Sodium Excretion Pattern at 1 Year After Kidney Transplantation and High Blood Pressure

High blood pressure (BP) after kidney transplantation decreases graft and patient survival. There is a causal relationship between high salt intake and increased BP in the general population, but the role of salt intake on post-transplant hypertension remains controversial. The aims of our study were to determine the pattern of salt intake in the first year post-transplantation and its influence on BP in our kidney transplant population.

We selected 270 deceased-donor kidney transplant recipients with graft survival longer than 1 year and at least 1 adequate 24-h urinary sodium excretion measurement at the first year visit in order to be included in the analysis.

Some 87.0% patients had a sodium excretion (mean 165±73 mmol/day) higher than recommended. Male and younger recipients with a high body mass index had a higher sodium excretion. Among other variables, sodium excretion was independently related to higher systolic (b 3.529 per 100 mmol/day, 95%CI 0.725-6.334, p=0.014) and diastolic (b 1.866 per 100 mmol/day, 95%CI 0.237-3.496, p=0.025) BP.

A high percentage of kidney transplant recipients have salt intake higher than recommended, contributing to increased BP. Measurement of 24-h urinary sodium excretion identifies non-compliant kidney transplant recipients who need intervention to improve BP control and graft outcome.