The Role of Skin Sodium Accumulation in Chronic Kidney Disease

Cohort study (A): 60 CKD patients (eGFR 15 - 60 ml/min/1.73m2) are included in this cohort study. At the start of the study the association between tissue sodium content and micro-and macrovascular function will be evaluated. These patients will be followed up to investigate the association between tissue sodium content, quality of life and renal and cardiovascular events. Sodium intake intervention (B): A subgroup of 14 CKD patients (eGFR 15 - 60 ml/min/1.73m2) will be randomized to a 2-week low sodium diet and a 2-week high sodium diet in a cross-over study. Sodium excretion intervention (C): A subgroup of 12 CKD patients (eGFR 30 - 60 ml/min/1.73m2) with hypertension will be randomized to receive 6 weeks of treatment with hydrochlorothiazide, spironolactone and lercanidipine in a randomized open-label cross-over trial. Water intake intervention (D) A subgroup of 12 CKD patients (with eGFR 15-30 ml/min/1.73m2, hypertension and fasting morning urine osmolality \< 425 mOsm/kg for men and \< 400 mOsm/kg for women) will be randomized to a 4-week habitual water intake and 4-week increased water intake in a cross-over study.