Effects of a Ketoacid Supplementation in Patients With Stage III to IV Renal Failure

Patients with an estimated glomerular filtration rate of less than 25 ml/kg/min, not on renal substitution therapy, without important concomitant diseases and aged between 40 and 70 years, will be invited to participate in the study. They will be randomly assigned to a group that will receive receive a supplement of ketoacids (Ketosteril) 1 tablet containing 630 mg of ketoacids every 5 kg of body weight and a diet containing 25 to 35 kcal/kg and 0.3 g/protein per day or to a group receiving placebo and a diet containing 25 to 35 kcal/kg and 0.6 g/protein per day. The intervention will last 16 weeks. At baseline and the end of the intervention a blood sample will be obtained to measure creatinine, urea nitrogen and cystatin C. Also a spot urine sample will be obtained to measure urea nitrogen and creatinine excretion. The compliance with the dietary prescription and the ketoacid or placebo supplement will be assessed every 2 weeks.

Inclusion criteria

• Estimated glomerular filtration rate of less tan 25/ml/min/1.73m2
• Not on renal substitution therapy
• Absence of severe life threatening concomitant diseases

Exclusion criteria

• Malignant or renovascular hypertension
• Use of systemic steroids or immunosuppressant drugs
• Alcohol or illicit drug abuse
• A body mass index of less tan 18 kg/m2