[Relationship between serum angiotensin I-converting enzyme activity and diabetic nephropathy in patients with type II diabetes].

To clarify the relationship between serum angiotensin I-converting enzyme (ACE) activity and Type II diabetic patients with or without diabetic nephropathy. We examined 36 healthy controls, 58 Type II diabetic patients without diabetic nephropathy, and 50 Type II diabetic with diabetic nephropathy. The diabetic duration of all of Type II diabetic patients was more than 5 years. All patients matched well in age and BMI. An insertion/deletion polymorphism of ACE gene was identified by polymerase chain reaction(PCR). Serum ACE activity was determined using spectrophotometry. Although the distribution of DD, ID, and II genotypes of the ACE gene did not differ among the three groups, serum ACE activity was significantly higher in Type II diabetic patients with diabetic nephropathy than in that without diabetic nephropathy(P < 0.05), especially in the groups with D allele of ACE gene. Serum ACE activity had no difference between healthy controls and Type II diabetic patients without diabetic nephropathy. There is no association between serum ACE activity and Type II diabetic patients without diabetic nephropathy in any genotype of ACE gene. The increasing serum ACE activity plays a role in the initiation of diabetic nephropathy or may serve as a risk marker for later development of overt diabetic nephropathy in Type II diabetic patients.