Abstract: PUB464
Physiology or Pathology? An Interesting Case of Rise in Serum Creatinine in a Female-to-Male Transgender Patient
Session Information
Category: Trainee Case Report
- 103 AKI: Mechanisms
Authors
- Gandhi, Pulkit, Brown University, Providence, Rhode Island, United States
- Shah, Ankur, Brown University, Providence, Rhode Island, United States
- Medeiros, Edward G., Brown University, Providence, Rhode Island, United States
Introduction
Transgender hormone therapy is a mainstay in the management of gender incongruence. Female to Male (FTM) transgender individuals are typically maintained on testosterone to induce a phenotype that matches their identity. Testosterone is known to have multiple renal adverse effects including tubular injury and FSGS. We present an interesting case of FTM transgender with a benign creatinine elevation while on testosterone and discuss the interpretation of serum creatinine (sCr) in transgendered individuals.
Case Description
A 36yo FTM transgender patient with past medical history of TIA secondary to PFO on clopidogrel was referred to our Nephrology clinic for consultation for an elevation in sCr. A review of records shows that his sCr has fluctuated between 1.1 and 1.3 mg/dl over the preceding 8 years. He denied any acute changes in health, recent or remote NSAID use, no LUTS. His only medications are clopidogrel, dextroamphetamine, and testosterone. Urinary microscopy was negative for cellular elements or casts. Urinary microalbumin/creatinine ratio was 3.8 mg/g. The most recent sCr was 1.3, estimating a GFR of 53 ml/min via the CKD-epi equation. A 24 hour urine collection was performed and the 24 hr urinary creatinine clearance was found to be 92 ml/min.
Discussion
Creatinine elevations in the setting of testosterone therapy can represent physiology or pathology. Acute kidney injury due to testosterone has a differential diagnosis including ATN, FSGS while a physiologic increase in skeletal muscle mass may result in increased creatinine generation. A careful examination of the urine and measurement of urinary protein excretion can help differentiate pathology and physiology. A 24 hour urine creatinine to estimate creatinine clearance was diagnostic in our patient of a state of altered physiology, not pathology. Interestingly, the creatinine clearance more closely approximated the CKD-Epi estimation of the male gender, not female gender in our patient. This experience was also seen in two case series of metabolic parameters during transgender hormone therapy, in which sCr was shown to rise 19-42% after initiation of therapy. In estimating eGFR in FTM patients on transgender hormone therapy, we recommend the male gender in calculations.