Influence of glycemic control and hypertension on urinary microprotein excretion in non-insulin-dependent diabetes mellitus

In order to evaluate the influence of glycemic control and hypertension on the development of diabetic nephropathy, we measured urinary excretion of albumin (AER) and other microproteins in non-insulin-dependent diabetes mellitus (NIDDM), and reexamined the 103 patients who had had AER < 300 μg/min at the initial study 12–18 months later. AER in the patients with HbA₁c ≧ 7.5% increased significantly in both the normoalbuminuric (AER < 30 μg/min) and microalbuminuric (30–300 μg/min) groups, whereas no significant change in AER was observed in the patients with HbA₁c < 7.5%. In the microalbuminuric group, AER in both hypertensive and normotensive patients increased significantly. In this group, the change in AER correlated positively with the change in α₁-microglobulin (α 1M). These results indicate that glycemic control has a greater influence on the development of nephropathy in its early stage than hypertension and that α 1M is as a good predictor of nephropathy as albumin.