Abstract:

ABSTRACT Objective: To investigate the association between hyperphosphatemia and renal injuries and long-term outcome in patients with type 2 diabetes and diabetic nephropathy (DN). Methodology: From January 2004 to July 2015 in National Clinical Research Center of Kidney Diseases, Jinling Hospital, a total of five hundred ninety seven patients with type 2 diabetes and DN were enrolled in this retrospective study. The median follow-up period was 36 months. The prevalence of hyperphosphatemia and the association between hyperphosphatemia and renal injuries and the risk of renal outcome were analyzed. Results: The prevalence of hyperphosphatemia (serum phosphate >1.45 mmol/L) in the enrolled DN patients with eGFR >90, between 60 and 90, and <60 ml/min/1.73 m2 were 25/214 (11.7%), 25/150 (16.7%), and 71/233 (30.5%), respectively. Hyperphosphatemia was significantly associated with enhanced tubulointerstitial injury markers (P<0.01) as well as a high rate of tubulointerstitial injury (interstitial fibrosis tubular atrophy scores and interstitial inflammation scores, P<0.05) in DN patients with eGFR ≥60 ml/min/1.73 m2. Additionally, the patients with baseline serum phosphate levels in higher quartiles had a higher cumulative incidence of end-stage renal disease (ESRD) (log-rank, P<0.01). Risk persisted after adjusting for age, sex, blood pressure, lipid level, body mass index, proteinuria, plasma calcium and eGFR (P <0.001). Conclusion: These findings suggested that hyperphosphatemia is an independent risk factor of ESRD and significantly associated with tubulointerstitial injury in patients with DN, especially in patients with eGFR ≥60 ml/min/1.73 m2.

Key words: diabetic nephropathy , hyperphosphatemia, renal injury, long-term outcome;