Background: Men with chronic kidney disease (CKD) experience faster kidney function decline than women. Studies in individuals undergoing sex hormone therapy suggest a role for sex hormones, as estimated glomerular filtration rate (eGFR) increases with feminizing therapy and decreases with masculinizing therapy. However, effects on measured GFR (mGFR), glomerular and tubular function, and involved molecular mechanisms remain unexplored. Methods: This prospective, observational study included individuals initiating feminizing (estradiol and antiandrogens; n=23) or masculinizing (testosterone; n=21) therapy. Baseline and three-month assessments included mGFR (Iohexol clearance), kidney perfusion (para-aminohippuric acid clearance), tubular injury biomarkers, and plasma proteomics. Results: During feminizing therapy, mGFR and kidney perfusion increased (+3.6% and +9.1%, respectively; p<0.05), without increased glomerular pressure. Tubular injury biomarkers, including urine neutrophil gelatinase-associated lipocalin, EGF, monocyte chemoattractant protein-1, and chitinase 3-like protein 1 (YKL-40), decreased significantly (-53%, -42%, -45%, and -58%, respectively). During masculinizing therapy, mGFR and kidney perfusion remained unchanged, but urine YKL-40 and plasma TNFR-1 increased (+134% and +8%, respectively; p<0.05). Proteomic analysis revealed differential expression of 49 proteins during feminizing, and 356 proteins during masculinizing therapy. Many kidney-protective proteins were positively associated with estradiol and negatively associated with testosterone, including proteins involved in endothelial function (SFRP4, SOD3), inflammation reduction (TSG-6), and maintaining kidney tissue structure (agrin). Conclusion: Sex hormones influence kidney physiology, with estradiol showing protective effects on glomerular and tubular function, while testosterone predominantly exerts opposing effects. These findings emphasize the role of sex hormones in sexual dimorphism observed in kidney function and physiology and suggest new approaches for sex-specific precision medicine.
Sarah A. van Eeghen, Laura Pyle, Phoom Narongkiatikhun, Ye Ji Choi, Wassim Obeid, Chirag R. Parikh, Taryn G. Vosters, Irene GM van Valkengoed, Merle M. Krebber, Daan J. Touw, Martin den Heijer, Petter Bjornstad, Daniël Raalte, Natalie J. Nokoff