Kidney Week

Abstract: TH-PO176

Early Post-Transplant Hypophosphatemia Predicts Better Graft Function After Kidney Transplantation

Session Information

• Transplantation: Cardiovascular and Metabolic Diseases
  October 25, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Transplantation

• 1802 Transplantation: Clinical

Authors

• Nakai, Kentaro, Japanese red cross fukuoka hospital, Fukuoka, Japan

Kentaro Nakai,

• Kuroki, Yusuke, Japanese red cross fukuoka hospital, Fukuoka, Japan

Yusuke Kuroki,

• Ishimatsu, Yukiko, Japanese red cross fukuoka hospital, Fukuoka, Japan

Yukiko Ishimatsu,

• Inoue, Megumi, Japanese red cross fukuoka hospital, Fukuoka, Japan

Megumi Inoue,

• Kohara, Chiaki, Japanese red cross fukuoka hospital, Fukuoka, Japan

Chiaki Kohara,

• Yamamoto, Shutaro, Japanese red cross fukuoka hospital, Fukuoka, Japan

Shutaro Yamamoto,

• Takae, Keita, Japanese red cross fukuoka hospital, Fukuoka, Japan

Keita Takae,

• Nishiki, Takehiro, Japanese red cross fukuoka hospital, Fukuoka, Japan

Takehiro Nishiki,

• Motoyama, Kentaro, Japanese red cross fukuoka hospital, Fukuoka, Japan

Kentaro Motoyama,

• Mitsuiki, Koji, Japanese red cross fukuoka hospital, Fukuoka, Japan

Koji Mitsuiki,

Background

Hyperphosphatemia is a well-established and independent risk factor for fracture, cardiovascular disease, and mortality in dialyzed and non-dialyzed patients with chronic kidney disease. Recent studies showed that high serum phosphate is associated with rapid decline in kidney function. Kidney transplantation dramatically decreases serum phosphate levels; however, the association of hypophosphatemia with graft survival remains unclear.

Methods

This was a single-center, retrospective study comprising 90 patients who underwent a kidney transplant at our institution between 2008 and 2016. Patients were divided into two groups, with and without hypophosphatemia. The hypophosphatemia was defined as those with less than or equal to the lowest quartile of serum phosphate levels at 3 months post-transplant. The endpoints were defined as 30% decrease in the eGFR. The cumulative kidney survival rates were calculated for each group using the Kaplan–Meier method, and the adjusted hazard ratio (HR) was calculated using the Cox regression model.

Results

No significant differences were observed in age, diabetes, living donor, pre-emptive kidney transplantation, ABO incompatibility, donor-specific antigen, or biochemical parameters of mineral bone disorders at transplantation between the two groups. The proportion of male recipients was higher in the hypophosphatemia group than in the control group (88% vs. 65%). The hypophosphatemia group received a higher proportion of cinacalcet prescriptions during the dialysis period than the control group (33% vs. 14%). The median follow-up duration was 47.5 months, and the 90 transplantations resulted in 6 cases of graft loss, 2 of mortality, and 37 of 30% decline in eGFR. The Kaplan–Meier analysis revealed that patients in the hypophosphatemia group had a significantly lower risk of 30% decline in eGFR than those in the control group. After adjusting for confounding factors, hypophosphatemia was associated with a significantly lower risk of 30% decline in eGFR [HR, 0.37; 95% confidence interval (CI), 0.14–0.88] compared with the control group.

Conclusion

The results of the present study suggested that hypophosphatemia at 3 months post transplant is a favorable sign for the successful outcome of transplantation.