Changes in Glomerular Filtration Rate in Transgender Individuals Receiving Hormone Therapy: A Longitudinal Study.

BACKGROUND: The changes that occur over time in the estimated glomerular filtration rate (eGFR) of transgender individuals receiving hormone therapy, and the factors that influence these changes, have not yet been fully evaluated. METHODS: This is a longitudinal study based on a retrospective cohort of transgender people treated at Hospital Universitario San Ignacio in Bogotá, Colombia. Changes in eGFR (calculated using the CKD-EPI 2021 formula for both sexes) were analyzed over 36 months. The impact of age, BMI, previous gender affirmation surgery and hormone therapy was analyzed using a generalized estimating equation (GEE) model. RESULTS: 166 transgender patients were included in the study (Median age 29 years, 94 women and 72 men). For transgender women, eGFR did not change over time; however, estrogen therapy was associated with a higher eGFR (+17.2 ml/min/1.73 m2, p<0.05). In transgender men, both CKD-EPI 2021 formulas showed a significant decrease in GFR over time. The GEE model showed a significant change in eGFR ranging from -0.63 to -0.79 per month (p < 0.05), depending on the formula used. A significant impact of age on eGFR was demonstrated in both groups. CONCLUSION: This study suggests that transgender women did not experience significant changes in eGFR over time. Estrogen use showed a possible positive modyfing effect on eGFR. In transgender men, an overall decrease in eGFR was evident over time. Our findings emphasize the need for periodic renal assessment in transgender individuals using the same evaluation formula, and highlight the need to optimize the available diagnostic tools.