Hypertension in chronic kidney disease: the influence of renal transplantation

Abstract

Background: Hypertension is one of the most prevalent cardiovascular risk factors in chronic kidney disease (CKD) and kidney transplants. The contribution of transplantation to hypertension in comparison to patients with CKD and similar renal function has not been characterized.

Methods: Ninety-two transplants and 97 CKD patients with an estimated glomerular filtration rate less than 60 mL/min/1.73 m not receiving dialysis were enrolled. At entry, office blood pressure (BP) and 24-hr ambulatory blood pressure monitoring (ABPM) were obtained.

Results: Office BP was not different between transplants and CKD patients (139.5±14.3 vs. 135.2±19.3, P=1.00, respectively). ABPM 24-hr systolic blood pressure (SBP) (133.9±14.3 vs. 126.2±16.1, P=0.014), awake SBP (135.6±15.2 vs. 128.7±16.2, P=0.042), and sleep SBP (131.2±16.2 vs. 120.2 ±17.9, P=0.0014) were higher in renal transplants. When patients were classified according to BP patterns associated with highest cardiovascular risk, the proportion of patients with both nocturnal hypertension and non-dipper pattern was higher in transplants (68.5% vs. 47.4%, P=0.03). In the multivariate regression analysis, transplantation was an independent predictor of 24-hr, awake, and sleep SBP.

Conclusion: Office BP is similar in kidney transplants and CKD patients with similar renal function. On the contrary, hypertension is more severe in kidney transplants when evaluated with ABPM mainly as a result of increased sleep systolic BP. Thus, precise evaluation of hypertension in kidney transplants requires ABPM.