Angiotensin-converting enzyme inhibitors and probucol suppress the time-dependent increase in urinary Type IV collagen excretion of Type II diabetes mellitus patients with early diabetic nephropathy

Back,round: A multicenter prospective clinical trial was carried out in 9 N ational Hospitals in Japan to elucidate the time-dependent change in urinar y Type IV Collagen excretion rate of Type II diabetes mellitus (DM) patient s, and to investigate whether an angiotensin-converting enzyme inhibitor (A CE-I) or probucol is effective in preventing progression of renal involveme nt of diabetics by evaluating urinary Type IV Collagen excretion. Methods: Normo- and microalbuminuric patients with Type II DM were recruited. Patien ts were assigned to either the control (n = 88), ACE-I (n = 43) or probucol (n = 37) group and treated for 24 months. Besides albumin excretion rate ( AER), urinary Type IV Collagen excretion rate was also measured. Results: A lthough, AER, urinary N-acetyl-beta -D-glucosaminidase and beta (2)-microgl obulin excretion rates in the control group did not vary over 24 months, ur inary Type IV Collagen excretion rate in the control group increased time-d ependently (p < 0.01 vs baseline at 18 months and p < 0.005 vs baseline at 24 months). In the ACE-I and probucol groups, time-dependent increases in u rinary Type IV Collagen excretion rates were not observed. In the ACE-I gro up, the urinary Type IV Collagen excretion rate was significantly lower tha n that in the control group at 24 months (p < 0.05). In the probucol group, the urinary Type IV Collagen excretion rate was significantly lower than t hat in the control group at 6 months (p < 0.05). In the ACE-I group, AER de creased significantly compared with baseline at 18 months (p < 0.05) and at 24 months (p < 0.005). Conclusions: ACE-I has a beneficial effect and prob ucol may have a beneficial effect in preventing the progression of early di abetic nephropathy. Measurement of the urinary Type IV Collagen excretion r ate in combination with AER would be useful for the management of early ren al involvement in Type II DM.