Instructor in Medicine
Endocrinology, Metabolism and Lipid Research
Washington University School of Medicine
Carlos Bernal-Mizrachi, M.D. and Victor G. Davila-Roman, M.D.
Amy was raised in New Hampshire and moved to Wisconsin with her family to finish high school. She received a B.S. in biochemistry and molecular biology at the University of Wisconsin in Madison in 2001. She attended Washington University in St. Louis for medical school and stayed on to train in Internal Medicine at Barnes-Jewish Hospital. Her first experience with clinical research was when she worked with Dr. Garry Tobin on a study examining the effectiveness of a standardized insulin protocol for inpatients on a surgical service that was published in Endocrine Practice and has now become the standard of care for Barnes-Jewish Hospital. Because of her previous clinical experience with vitamin D deficiency and past work in calcium regulation, Dr. Riek joined the lab of Dr. Bernal-Mizrachi to investigate the relationship between vitamin D deficiency and cardiovascular disease. Her work during the fellowship led to a successful application for the KL2 Career Development Program. In 2011, Dr. Riek completed her fellowship in Endocrinology and Metabolism at Washington University in St. Louis. After fellowship, she was offered a position to stay on as faculty as an Instructor of Medicine in the Division of Endocrinology, Metabolism, and Lipid Research.
Vitamin D is well-recognized for its role in calcium homeostasis through its effects on intestinal calcium absorption and osteoclast stimulation. Less well-recognized, however, are the additional targets of vitamin D in many other tissues, including the heart and vascular system, which may have implications in the management of vascular disease and atherosclerosis. The actions of vitamin D are mediated by vitamin D receptor (VDR), a nuclear receptor which binds 1α, 25-dihydroxcholecalciferol, and interacts with vitamin D response elements to alter the expression of their target genes. We are currently using animal models to determine the role of vitamin D in vascular disease.
Awards and Honors
Dr. Riek has competed successfully for support from the Endocrine Fellows Foundation and won the $50,000 Lilly Endocrine Scholars Award from the Endocrine Society. In 2011, She was awarded a highly competitive KL2 Career Development Award through the WUSM Institute of Clinical and Translational Sciences (ICTS). Dr. Riek completed the courses required for the Master of Science in Clinical Investigation degree, which was conferred in December of 2012. She was selected as a 2009 recipient of the Knowlton Incentive for Excellence Award. The Knowlton Fund recognizes five internal medicine house staff physicians each year who best exemplify balancing compassionate care with a dedication to the science of internal medicine.
Vitamin D and Immune Biomarkers of Cardiovascular Disease in Women with Type 2 Diabetes
African American (AA) women have nearly twice the risk of developing type 2 diabetes mellitus (T2DM) and increased morbidity and mortality from cardiovascular disease (CVD) compared with Caucasian American women; however, the etiology of this increased susceptibility is unclear. Vitamin D deficiency is more prevalent in AA women and in patients with T2DM and is associated with excess CV mortality. Our recent studies show that monocytes from diabetic patients with vitamin D deficiency have atherogenic properties with increased adhesion and migration and a membrane receptor phenotype characteristic of the M2 monocyte subtype. In a mouse model of diabetes, absence of the vitamin D receptor in monocytes/macrophages induces atherosclerosis and atherogenic monocyte characteristics. Furthermore, gene expression arrays from macrophages of these mice indicate significantly increased expression of the activator protein 1 (AP-1) family of transcription factors, which are critical in the regulation of inflammation and cell differentiation, proliferation, and apoptosis, all critical pathways for atherosclerosis progression. This proposal is an ancillary study to our ongoing randomized clinical trial in AA with vitamin D deficiency and T2DM evaluating the effects of vitamin D supplementation, 4000 IU/day (high dose) vs. 600 IU/day (standard dose), for one year on markers of subclinical CVD (carotid intima-medial thickness and brachial artery reactivity testing), systemic inflammatory markers, and monocyte properties including adhesion, migration, and membrane receptor phenotype. Aim 1 of this ancillary study will identify novel pathways that explain the CV and inflammatory effects of high vs. standard dose vitamin D supplementation on AA women with T2DM. Microarray profiles will be performed in monocytes from a sub-cohort of 15 women per group at baseline and after one year of vitamin D treatment to identify differentially expressed pathways and correlate these genes with changes in CV and monocyte outcomes from the parent study. Aim 2 will quantify baseline expression of monocyte genes of interest identified in Aim 1 for all women in the parent study to determine whether they predict progression of markers of CVD in the standard dose vitamin D group and/or CV responsiveness to vitamin D in the high dose vitamin D group. This project will enable me to develop the skills to progress toward my long-term research goal, to learn multiple branches of bioinformatics techniques in order to integrate them with clinical outcomes to identify novel pathways and possible treatment targets contributing to the increased risk of CVD in women with T2DM.