Brief Summary

People who eat diets low in choline should deplete their choline (Cho) stores, and measurements of Cho pool size using isotope dilution should reflect this depletion. Investigators will identify a biomarker panel that correlates well with measured Cho pool size across the range of different degrees of depletion.The investigators propose that, as body stores of Cho diminish, cells and organs will reach the point when metabolism/function in the cell is altered, and that this will result in a progression of changes in biomarkers that reflect Cho status.

Trial Health

On Track

Trial Health Score

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

Enrollment

101

participants targeted

Target at P75+ for not_applicable healthy

Timeline

Completed

Started Nov 2018

Longer than P75 for not_applicable healthy

Geographic Reach

1 country

1 active site

Status

completed

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

Trial Relationships

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Study Timeline

Key milestones and dates

3 years study duration

First Submitted

Initial submission to the registry

October 25, 2018

Completed

6 days until next milestone

First Posted

Study publicly available on registry

October 31, 2018

Completed

1 day until next milestone

Study Start

First participant enrolled

November 1, 2018

Completed

3 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

October 20, 2021

Completed

Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

October 20, 2021

Completed

1.2 years until next milestone

Results Posted

Study results publicly available

January 6, 2023

Completed

Last Updated

January 6, 2023

Status Verified

October 1, 2022

Enrollment Period

3 years

First QC Date

October 25, 2018

Results QC Date

August 24, 2022

Last Update Submit

December 12, 2022

Conditions

Healthy

Outcome Measures

Primary Outcomes (6)

Ratio of Liver Choline Pool Size by Isotope Dilution
The liver choline pool determined by the dilution of the deuterated choline metabolites formed in liver and released to plasma as measured by isotopic enrichment ratio (IER). The IER for a given metabolite is defined as the concentration of a deuterated metabolite divided by the sum of deuterated and non-deuterated metabolite.
24 hours following administration of choline-d9 on day 12 of respective dietary intervention
Difference in Choline Deficiency Signature
Plasma choline metabolites (micromolar): choline, dimethylglycine, betaine, phosphatidylcholine, sphingomyelin, trimethylamine-oxide, and homocysteine measured by targeted metabolomic profiling. The signature for choline deficiency is defined by choline \<0.793 mmol/L or betaine \<34.9 mmol/L. The levels of these metabolites at the end of each intervention will be compared. The association between choline metabolites and choline pool size will be investigated.
At the end of 2 weeks of respective Cho diet
Comparison of Choline Pool Size Between Participants With and Without Choline Metabolites Signature During Cho Depletion
The 25% Cho arm was selected because only at that intake level is sufficient depletion achieved. Participants with plasma choline \<0.793 mmol/L or betaine \<34.9 mmol/L were considered as choline depleted (showing signature), participants with plasma choline \>=0.793 mmol/L and betaine \>=34.9 mmol/L were considered as not choline depleted (not showing signature). Available choline pool size was determined by the dilution of the deuterated choline metabolites formed in liver and released to plasma as measured by isotopic enrichment ratio (IER). The IER for a given metabolite is defined as the concentration of a deuterated metabolite divided by the sum of deuterated and non-deuterated metabolite.
24 hours following administration of choline-d9 on day 12 of 25% Cho diet
Ion Abundance (Intensity) of Metabolites as Indicators of the Intake of 25%, 50%, or 100% Choline in the Diet. The Ratio of the Intensity of Metabolite Signals for Each Dietary Group Can be Calculated and Correlated With the Level of Choline in the Diet
Metabolomics was conducted on plasma that was collected from individuals at the end of each 2-week diet period. UHPLC High Resolution Mass Spectrometry was used for differential profiling (PMID: 33415121). Supervised Orthogonal Partial Least Squares Discriminant Analysis was used to determine signals that differentiated the 25% choline dietary group from the 100% choline dietary group. Metabolites that differentiated the 25% and 100% choline dietary groups with variable importance to projection (VIP) \>1 and p-value \< 0.05 are reported. The signals for these metabolites were matched by retention time, exact mass, and MS/MS to standards run on the same platform. Because this is a differential profiling method (not quantitative), the mean and standard deviation of peak intensities detected on the untargeted platform are reported. Results are reported for the selected metabolites for the 25%, 50%, and 100% choline dietary groups. Ratios can be obtained by division of the intensity data.
At the end of 2 weeks of respective Cho diet
Comparison of Choline Pool Size Between Participants With Different Genotypes in Phosphatidylethanolamine-N-methyltransferase (PEMT) Single Nucleotide Polymorphism (SNP rs12325817)
DNA was collected and evaluated for the presence of the PEMT SNP rs12325817. Genotypes was measured by real time polymerase chain reaction (RT-PCR). The magnitude of changes in choline pool size as measured by IER at the end of each dietary intervention was compared among subjects with different genotypes in the PEMT SNP. Linear mixed model with repeated measures was performed for each group (healthy males, pre- and postmenopausal females) separately to study the genotype effect and genotype x diet interaction effect on choline pool size.
24 hours following administration of choline-d9 on day 12 of respective dietary intervention
Change in Liver Fat Content Based on CAP Values
Controlled attenuation parameter (CAP) as measured by Fibroscan is an ultrasound-based technique to measure liver fat. This method will be used with other biomarkers to indicate functional signs of choline status.
Day 1 and Day 15 of respective Cho diet

Secondary Outcomes (1)

Validation of Isotope Dilution Method to Assess Choline Pool Size by Magnetic Resonance Spectroscopy (MRS)
At the end of 2 weeks of respective Cho diet

Other Outcomes (1)

SNPs That Create Inefficiencies in Choline Metabolism Associated With Change in Choline Pool Size and Choline Biomarkers
At baseline visit

Study Arms (6)

25%Cho, 50%Cho, 100%Cho

EXPERIMENTAL

Diets containing 137.5mg (25% Cho diet), 275mg (50% Cho diet), and 550mg (100% Cho diet) will be given in that order for two weeks each with 2 weeks of washout between.