Objective: To study the association between apolipoprotein E (apoE) genotype and the rate of decline in glomerular filtration rate (GFR) in type 2 diabetic patients in a 9-year prospective study.
Methods: GFR was determined in 84 type 2 diabetic patients by plasma clearance of (51)Cr-EDTA at baseline and after 9 years of follow-up. ApoE genotypes were determined by polymerase chain reaction and restriction enzyme HHAI digestion and designated as epsilon4 allele group (apoE4/2, 4/3 and 4/4 genotypes; n = 20) and non-epsilon4 allele group (apoE3/3 and E3/2 genotypes; n = 64). We focused our analysis on those patients who were more likely to progress to diabetic renal disease, i.e. whose GFR fell more than expected in the normal course of ageing [1 ml x min(-1) x (1.73 m(2))(-1) per year].
Results: In the whole population, the decline in the GFR did not differ statistically significantly between the apoE genotype groups [p = 0.65 with analysis of variance for repeated variables (RANOVA) for interaction between apoE genotype group and time point]. However, among patients whose GFR changed more than 9 ml x min(-1) x (1.73 m(2))(-1), GFR showed a statistically significantly greater decline in the epsilon4 allele group (n = 11) than in the non-epsilon4 allele group (n = 43) [from 116 +/- 36 to 80 +/- 29 ml x min(-1) x (1.73 m(2))(-1) vs. from 119 +/- 20 to 96 +/- 18 ml x min(-1) x (1.73 m(2))(-1); p = 0.005 with RANOVA].
Conclusion: ApoE allele epsilon4 may speed up the rate of decline of the GFR in patients with progressive diabetic renal disease.
Copyright 2003 National Science Council, ROC and S. Karger AG, Basel