ANGIOTENSIN-CONVERTING ENZYME GENE POLYMORPHISM AND RENAL-ARTERY RESISTANCE IN PATIENTS WITH INSULIN-DEPENDENT DIABETES-MELLITUS

The present study was carried out to elucidate whether renal hemodynam ic changes are associated with angiotensin converting enzyme (ACE) gen e polymorphism in patients with insulin dependent diabetes mellitus (I DDM). We studied 32 Japanese patients with IDDM (aged 15 +/- 3 years i n mean +/- SD) without renal failure or retinopathy. Renal hemodynamic s were examined by duplex Doppler sonography and arterial resistance i ndex was calculated. ACE genotypes were determined by polymerase chain reaction amplification. Resistance index (RI) of arcuate arteries In IDDM patients with DD genotype was significantly elevated, being 0.64 +/- 0.04, 0.66 +/- 0.05, and 0.71 +/- 0.05 for II, ID and DD genotype groups, respectively (II vs. DD, p < 0.02). In patients with DD genoty pe with normoalbuminuria (n = 27), it was also significantly elevated in DD genotype patients (II vs. DD, p < 0.02). In addition, multiple r egression analysis with a forward elimination procedure showed that on ly the ACE genotype was associated with RI of arcuate arteries (R(2) = 0.24, p < 0.01) among the parameters of sex, age, IDDM duration, body mass index, HbA1c, plasma glucose levels, serum levels of total chole sterol and creatinine, urinary albumin excretion index, mean blood pre ssure and ACE genotype. The present study demonstrated that renal arte rial resistance is elevated in IDDM patients with DD genotype. ACE gen e polymorphism which could be linked to intrarenal circulatory disturb ance may be associated with the initiation and progression of diabetic nephropathy.