Eastern Colorado Geriatric Research, Education and Clinical Center (EC-GRECC) - VA Eastern Colorado Health Care System
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Eastern Colorado Geriatric Research, Education and Clinical Center (EC-GRECC)


Eastern Colorado GRECC Investigators

30 December 2020


Sean Iwamoto, MD
Title: Assistant Professor of Medicine, Endocrinology
Contact: sean.iwamoto@cuanschutz.edu
Personal Statement
Transgender (trans) people have a gender identity that does not align with their sex assigned at birth. Many trans people experience distress associated with this gender incongruence, known as gender dysphoria. Health care disparities among trans people are prevalent and related to gender dysphoria, fears of discrimination and many other barriers. There is increasing research around the world to better understand the basis for and evaluate solutions to reduce differential health outcomes based on gender identity.
As an early career endocrinologist, my trajectory in academics is to explore the impacts of aging, obesity and gender-affirming hormone therapy (GAHT, or using sex hormones of the affirmed gender) on cardiometabolic risk in trans people. My current research on vascular endothelial function and aging in trans women will provide preliminary data for further investigations on the effects of sex steroids in trans as well as cisgender (cis) people, individuals whose gender identity aligns with their sex assigned at birth. My interest in trans health outcomes research, though in its infancy, has a foundation in years of volunteer work within the trans and other sexual/gender minority communities. Over the years, I have heard from trans patients about continued stigma within medicine regarding access to culturally sensitive and comprehensive care. These patients deserve evidence-based best practices for health care delivery, particularly in the setting of GAHT, which has been associated with an increased risk of cardiovascular disease (CVD) and venous thromboembolism in trans women.
In September 2017, I co-founded the UCHealth Integrated Transgender Program (ITP) with my mentor, Dr. Micol Rothman, and other specialists in psychiatry, internal medicine, gynecology and plastics and reconstructive surgery, to provide safe and comprehensive care to our trans patients during a single clinic visit within the Endocrinology Clinic. ITP has also been involved in educating providers, staff and learners across the hospital system and within the community. We received a 2018 University of Colorado President’s Diversity & Inclusive Excellence Grant to hold a Provider Education Day in November 2018 about managing trans patients. We have also begun collecting qualitative (e.g., patient and provider needs assessments, focus groups and surveys) and quantitative (e.g., Pap test and other cancer screening compliance, smoking cessation rates, hormone monitoring, body mass index [BMI] and body composition changes, laboratory trends, pre-/post-Provider Education Day knowledge differences) data. As our clinic demand has increased, we hope to establish a Community Advisory Board to engage community stakeholders in developing ideas for future research collaborations and participant recruitment. We are also establishing a registry of trans patients at the University of Colorado and will collect prospective data on health outcomes (i.e., metabolic parameters, bone mineral density and mental health).
To learn more about trans health research, I worked with Dr. Guy T’Sjoen (Ghent University Hospital, Belgium) and Dr. Martin den Heijer (Amsterdam University Medical Center, the Netherlands) as part of a 2017 American Association of Clinical Endocrinologists/American College of Endocrinology Dr. Lewis E. Braverman Educational Fund Travel Grant. Both are clinician researchers, endocrinologists and primary investigators of the European Network for the Investigation of Gender Incongruence (ENIGI), the first collaboration to create a multicenter, multinational, standardized treatment and follow up protocol to prospectively investigate the effects of GAHT in trans people. Since then, we have collaborated on a workshop about GAHT outcomes at the European Professional Association for Transgender Health in April 2019 and submitted a narrative review manuscript on feminizing GAHT. I have also submitted a proposal to conduct subgroup analyses on existing ENIGI data to see if/how BMI and age influence various health outcomes in that cohort of patients.
In summary, I hope to establish myself as an advocate and part of a new wave of academic physicians who are dedicated to improving health care and outcomes for trans patients through clinical translational research, particularly with a focus on obesity and aging, and fostering more international collaborations.

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Recent Publications


Walch A, Davidge-Pitts C, Safer JD, Lopez X, Tangpricha V, Iwamoto SJ. Proper Care of Transgender and Gender Diverse Persons in the Setting of Proposed Discrimination: A Policy Perspective. J Clin Endocrinol Metab. 2020 Dec 16:dgaa816. doi: 10.1210/clinem/dgaa816. Epub ahead of print.
PMID: 33326028.

Defreyne J, Vanwonterghem Y, Collet S, Iwamoto SJ, Wiepjes CM, Fisher AD, Schreiner T, Heijer MD, T'Sjoen G. Vaginal bleeding and spotting in transgender men after initiation of testosterone therapy: A prospective cohort study (ENIGI). Int J Transgend Health. 2020 Feb 12;21(2):163-175.
PMID: 32935087; PMCID: PMC7489282.

Iwamoto SJ, Rothman MS, Duan S, Baker JC, Mumm S, Whyte MP. Early-onset Paget's disease of bone in a Mexican family caused by a novel tandem duplication (77dup27) in TNFRSF11A that encodes RANK. Bone. 2020 Apr; 133:115224.
PMID: 31923705.

Saxon DR, Iwamoto SJ, Mettenbrink CJ, McCormick E, Arterburn D, Daley MF, Oshiro CE, Koebnick C, Horberg M, Young DR, Bessesen DH. Antiobesity Medication Use in 2.2 Million Adults Across Eight Large Health Care Organizations: 2009-2015. Obesity (Silver Spring). 2019 12; 27(12):1975-1981.
PMID: 31603630.

Iwamoto SJ, Defreyne J, Rothman MS, Van Schuylenbergh J, Van de Bruaene L, Motmans J, T'Sjoen G. Health considerations for transgender women and remaining unknowns: a narrative review. Ther Adv Endocrinol Metab. 2019; 10:2042018819871166.
PMID: 31516689.

Saxon DR, Chaussee EL, Juarez-Colunga E, Tsai AG, Iwamoto SJ, Speer RB, Heyn H, Kealey EH, Bessesen DH. A Toolbox Approach to Obesity Treatment in Urban Safety-Net Primary Care Clinics: a Pragmatic Clinical Trial. J Gen Intern Med. 2019 11; 34(11):2405-2413.
PMID: 31485965.

Iwamoto SJ, T'Sjoen G, Safer JD, Davidge-Pitts CJ, Wierman ME, Glodowski MB, Rothman MS. Letter to the Editor: "Progesterone Is Important for Transgender Women's Therapy-Applying Evidence for the Benefits of Progesterone in Ciswomen". J Clin Endocrinol Metab. 2019 08 01; 104(8):3127-3128.
PMID: 30860591.

Rothman MS, Iwamoto SJ. Bone Health in the Transgender Population. Clin Rev Bone Miner Metab. 2019 Jun; 17(2):77-85.
PMID: 31452648.

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