Development and validation of equations estimating glomerular filtration rates in Chinese patients with type 2 diabetes.

Existing equations to calculate the estimated glomerular filtration rate (eGFR) were derived from nondiabetic Caucasian patients with chronic kidney disease. Here, we developed formulas to more accurately predict the eGFR in Chinese patients with type 2 diabetes and validated their performance in 202 type 2 diabetic and 46 nondiabetic individuals. Within the diabetic cohort, 135 were randomly assigned to a training group, whereas the remaining 67 diabetic and all of the nondiabetic patients were assigned to a validation group. Reference GFR was measured by (51)Cr-EDTA plasma clearance. The new eGFR-estimating formulas, derived using a stepwise regression model, were compared with existing prediction equations in the validation group. The formulas are: 313 x (Age)-0.494 (years) x [SCr]-1.059 (mg/dl) x [Alb]+0.485 (g/dl) for men, and 783 x (Age)-0.489 (years) x [SCr]-0.877 (mg/dl) x [SUN]-0.150 (mg/dl) for women. Compared with existing equations, the new formulas were more accurate and precise in calculating eGFR in diabetic patients, but, similar to other equations, were less accurate in the nondiabetic cohort. Our newly developed equations are simple to use and can be applied in routine clinical practice to calculate eGFR in Chinese patients with type 2 diabetes.

The renoprotective effects of structured care in a clinical trial setting in type 2 diabetic patients with nephropathy.

BACKGROUND: The RENAAL Study has confirmed the renoprotective effects of Losartan in type 2 diabetes. In this subgroup analysis from the RENAAL Study, we hypothesized that the intensive care received by patients in a clinical trial setting also reduced the rate of decline in renal function through optimization of all risk factors. METHODS: We compared the rate of deterioration in renal function, expressed as the regression coefficient of the monthly serum creatinine (SeCr) reciprocal (beta-1/Cr) in 55 Chinese type 2 diabetic patients before and after entry into the RENAAL Study. RESULTS: Of the 55 patients, 44 had at least three out-patient SeCr measurements both before (2.9+/-2.4 years) and after (3.3+/-0.8 years) entry into the study for evaluation. In the Losartan group (n = 24), the median beta-1/Cr fell from -11.4 x 10(-5) l micro mol(-1) month(-1) before entry into the trial to -4.7 x 10(-5) l micro mol(-1) month(-1) following entry (P = 0.001). The respective figures were -9.1 x 10(-5) and -5.0 x 10(-5) l micro mol(-1) month(-1) (P = 0.01) in the placebo group (n = 20). A decrease in beta-1/Cr was observed in 21 (87.5%) and 14 (70.0%) patients in the Losartan and placebo groups, respectively. Spot urinary albumin-to-creatinine ratio was reduced by 56% (P = 0.001) in the Losartan group but the change was not significant in the placebo group. At the end of the study, patients in both groups had lower blood pressure and better lipid control. The frequency of patient visits to doctors and nurses were doubled. CONCLUSIONS: The rate of renal function decline was significantly reduced in the majority of patients allocated to either Losartan or placebo following entry into the RENAAL study. These results suggest that in patients with diabetic nephropathy, implementation of a structured care protocol in a clinical trial setting facilities intensive treatment of risk factors confering renoprotective effects in addition to those resulting from Losartan treatment.