Renal function outcomes and kidney biopsy features of living kidney donors with hypertension.

Abstract

The medium- to long-term outcomes of living kidney donors with hypertension compared to normotensive donors are not well understood, especially with the recent changes in hypertension guidelines. We studied a cohort of 950 living kidney donors using different definitions of hypertension based on either ≥140/90 or ≥130/80mmHg thresholds and based on either office or ambulatory blood pressure readings. Microstructural features on kidney biopsy at the time of donation were compared using different definitions of hypertension. After adjusting for years of follow-up, age, sex, and baseline eGFR, hypertension (by any definition) did not significantly predict an eGFR<45ml/min/1.73m2 at a median follow-up of 10years postdonation, though there was a borderline association with ambulatory blood pressure≥130/80mmHg predicting a 40% decline in eGFR (OR=1.53, 1.00-2.36; p=.051). Proteinuria was predicted by office blood pressure≥140/90mmHg and by nondipper profile on nocturnal ambulatory blood pressure measurements. At the time of donation, larger glomeruli and arterial hyalinosis on biopsy were associated with hypertension defined by either ≥140/90 or ≥130/80mmHg (by office or ambulatory measurements). Nocturnal nondipper status was associated with larger glomeruli size but not arteriolar hyalinosis when compared to dippers. In programs that accept donors with controlled hypertension, various definitions of hypertension are associated with histological findings in the donated kidney, but none predict a clinically significant decline in kidney function 10years after donation. These data support allowing healthy individuals with controlled hypertension to donate a kidney. However, donors with office hypertension (≥140/90mmHg) and nondippers (regardless of hypertension status) are at greater long-term risk for proteinuria, and particularly for these donors, longer follow-up is warranted.