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Abstract: PO2032

Interplay Between Dietary Phosphorus and Protein Intake with Mortality in a Prospective Hemodialysis Cohort

Session Information

Category: Health Maintenance, Nutrition, and Metabolism

  • 1300 Health Maintenance, Nutrition, and Metabolism

Authors

  • Tortorici, Amanda R., University of California Irvine, Irvine, California, United States
  • Narasaki, Yoko, University of California Irvine, Irvine, California, United States
  • You, Amy Seung, University of California Irvine, Irvine, California, United States
  • Norris, Keith C., University of California Los Angeles, Los Angeles, California, United States
  • Streja, Elani, University of California Irvine, Irvine, California, United States
  • Amel Peralta, Rene, University of California Irvine, Irvine, California, United States
  • Guerrero, Yalitzi, University of California Irvine, Irvine, California, United States
  • Daza Aguilar, Andrea C., University of California Irvine, Irvine, California, United States
  • Arora, Ria, University of California Irvine, Irvine, California, United States
  • Lo, Robin H., University of California Irvine, Irvine, California, United States
  • Nakata, Tracy, University of California Irvine, Irvine, California, United States
  • Nguyen, Danh V., University of California Irvine, Irvine, California, United States
  • Kalantar-Zadeh, Kamyar, University of California Irvine, Irvine, California, United States
  • Rhee, Connie, University of California Irvine, Irvine, California, United States
Background

Current dietary recommendations for dialysis patients suggest that high phosphorus (P) diets may be associated with negative outcomes such as increased serum P and death. However, caution must be practiced to ensure dietary P intake is not compromised at the expense of dietary protein intake. We hypothesized that higher concentrations of dietary P intake is associated with higher mortality among a diverse cohort of hemodialysis (HD) patients.

Methods

Among 415 patients from the prospective multi-center Malnutrition, Diet, and Racial Disparities in Kidney Disease Study, we conducted standardized collection of dietary and dialysis treatment characteristics every six months starting in 2011. We examined the association of quartiles of dietary P scaled to 1000 kcal (mg/kcal), as measured by food frequency questionnaires, with all-cause mortality using Cox models adjusted for expanded case-mix+laboratory+nutrition covariates. To model the association between continuous daily dietary P intake scaled to protein (mg/g) and mortality, we conducted analyses in which dietary P/protein intake was examined as a restricted cubic spline.

Results

In baseline analyses, patients in the lowest quartile of dietary P scaled to 1000 kcal had increased mortality risk compared to those in the highest quartile: adjusted HR (95%CI) 1.80 (1.05, 3.09). In analyses examining the association between continuous dietary P/protein (mg/g) intake and mortality using a cubic spline, we observed that there was a monotonic decrease in death risk with higher dietary P/protein intake.

Conclusion

Contrary to current practice, we found that lower intakes of dietary P scaled to protein and caloric intake were each associated with higher mortality risk. National nutrient databases indicate that foods with lower vs. higher P/protein ratios tend to be from animal proteins vs. plant proteins and dairy. Further studies are needed to clarify the relationship between sources of dietary P intake and mortality in HD patients.

Funding

  • NIDDK Support