Sir.—The frequency of diabetic nephropathy appears to be decreasing. Studies of the incidence of diabetic microvascular disease from the early 1950s and 1960s indicated that about 50% of patients with insulin-dependent diabetes would develop renal disease after ten to 30 years of diabetes.1-3 More recent studies indicate that the percent of patients developing renal failure is about 35%. Kofoed-Enevoldsen et al4 and Krolewski et al5 indicate that both hyperglycemia and individual susceptibility play a role in the development of diabetic renal disease. Thus, patients with higher blood glucose levels are more likely to develop this complication of diabetes.
The quantitation of the severity of hyperglycemia has only been possible in the last ten years with the advent of the measurement of glycosylated hemoglobin and the feasibility of monitoring blood glucose levels throughout the day at home. We have been measuring the former since July 1979 and