Usefulness of Dietary Salt Restriction in Kidney Transplant Recipients: Analysis of Blood Pressure Levels Depending on the Differences in the Levels of Salt Intake

BACKGROUND: Sodium retention causes post-transplant hypertension, and sodium restriction is recommended in kidney transplantation recipients. We investigated the changes in salt intake and age-specific differences in salt intake over the post-transplant periods and considered what guidance is important for salt reduction tailored to individual recipients. METHODS: We calculated salt intake for 38 recipients who underwent kidney transplantation from August 2013 to August 2018 using Tanaka's equation and extracted their blood pressure (BP) levels. RESULTS: The rate of achieving the desired level of salt intake (<6 g/d) was 7.9%. The average salt intake was 7.8 ± 1.4 g. Average BP by salt intake was as follows: <6 g/d, 109/71 mm Hg; 6 to <7 g/d, 127/84 mm Hg; 7 to <8 g/d, 124/79 mm Hg, 8 to <9 g/d, 130/73 mm Hg; 9 to <10 g/d, 133/83 mm Hg; and >10g/d, 137/81 mm Hg. DISCUSSION: Awareness of the need for salt restriction diminishes as time passes after transplantations, leading to increased salt uptake; therefore, regular guidance for keeping salt intake low is necessary for patients to maintain the awareness of salt restriction. The recipients with higher salt intake had higher blood pressure, suggesting the need for managing salt reduction. CONCLUSIONS: Dietary counseling showed a short-term efficacy for reducing sodium intake and clinically relevant BP improvement in renal allograft recipients.