., more severe depressed mood; the absolute values at each time point are presented here rather than change of values between time points; zero (0) in mean and standard deviation reflect measured data and not placeholder values.

Outcome measures

Outcome measures
Measure
PO Leucine & IV LPS
n=23 Participants
Oral (PO) leucine 6 g twice a day for 2 weeks followed by a single intravenous (IV) bolus of lipopolysaccharide (LPS) 0.8 ng/kg of body weight leucine: amino acid leucine in powder lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Placebo & IV LPS
n=18 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of LPS 0.8 ng/kg of body weight PO placebo: maltodextrin lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Leucine & IV Placebo
n=8 Participants
PO leucine 6 g twice a day for 2 weeks followed by a single IV bolus of 0.9% saline leucine: amino acid leucine in powder IV placebo: 0.9% saline
PO Placebo & IV Placebo
n=10 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of 0.9% saline PO placebo: maltodextrin IV placebo: 0.9% saline
Change in Depressed Mood From Baseline
3 hours
.5909091 score on a scale
Standard Deviation 2.363595
.5625 score on a scale
Standard Deviation 1.364734
.375 score on a scale
Standard Deviation 1.06066
.1111111 score on a scale
Standard Deviation .3333333
Change in Depressed Mood From Baseline
4 hours
.4285714 score on a scale
Standard Deviation 1.963961
.3333333 score on a scale
Standard Deviation .9701425
.1428571 score on a scale
Standard Deviation .3779645
0 score on a scale
Standard Deviation 0
Change in Depressed Mood From Baseline
5 hours
.4545455 score on a scale
Standard Deviation 2.132007
.0555556 score on a scale
Standard Deviation .2357023
.1666667 score on a scale
Standard Deviation .4082483
0 score on a scale
Standard Deviation 0
Change in Depressed Mood From Baseline
6 hours
.5238095 score on a scale
Standard Deviation 2.182179
0 score on a scale
Standard Deviation 0
.1428571 score on a scale
Standard Deviation .3779645
0 score on a scale
Standard Deviation 0
Change in Depressed Mood From Baseline
Baseline
.6818182 score on a scale
Standard Deviation 1.86155
.5294118 score on a scale
Standard Deviation 1.178858
.2857143 score on a scale
Standard Deviation .48795
.6 score on a scale
Standard Deviation 1.074968
Change in Depressed Mood From Baseline
1 hour
1.619048 score on a scale
Standard Deviation 3.879126
.7647059 score on a scale
Standard Deviation 1.480262
.375 score on a scale
Standard Deviation .7440238
0 score on a scale
Standard Deviation 0
Change in Depressed Mood From Baseline
1.5 hours
1.55 score on a scale
Standard Deviation 3.817894
1 score on a scale
Standard Deviation 2.371708
.25 score on a scale
Standard Deviation .46291
.1 score on a scale
Standard Deviation .3162278
Change in Depressed Mood From Baseline
2 hours
1 score on a scale
Standard Deviation 3.829708
1.111111 score on a scale
Standard Deviation 3.103866
.7142857 score on a scale
Standard Deviation 1.253566
.4 score on a scale
Standard Deviation .6992059

SECONDARY outcome

Timeframe: At baseline and then at 2 and 4 hours after LPS (or saline) administration

Montgomery-Asberg Depression Rating Scale (MADRS): a clinician-rated questionnaire of depressive symptoms with scores ranging from 0 to 60, with higher scores indicating more severe depressive symptoms.

Outcome measures

Outcome measures
Measure
PO Leucine & IV LPS
n=23 Participants
Oral (PO) leucine 6 g twice a day for 2 weeks followed by a single intravenous (IV) bolus of lipopolysaccharide (LPS) 0.8 ng/kg of body weight leucine: amino acid leucine in powder lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Placebo & IV LPS
n=18 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of LPS 0.8 ng/kg of body weight PO placebo: maltodextrin lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Leucine & IV Placebo
n=8 Participants
PO leucine 6 g twice a day for 2 weeks followed by a single IV bolus of 0.9% saline leucine: amino acid leucine in powder IV placebo: 0.9% saline
PO Placebo & IV Placebo
n=10 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of 0.9% saline PO placebo: maltodextrin IV placebo: 0.9% saline
Change in Depressive Symptoms From Baseline
Baseline
2.086957 score on a scale
Standard Deviation 2.574579
2.125 score on a scale
Standard Deviation 3.052322
2.5 score on a scale
Standard Deviation 3.891382
1.222222 score on a scale
Standard Deviation 1.301708
Change in Depressive Symptoms From Baseline
2 hours
3 score on a scale
Standard Deviation 5.485913
4 score on a scale
Standard Deviation 6.184658
1.875 score on a scale
Standard Deviation 2.295181
.7 score on a scale
Standard Deviation .9486833
Change in Depressive Symptoms From Baseline
4 hours
1.045455 score on a scale
Standard Deviation 1.812057
1.529412 score on a scale
Standard Deviation 1.907801
2.142857 score on a scale
Standard Deviation 1.864454
.2 score on a scale
Standard Deviation .421637

SECONDARY outcome

Timeframe: At baseline and then at 1, 1.5, 2, 3, 4, 5, and 6 hours after LPS (or saline) administration

Feelings of Social Disconnection Scale: a self-report questionnaire of feelings of social disconnection with scores ranging from 0 to 28, with higher scores indicating more severe feelings of social disconnection.

Outcome measures

Outcome measures
Measure
PO Leucine & IV LPS
n=23 Participants
Oral (PO) leucine 6 g twice a day for 2 weeks followed by a single intravenous (IV) bolus of lipopolysaccharide (LPS) 0.8 ng/kg of body weight leucine: amino acid leucine in powder lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Placebo & IV LPS
n=18 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of LPS 0.8 ng/kg of body weight PO placebo: maltodextrin lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Leucine & IV Placebo
n=8 Participants
PO leucine 6 g twice a day for 2 weeks followed by a single IV bolus of 0.9% saline leucine: amino acid leucine in powder IV placebo: 0.9% saline
PO Placebo & IV Placebo
n=10 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of 0.9% saline PO placebo: maltodextrin IV placebo: 0.9% saline
Change in Feelings of Social Disconnection From Baseline
4 hours
15.71429 score on a scale
Standard Deviation 7.26046
16.66667 score on a scale
Standard Deviation 9.749811
16.42857 score on a scale
Standard Deviation 6.803361
19.6 score on a scale
Standard Deviation 19.65932
Change in Feelings of Social Disconnection From Baseline
5 hours
16.28571 score on a scale
Standard Deviation 7.444077
19.38889 score on a scale
Standard Deviation 13.3775
19.5 score on a scale
Standard Deviation 10.96814
17.6 score on a scale
Standard Deviation 14.19859
Change in Feelings of Social Disconnection From Baseline
Baseline
22.52381 score on a scale
Standard Deviation 7.639496
24 score on a scale
Standard Deviation 8.581786
22.57143 score on a scale
Standard Deviation 6.704654
21.6 score on a scale
Standard Deviation 10.7827
Change in Feelings of Social Disconnection From Baseline
1 hour
16.65217 score on a scale
Standard Deviation 7.327462
17.83333 score on a scale
Standard Deviation 9.463552
18 score on a scale
Standard Deviation 6.21059
15.44444 score on a scale
Standard Deviation 12.26898
Change in Feelings of Social Disconnection From Baseline
1.5 hours
16.86364 score on a scale
Standard Deviation 7.942025
16.77778 score on a scale
Standard Deviation 9.42809
17.125 score on a scale
Standard Deviation 6.220645
13.625 score on a scale
Standard Deviation 7.836499
Change in Feelings of Social Disconnection From Baseline
2 hours
15.33333 score on a scale
Standard Deviation 7.308335
17.05556 score on a scale
Standard Deviation 9.276613
17 score on a scale
Standard Deviation 6.546537
18.3 score on a scale
Standard Deviation 14.95215
Change in Feelings of Social Disconnection From Baseline
3 hours
15.38095 score on a scale
Standard Deviation 6.6744
15.8125 score on a scale
Standard Deviation 9.914426
18 score on a scale
Standard Deviation 5.744563
13.55556 score on a scale
Standard Deviation 9.166667
Change in Feelings of Social Disconnection From Baseline
6 hours
16.25 score on a scale
Standard Deviation 7.27559
17.72222 score on a scale
Standard Deviation 8.68945
14.57143 score on a scale
Standard Deviation 7.807201
19.9 score on a scale
Standard Deviation 18.62167

SECONDARY outcome

Timeframe: At baseline and then at 1, 1.5, 2, 3, 4, 5, and 6 hours after LPS (or saline) administration

Fatigue Subscale of the Short Form of the Profile of Mood States (POMS-SF): total score ranges from 0 to 20; higher values represent worse outcome, i.e., more severe fatigue; the absolute values at each time point are presented here rather than change of values between time points.

Outcome measures

Outcome measures
Measure
PO Leucine & IV LPS
n=23 Participants
Oral (PO) leucine 6 g twice a day for 2 weeks followed by a single intravenous (IV) bolus of lipopolysaccharide (LPS) 0.8 ng/kg of body weight leucine: amino acid leucine in powder lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Placebo & IV LPS
n=18 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of LPS 0.8 ng/kg of body weight PO placebo: maltodextrin lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Leucine & IV Placebo
n=8 Participants
PO leucine 6 g twice a day for 2 weeks followed by a single IV bolus of 0.9% saline leucine: amino acid leucine in powder IV placebo: 0.9% saline
PO Placebo & IV Placebo
n=10 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of 0.9% saline PO placebo: maltodextrin IV placebo: 0.9% saline
Change in Fatigue From Baseline
Baseline
2.409091 score on a scale
Standard Deviation 2.839502
2.117647 score on a scale
Standard Deviation 2.027386
1.857143 score on a scale
Standard Deviation 3.338092
2 score on a scale
Standard Deviation 1.885618
Change in Fatigue From Baseline
1 hours
3.666667 score on a scale
Standard Deviation 4.09064
3.611111 score on a scale
Standard Deviation 3.310214
2.25 score on a scale
Standard Deviation 3.412163
.6666667 score on a scale
Standard Deviation .8660254
Change in Fatigue From Baseline
1.5 hours
5.095238 score on a scale
Standard Deviation 5.290603
4.444444 score on a scale
Standard Deviation 2.994548
2.25 score on a scale
Standard Deviation 4.399675
1 score on a scale
Standard Deviation 1.247219
Change in Fatigue From Baseline
2 hours
4.681818 score on a scale
Standard Deviation 5.083928
4.333333 score on a scale
Standard Deviation 3.694193
2.375 score on a scale
Standard Deviation 3.73927
.9 score on a scale
Standard Deviation 1.449138
Change in Fatigue From Baseline
3 hours
4.590909 score on a scale
Standard Deviation 4.584229
3.555556 score on a scale
Standard Deviation 3.014128
2.625 score on a scale
Standard Deviation 4.10357
1.777778 score on a scale
Standard Deviation 1.855921
Change in Fatigue From Baseline
4 hours
3.272727 score on a scale
Standard Deviation 4.322497
2.111111 score on a scale
Standard Deviation 2.246275
2.571429 score on a scale
Standard Deviation 4.197505
.6 score on a scale
Standard Deviation 1.074968
Change in Fatigue From Baseline
5 hours
3.454545 score on a scale
Standard Deviation 4.925418
2.222222 score on a scale
Standard Deviation 2.438793
2.833333 score on a scale
Standard Deviation 4.167333
1.3 score on a scale
Standard Deviation 1.946507
Change in Fatigue From Baseline
6 hours
2.666667 score on a scale
Standard Deviation 4.564355
1.944444 score on a scale
Standard Deviation 2.508157
1.571429 score on a scale
Standard Deviation 2.935821
1 score on a scale
Standard Deviation 1.581139

SECONDARY outcome

Timeframe: At baseline and then at 1, 1.5, 2, 3, 4, 5, and 6 hours after LPS (or saline) administration

Confusion Subscale of the Short Form of the Profile of Mood States (POMS-SF): total score ranges from 0 to 20; higher values represent worse outcome, i.e., more severe confusion; the absolute values at each time point are presented here rather than change of values between time points; zero (0) in mean and standard deviation reflect measured data and not placeholder values.

Outcome measures

Outcome measures
Measure
PO Leucine & IV LPS
n=23 Participants
Oral (PO) leucine 6 g twice a day for 2 weeks followed by a single intravenous (IV) bolus of lipopolysaccharide (LPS) 0.8 ng/kg of body weight leucine: amino acid leucine in powder lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Placebo & IV LPS
n=18 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of LPS 0.8 ng/kg of body weight PO placebo: maltodextrin lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Leucine & IV Placebo
n=8 Participants
PO leucine 6 g twice a day for 2 weeks followed by a single IV bolus of 0.9% saline leucine: amino acid leucine in powder IV placebo: 0.9% saline
PO Placebo & IV Placebo
n=10 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of 0.9% saline PO placebo: maltodextrin IV placebo: 0.9% saline
Change in Confusion From Baseline
Baseline
1.409091 score on a scale
Standard Deviation 1.991867
1.125 score on a scale
Standard Deviation 1.408309
1 score on a scale
Standard Deviation 1.825742
1.1 score on a scale
Standard Deviation 1.286684
Change in Confusion From Baseline
1 hours
2.238095 score on a scale
Standard Deviation 3.845839
.8888889 score on a scale
Standard Deviation 1.07861
1 score on a scale
Standard Deviation 1.414214
.4444444 score on a scale
Standard Deviation 1.013794
Change in Confusion From Baseline
3 hours
1.454545 score on a scale
Standard Deviation 2.063914
.8888889 score on a scale
Standard Deviation 1.131833
.625 score on a scale
Standard Deviation 1.06066
.3333333 score on a scale
Standard Deviation .7071068
Change in Confusion From Baseline
4 hours
.6363636 score on a scale
Standard Deviation 1.216766
.6111111 score on a scale
Standard Deviation 1.195033
.5714286 score on a scale
Standard Deviation 1.133893
0 score on a scale
Standard Deviation 0
Change in Confusion From Baseline
1.5 hours
2.095238 score on a scale
Standard Deviation 3.462727
1.222222 score on a scale
Standard Deviation 1.308594
.375 score on a scale
Standard Deviation 1.06066
.1 score on a scale
Standard Deviation .3162278
Change in Confusion From Baseline
2 hours
1.772727 score on a scale
Standard Deviation 3.435554
1.111111 score on a scale
Standard Deviation 1.323493
.625 score on a scale
Standard Deviation 1.407886
.1 score on a scale
Standard Deviation .3162278
Change in Confusion From Baseline
5 hours
.6363636 score on a scale
Standard Deviation 1.398824
.6111111 score on a scale
Standard Deviation 1.036901
.5 score on a scale
Standard Deviation .5773503
.1 score on a scale
Standard Deviation .3162278
Change in Confusion From Baseline
6 hours
.4761905 score on a scale
Standard Deviation 1.435933
.4705882 score on a scale
Standard Deviation 1.06757
.1428571 score on a scale
Standard Deviation .3779645
0 score on a scale
Standard Deviation 0

SECONDARY outcome

Timeframe: At baseline and then 3 hours after LPS (or saline) administration

Memory domains of cognitive function were measured using the computerized tests from CNS Vital Signs™: verbal memory using "Verbal Memory Test" (total scores ranging from 0 to 60; higher scores mean a better outcome); and visual memory using "Visual Memory Test" (total scores ranging from 0 to 60; higher scores mean a better outcome). The absolute values at each time point are presented.

Outcome measures

Outcome measures
Measure
PO Leucine & IV LPS
n=23 Participants
Oral (PO) leucine 6 g twice a day for 2 weeks followed by a single intravenous (IV) bolus of lipopolysaccharide (LPS) 0.8 ng/kg of body weight leucine: amino acid leucine in powder lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Placebo & IV LPS
n=18 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of LPS 0.8 ng/kg of body weight PO placebo: maltodextrin lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Leucine & IV Placebo
n=8 Participants
PO leucine 6 g twice a day for 2 weeks followed by a single IV bolus of 0.9% saline leucine: amino acid leucine in powder IV placebo: 0.9% saline
PO Placebo & IV Placebo
n=10 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of 0.9% saline PO placebo: maltodextrin IV placebo: 0.9% saline
Change in Memory Domains of Cognitive Function From Baseline
Verbal memory baseline
51.30435 score on a scale
Standard Deviation 8.298054
53.23529 score on a scale
Standard Deviation 6.139314
51.125 score on a scale
Standard Deviation 4.580627
52.3 score on a scale
Standard Deviation 8.525126
Change in Memory Domains of Cognitive Function From Baseline
Verbal memory 3 hours
48.66667 score on a scale
Standard Deviation 5.695027
52.58824 score on a scale
Standard Deviation 6.538911
48.5 score on a scale
Standard Deviation 5.976143
45.5 score on a scale
Standard Deviation 10.31988
Change in Memory Domains of Cognitive Function From Baseline
Visual memory baseline
44.04348 score on a scale
Standard Deviation 6.588408
47.76471 score on a scale
Standard Deviation 5.695716
46.125 score on a scale
Standard Deviation 6.490377
43.9 score on a scale
Standard Deviation 8.736259
Change in Memory Domains of Cognitive Function From Baseline
Visual memory 3 hours
42.2381 score on a scale
Standard Deviation 6.106593
46.29412 score on a scale
Standard Deviation 7.405781
41.75 score on a scale
Standard Deviation 4.26782
40.9 score on a scale
Standard Deviation 9.097619

SECONDARY outcome

Timeframe: At baseline and then 3 hours after LPS (or saline) administration

Non-memory domains of cognitive function were measured using the computerized tests from CNS Vital Signs™: executive function using "Stroop Test" (average reaction time in milliseconds thus ranging from 0 to infinite; shorter reaction time means a better outcome); and attention using "Shifting Attention Test" (average reaction time for correct responses in milliseconds thus ranging from 0 to infinite; shorter reaction time means a better outcome) and "Continuous Performance Test" (average reaction time for correct responses in milliseconds thus ranging from 0 to infinite; shorter reaction time means a better outcome). The absolute values at each time point are presented.

Outcome measures

Outcome measures
Measure
PO Leucine & IV LPS
n=23 Participants
Oral (PO) leucine 6 g twice a day for 2 weeks followed by a single intravenous (IV) bolus of lipopolysaccharide (LPS) 0.8 ng/kg of body weight leucine: amino acid leucine in powder lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Placebo & IV LPS
n=18 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of LPS 0.8 ng/kg of body weight PO placebo: maltodextrin lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Leucine & IV Placebo
n=8 Participants
PO leucine 6 g twice a day for 2 weeks followed by a single IV bolus of 0.9% saline leucine: amino acid leucine in powder IV placebo: 0.9% saline
PO Placebo & IV Placebo
n=10 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of 0.9% saline PO placebo: maltodextrin IV placebo: 0.9% saline
Change in Non-memory Domains of Cognitive Function From Baseline
Shifting attention baseline
1014.174 milliseconds
Standard Deviation 199.4204
899.6471 milliseconds
Standard Deviation 140.7502
935.75 milliseconds
Standard Deviation 185.7423
947.9 milliseconds
Standard Deviation 140.4457
Change in Non-memory Domains of Cognitive Function From Baseline
Shifting attention 3 hours
957.2857 milliseconds
Standard Deviation 211.8759
829.7647 milliseconds
Standard Deviation 131.7823
943 milliseconds
Standard Deviation 109.6696
957.5 milliseconds
Standard Deviation 156.2358
Change in Non-memory Domains of Cognitive Function From Baseline
Continuous performance baseline
449.1304 milliseconds
Standard Deviation 73.88954
426 milliseconds
Standard Deviation 44.63743
442.25 milliseconds
Standard Deviation 27.41089
458.2 milliseconds
Standard Deviation 44.96122
Change in Non-memory Domains of Cognitive Function From Baseline
Stroop test 3 hours
386.2381 milliseconds
Standard Deviation 93.90842
316.2353 milliseconds
Standard Deviation 53.88475
324.25 milliseconds
Standard Deviation 36.86946
337.4 milliseconds
Standard Deviation 45.80442
Change in Non-memory Domains of Cognitive Function From Baseline
Stroop test baseline
356.913 milliseconds
Standard Deviation 95.80563
307.6471 milliseconds
Standard Deviation 57.51515
304.125 milliseconds
Standard Deviation 38.96679
268.8 milliseconds
Standard Deviation 146.5619
Change in Non-memory Domains of Cognitive Function From Baseline
Continuous performance 3 hours
456.619 milliseconds
Standard Deviation 65.31422
423.8235 milliseconds
Standard Deviation 54.88993
439.25 milliseconds
Standard Deviation 35.05812
460.6 milliseconds
Standard Deviation 55.05795

OTHER_PRE_SPECIFIED outcome

Timeframe: 2 hours after LPS (or saline) administration

Population: The study was paused during the COVID pandemic because endotoxin, a biologic derived from an infectious agent, was being used. Then, the request for COIVD supplement to NIMH was denied, and due to the lack of funds, the study was prematurely terminated. As the raw data of this particular outcome measure consist in recordings of facial expression and skin conductance, further processing by a specialized technician and additional funds are required. Thus we are currently unable to report the data.

Facial expressions and skin conductance in response to funny film clips using the iMotions®Attention Tool (iMotions Inc., Cambridge, MA) which performs automatic analysis of facial expressions from video and integrates simultaneous measurement of skin conductance

Outcome measures

Outcome data not reported

OTHER_PRE_SPECIFIED outcome

Timeframe: 2 hours after LPS (or saline) administration

Using the Cyberball Social Exclusion Task, feelings of social distress to social rejection are evaluated based on a scale with the total score ranging from 0 to 48; higher values represent worse outcome, i.e., more severe social distress. The Overall Number of Participants Analyzed is different from numbers of participants reported in the Participant Flow module because some participants declined to complete this task.

Outcome measures

Outcome measures
Measure
PO Leucine & IV LPS
n=20 Participants
Oral (PO) leucine 6 g twice a day for 2 weeks followed by a single intravenous (IV) bolus of lipopolysaccharide (LPS) 0.8 ng/kg of body weight leucine: amino acid leucine in powder lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Placebo & IV LPS
n=17 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of LPS 0.8 ng/kg of body weight PO placebo: maltodextrin lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Leucine & IV Placebo
n=8 Participants
PO leucine 6 g twice a day for 2 weeks followed by a single IV bolus of 0.9% saline leucine: amino acid leucine in powder IV placebo: 0.9% saline
PO Placebo & IV Placebo
n=10 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of 0.9% saline PO placebo: maltodextrin IV placebo: 0.9% saline
Subjective Sensitivity to Social Rejection
18.05 score on a scale
Standard Deviation 5.670561
16.17647 score on a scale
Standard Deviation 5.282463
18.25 score on a scale
Standard Deviation 7.245688
17.6 score on a scale
Standard Deviation 5.481281

OTHER_PRE_SPECIFIED outcome

Timeframe: 2 hours after LPS (or saline) administration

Population: The study was paused during the COVID pandemic because endotoxin, a biologic derived from an infectious agent, was being used. Then, the request for COIVD supplement to NIMH was denied, and due to the lack of funds, the study was prematurely terminated. As the raw data of this particular outcome measure require further processing by a specialized technician and thus additional funds, we are currently unable to process and report the data.

Emotional Face Recognition Task consists in showing participants a series of black and white photographs (Ekman Pictures of facial affect), in which the facial expression is morphed from neutral to either Sad, Angry, or Happy. For each image, participants will be asked to make a forced choice about the emotion expressed, and rate their certainty.

Outcome measures

Outcome data not reported

OTHER_PRE_SPECIFIED outcome

Timeframe: 2 hours after drug administration

Prior to the experimental session, participants are asked to complete a survey that contains several personality questionnaires and are video-recorded for 2-5 minutes as they discuss what they like about themselves. Participants are told that 8 people will form impressions of them by selecting personality traits to describe them. Participants then see a photograph of themselves along with a descriptive word underneath (supposedly provided by the evaluators), which is pre-rated based on desirability, and are asked to rate subjective happiness when each of the feedback items is presented. The total score of the scale ranges from 0 to 105; higher values represent better outcome, i.e., higher social reward. The Overall Number of Participants Analyzed is different from numbers of participants reported in the Participant Flow module because some participants declined to complete this task.

Outcome measures

Outcome measures
Measure
PO Leucine & IV LPS
n=21 Participants
Oral (PO) leucine 6 g twice a day for 2 weeks followed by a single intravenous (IV) bolus of lipopolysaccharide (LPS) 0.8 ng/kg of body weight leucine: amino acid leucine in powder lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Placebo & IV LPS
n=18 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of LPS 0.8 ng/kg of body weight PO placebo: maltodextrin lipopolysaccharide (LPS): purified bacterial wall component as an inflammatory challenge
PO Leucine & IV Placebo
n=7 Participants
PO leucine 6 g twice a day for 2 weeks followed by a single IV bolus of 0.9% saline leucine: amino acid leucine in powder IV placebo: 0.9% saline
PO Placebo & IV Placebo
n=10 Participants
PO maltodextrin (placebo) twice a day for 2 weeks followed by a single IV bolus of 0.9% saline PO placebo: maltodextrin IV placebo: 0.9% saline
Subjective Sensitivity to Social Acceptance
76.7619 score on a scale
Standard Deviation 9.229869
77.38889 score on a scale
Standard Deviation 5.94226
76.28571 score on a scale
Standard Deviation 3.77334
78.3 score on a scale
Standard Deviation 6.037844

OTHER_PRE_SPECIFIED outcome

Timeframe: 2 hours after LPS (or saline) administration

Population: The study was paused during the COVID pandemic because endotoxin, a biologic derived from an infectious agent, was being used. Then, the request for COIVD supplement to NIMH was denied, and due to the lack of funds, the study was prematurely terminated. As the raw data of this particular outcome measure require further processing by a specialized technician and thus additional funds, we are currently unable to process and report the data.

Reward Learning Task (a laboratory based probabilistic reward task that objectively measures participants' ability to modulate behavior as a function of reward)

Outcome measures

Outcome data not reported

OTHER_PRE_SPECIFIED outcome

Timeframe: At baseline and then at 1, 1.5, 2, 3, 4, 5, and 6 hours after LPS (or saline) administration

Population: The study was paused during the COVID pandemic because endotoxin, a biologic derived from an infectious agent, was being used. Then, the request for COIVD supplement to NIMH was denied, and due to the lack of funds, the study was prematurely terminated. As the raw data of this particular outcome measure require further processing and thus further funds, we are currently unable to process and report the data.

Plasma proinflammatory cytokines (interleukin-1 receptor antagonist, interleukin-6, tumor necrosis factor-α, and soluble tumor necrosis factor receptor)

Outcome measures

Outcome data not reported

OTHER_PRE_SPECIFIED outcome

Timeframe: At baseline and then at 1, 1.5, 2, 3, 4, 5, and 6 hours after LPS (or saline) administration

Population: The study was paused during the COVID pandemic because endotoxin, a biologic derived from an infectious agent, was being used. Then, the request for COIVD supplement to NIMH was denied, and due to the lack of funds, the study was prematurely terminated. Due to the lack of funds, the blood sample could not be assayed, and we are currently unable to report the data for this particular outcome measure.

Plasma tryptophan, kynurenine, quinolinic acid, and kynurenic acid

Outcome measures

Outcome data not reported

OTHER_PRE_SPECIFIED outcome

Timeframe: At baseline and 30 minutes after LPS (or saline) administration

Population: The study was paused during the COVID pandemic because endotoxin, a biologic derived from an infectious agent, was being used. Then, the request for COIVD supplement to NIMH was denied, and due to the lack of funds, the study was prematurely terminated. Due to the lack of funds, the blood sample could not be assayed, and we are currently unable to report the data for this particular outcome measure.

Genome-wide transcriptional profiling conducted using Illumina HT-12 BeadArrays

Outcome measures

Outcome data not reported

Adverse Events

PO Leucine & IV LPS

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

PO Placebo & IV LPS

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

PO Leucine & IV Placebo

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

PO Placebo & IV Placebo

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

Joshua H. Cho, MD, PhD

UCLA

Phone: 3104286218

Results disclosure agreements

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