Medical nutrition therapy using plant-focused low-protein meal plans for management of chronic kidney disease in diabetes.

PURPOSE OF REVIEW: Nearly half of all Americans with chronic kidney disease (CKD) also have type-2-diabetes (T2D). Whereas traditional and emerging pharmacotherapies are increasingly frequently used for the management of CKD in diabetes (CKD/DM), the role of integrated or multimodal interventions including the potentially synergistic and additive effect of diet and lifestyle modifications in addition to pharmacotherapy has not been well examined, in sharp contrast to the well-known integrated approaches to heart disease. RECENT FINDINGS: Low-carbohydrate low-fat diets are often recommended in T2D, whereas low-protein diets (LPD) are recommended by guidelines for nondiabetic CKD with increasing emphasis on plant-based protein sources. High-protein diets with greater animal protein lead to glomerular hyperfiltration, especially in patients with T2D, and faster decline in renal function. Guidelines provide differing recommendations regarding the amount (low vs high) and source (plant vs animal) of dietary protein intake (DPI) in CKD/DM. Some such as KDIGO recommend 0.8 g/kg/day based on insufficient evidence for DPI restriction in CKD/DM, whereas KDOQI and ISRNM recommend a DPI of 0.6 to <0.8 g/kg/day. A patient-centered plant-focused LPD for the nutritional management of CKD/DM (PLAFOND), a type of PLADO diet comprising DPI of 0.6 to <0.8 g/kg/day with >50% plant-based sources, high dietary fiber, low glycemic index, and 25-35 Cal/kg/day energy, can be implemented by renal dietitians under Medical Nutrition Therapy. SUMMARY: Potential risks vs benefits of high vs low protein intake in CKD/DM is unknown, for which expert recommendations remain opinion based. Randomized controlled studies are needed to examine safety, acceptability and efficacy of PLAFOND.

A Mini Review of Plant-Based Diets in Hemodialysis.

BACKGROUND: Plant-based diets are defined as an eating pattern focused on the consumption of unprocessed fruits, vegetables, nuts, whole grains, oils, and beans. They can include various forms of vegetarian, vegan, DASH, and Mediterranean diets. Plant-based diets have proven useful in the prevention and treatment of several lifestyle diseases like type 2 diabetes, hypertension, and obesity. Recently, a growing body of literature has emerged regarding plant-based diets for patients with kidney failure, including those on dialysis. Although evidence is still limited, preliminary findings are encouraging. SUMMARY: This article reviews current literature on the use of plant-based diets in the treatment of patients on dialysis.

The International Society of Renal Nutrition and Metabolism Commentary on the National Kidney Foundation and Academy of Nutrition and Dietetics KDOQI Clinical Practice Guideline for Nutrition in Chronic Kidney Disease.

The Academy of Nutrition and Dietetics and the National Kidney Foundation collaborated to provide an update to the Clinical Practice Guidelines (CPG) for nutrition in chronic kidney disease (CKD). These guidelines provide a valuable update to many aspects of the nutrition care process. They include changes in the recommendations for nutrition screening and assessment, macronutrients, and targets for electrolytes and minerals. The International Society of Renal Nutrition and Metabolism assembled a special review panel of experts and evaluated these recommendations prior to public review. As one of the highlights of the CPG, the recommended dietary protein intake range for patients with diabetic kidney disease is 0.6-0.8 g/kg/day, whereas for CKD patients without diabetes it is 0.55-0.6 g/kg/day. The International Society of Renal Nutrition and Metabolism endorses the CPG with the suggestion that clinicians may consider a more streamlined target of 0.6-0.8 g/kg/day, regardless of CKD etiology, while striving to achieve intakes closer to 0.6 g/kg/day. For implementation of these guidelines, it will be important that all stakeholders work to detect kidney disease early to ensure effective primary and secondary prevention. Once identified, patients should be referred to registered dietitians or the region-specific equivalent, for individualized medical nutrition therapy to slow the progression of CKD. As we turn our attention to the new CPG, we as the renal nutrition community should come together to strengthen the evidence base by standardizing outcomes, increasing collaboration, and funding well-designed observational studies and randomized controlled trials with nutritional and dietary interventions in patients with CKD.

The Interplay between Dietary Phosphorous, Protein Intake, and Mortality in a Prospective Hemodialysis Cohort.

(1) Background: Current dietary recommendations for dialysis patients suggest that high phosphorus diets may be associated with adverse outcomes such as hyperphosphatemia and death. However, there has been concern that excess dietary phosphorus restriction may occur at the expense of adequate dietary protein intake in this population. We hypothesized that higher dietary phosphorus intake is associated with higher mortality risk among a diverse cohort of hemodialysis patients. (2) Methods: Among 415 patients from the multi-center prospective Malnutrition, Diet, and Racial Disparities in Kidney Disease Study, we examined the associations of absolute dietary phosphorus intake (mg/day), ascertained by food frequency questionnaires, with all-cause mortality using multivariable Cox models. In the secondary analyses, we also examined the relationship between dietary phosphorus scaled to 1000 kcal of energy intake (mg/kcal) and dietary phosphorus-to-protein ratio (mg/g) with survival. (3) Results: In expanded case-mix + laboratory + nutrition adjusted analyses, the lowest tertile of dietary phosphorus intake was associated with higher mortality risk (ref: highest tertile): adjusted HR (aHR) (95% CI) 3.33 (1.75-6.33). In the analyses of dietary phosphorus scaled to 1000 kcal of energy intake, the lowest tertile of intake was associated with higher mortality risk compared to the highest tertile: aHR (95% CI) 1.74 (1.08, 2.80). Similarly, in analyses examining the association between dietary phosphorus-to-protein ratio, the lowest tertile of intake was associated with higher mortality risk compared to the highest tertile: aHR (95% CI) 1.67 (1.02-2.74). (4) Conclusions: A lower intake of dietary phosphorus was associated with higher mortality risk in a prospective hemodialysis cohort. Further studies are needed to clarify the relationship between specific sources of dietary phosphorus intake and mortality in this population.

Serum albumin is incrementally associated with increased mortality across varying levels of kidney function.

OBJECTIVES: Serum albumin (sAlb) may be a strong predictor of longevity in the general population and in chronic kidney disease. This study aimed to determine the relationship between sAlb concentrations and mortality risk independent of kidney function. METHODS: This was a retrospective cohort study of 31 274 adults from the 1999-2010 National Health and Nutrition Examination Survey. The estimated glomerular filtration rate (eGFR) was examined as both a confounder and modifier of the association of sAlb with mortality risk. We examined the association of sAlb (categorized as <3.8, 3.8 to <4.0, 4.0 to <4.2, 4.2 to <4.4, 4.4 to <4.6, 4.6 to <4.8, and ≥4.8 g/dL) with mortality using Cox models. Subsequently, we conducted spline analyses to estimate the association of sAlb with all-cause mortality across varying eGFR levels. RESULTS: In unadjusted analyses, participants with incrementally lower sAlb concentrations of <4.6 g/dL had an increasingly higher mortality risk compared with those with sAlb levels ranging from 4.6 to <4.8 g/dL (reference), whereas those with higher sAlb levels of ≥4.8 g/dL had a lower mortality risk (hazard ratios [95% confidence interval]: 3.88 [3.26-4.62], 3.59 [3.01-4.27], 2.79 [2.37-3.29], 2.10 [1.79-2.48], 1.72 [1.45-2.03], and 0.71 [0.55-0.92] for sAlb concentrations of <3.8, 3.8 to <4.0, 4.0 to <4.2, 4.2 to <4.4, 4.4 to <4.6, and ≥4.8 g/dL, respectively). Adjusted analyses showed similar findings, although the association of higher sAlb levels of ≥4.8 g/dL with better survival was attenuated to the null. Spline analyses showed that participants with sAlb levels of <4.6 g/dL had higher mortality across all concentrations of eGFR, ranging from 30 to 120 mL/min/1.73 m2 (reference: sAlb ≥ 4.6 g/dL). CONCLUSIONS: Among a nationally representative U.S. cohort, a graded association was observed between lower sAlb concentrations and higher death risk, which was robust across varying levels of kidney function.

Plant-Dominant Low-Protein Diet for Conservative Management of Chronic Kidney Disease.

Chronic kidney disease (CKD) affects >10% of the adult population. Each year, approximately 120,000 Americans develop end-stage kidney disease and initiate dialysis, which is costly and associated with functional impairments, worse health-related quality of life, and high early-mortality rates, exceeding 20% in the first year. Recent declarations by the World Kidney Day and the U.S. Government Executive Order seek to implement strategies that reduce the burden of kidney failure by slowing CKD progression and controlling uremia without dialysis. Pragmatic dietary interventions may have a role in improving CKD outcomes and preventing or delaying dialysis initiation. Evidence suggests that a patient-centered plant-dominant low-protein diet (PLADO) of 0.6­0.8 g/kg/day composed of >50% plant-based sources, administered by dietitians trained in non-dialysis CKD care, is promising and consistent with the precision nutrition. The scientific premise of the PLADO stems from the observations that high protein diets with high meat intake not only result in higher cardiovascular disease risk but also higher CKD incidence and faster CKD progression due to increased intraglomerular pressure and glomerular hyperfiltration. Meat intake increases production of nitrogenous end-products, worsens uremia, and may increase the risk of constipation with resulting hyperkalemia from the typical low fiber intake. A plant-dominant, fiber-rich, low-protein diet may lead to favorable alterations in the gut microbiome, which can modulate uremic toxin generation and slow CKD progression, along with reducing cardiovascular risk. PLADO is a heart-healthy, safe, flexible, and feasible diet that could be the centerpiece of a conservative and preservative CKD-management strategy that challenges the prevailing dialysis-centered paradigm.