Provider Bios

Dr. Steven Zorn, M.D.

Dr. Steven Zorn, M.D.

Fellow, American Academy of Sleep Medicine Diplomate, ABIM

Sleep Medicine

Dr. Steven Zorn is the founder of Iowa Sleep and is Board Certified in Sleep Medicine, as well as Pulmonary Medicine and Internal Medicine.  A graduate from the University of Wisconsin, Dr. Zorn completed his internal medicine residency and fellowship at the Cleveland Clinic.  As a Pulmonary Fellow at Yale University Medical School, he received a NIH research fellowship award.

With over 25 years of experience in sleep medicine & treatment, Dr. Zorn’s philosophy is that every patient should know as much as possible about their sleep condition.  Information and understanding always improves outcomes.

Dr. Zorn has been awarded memberships in the Delta Chi Sigma Honorary Science and Mathematics Fraternity, the American College of Chest Physicians, the American College of Physicians, the American Thoracic Society, and the American Academy of Sleep Medicine.  He has published articles in the journals of Geriatrics, American Review of Respiratory Disease, Thorax, Lung, Clinical Research, and the CRC Handbook Series of Clinical Laboratory Science.

Dr. Zorn enjoys lecturing, both locally and nationally.  He has delivered lectures on a variety of sleep issues to the Des Moines and West Des Moines School Districts, Des Moines University, Grinnell College, civic, business and community groups. Dr. Zorn has also been featured on local TV and radio stations and in The Des Moines Register. He is married, and has one son.


Dr. Stephen B. Grant, M.D.

Dr. Stephen B. Grant, M.D.

Diplomate, ABIM

Sleep Medicine

Dr. Grant joined Iowa Sleep in 2009 after completing a combined Internal Medicine/Psychiatry residency at Dartmouth Hitchcock Medical Center in Lebanon, New Hampshire. Dr. Grant served with distinction, having been elected Chief Resident in both his specialties. After an additional year as Chief Resident in Internal Medicine, he completed a formal Fellowship in Sleep Medicine at Dartmouth, then relocating to Des Moines Iowa to join Iowa Sleep.

Dr. Grant received his B.A. from the University of Colorado, Boulder CO and hIs M.D. from the University of Colorado Health Sciences Center in Denver CO. Dr. Grant is a Sleep Fellowship-trained physician, board-certified in Sleep Medicine and Internal Medicine with both board certifications held under the American Board of Internal Medicine (ABIM). Dr. Grant holds board eligibility in Psychiatry (ABPN). Among associations that Dr. Grant is an active member include the American Academy of Sleep Medicine, the American Medical Association, the American Psychiatric Association and the Association of Medicine and Psychiatry.

Dr. Grant has great passion for his work and the care of his patients. He has been recognized for that work with the Martin Fenton Award for excellence in medicine and psychiatry, as well as an Excellence in Teaching Award for the Dartmouth Medical School.

Dr. Grant proudly serves in the Iowa Air National Guard and truly enjoys caring for America’s heroes—active duty and prior service veterans. Dr. Grant participates in a number of national and local speaking engagements including seminars, radio shows, business leadership forums and conferences. Dr. Grant is married with 5 children and enjoys raising his family in Iowa.


Diedre Benson, ARNP

Diedre Benson, ARNP

Sleep Nurse Practitioner

Diedre (Dede) Benson joined Iowa Sleep in 2012 after an extensive work history in Cardiology and Electrophysiology.  Since then she has taken comprehensive course work and training in Sleep Medicine.  She received her Bachelor of Science degree in Nursing from Grand View College (now Grand View University) as a member of the first graduating class of baccalaureate nurses.  Dede later received her Master of Science in Nursing from the University of Illinois at Chicago as a clinical nurse specialist and advanced practice nurse in adult health.

She has been licensed as an Advanced Registered Nurse Practitioner in adult health since 2003.  Dede is a member of the American Academy of Sleep Medicine.  She has given many presentations to local community groups and health care groups on various topics in sleep medicine.

Dede’s passion in excellence of patient care and education, enables her to be a strong advocate in bringing awareness of the frequency and complications of unrecognized sleep disorders to her patients. 

Dede has four adult children in whom she takes exceptional pride:  two are physicians, one is in business management, and the youngest is a social worker.  She takes great delight in her growing number of grandchildren.


Carol Smith, PA-C

Carol Smith, PA-C

Physician Assistant

Carol Smith joined Iowa Sleep in July 2015 with over 20 years experience as a Physician Assistant. She received her physician assistant training through Des Moines University. Since becoming a PA, Carol has specialized in Family Practice/Urgent Care, Gastroenterology and Women's Health. Prior to becoming a PA, Carol worked as a critical care RN in ICU/CCU, Post Anesthesia Recovery, Dialysis and the Cardiac Cath Lab. Carol completed her nurse's training at Santa Rosa Junior College in California.

Carol maintains her PA-C certification through the National Commission on Certification of Physical Assistants by completing periodic testing and annual education requirements. She has attended advanced medical training courses in Sleep Medicine through the American Association of Sleep Medicine (AASM), Atlanta School of Sleep Medicine, and The Institute for the Advancement of Human Behavior. Carol is a member of AASM, The Iowa Sleep Society, and the Society of Behavioral Sleep Medicine. 

Carol's passion for medicine began early in life and has stayed strong. She enjoys spending time listening to her patients, gaining knowledge of their concerns, and helping them find answers to their needs. Carol is married, has an adult daughter and has been an Ankeny resisdent for over 15 years. 


Iowa Sleep helped me understand what was really happening to my body and the different ways to treat it. I am impressed with their knowledge and caring.