Dietary protein restriction may improve determinants of CKD progression. However, the extent of improvement and effect of ketoanalogue supplementation are unclear. We conducted a prospective, randomized, controlled trial of safety and efficacy of ketoanalogue–supplemented vegetarian very low–protein diet (KD) compared with conventional low–protein diet (LPD). Primary end point was RRT initiation or >50% reduction in initial eGFR. Nondiabetic adults with stable eGFR<30 ml/min per 1.73 m², proteinuria <1 g/g urinary creatinine, good nutritional status, and good diet compliance entered a run-in phase on LPD. After 3 months, compliant patients were randomized to KD (0.3 g/kg vegetable proteins and 1 cps/5 kg ketoanalogues per day) or continue LPD (0.6 g/kg per day) for 15 months. Only 14% of screened patients patients were randomized, with no differences between groups. Adjusted numbers needed to treat (NNTs; 95% confidence interval) to avoid composite primary end point in intention to treat and per-protocol analyses in one patient were 4.4 (4.2 to 5.1) and 4.0 (3.9 to 4.4), respectively, for patients with eGFR<30 ml/min per 1.73 m². Adjusted NNT (95% confidence interval) to avoid dialysis was 22.4 (21.5 to 25.1) for patients with eGFR<30 ml/min per 1.73 m² but decreased to 2.7 (2.6 to 3.1) for patients with eGFR<20 ml/min per 1.73 m² in intention to treat analysis. Correction of metabolic abnormalities occurred only with KD. Compliance to diet was good, with no changes in nutritional parameters and no adverse reactions. Thus, this KD seems nutritionally safe and could defer dialysis initiation in some patients with CKD.

Background. Intravenous iron is a recognized therapy of anaemia in chronic haemodialyzed patients, especially in those receiving erythropoietin (Epo), while its role in the anaemia of pre-dialyzed chronic renal failure (CRF) patients is much less clear. This study attempted to evaluate the effects of intravenous iron in anaemic pre-dialyzed patients. Methods. Sixty anaemic (haemoglobin <11 g/dl) non-diabetic patients with moderate CRF [32 males, 28 females; mean age 52.2±12.5 years; mean glomerular filtration rate 36.2±5.2 ml/min], without iron deficiency, iron overload or inflammation, without concomitant erythropoietin treatment and without any previous iron therapy were enrolled. Intravenous iron was administered as iron sucrose, 200 mg elemental iron per month for 12 months, with 1 month pre-study survey and 1 month follow-up after the last iron dose. Results. Intravenous iron supplementation was associated with a significant increase in haemoglobin (from 9.7±1.1 at the baseline to 11.3±2.5 g/dl after 12 months, a mean increase of 1.6 g/dl), a further 36% of patients reaching the target haemoglobin of 10 g/dl. There was a significant increase in serum iron from 73.9±17.2 to 101.8±12.2 µg/dl, in serum ferritin from 98.0 (24.8–139.0) to 442.5 (86.0–496.0) µg/l and in transferrin saturation from 21.6±2.6 to 33.6±3.2%. No worsening of renal function, no increase in blood pressure and no other side effects were noted. Conclusions. Intravenous iron therapy in pre-dialysis patients with no Epo seems often to ameliorate the anaemia, avoiding the necessity of Epo or blood transfusions in one-third of pre-dialyzed non-diabetic patients. Intravenous iron supplementation appears to be an effective and safe treatment for anaemia in pre-dialysis CRF patients.

Recent data reiterate low-protein diets (LPDs) as cornerstones in the conservative management of chronic kidney disease (CKD). The reduction in proteinuria, better blood pressure control and the reduction in the rate of decline in kidney function with LPDs were reported, both in non-diabetics and diabetics patients. Supplemented, vegetarian, very-low-protein diets (sVLPD, 0.3 g/kg-day) could postpone kidney replacement therapy (KRT) initiation, mainly through the better control of metabolic disorders of advanced CKD in non-diabetic patients. Plant-based diets could ameliorate gut microbiota and appear to be superior to mixed hypoproteic diets in treating advanced CKD: better control of nitrogen balance, acid-base metabolism and bone mineral disorders. Vegetarian diets generate fewer uremic toxins and reduce salt intake and acid overload. At the same time, they can improve lipid metabolism, providing a high ratio of unsaturated to saturated fatty acids, as well as insulin resistance.

Low protein diets (LPD) have long been prescribed to chronic kidney disease patients with the goals of improving metabolic abnormalities and postpone the start of maintenance dialysis. We reviewed the recent literature addressing low protein diets supplemented with ketoacids/essential aminoacids prescribed during chronic kidney disease and their effects on metabolic, nutritional and renal parameters since 2013. We show new information on how to improve adherence to these diets, on metabolic improvement and delay of the dialysis needs, and preliminary data in chronic kidney disease associated pregnancy. In addition, data on incremental dialysis have been reviewed, as well as potential strategies to reverse protein energy wasting in patients undergoing maintenance dialysis. These recent data help to better identify the use of low protein diets supplemented with ketoacids/essential aminoacids during chronic kidney disease.