Kidney Week

Abstract: FR-PO268

Dietary Protein Intake and Outcomes in Patients with CKD

Session Information

• CKD: Epidemiology and Risk Factors
  November 08, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2101 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention

Authors

• Abu Farsak, Hisham Neyazi, University of Tennessee Health Science Center, Memphis, Tennessee, United States

Hisham Neyazi Abu Farsak,

• Patel, Abhishek J., University of Tennessee Health Science Center, Memphis, Tennessee, United States

Abhishek J. Patel,

• Akhtar, Jawed, University of Tennessee Health Science Center, Memphis, Tennessee, United States

Jawed Akhtar,

• Mahmoud, Mahmoud A., University of Teneessee Health Science Center, Memphis, Tennessee, United States

Mahmoud A. Mahmoud,

• Sumida, Keiichi, University of Tennessee Health Science Center, Memphis, Tennessee, United States

Keiichi Sumida,

• Molnar, Miklos Zsolt, University of Tennessee Health Science Center, Memphis, Tennessee, United States

Miklos Zsolt Molnar,

• Wall, Barry M., Veterans Affairs Medical Center, Memphis, Tennessee, United States

Barry M. Wall,

• Kovesdy, Csaba P., University of Tennessee Health Science Center, Memphis, Tennessee, United States

Csaba P. Kovesdy,

Background

Protein energy wasting is common in patients with CKD, but the trajectory of dietary protein intake (DPI) in patients with worsening CKD and the outcomes associated with DPI in this population are unclear.

Methods

We performed repeated collections of spot urine for the measurement of urine urea nitrogen and creatinine in 605 patients with non-dialysis dependent CKD followed at a single institution. We used the urine urea nitrogen-to-creatinine ratio to estimate daily excretion of urea nitrogen, and the Maroni formula to estimate dietary protein intake (DPI). We examined the association of DPI with estimated GFR using mixed effect models and penalized splines, and the association of baseline DPI with all-cause mortality and ESRD in multivariable adjusted Cox models with adjustment for demographic characteristics, smoking status, eGFR and comorbidities.

Results

Patients were 66±11 years old, 97% were men and 37% were African American. The baseline eGFR was 37±20 ml/min/1.73m², 210 patients died (mortality rate, 95%CI: 113/1000PY, 98-129) and 121 patients developed ESRD (65/1000PY, 57-78) over a median follow-up of 3.8 years. Patients underwent a median of 7 urine collections (range: 1-16). Lower eGFR was associated with a linear decrease in DPI (0.92 gm/kgBW/day lower DPI for every 15 ml/min/1.73m² lower eGFR, 95%CI: 0.38-1.46, p=0.001), with a steeper decline below an eGFR of ~20 ml/min/1.73m² (Figure). Higher baseline DPI was associated with higher mortality (adjusted hazard ratio associated with 1 gm/kgBW/day higher DPI, 95%CI: 1.015, 1.002-1.028, p=0.021) and higher ESRD risk (1.023, 1.006-1.041, p=0.009).

Conclusion

In patients with moderate to advanced CKD, DPI declines with progressive loss of kidney function, and higher DPI is associated with increased risk of all-cause mortality and ESRD.