Pranav Gupta, Pichatorn Suppakitjanusant, Mary Stevenson, Michael Goodman, Vin Tangpricha
OBJECTIVE: To assess the incidence of hyperkalemia in transgender women using spironolactone.
METHODS: This was a retrospective chart review of transgender women who received gender-affirming hormone therapy that included spironolactone between January 2000 and September 2018. Forty-four participants who had paired Potassium concentrations documented and were on spironolactone were included and analyzed. Study outcomes included the incidence of hyperkalemia (serum Potassium concentrations > 5.0 mmol/L), the relationship between the duration of treatment and degree of hyperkalemia, and difference between serum Potassium concentrations at the beginning of spironolactone treatment versus last serum Potassium concentrations.
RESULTS: The median age of the participants was 36.5 years. The cohort was predominantly non-Hispanic White (32/44). No serum Potassium concentration was >5.5 mmol/L, and all participants had serum creatinine level of <2 mg/dL. Median duration of treatment was 25 months (range 2-92 months) and 140 Potassium measurements were available. The mean Potassium concentration (3.87 mmol/L) before the initiation of spironolactone was lower than the mean Potassium concentration (4.03 mmol/L) while on spironolactone (mean difference, 0.16 mmol/L, P = .013). The regression β, that is, the average change in Potassium concentration per 1 additional month of treatment duration, was -.001 (95% CI [-.004, .001]; P = .255) signifying no relation between treatment duration and spironolactone use.
CONCLUSION: No participant had laboratory evidence of significant hyperkalemia (K > 5.5 mmol/L) after initiation of spironolactone. Frequent measurement of Potassium concentrations might be unnecessary in transgender women taking spironolactone in patients with serum creatinine levels of <2 mg/dL.
