ROLE OF GLYCEMIC CONTROL AND BLOOD-PRESSURE IN THE DEVELOPMENT AND PROGRESSION OF NEPHROPATHY IN ELDERLY JAPANESE NIDDM PATIENTS

OBJECTIVE - To investigate che role of glycemic control and blood pres sure in the development and progression of nephropathy and to suggest goals for glycemic control and blood pressure for the prevention of ne phropathy in elderly Japanese NIDDM patients. RESEARCH DESIGN AND METH ODS-A total of 123 age- and diabetes duration-matched elderly Japanese NIDDM patients (ages 60-75 years; 74 normoalbuminuric and 49 microalb uminuric) were retrospectively studied for 6 years. RESULTS - The grou p that developed microalbuminuria from normoalbuminuria (group NM: n = 24) showed a higher 6-year mean HbA(1c) than the group that remained normoalbuminuric (group NN: n = 50; 9.0 +/- 0.8 vs. 8.1 +/- 0.8%, P < 0.01) in spite of no significant difference in 6-year mean blood press ure (MBP). On the other hand, the group that progressed from microalbu minuria to overt proteinuria (group MP: n = 26) showed a higher g-year MBP than the group that remained microalbuminuric (group MM: n = 23; 106 +/- 5 vs. 95 +/- 6 mmHg, P < 0.01) in spite of no significant diff erence in 6-year mean HbA(1c). The cutoff level of HbA(1c) separating group NN from group NM was 8.5% (normal range less than or equal to 6. 5%), and that of MBP separating group MM from group MP was 100 mmHg. C ONCLUSIONS - Glycemic control is a more potent factor than blood press ure level on the development of microalbuminuria. However, as far as t he progression of microalbuminuria to overt proteinuria is concerned, hypertension is the most crucial factor in elderly NIDDM patients. Sug gested goals for glycemic control and blood pressure level for the pre vention of nephropathy in elderly Japanese patients are an HbA(1c) of less than or equal to 8.5% (equivalent to 7.8% in the current measurem ent of stable HbA(1c); normal range less than or equal to 5.8%) and an MBP of less than or equal to 100 mmHg.