1Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA

2Division of Clinical Trials and Biostatistics, Mayo Clinic, Rochester, MN, USA

3Department of Pharmacy, Mayo Clinic, Rochester, MN, USA

4Department of Urology, Mayo Clinic, Rochester, MN, USA

5Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA

aCorresponding author: Andrew D. Rule, MD, MSc, 200 First Street SW, Rochester, MN, 55905, USA, Phone: 507-266-1045, Fax: 507-266-7891, E-mail: [email protected]