Postdonation eGFR and New-Onset Antihypertensive Medication Use After Living Kidney Donation

BACKGROUND: Limited data are available regarding clinical implications of lower renal function after living kidney donation. We examined a novel integrated database to study associations between postdonation estimated glomerular filtration rate (eGFR) and use of antihypertensive medication (AHM) treatment after living kidney donation. METHODS: Study data were assembled by linking national U.S. transplant registry identifiers, serum creatinine (SCr) values from electronic medical records, and pharmacy fill records for 3222 living donors (1989-2016) without predonation hypertension. Estimated GFR (mL/min per 1.73 m²) was computed from SCr values by the CKD-EPI equation. Repeated measures multivariable mixed effects modeling examined the associations (adjusted odds ratio, _95%LCLaOR_{95% UCL}) between AHM use and postdonation eGFR levels (random effect) with fixed effects for baseline donor factors. RESULTS: The linked database identified an average of 3 postdonation SCr values per donor (range: 1-38). Lower postdonation eGFR (vs ≥75) bore graded associations with higher odds of AHM use (eGFR 30-44: aOR _0.951.47_2.26; <30: aOR _1.082.52_5.90). Other independent correlates of postdonation AHM use included older age at donation (aOR per decade: _1.081.23_1.40), black race (aOR _1.031.51_2.21), body mass index > 30 kg/m² (aOR _1.011.45_2.09), first-degree donor-recipient relationship (aOR _1.071.38_1.79), "prehypertension" at donation (systolic blood pressure 120-139: aOR _1.101.46_1.94; diastolic blood pressure 80-89: aOR _1.061.45_1.99). CONCLUSIONS: This novel linkage illustrates the ability to identify postdonation kidney function and associate it with clinically meaningful outcomes; lower eGFR after living kidney donation is a correlate of AHM treatment requirements. Further work should define relationships of postdonation renal function, hypertension, and other morbidity measures.