Comparison of early renal dysfunction in type I and type II diabetes: differing associations with blood pressure and glycaemic control

Abstract

This study has investigated the relationship of glycaemic control, blood pressure and proteinuria to early renal dysfunction in a cohort of 50 type I and 65 type II diabetics, with renal function ranging from normal to mildly impaired (serum creatinine less than 0.2 mM). Repeated measurements were made over a mean interval of 7 years and mean data from each subject were analysed by stepwise multiple linear regression. This enabled associations to be determined independently of the confounding influence of age and duration of disease. In type I diabetics, mean creatinine clearance was inversely related to systolic blood pressure (P less than 0.001), glycosylated haemoglobin (P less than 0.05), fasting plasma glucose (P less than 0.05) and to the renal clearance of albumin (P less than 0.001), transferrin (P less than 0.01) and IgG (P less than 0.05). By contrast, in type II diabetics, none of these associations were significant. No significant relationships were found with the rate of decline of creatinine clearance in either type of diabetic. Further studies will be needed to determine whether the changes in blood pressure and glycaemic control precede or follow the development of renal disease. However, these findings raise the possibility of a difference in the pathogenesis of renal disease in type I and type II diabetes.