Association between ACE gene polymorphism and diabetic nephropathy in South Indian patients

To study the association of ACE gene polymorphism and diabetic nephropathy in South Indian subjects.

Outpatient clinic of a specialized hospital.

The study included 109 South Indian type 2 diabetic patients (72 males and 37 females; age 56.7 plus/minus 9.0 years, mean plus/minus SD). The patients were subdivided into two groups: nephropathic (n=86) and normoalbuminuric patients (n=23).

Genomic DNA was isolated from the peripheral blood leukocytes. To determine the ACE genotype, genomic DNA was amplified by PCR initially using a flanking primer pair and, subsequently when necessary, with a primer pair that recognizes the insertion specific sequence for confirmation of the specificity of the amplification reactions.

ACE genotype distribution in the two study groups.

In the nephropathic patients, ID and DD genotypes were present in 52.3% and 27.9% of the patients, respectively as compared to 34.8% and 21.7% respectively in those with normoalbuminuria. The D allele was present in 80.2% of the nephropathic patients and 56.5% of the normoalbuminuric patients (chi-squared=4.28, P=0.039; odds ratio 3.12). Therefore, the higher percentage of II genotype in the normoalbuminuric group was 43.5% as compared to the 19.8% in nephropathic patients.

This study showed a positive association between the D allele (ID and DD genotype) of the ACE polymorphism and diabetic proteinuria in South Indian type 2 diabetic patients. Our findings are in keeping with several earlier studies showing a strong association of the D allele of the ACE gene with diabetic nephropathy.