Relationship Between Serum Phosphorus Concentration And Renal Prognosis In Patients With Type 2 Diabetes Mellitus With Proteinuria

Background Blood phosphorus is an influential factor in the incidence and mortality of cardiovascular events in chronic kidney disease,especially in dialysis patients.Studies have shown that high blood phosphorus concentration can increase the risk of progression to ESRD in patients with stage CKD3-5,and have found an increased risk of progression to ESRD compared with those without diabetes.Patients with Ig A nephropathy and diabetic nephropathy were divided into four groups according to blood phosphorus concentration,cox multivariate analysis showed that high phosphorus group had an increased risk of reaching renal end point compared with low phosphorus group,suggesting that blood phosphorus concentration was a risk factor for renal prognosis in diabetic kidney disease.At present,there are few studies on the effect of blood phosphorus concentration on renal prognosis,and the relationship between blood phosphorus concentration and renal prognosis of diabetic kidney disease is not clear.Diabetic kidney disease progress faster than other chronic kidney disease,comprehensive prevention and treatment is particularly important,this study intends to study blood phosphorus and kidney prognosis on the basis of comprehensive analysis of other indicators.Objective To investigate the relationship between serum phosphorus concentration and renal prognosis in patients with type 2 diabetes mellitus with proteinuria.Methods From January 2011 to December 2015,the patients with type 2 diabetes mellitus with proteinuria were divided into three groups according to the triquartile of blood phosphorus concentration:low?<1.12mmol/L?,middle?1.12-1.32mmol/L?and high?>1.32mmol/L?.The differences of demography and clinical biochemical indexes among the three groups were compared.The study endpoint was an estimated decrease in glomerular filtration rate?e GFR?by more than 50%,entry into ESRD(e GFR<15ml·min^-1·?1.73 m²?^-1)or initiation of renal replacement therapy.Cox regression analysis,kaplan-meier and hierarchical analysis were used to analyze the effect of serum phosphorus concentration on renal prognosis.Results Compared with the low-level group,the high-level group had higher age,lower estimated glomerular filtration rate?e GFR?and hemoglobin concentration?P=0.035,0.010 and 0.039,respectively?.The proportion of ACEI or ARB drugs used in patients with high blood phosphorus group was lower than that in patients with middle and low blood phosphorus group?P=0.005?.Baseline e GFR,hemoglobin concentra-tion,serum albumin concentration,use of ACEI or ARB drugs were protective factors for renal prognosis in diabetic patients with proteinuria?HR=0.963,95%CI 0.950-0.975,P<0.001;HR=0.961,95%CI 0.949-0.973,P<0.001;HR=0.907,95%CI0.872-0.944,P<0.001;HR=0.142,95%CI 0.078-0.262,P<0.001?.Systolic blood pressure,low-density lipoprotein,urinary albumin,urinary albumin excretion rate?200ug/min,urinary total protein were risk factors for renal prognosis?HR=1.032,95%CI 1.019-1.046,P<0.001;HR=1.463,95%CI 1.144-1.870,P=0.002;HR=1.000,95%CI 1.000-1.001,P<0.001;HR=10.660,95%CI 3.808-29.848,P<0.001;HR=1.000,95%CI 1.000-1.000,P<0.001?.After adjusting for related confounding factors,multivariate Cox analysis showed that for every 0.1mmol/L increase in blood phosphorus,the risk of renal function progression to the end of the study increased by16.4%?HR=1.164,95%CI interval?1.021,1.328?,P=0.024?.The analysis of K-M survival curve showed that the renal prognosis of patients in the high phosphorus group was worse than that in the low phosphorus group.The results of smooth curve fitting showed that the relationship between serum phosphorus and renal prognosis was linear.The results of stratified analysis showed that total protein in urine?500mg/24h,urinary protein excretion rate?200ug/min and eGFR<60ml·min^-1·?1.73m²?^-1is factor in the worse renal prognosis of diabetic patients with proteinuria?HR=1.296,95%CI 1.125-1.493,P for interaction=0.001;HR=1.267,95%CI 1.096-1.463,P for interaction=0.003;HR=1.325,95%CI 1.132-1.551,P for interaction=0.003;HR=1.325,95%CI 1.132-1.551 interaction=0.027?.However,when the total protein in urine was less than 500mg/24h,the excretion rate of protein in urine was less than200ug/min and e GFR?60ml·min^-1·?1.73m²?^-1,the influence of blood phosphorus on the renal prognosis of diabetic patients with proteinuria was weakened?HR=0.494,95%Ci 0.270-0.904;HR=0.545,95%CI 0.315-0.943;HR=0.792,95%CI 0.387-1.620?.The area under ROC curve was 0.741,and the best critical point of blood phosphorus was 1.275mmol/L,that is to say,when the blood phosphorus was more than 1.275mmol/L,the risk of progression to the end of the study increased significantly.Conclusion?1?Blood phosphorus is an independent risk factor for poor renal prognosis in patients with type 2 diabetes with proteinuria.?2?The risk of renal progression to the end of the study increased by 16.4% for every 0.1 mmol/L increase in serum phosphorus concentration in diabetic patients with proteinuria.?3?The risk of deterioration of renal function in diabetic patients with proteinuria increased significantly when serum phosphorus concentration exceeded 1.275 mmol/L.?4?The effect of blood phosphorus level on renal prognosis of diabetic patients with proteinuria was more significant when urinary total protein?500 mg/24 h,urinary protein excretion rate ?200 ug/min and e GFR<60ml · min^-1 ·?1.73m²?^-1.