2University of Health Sciences Turkey, Bakırköy Dr. Sadi Konuk Training and Research Hospital, Clinic of Nephrology, İstanbul, Turkey
3University of Health Sciences Turkey, Gülhane Training and Research Hospital, Clinic of Nephrology, İstanbul, Turkey
4University of Health Sciences Turkey, Bakırköy Dr. Sadi Konuk Training and Research Hospital, Clinic of Internal Medicine, İstanbul, Turkey
5İstanbul Göztepe Medical Park Hospital, Clinic of Nephrology, İstanbul, Turkey
Abstract
Objective: Hypophosphatemia is a common complication of kidney transplantation. However, the relationship between hypophosphatemia and renal function in patients undergoing kidney transplantation remains uncertain. This study aimed to evaluate the relationship between serum phosphate levels and graft function in patients undergoing renal transplantation within the first 3 months after transplantation.
Methods: We conducted a retrospective cohort study included patients who underwent kidney transplantation between 2016 and 2020. Data on patient demographics and clinical and laboratory findings, such as serum creatinine, phosphate, calcium, hemoglobin and parathormone levels, were collected from the hospital database.
Results: Hypophosphatemia was observed in 59 (47.5%), 41 (33.06%) and 32 (25.8%) patients at the 1st week, 1st month and 3rd month after transplantation. The post-transplant median creatinine levels decreased to 1.36 (1.01-1.58) mg/dL, 1.22 (1.04-1.5) mg/dL, and 1.20 (1.0-1.49) mg/dL at week 1, month 1 and month 3. The median phosphate level before transplantation was 5.1 (4.8-5.7) mg/dL. This value decreased to 2.5 (1.8-3.27) mg/dL, 2.82 (2.05-3.55) mg/dL, and 3.01 (2.30-3.73) mg/dL at week 1, month 1 and month 3. There was no significant difference in serum creatinine and estimated glomerular filtration rate between the hypophosphatemic and normophosphatemic groups at week 1 (p=0.839, p=0.931), month 1 (p=0.453, p=0.441) and month 3 (p=0.592, p=0.570). The causes of end-stage renal disease were chronic glomerulonephritis in 20 patients (16.1%), hypertension in 35 (28.2%), diabetes mellitus in 18 (14.5%) (17 type 2 and 1 type 1), and secondary amyloidosis in 5 (4%). Nephrolithiasis, autosomal dominant polycystic kidney disease, vesicoureteral reflux, and no identifiable cause were found in 7 (5.6%), 4 (3.2%), 16 (12.9%) and 19 (15.3%), patients respectively.
Conclusion: Hypophosphatemia is common after kidney transplantation. No correlation was identified between hypophosphatemia and functional performance of the transplanted kidney.