Sodium intake and blood pressure in renal transplant recipients

Hypertension is common among renal transplant recipients (RTR) and a risk factor for graft failure and mortality. Sodium intake is a well-established determinant of blood pressure (BP) in the general population. However, data in RTR are limited. International guidelines recommend a maximum daily sodium intake of 70 mmol. We investigated sodium intake in RTR as compared to healthy controls and its association with BP. We included 660 RTR (age 53 13 years, 58 male) and 201 healthy controls (age 54 11 years, 46 male). Sodium intake was assessed from 24-h urine collections. The morning after completion of urine collection, BP was measured according to a strict protocol. Urinary sodium excretion was 156 62 mmol/24 h in RTR and 195 75 in controls (difference: P 0.001), and 95 of RTR had a urinary sodium excretion 70 mmol/24 h. Systolic BP (SBP) and diastolic BP (DBP) were 136 18 and 82 11 mmHg, respectively. Sodium intake was positively associated with SBP ( 0.042 mmHg/mmol/24 h, P 0.002) and DBP ( 0.023 mmHg/mmol/24 h, P 0.007), independent of potential confounders. Although RTR had a lower sodium intake than healthy controls, their intake still exceeded current guidelines. Reduction of sodium intake to recommended amounts could reduce SBP by 45 mmHg. Better control of sodium intake may help to prevent graft failure and mortality due to hypertension among RTR.