Con: The role of diet for people with advanced Stage 5 CKD

Abstract

Restriction of dietary protein intake has been used in the management of chronic kidney disease (CKD) for many decades, yet remains controversial, with marked variations in its application in clinical practice. There is extensive literature on the subject, with some expert opinion advocating the use of protein restriction based on the balance of the available evidence. The largest randomized trial of low-protein diets is the Modification of Diet in Renal Disease study. Despite multiple secondary analyses, the essential intention-to-treat analysis failed to demonstrate a benefit in the primary outcome of rate of decline of glomerular filtration rate. There are criticisms of many published studies and meta-analyses, including the likelihood of publication bias and unsuitable biochemical endpoints that may be affected by dietary restriction in the absence of effects on kidney function, leading to false positive findings. It is also uncertain whether any benefits observed in these often older studies would be derived in patients undergoing modern standards of CKD management, including blood pressure control and renin-angiotensin blockade. Thus it is unclear whether, even in the strictly controlled environment of a clinical study, low-protein diets significantly slow CKD progression. Important questions exist regarding the applicability of these diets in routine clinical practice. Even in carefully selected study populations with intensive dietetic input, adherence to low-protein diets is poor. It is likely that only a small minority of CKD patients in routine practice could adhere to these diets, and although risks of malnutrition arising from protein restriction are uncertain, they will be greater in less supervised care outside of studies.

Very Low Protein Diet for Patients with Chronic Kidney Disease: Recent Insights

“…There is still a great debate among nephrologists regarding the efficacy of NT in CKD patients [1,2,3]. Nevertheless, NT has a fundamental role in this medical setting and it has been used for years in the clinical practice with several goals.…”

High rates of protein intake are associated with an accelerated rate of decline of residual kidney function in incident peritoneal dialysis patients

“…Thus, moderate protein restriction represents now the most common approach, and is endorsed by current practice guidelines [1,10]. However, the benefits of moderate protein restriction are still controversial [5,19], because of contradictory reports (including several systematic reviews and metaanalyses) on the effects of this measure on progression of CKD and patient mortality [6][7][8][9]. Potential reasons for the discrepancies observed include differences among the populations involved in the studies, variable degrees of protein restriction, a relatively high incidence of non-compliance among patients participating in trials [5,20] and, for more recent studies, a downplayed effect of protein restriction brought about by a reinforced implementation of complementary measures, including systematic prescription of ACEI-ARA drugs and improved control of acidosis and hyperphosphataemia [5,18].…”

Supplemented Very Low Protein Diet (sVLPD) in Patients with Advanced Chronic Renal Failure: Clinical and Economic Benefits

“…Nutrients 2023, 15 Although to date, there are conflicting opinions on the use and benefits of DNT in CKD [1,[26][27][28] and the investigation is ongoing, the latest KDOQI 2020 guidelines recommend a strict hypoproteic diet in stages 3-5 and several studies show that the use of sVLPD in patients with advanced chronic renal failure yields greater benefits than a low-protein diet (LPD) alone [11,12,23,[29][30][31]. It is not clear whether the effects emerging from the use of sVLPD with KAs/eAAs are attributable to the reduced protein intake or to the role of KAs, in the short and long term, in stage 5 patients [15,[32][33][34].…”