Is ACE Gene Polymorphism a Useful Marker for Diabetic Albuminuria in Japanese NIDDM Patients?

OBJECTIVE: We studied the relationship between an insertion/deletion (I/D) polymorphism in the ACE gene and albuminuria/proteinuria in Japanese NIDDM patients. RESEARCH DESIGN AND METHODS: A total of 142 Japanese NIDDM patients (89 men, 53 women) with a known diabetes duration of 14 +/- 5 (mean +/- SD) years and an age of 56 +/- 6 years were divided into three groups according to the stage of nephropathy: 41 patients with normoalbuminuria, 47 patients with microalbuminuria, and 54 with overt proteinuria. The three groups were similar in age, diabetes duration, and recent HbAic level. RESULTS: The distribution of DD, ID, and II genotypes of the ACE gene did not differ among the three groups (10, 46, and 44% in the normoalbuminuric patients; 13, 53, and 34% in the microalbuminuric patients; and 15, 46, and 39% in the proteinuric patients, respectively). Meanwhile, the frequency of the D allele in the proteinuric male patients was slightly higher than in the normoalbuminuric male patients (45 vs. 27%, chi 2 = 3.9, P < 0.05), while the D allele frequency was nonsignificantly lower in the proteinuric female patients than in the normoalbuminuric female patients. CONCLUSION: These results did not support the hypothesis that the genotype of the ACE gene would be a clinically useful genetic marker for predicting the development of nephropathy in Japanese NIDDM patients. However, the role of D allele of ACE gene in the progression of nephropathy in male patients remains to be seen.