Abstract: Angiotensin Ⅰ converting enzyme (ACE) genotypes of 274 cases with type Ⅱ diabetes mellitus without nephropathy (NIDDM), 102 with diabetic nephropathy complicated with renal insufficiency (RI) and 124 diabetic nephropathy without renal insufficiency (NRI), and 242 controls were determined by polymerase chain reaction (PCR) amplification of the insertion/deletion polymorphism of ACE gene. Serum ACE levels were measured with ultraviolet photometry as well. The increased frequencies of D allele (0.52) and DD genotype (0.30) were observed in 102 subjects with RI compared with 242 control subjects (0.38 and 0.16 respectively, P<0.05 and P<0.001). The odds ratio associated with DD/II genotype was 2.91 (95% CI 1.52～5.58, P<0.01) for RI. Individuals with DD genotype had the highest serum ACE in all groups, and with II genotype the lowest levels. Patients with diabetic nephropathy and RI had higher serum ACE levels compared with controls (P<0.001). There was no difference in allele distribution between 274 NIDDM patients, 124 patients with NRI and the controls. ACE gene polymorphism is associated with serum ACE levels (r=0.65, P<0.01). This result suggested that the raised serum ACE concentration may play a role in the initiation and development of diabetic nephropathy; deletion polymorphism of the ACE gene might be an important risk factor of progression to end stage renal failure in Chinese type Ⅱ diabetes patients.

Key words: angiotensin converting enzyme, gene polymorphism, diabetic nephropathy