BENJAMIN W. Van TASSELL, PHARM.D
Experimental Cardiovascular Pharmacotherapy Fellow
Department of Pharmacotherapy, College of Pharmacy, University of Utah

Proposed Research Report

AFPE Award: Pfizer–AFPE Clinical Pharmacy Post-Pharm.D. Fellowship in the Biomedical Research Sciences

Major Advisor: Mark A. Munger, Pharm.D., FCCP

Major Advisor Title: Professor, Pharmacology and Internal Medicine, University of Utah

Title of Research: "The Effects of Calcitriol in Renin Expression in Hypertensive Patients without Vitamin D Deficiency"

Research Aims:

(1) Compare plasma renin activity (PRA) and plasma renin concentration (PRC) in hypertensive patients (JNC VII stage I) following 14
days treatment with calcitriol (1a, 25-[OH]2 vitamin D3) or matched placebo.

(2) Compare mononuclear leukocyte renin transcription (mRNA) between calcitriol and matched placebo.

(3) Measure hemodynamic changes (daytime, evening, and 24 hour SBP, DBP, MBP, and HR) and inflammatory markers between
calcitriol and placebo.

(4) Determine if VDR gene polymorphisms impact the calcitriol effects on renin transcription and cardiovascular hemodynamics.

Studies and Results:

This will be a randomized, double-blind, placebo-controlled, double-dummy, experimental crossover study. Enrolled subjects will have stage I
hypertension after discontinuation of anti-hypertensive medications. Following enrollment, each subject will undergo a baseline 24-hour renin
assessment (see Doctor’s Orders) to measure PRA, PRC, renin mRNA, and 24-hour blood pressure. Blood for VDR genotyping will also be
drawn at this baseline 24-hour renin assessment. Upon completion of baseline 24-hour renin assessment, subjects will be randomized to 2-
weeks oral therapy with calcitriol 1 mcg daily or placebo. Subjects will then return to the GCRC for a second 24-hour renin assessment
(endpoint measurement for first treatment). Subjects will then enter a 1-week washout before crossover to 2-weeks therapy with the alternate
treatment arm, either calcitriol or placebo. Upon completion of the second treatment, subjects will return to the GCRC for a third 24-hour renin
assessment (endpoint measurement for second treatment).

The primary endpoints will be a change from baseline in PRA, PRC, and renin mRNA concentrations at 6-hours post-dose with 1a, 25-(OH)2
vitamin D3 (calcitriol) versus placebo. Sample size calculation is derived from previous reports of PRA reduction in ESRD patients treated with
calcitriol. Based on a t test for paired data (normally distributed data), n=10 subjects crossed-over to both treatment arms will provide 80%
power, with alpha=0.05, using a two-sided comparison, to detect a 25% reduction in PRA. To provide for approximately 20% reduction in
evaluative subjects, due to dropouts or losses-to-follow-up, we will enroll a total sample of n=12 subjects. If necessary, Mann-Whitney U test
will be used for skewed data. Baseline demographics will be characterized by descriptive statistics. All statistical tests will be preformed with
alpha = 0.05.

Secondary endpoints include comparisons versus baseline of PRA and PRC at 0, 1, 3, 10, and 24 hours post-dose, PRA area-under-the-curve
(PRA-AUC), mean 24-hour systolic blood pressure, mean 24-hour diastolic blood pressure, mean 24-hour arterial pressure, mean 24-hour heart
rate, systolic blood pressure-heart rate double product, serum calcium, serum vitamin D, and serum PTH between 1a, 25-(OH)2 vitamin D3
(calcitriol) and placebo. Continuous variables will be evaluated with t tests for paired data with appropriate correction employed for multiple
comparisons. The impact of VDR polymorphisms and demographics on PRA, PRC, and mRNA, and hemodynamic end points will be modeled
by regression analysis.

Significance:

Vitamin D deficiency is associated with cardiovascular disease, through up-regulation of the renin-angiotensin system. Animal models suggest
a therapeutic role for vitamin D as a direct inhibitor of renin transcription. Although epidemiologic studies report conflicting results, the
cardiovascular effects of vitamin D treatment (beyond supplementation for vitamin D deficiency) have not been explored in human subjects.
This study will measure PRA, PRC, and renin mRNA following two weeks treatment with activated vitamin D (calcitriol). Genetic polymorphisms
in the vitamin D receptor (VDR) may also affect renin transcription; patients will therefore be genotyped for several common VDR
polymorphisms.

Training Activities:

The goal of the Experimental Cardiovascular Pharmacotherapy Fellowship at the University of Utah is to provide intense training in translational
research in preparation for a career dedicated to academia. Directed by Mark A. Munger, PharmD, FCCP, the fellowship follows the guidelines
of the Research Fellowship Training Programs set forth by the American College of Clinical Pharmacy. As primary preceptor, Dr. Munger
maintains direct oversight of all fellowship activities. The fellowship focuses on cardiovascular pathophysiology and therapeutics, following
interventions from the genome to the bedside, and from the clinic to public health policy. Fellowship training also includes graduate level
coursework in statistics and epidemiology, research ethics, and research design.

Training in Biostatistics and Epidemiology is overseen by Gregory Stoddard, MS, Head of Biostatistics in the Department of Clinical
Epidemiology. Coursework includes three 15-hour lecture series combined with real-time training and data analysis with Stata 9.0 statistical
software (Computer Practicum, MD CRC 6030). Course topics in Introduction to Biostatistics (MD CRC 6000) include variable description, logic
of significance tests, power analysis, multiplicity, correlation, linear regression, overfitting, equivalence tests, logistic regression, and Cox
regression. Course topics in Introduction to Epidemiology (MD CRC 6010) include component cause theory, causal criteria, logic and errors,
effect measures, study design, bias and confounding, random error, crude analysis, and stratified analysis. All three classes meet weekly for
lecture and data analysis in small group (2 students) sessions. This curriculum is part of the University of Utah NIH K30 program.

Training in research design and research ethics are taught in conjunction with the School of Medicine and Department of Philosophy as a
graduate courses (PHIL 7570 Case Studies and Research Ethics and PHTX 6600 Methods of Pharmacology). Designed for graduate students,
post-doctoral fellows, and other faculty, PHIL 5750 consists of weekly discussions addressing topics such as research integrity, scientific fraud,
conflicts of interest, plagiarism, and authorship designation. The PHTX 6600 course is designed to provide students with design of
pharmacological experiments and statistical evaluation of experimental observations.

Fellows also participate in professional student (Pharm.D.) didactic teaching and advanced pharmacy practice clerkship teaching within the
Department of Pharmacotherapy. Didactic teaching involves 3 – 5 lectures per year (2 hours each) on cardiovascular topics in the Therapeutics
series (PTCH 7322). Clerkship teaching involves 1 – 2 hour daily topic discussions with students during a single 6-week rotation blocks and
oversight of the students in the clinics. Teaching responsibilities represent less than 5% of total time dedicated to the fellowship.

Other Support:

Part of this research will be carried out at the Huntsman Clinical Research Center at the University of Utah Medical Center. The Huntsman
Clinical Research Center is supported by Public Health Service research grant No. M01-RR00064 from the National Center for Research
Resources (NCRS).