NCT00071526 Urinary Vitamin C Loss in Diabetic Subjects
| NCT ID | NCT00071526 |
| Status | Recruiting |
| Phase | — |
| Sponsor | National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) |
| Condition | Diabetes |
| Study Type | OBSERVATIONAL |
| Enrollment | 5,000 participants |
| Start Date | 2006-04-11 |
| Primary Completion | — |
Eligibility & Interventions
Eligibility Fast-Check
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What to Expect as a Participant
This is an observational study. You will not receive an experimental treatment; researchers will collect data based on your existing condition or standard treatment.
This trial targets 5,000 participants in total. It began in 2006-04-11.
⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.
Brief Summary
Several studies have reported that diabetic subjects have lower plasma vitamin C concentrations than non-diabetic subjects. Although urinary vitamin C loss in diabetic subjects was reported to be increased in two studies, these are difficult to interpret due to lack of controlled vitamin C intake, inadequate sampling, lack of control subjects, or methodology uncertainties in vitamin C assay and sample processing. Consequently, it is unclear whether diabetic subjects truly have both low plasma and high urine vitamin C concentrations. We propose that low plasma vitamin C concentrations in diabetic subjects are due in part to inappropriate renal loss of vitamin C in these subjects but not in healthy controls. We will study nondiabetic controls and cohorts with diabetes. Vitamin C concentrations in plasma, RBCs, and urine will be measured in outpatients. In those willing to be admitted to the Clinical Center, we will measure vitamin C pharmacokinetics to determine the relative bioavailability for vitamin C in individuals with and without abnormal urinary loss of vitamin C (or renal leak). Single nucleotide polymorphisms (SNPs) will be determined in genomic DNA responsible for the two proteins mediating sodium dependent vitamin C transport, SVCT1 and SVCT2. We will also explore mechanisms underlying abnormal urinary vitamin C loss.
Eligibility Criteria
* INCLUSION CRITERIA: To be included in the study, study subjects should be: * Aged 18-65 years. * Either: * Have no diagnosis of diabetes: "nondiabetic controls", or * Have a diagnosis in their medical history of either Type 1 or Type 2 diabetes EXCLUSION CRITERIA (for outpatient study, arm 1) Exclusion criteria will include the following: * Unable or unwilling to provide a signed and dated informed consent form * Unable or unwilling to comply with study procedures and lifestyle considerations EXCLUSION CRITERIA (for inpatient studies, arms 2 and 3) Study participants interested in participating in Arms 2 and/or 3 will be excluded from this further participation if they meet any of the following: * significant organ malfunction leading to clinical instability including liver disease, pulmonary disease, ischemic heart disease, heart failure, stroke, peripheral vascular disease, and anemia at investigator discretion * other serious or chronic illness; history of serious or chronic illness; coronary artery disease, or peripheral vascular disease resulting in clinical instability * pregnancy or lactation * presence of other conditions which, in the judgment of the investigators, can influence vitamin C metabolism or vitamin C renal handling
Contact & Investigator
Ifechukwude C Ebenuwa, M.D.
PRINCIPAL INVESTIGATOR
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Frequently Asked Questions
Who can join the NCT00071526 clinical trial?
This trial is open to participants of all sexes, aged 18 Years or older, up to 65 Years, studying Diabetes. Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.
Is NCT00071526 currently recruiting?
Yes, NCT00071526 is actively recruiting participants. Contact the research team at razi.berman@nih.gov for enrollment information.
Where is the NCT00071526 trial being conducted?
This trial is being conducted at Bethesda, United States.
Who is sponsoring the NCT00071526 clinical trial?
NCT00071526 is sponsored by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). The principal investigator is Ifechukwude C Ebenuwa, M.D. at National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). The trial plans to enroll 5,000 participants.
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