Clinical trial NCT03726671: Choline Nutritional Status: Development of a Biomarker Panel
Official title: Choline Nutritional Status: Development of a Biomarker Panel
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Healthy
Lead sponsor: University of North Carolina, Chapel Hill
Sponsor class: OTHER
Collaborators: name: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
First posted: 2018-10-31
Enrollment: 101
Sex: ALL
Minimum age (years): 17
Maximum age (years): 70
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Healthy volunteers will consume meals, provided by the investigator, in two week intervals with 3 different levels of choline (Cho). Participants will receive 100% of the recommended daily intake (RDI) of Cho (550 mg Cho/day); 50% of the RDI of Cho (275mg/day); and 25% of the RDI of Cho (137.5 mg/day). The meal order will be randomly assigned and all participants will receive all diets at some point in the study. There will be a minimum of a two week washout between diet intervals where participants return to their regular diets. Both participants and researchers will be blinded to the diet order.
Primary purpose: SCREENING

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.

Detailed description: Choline (Cho) is an essential nutrient and most Americans' diets do not achieve the recommended intake. Diets low in Cho are associated with liver and muscle disease and with suboptimal fetal development, while diets too high in choline may be associated with increased risk for heart disease. Cho is a required nutrient and in 1998, an Adequate Intake (AI) and a Tolerable Upper Limit (UL) for Cho was established In 2016, the US Food and Drug Administration (FDA) set a Recommended Daily Intake (RDI) for Cho based on the AIs as part of the new Nutrition Facts label for packaged foods (published in the Federal Register on May 27, 2016; FDA-2012-N-1210-0875, Federal Register Number:2016-11867). The AI/RDI varies by age and gender, but is 550 mg/d in adolescent and adult men and 425 mg/d in adult women (more in pregnant and lactating women) and 400 mg/day for adolescent women.

There is no validated biomarker for choline status (the availability of the various forms of Cho needed to sustain optimal cellular function). Measurement of plasma Cho concentrations is not adequate as plasma choline is homeostatically regulated. Based on extensive preliminary and published data this group identified a panel of potential biomarkers that could be used to assess Cho status, and now the investigators propose to validate this biomarker panel against measures of Cho pool size using isotope dilution. The largest stores of Cho are located in the liver, and mass resonance spectroscopy (MRS) of liver has been used in the past to assess Cho status in humans. This method is not practical for use as a biomarker in clinical or public health practice as it is expensive and the availability of the instrumentation is limited. However, the MRS can be utilized to confirm correlations between the biomarker panel and the isotope dilution method. Liver biopsy is risky and not practical, making measurement of hepatic Cho and Cho metabolites concentrations a poor choice for assessing Cho status.

Perhaps there is a panel of biomarkers that together will more accurately and reliably reflect Cho status. By making measurements in people fed 3 different dietary amounts of Cho for two weeks at a time, and comparing the biomarker measures to body total Cho pool size assessed using isotope dilution (a proxy for the availability of the various forms of Cho), investigators will be able to identify the combination of biomarkers and algorithm for calculating a Cho status score that best predicts total Cho pool size, and therefore predicts choline nutritional status (the availability of the various forms of Cho needed to sustain cellular function). People who eat diets low in choline should deplete their choline (Cho) stores, and measurement of Cho pool size using isotope dilution should reflect this depletion. The investigators will identify a biomarker panel that correlates well with measured Cho pool size across the range of different degrees of depletion. This study tests a method for using stable isotope dilution to measure body choline stores, and then asks how this measure correlates with a panel of biomarkers in plasma and with liver fat measured using Fibroscan®. Using isotope dilution can provide an estimate of the size of the body pool of Cho. The investigators' proposed method is conceptually similar to the method for measuring total body water from a bolus dose of labeled water. Similar methodology was used recently in studies of metabolic flux of Cho in pregnant women. Isotope dilution is a well-established method used to estimate pool size for other nutrients, such as vitamin A. Similar to vitamin A, the major storage pools for Cho are in the liver, and ingested Cho is rapidly absorbed and accumulated by liver. MRS/MRI scans will also be performed to investigate correlation between these "gold standard" measures and the other methods described above.

Participants will consume meals provided in two week dietary intervals with 3 different levels of choline with a 2 week washout periods between those dietary intervals. Participants will receive 100% of the recommended intake (RDI) of Cho (550mg Cho/day); 50% of the RDI of Cho (275mg/day); and 25% of the RDI of Cho (137.5mg/day). The meal order will be randomly assigned and all participants will receive all diets at some point in the study. There will be a minimum of a two week washout between diet intervals. Both participants and researchers will be blinded to the diet order.

Participants will have brief exercise challenges (Biodex) to assess muscle function as an additional predictor of choline status.

Participants enrolled prior to 3/2020 completed MRI/MRS scans. We have determined that Fibroscan provides adequate measurement of liver fat such that we eliminated the added inconvenience to participants of travel to Winston-Salem for MR scanning.

Saliva, stool, and urine samples will be collected.

Eligibility criteria: Inclusion Criteria:

* Provision of signed and dated informed consent form
* Weigh 130-177lbs (or if over 177 must have BMI under 28)
* Stated willingness to comply with all study procedures and availability for the duration of the study
* Male or female, aged 17-70 years
* In good general health as evidenced by medical history, clinical chemistries, physical exam, and BMI≤ 30 or if over 177lbs with a BMI under 28
* Women who are included in the study and are of pregnancy potential will have a urine pregnancy test at the beginning and end of each dietary intervention arm and must be using some form of birth control during the study.

Exclusion Criteria:

* using drugs or medication known to be damaging to liver or muscle at typically prescribed doses or that have the potential to alter Cho metabolism (e.g., methotrexate);
* history of hepatic, renal, or other chronic systemic disease.
* subjects with liver abnormalities (e.g.cysts) as determined by ultrasound
* current smokers
* consume \>2 alcoholic beverages/d or \>14/wk
* substance abusers or drug addicted
* eating unusual diet that would interfere with the study
* food allergies, (e.g., soy) or any problems with eating all foods on required study diet
* using Cho-containing dietary supplements
* women who are breastfeeding, pregnant, or plan to become pregnant due to potential risk to fetus/child of low choline diet
* performing intense exercise of more than 1 hour a day or other intense muscle building exercise (such as weightlifting beyond low weight repetitions)
* Actively participating in other research study where required to exercise or ingest any food, medicine, or supplement in any manner
* have been screened for this study between August and March and have not provided proof of flu vaccination prior to enrollment

Primary outcomes:
measure: Ratio of Liver Choline Pool Size by Isotope Dilution
timeFrame: 24 hours following administration of choline-d9 on day 12 of respective dietary intervention
measure: Difference in Choline Deficiency Signature
timeFrame: At the end of 2 weeks of respective Cho diet
measure: Comparison of Choline Pool Size Between Participants With and Without Choline Metabolites Signature During Cho Depletion
timeFrame: 24 hours following administration of choline-d9 on day 12 of 25% Cho diet
measure: 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
timeFrame: At the end of 2 weeks of respective Cho diet
measure: Comparison of Choline Pool Size Between Participants With Different Genotypes in Phosphatidylethanolamine-N-methyltransferase (PEMT) Single Nucleotide Polymorphism (SNP rs12325817)
timeFrame: 24 hours following administration of choline-d9 on day 12 of respective dietary intervention
measure: Change in Liver Fat Content Based on CAP Values
timeFrame: Day 1 and Day 15 of respective Cho diet
Secondary outcomes:
measure: Validation of Isotope Dilution Method to Assess Choline Pool Size by Magnetic Resonance Spectroscopy (MRS)
timeFrame: At the end of 2 weeks of respective Cho diet
Other outcomes:
measure: SNPs That Create Inefficiencies in Choline Metabolism Associated With Change in Choline Pool Size and Choline Biomarkers
timeFrame: At baseline visit
Locations:
city: Kannapolis
country: United States
facility: UNC Chapel Hill Nutrition Research Institute
state: North Carolina
Study officials:
affiliation: UNC Chapel Hill - Nutrition Research Institute
name: Steven H. Zeisel, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Horita DA, Hwang S, Stegall JM, Friday WB, Kirchner DR, Zeisel SH. Two methods for assessment of choline status in a randomized crossover study with varying dietary choline intake in people: isotope dilution MS of plasma and in vivo single-voxel magnetic resonance spectroscopy of liver. Am J Clin Nutr. 2021 Jun 1;113(6):1670-1678. doi: 10.1093/ajcn/nqaa439.