WASHINGTON—Low protein excretion is another risk factor for early mortality, according to data presented at the American Society of Nephrology’s Kidney Week 2019 meeting.

Among 725 incident dialysis patients (mean age 60.1 years, 32.4% white, 54.2% black, 59.0% male) in the Chronic Renal Insufficiency Cohort (CRIC) study, 333 died over a median 3.5 years.  Manabu Hishida, MD, of Johns Hopkins University in Baltimore, and colleagues stratified CRIC patients by their urinary protein-to-creatinine ratio (PCR) within 2 years of dialysis initiation for analysis: less than 0.5, 0.5 to 0.9, 1.0 to 3.4, and 3.5 or more g/g.

The team observed a J-shaped association between PCR and mortality. Patients in the lowest PCR category (less than 0.5 g/g) had a 2.7-fold increased risk for mortality compared with those who had a PCR of 0.5 to less than 0.9 g/g.

Patients in the highest PCR category (3.5 or more g/g) had a 1.5-fold higher risk for mortality. Patients with the lowest PCR level were more likely to be older and have lower blood pressure (BP). After adjusting for BP, serum albumin, history of cardiovascular disease (including heart failure), and other potential confounders, the excess risk in low PCR patients partially attenuated but remained statistically significant.

“While the reasons for this association are uncertain, our findings suggest that healthcare providers should be aware that low protein excretion, not just high protein excretion, is a marker for an increased risk of mortality in patients who start dialysis,” Dr Hishida’s team concluded.

Reference

Hishida M, Ishigami J, Shafi T, et al. Low proteinuria is associated with increased mortality in incident dialysis patients: Results from the CRIC study. Presented at the American Society of Nephrology’s Kidney Week 2019 meeting held November 5-10 in Washington DC. Abstract FR-PO431.