Hypertension, cardiovascular disease and cause of death in Danish living kidney donors: matched cohort study

Abstract

Objectives We aimed to investigate the long-term absolute risk of hypertension and cardiovascular disease after kidney donation in living kidney donors.Design Living kidney donors were matched to 10 controls from the general population.Setting Multiple Danish national registries were used to identify living kidney donors from 1 January 1996 to 31 December 2017 nationwide.Participants 1262 living kidney donors and 12 620 controls.Main outcome measures Hypertension, cardiovascular disease and diabetes.Results The median age of living kidney donors was 52 (men 43%). Hypertension developed in 50 (4%) and 231 (1.8%) with a median follow-up of 7 years (IQR 3.3–12.1 years with a maximum follow-up of 22 years) and 6.9 years (IQR 3.2–11.7 years and maximum follow-up of 22 years) for donors and controls, respectively. The absolute risk of hypertension was 2.3% (95% CI 1.4% to 3.2%) and 1.2% (95% CI 1.0% to 1.4%), 4.2% (95% CI 2.8% to 5.7%) and 2.4% (95% CI 2.1% to 2.8%), 8.6% (95% CI 6.0% to 11.3%) and 3.3% (95% CI 2.8% to 3.8%) within 5, 10, 15 years for donors and controls, respectively. The ratio of the 10-year absolute risks for hypertension was 1.64 (95% CI 1.44 to 1.88) for donors compared with the controls. Two donors and four controls developed renal replacement therapy requiring end-stage renal disease during follow-up. The absolute risk of cardiovascular disease and diabetes was 7.3% (95% CI 5.7% to 9.5%) and 8.3% (95% CI 7.7% to 9.0%), 1.7% (95% CI 0.7% to 2.8%) and 3.2% (95% CI 2.7% to 3.6%) at 10 years for donors and controls, respectively.Conclusions Living kidney donors have an increased long-term absolute risk of hypertension compared with controls from the general population.