Up to 90% of kidney transplant recipients (KTx) develop hypertension. Both systolic and diastolic post-transplant hypertension relate to patient and allograft survival. In the general population a lower salt intake relates to lower hypertension, lower risk of cardiovascular events and lower mortality, but it is unclear if these relationships apply to kidney graft recipients. The aim of this study was to analyze the relationships between sodium intake, hypertension and graft survival in KTx.
Methods: Included are 397 deceased-donor kidney transplants from 1997 to 2009 with a mean follow-up of 7.0 ± 3.7 years. Sodium intake was estimated by urinary sodium excretion on 24-hour urine collections one year after transplantation. Blood pressure levels represent an average of three office consecutive measurements. Hypertension was defined when blood pressure was ≥ 140 and/or ≥ 90 mmHg.
Results: Mean sodium intake was 165 ± 77 mmol/day. Higher sodium intake related to lower recipient age (r = -0.164, p = 0.001), lower donor age (r = -0.128, p = 0.011), higher body mass index (r = 0.190, p < 0.001) and lower creatinine at 1 year (r = -0.104, p = 0.039). Percentage of hypertension among patients (89.5% vs. 81.1%, p = 0.031) and the number of antihypertensive drugs (1.60 vs. 1.32, p = 0.015) were significantly higher in patients in the highest tertile of sodium intake. After multivariate linear regression analysis high systolic hypertension related to high creatinine (6.628, 95% CI 3.592-9.665, p < 0.001), high recipient age (0.450, 95% CI 0.290-0.611, p < 0.001), high sodium intake (0.300 per 10 mmol/day, 95% CI 0.059-0.541, p = 0.015) and delayed graft function (4.477, 95% CI 0.425-8.530, p = 0.030). A systolic blood pressure ≥ 160 mmHg (13.1%) was a risk factor for graft loss (HR 1.512, 95% CI 1.014-2.254, p = 0.042) independent of recipient age and serum creatinine at 1-year.
Conclusions: High sodium intake relates to post-transplant hypertension. Furthermore, high blood pressure relates to a higher risk for graft loss after kidney transplantation. Applying salt restriction to kidney transplant patients can help to control blood pressure and perhaps improve graft survival.
To cite this abstract in AMA style:Rodrigo E, Monfá E, Fernández-Fresnedo G, Ruiz J, Piñera C, Palomar R, Gómez-Alamillo C, Arias M. Salt Intake and Post-Transplant Hypertension in Kidney Transplant Recipients [abstract]. Am J Transplant. 2013; 13 (suppl 5). https://atcmeetingabstracts.com/abstract/salt-intake-and-post-transplant-hypertension-in-kidney-transplant-recipients/. Accessed May 17, 2021.
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