Determinants of Alpha-aminoadipic Acid (2-AAA) and Relationship to Diabetes: Study 2

Diabetes is an important health concern worldwide. It is associated with significantly increased mortality as well as high incidence of co-morbidities. Unfortunately, treatment efficacy and successful disease management is highly variable among treated patients, and this is partly due to the fact that diabetes has multiple underlying causes most of which are still unknown. A newly identified biomarker, α-aminoadipic acid (2-AAA), has the potential to successfully predict the development of diabetes in humans, even before the development of other known risk markers. However, little is known about the function of 2-AAA; it is unclear whether 2-AAA itself causes the development of diabetes or if it is a biomarker for altered metabolic processes that then lead to diabetes.

The aim of the first phase of the study was to measure plasma 2-AAA levels from healthy individuals from the general population to identify subjects with high or low 2-AAA. Now in the second phase of the study, 80 subjects with high or low 2-AAA will be invited to participate in a dietary lysine modification study to access the effect of controlled lysine intake on plasma and urine 2AAA. Participants will be asked to complete two one-week dietary interventions. Subjects will be screened and consented via email, online, or phone. Each subject will be required to come to Vanderbilt University Medical Center for four study visits, at which the study team will obtain a blood sample, a urine sample, stool sample, vital signs, waist and hip circumference, and 1-3 surveys will be completed if the subject did not complete them prior to the visit. Each subject that completes the entire study visit will be compensated $250. DNA samples will be obtained to allow for identification of genetic predictors of 2-AAA levels. Some individuals may be asked to return for a future follow-up study.

Inclusion criteria

• Prior participant in 2-AAA screening study.
• Identified as eligible due to high or low plasma 2-AAA, in the absence of hyperglycemia, as defined by study team.

Exclusion criteria

• Individuals who currently use tobacco products.
• Use of prescription or over-the-counter medications or dietary supplements which could modulate levels of 2-AAA and unwilling to discontinue use (from 24 hours prior to first study visit until completion of study). Hormonal birth control is acceptable.
• Follow a severely restricted diet or have food allergies, which would preclude adherence to study diet.
• Newly diagnosed disease (since screening visit), including cardiovascular, renal, or liver disease, or Diabetes mellitus.
• Individuals who are pregnant or lactating
• Inability to provide written or electronic informed consent
• Inability to fast for 8 hours