Study On GFR Equations And Uae In Type 2 Diabetes Mellitus Patients Complicated With Hypertension

Background:Diabetic kidney disease(DKD)has gradually become the leading cause of end-stage renal disease(ESRD)in excess of glomerulonephritis worldwide,and diabetic interaction with hypertension,a common complication of diabetes,to damage the kidney which makes the impairment of renal function more severely.However,there are not many researches on the Characteristics and progress of kidney impairment of type 2diabetes mellitus patients with hypertension in China,and each have advantages and disadvantages of assessment of renal function in patients with such means.At present,Glomerular filtration rate(GFR)and proteinuria are the two mostly used indices of renal function for diabetic patients.GFR is of great importance on evaluating the function of kidney.Accurately assessing GFR in patients may provide messages on diagnose,CKD staging and treatments.The Cockcroft and Gault-formula(C-G)and the Modification of Diet in Renal Disease(MDRD)equations are the most widely used formulas for estimating GFR.Moreover,the modified MDRD7 equation for Chinese CKD patients proposed by Ying-Chun Maetc.is also commonly known.Regrettably,whether these equations are suitable for the evaluation of renal function of type 2 diabetes mellitus patients with hypertension still remains to be validated.Proteinuria is commonly expressed as urinary albumin excretion rate(UAE).UAE is an early indicator of renal function damage,but new researches showed the limits of UAE.Objective: Analysis the clinical features of patients with type 2 diabetes with hypertension.Discuss the significance of UAE in the renal function evaluation.Estimated glomerular filtration rates measured by C-G/BSA formula,MDRD1 equation,the abbreviated MDRD equation and the modified MDRD7 Chinese equation were compared with GFR measured by 99 m Tc-DTPA nephro-dynamicimaging(recommended as gold standard)to determine the applicability of the four equations on evaluating the renal function of T2 DM with hypertension.Find an equation which may predict the renal function in type 2 diabetes mellitus patients with hypertension.Methods: A total of 271 adult T2 DM patients with hypertension hospitalized in endocrine department of Shanghai Changzheng Hospital from October 2014 to November2016 were investigated in our research.All the patients were measured reference glomerular filtration(r GFR)by 99 m Tc-DTPA nephro-dynamicimaging,and simultaneously recorded serum creatinine,blood urea nitrogen,ratio of urinary microalbumin to creatinine and serum albumin etc.and the age,sex,height and weight of patients were also collected.The clinical indicators and r GFR do pearson or spearman correlation analysis.According to Urinary albumin excretion rate,analyzing the applicability of UAE in the assessment of renal function.Comparing the bias,absolute bias,percentage relative to r GFR,and accuracy(percentage estimates±30% of r GFR,p30)between e GFRs calculated by C-G/BSA formula,MDRD1 equation,the abbreviated MDRD equation and the modified MDRD7 Chinese equation separately and r GFR.Linear correlation and linear regression were used to analyze the correlation of e GFRs and r GFR.Analyze the precision of the four equations by Bland-Altman.Building a new GFR equation fitting for the evaluation of renal function in T2 DM patients complicated with hypertension by method of leave-one–out and k-Fold Cross Validation.Results:(1)The factor of age,serum albumin,BUN,Scr,Urine microalbumin in24 h,ACR and total urinary protein in 24 h are correlated with r GFR significantly.Early in kidney disease,UAE as an independent testing index prediction kidney disease result is not very well;(2)There were significant differences between the e GFRs measured by the four equations and the r GFR measured by 99 m Tc-DTPA nephro-dynamicimaging: C-G/BSA formula underestimated the r GFR,while the other three overestimated that,among which MDRD1 equation showed the least bias,and modified MDRD7 Chinese equation the most.The difference between e GFR calculated by C-G/BSA formula and r GFR is higher in GFR≥ 60ml/min/1.73m2 group than GFR < 60ml/min/1.73m2 group.And the other equations showed the opposite.(3)Overall results of C-G/BSA formula,MDRD1 equation,the abbreviated MDRD equation and the modified MDRD7 Chinese equation were: P3077.12%/73.43%/57.93%/76.01%.P30 of all the four equations were higher in GFR ≥60ml/min/1.73m2 group.P30 figure is lower in the abbreviated MDRD equation.(4)The four e GFRs are corrected with r GFR significantly,and the correlation coefficients are similar.In GFR ≥ 60ml/min/1.73m2 group,all the coefficients are lower than that in wholeseparately.However,there is no significant correlation between e GFRs and r GFR in GFR<60ml/min/1.73m2 group.(5)The accuracy of staging CKD expressed as kappa value in C-G/BSA formula,MDRD1 equation,the abbreviated MDRD equation and the modified MDRD7 Chinese equation were 0.437,0.499,0.47,0.451 respectively.(6)C-G/BSA formula showed improved precision than the other equations in Bland-Altman analysis,and modified MDRD7 Chinese equation the worst.(7)new equation expresses as:e GFR= 265.88×SCr-0.57×age-0.42×albumin0.28×ACR-0.0076×(1.24 female)。The correlation coefficient is 0.50614,less than the other equations;but it shows advantages in biascompared with abbreviated MDRD equation and modified MDRD7 Chinese equation;P30are improved than the abbreviated MDRD equation;it shows the same precision with the four equations,but smaller deviation than C-G/BSA formula and the abbreviated MDRD equation.Conclusions: In the early days of renal disease,the urine microalbumin as an independent test indicator predicted that renal disease outcomes were not ideal.however,Urinary albumin excretion rate is corrected with r GFR,which plays an important role in evaluating renal function.In evaluation of GFR of T2 DM patients with hypertension,the C-G/BSA formula,MDRD1 equation,the abbreviated MDRD equation and the modified MDRD7 Chinese equation are all obviously bias with the real r GFR,and the modified MDRD7 Chinese equation has deteriorated bias and precision than others,while the abbreviated MDRD equation has lower accuracy.Four equations staging accuracy has no obvious difference.The new equation has advantages on bias than the abbreviated MDRD equation and modified MDRD7 Chinese equation,but it needs further validation before applied in the evaluaction of renal function of T2 DM patients complicated with hypertension.