Dietary Protein Source and Phosphate Levels in Patients on Hemodialysis.

OBJECTIVE: To determine the sources of protein and phosphorus levels from the food consumed by patients on dialysis. DESIGN AND METHODS: This is a retrospective, secondary data analysis of the Comprehensive Dialysis Survey study participants who had a baseline food frequency questionnaire and baseline lab data (N = 358). We examined intake of protein, phosphorus, and 7 other key nutrients from a subcohort of the Comprehensive Dialysis Survey based on the published National Kidney Foundation Kidney Dialysis Outcome Quality Initiative's nutrition recommendations. We studied the relationship of dietary protein source (plant or animal) with phosphorus intake using self-reported data from food frequency questionnaires. Variables included in final analysis are demographic, lab variables (albumin and prealbumin, alpha-1 acid glycoprotein, and C-reactive protein), and nutrition variables (calorie density, protein density, total fat, saturated fat, cholesterol, carbohydrates, phosphorus, calcium, sodium, potassium, plant-based protein, animal-based protein, and daily protein intake). RESULTS: Most of the patients had a lower than recommended consumption of calories, protein, phosphorus, and potassium while sodium, total, and saturated fats were overconsumed. Patients intake of dietary protein and calories was proportional to the amount of food consumed for both plant- and animal-based food. The levels of dietary protein and phosphorus were significantly (P < .05) lower in patients who primarily consumed a plant-based diet than in those who mainly consumed an animal-based diet. CONCLUSIONS: Consuming more plant-based protein as part of a varied diet could be nutritionally adequate while limiting intake of absorbable dietary phosphorus. More research in plant-based protein diets and their impact on patients with end-stage renal disease is needed.

Is Dietary Protein Intake Predictive of 1-Year Mortality in Dialysis Patients?

BACKGROUND: High mortality in dialysis patients may be associated with protein-energy wasting (PEW) syndrome characterized by progressively depleted protein and energy stores. While early diagnosis and treatment of PEW can reduce mortality, clinically practical measures for its detection are lacking. Poor dietary protein intake (DPI) is associated with risk of malnutrition and PEW. However, the impact of DPI on mortality is unclear. The purpose of this study is to examine the ability of DPI to predict 1-year mortality in dialysis patients. METHODS: This prospective, secondary study using data from the Comprehensive Dialysis Study and United States Renal Data System examined risk factors associated with 1-year mortality in dialysis patients. RESULTS: Seventeen (7.5%) of the 227 subjects died within 1 year following baseline data collection. One year survivors were significantly younger (60 ± 13.6 versus 71 ± 12.8; P = 0.0043), had a lower Charlson Comorbidity Index score (1.6 ± 2.3 versus 4.0 ± 3.6; P = 0.0157), higher serum albumin level (3.5 ± 0.5 versus 3.3 ± 0.4; P = 0.0173) and had higher DPI (63 ± 33.7 versus 49.5 ± 21.5 g/day; P = 0.0386) than those who died. In multivariable Cox proportional hazards model analyses, only the Charlson Comorbidity Index adjusted hazard ratio for death (1.24) was significantly associated with increased mortality. The Comprehensive Dialysis Study data showed no association between DPI and 1-year mortality in dialysis patients. CONCLUSIONS: Future studies using more precise measures should further examine the impact of DPI on mortality given the known association of DPI with PEW syndrome and the definitive link between PEW syndrome and survival in dialysis patients.