Role of peritoneal equilibration test in assessing folate transport during peritoneal dialysis.

BACKGROUND: Low plasma folate levels have been reported in patients undergoing hemodialysis and peritoneal dialysis (PD) in clinical studies. However, folate transport has never been mentioned as a factor contributing to low plasma folate levels in patients undergoing PD. The peritoneal equilibrium test (PET) assesses the plasma creatinine level and glucose transport abilities. This study aimed to evaluate the association between plasma folate levels and folate transport during PD based on PET grades.

METHODS: This study recruited 50 patients who underwent PD for ≥ 3 months and were categorized according to PET grades. Data regarding plasma folate levels and dialysate folate were collected. The primary outcomes were the relationship between the PET grade and plasma folate level and between the PET grade and dialysate-to-plasma folate concentration ratio (D/P folate). Furthermore, the difference in the plasma folate level and D/P folate between men and women was assessed.

RESULTS: The plasma folate level and the D/P folate significantly differed among the four PET groups (both p < 0.001). PET grade was significantly negatively correlated with plasma folate levels (r=-0.56, p < 0.001) and positively correlated with D/P folate (r=0.686, p < 0.001). In subgroup analysis, neither the plasma folate level nor the D/P folate significantly differed between men and women.

CONCLUSIONS: Our study provides clinical evidence that the PET grade is associated with the plasma folate level and D/P folate, regardless of sex. Larger cohort studies are warranted to assess the importance of folate supplementation during PD based on PET grades.