Low-protein diets for chronic kidney disease patients: the Italian experience

Abstract

BackgroundNutritional treatment has always represented a major feature of CKD management. Over the decades, the use of nutritional treatment in CKD patients has been marked by several goals. The first of these include the attainment of metabolic and fluid control together with the prevention and correction of signs, symptoms and complications of advanced CKD. The aim of this first stage is the prevention of malnutrition and a delay in the commencement of dialysis. Subsequently, nutritional manipulations have also been applied in association with other therapeutic interventions in an attempt to control several cardiovascular risk factors associated with CKD and to improve the patient's overall outcome. Over time and in reference to multiple aims, the modalities of nutritional treatment have been focused not only on protein intake but also on other nutrients.DiscussionThis paper describes the pathophysiological basis and rationale of nutritional treatment in CKD and also provides a report on extensive experience in the field of renal diets in Italy, with special attention given to approaches in clinical practice and management.SummaryItalian nephrologists have a longstanding tradition in implementing low protein diets in the treatment of CKD patients, with the principle objective of alleviating uremic symptoms, improving nutritional status and also a possibility of slowing down the progression of CKD or delaying the start of dialysis. A renewed interest in this field is based on the aim of implementing a wider nutritional therapy other than only reducing the protein intake, paying careful attention to factors such as energy intake, the quality of proteins and phosphate and sodium intakes, making today’s low-protein diet program much more ambitious than previous. The motivation was the reduction in progression of renal insufficiency through reduction of proteinuria, a better control of blood pressure values and also through correction of metabolic acidosis. One major goal of the flexible and innovative Italian approach to the low-protein diet in CKD patients is the improvement of patient adherence, a crucial factor in the successful implementation of a low-protein diet program.

Association between Low Dietary Protein Intake and Geriatric Nutrition Risk Index in Patients with Chronic Kidney Disease: A Retrospective Single-Center Cohort Study

“…In fact, the bioimpedance phase angle, as a measure of nutritional status [42,43], was associated with GNRI levels. Hyperphosphotemia is an independent risk factor for adverse outcomes in patients with CKD [44], and serum phosphorus level depends on protein intake [5]. In this study, the phosphorus level was strongly associated with kidney function rather than protein intake and nutritional status.…”

“…However, protein restriction is only a part, though a very relevant part, of a more complex dietary management of CKD patients [3,4,5]. Phosphate intake should be reduced (700–400 mg/day), as well as sodium intake (2–3 g/day).…”

Urea, a true uremic toxin: the empire strikes back

“…The 2013 KDIGO (kidney disease improving global outcomes) guidelines suggest lowering protein intake to 0.8 g/kg/day in adults with estimated glomerular filtration rate (eGFR) <30 ml/min/1.73 m 2 (grade 2B evidence for pre-dialysis non-diabetic CKD patients, grade 2C evidence for diabetic CKD patients) [28]. An extensive review summarizing decades of experience with low-protein diets was recently published by a group of Italian nephrologists, where important variables including patient compliance, avoidance of malnutrition, and counselling on low phosphorus and low sodium intake are discussed [29].…”

Opponent’s comments

“…Moderator's view: Low-protein diet in chronic kidney disease: effectiveness, efficacy and precision nutritional treatments in nephrology Carmine Zoccali 1 and Francesca Mallamaci Correspondence and offprint requests to: Carmine Zoccali; E-mail: carmine.zoccali@tin.it, Twitter handle: @carminezoccali…”

“…In contrast, health care workers who recommend a protein-restricted diet to slow the rate of loss of GFR, as well to prevent nutritional or metabolic derangements, may recommend that these diets be commenced at less advanced CKD levels, i.e. CKD Stage 3, 4 or 5 [1]. Traditionally, two protein-restricted diets have been used for CKD patients who are not receiving chronic dialysis therapy: a low-protein diet (LPD, i.e.…”