NCT05251207

Brief Summary

The primary aims of the current study:

  • using L-carnitine supplementation modulate the level of plasma trimethylamine N-oxide to assess its effect on circulating cytokines related to diabetes and metabolic syndrome;
  • using simulated night-shift work intervention as a stress factor, explore the effect of circulating metabolites on insulin sensitivity The secondary aim is to evaluate the effect of carnitine supplementation on gut microbiome composition.

Trial Health

75
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
40

participants targeted

Target at P25-P50 for not_applicable

Timeline
13mo left

Started Feb 2022

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
active not recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress80%
Feb 2022May 2027

Study Start

First participant enrolled

February 7, 2022

Completed
4 days until next milestone

First Submitted

Initial submission to the registry

February 11, 2022

Completed
11 days until next milestone

First Posted

Study publicly available on registry

February 22, 2022

Completed
4.3 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

May 31, 2026

Expected
1 year until next milestone

Study Completion

Last participant's last visit for all outcomes

May 31, 2027

Last Updated

October 3, 2025

Status Verified

September 1, 2025

Enrollment Period

4.3 years

First QC Date

February 11, 2022

Last Update Submit

September 29, 2025

Conditions

Insulin Resistance

Outcome Measures

Primary Outcomes (5)

  • Circulating microbiome metabolites

    Determination of plasma trimethylamine and trimethylamine N-oxide using ultra performance liquid chromatography - tandem mass spectrometer (UPLC-MS/MS) method

    13 weeks

  • Circulating carnitine metabolites

    Determination of plasma free, total, and acyl-L-carnitines using ultra performance liquid chromatography - tandem mass spectrometer (UPLC-MS/MS) method

    13 weeks

  • Circulating diabetes biomarkers

    insulin, C-peptide, ghrelin, leptin, resistin using enzyme-linked immunosorbent assay

    13 weeks

  • Circulating inflammatory biomarkers

    tumor necrosis factor, C-reactive protein using enzyme-linked immunosorbent assay

    13 weeks

  • Oral Glucose Tolerance Test

    The subjects will consume 75 g of glucose solution drink within a 5-minute time frame. The glucose level will be continuously monitored with the FreeStyle Libre Sensor.

    1 week

Secondary Outcomes (1)

  • gut microbiome composition

    13 weeks

Study Arms (4)

carnitine

EXPERIMENTAL

2 grams of L-carnitine per day for 12 weeks

Dietary Supplement: L-carnitineBehavioral: Change of the circadian cycle

leucine

PLACEBO COMPARATOR

2 grams of L-leucine per day for 12 weeks

Dietary Supplement: L-leucineBehavioral: Change of the circadian cycle

modified circadian cycle

EXPERIMENTAL

no sleep at night for four consecutive days (enabling sleep between 8:00 and 17:00).

Dietary Supplement: L-carnitineDietary Supplement: L-leucine

normal circadian cycle

ACTIVE COMPARATOR

sleep at night for four consecutive days

Dietary Supplement: L-carnitineDietary Supplement: L-leucine

Interventions

L-carnitineDIETARY_SUPPLEMENT

L-carnitine-L-tartrate

carnitinemodified circadian cyclenormal circadian cycle
L-leucineDIETARY_SUPPLEMENT

L-leucine

leucinemodified circadian cyclenormal circadian cycle
Change of the circadian cycleBEHAVIORAL

Reducing sleep at night for four consecutive days (enabling sleep between 8:00 and 17:00)

carnitineleucine

Eligibility Criteria

Age20 Years - 30 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • healthy volunteers,
  • must be able to swallow tablets

You may not qualify if:

  • smokers,
  • cardiovascular disease
  • liver disease
  • kidney disease
  • gastrointestinal disorders (including stomach ulcers and erosions)
  • diabetes

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Akademia Wychowania Fizycznego

Poznan, 61-871, Poland

Location

Related Publications (2)

  • Samulak JJ, Sawicka AK, Hartmane D, Grinberga S, Pugovics O, Lysiak-Szydlowska W, Olek RA. L-Carnitine Supplementation Increases Trimethylamine-N-Oxide but not Markers of Atherosclerosis in Healthy Aged Women. Ann Nutr Metab. 2019;74(1):11-17. doi: 10.1159/000495037. Epub 2018 Nov 28.

    PMID: 30485835BACKGROUND

  • Bescos R, Boden MJ, Jackson ML, Trewin AJ, Marin EC, Levinger I, Garnham A, Hiam DS, Falcao-Tebas F, Conte F, Owens JA, Kennaway DJ, McConell GK. Four days of simulated shift work reduces insulin sensitivity in humans. Acta Physiol (Oxf). 2018 Jun;223(2):e13039. doi: 10.1111/apha.13039. Epub 2018 Feb 12.

    PMID: 29356345BACKGROUND

MeSH Terms

Conditions

Insulin Resistance

Interventions

CarnitineLeucine

Condition Hierarchy (Ancestors)

HyperinsulinismGlucose Metabolism DisordersMetabolic DiseasesNutritional and Metabolic Diseases

Intervention Hierarchy (Ancestors)

Trimethyl Ammonium CompoundsQuaternary Ammonium CompoundsAminesOrganic ChemicalsAmino Acids, Branched-ChainAmino AcidsAmino Acids, Peptides, and ProteinsAmino Acids, Essential

Study Officials

  • Robert Olek, PhD

    Poznan University of Physical Education

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
DOUBLE
Who Masked
PARTICIPANT, INVESTIGATOR
Purpose
PREVENTION
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Principal Investigator

Study Record Dates

First Submitted

February 11, 2022

First Posted

February 22, 2022

Study Start

February 7, 2022

Primary Completion (Estimated)

May 31, 2026

Study Completion (Estimated)

May 31, 2027

Last Updated

October 3, 2025

Record last verified: 2025-09

Locations

PL(1)