Renal involvement in subjects with peripheral atherosclerosis

Background: Ischemic nephropathy is an important cause of renal failure in western countries. Subclinical renal function abnormalities may exist in pa tients wi[th extrarenal atherosclerosis, and may precede the onset of overt ischemic nephropathy. Methods: To assess the impact of extrarenal atherosclerosis on the kidney, we evaluated renal function in 89 subjects with differing degrees of periph eral atherosclerosis, without manifest clinical or laboratory signs of isch emic nephropathy and renovascular hypertension. All laboratory testing, ult rasonography with Doppler analysis for the localization of peripheral vascu lar disease (carotid and lower limb arteries), and non-invasive evaluation of renal function by radionuclide studies of renal plasma flow (MAG(3) clea rance) and glomerular filtration (DTPA clearance), as well as total, LDL an d HDL cholesterol, and triglycerides were determined; smoking habit was rec orded. By combining sonographic data on arterial tree stenosis (ATS), the s ubjects were grouped according to the atherosclerotic vascular damage (ATS involvement). Results: Despite no change in plasma creatinine and DTPA clearance (from 91 .58 +/- 26.53 mL/min /1.73 m(2) to 93.47 +/- 24.82), MAG(3) clearance progr essively declined with the severity of vascular damage (from 244.86 +/- 60. 60 mL/min/1.73 m(2) to 173.59+/-58.74). Stepwise multiple regression analys is indicated that MAG(3) clearance was best explained by ATS involvement (s tandardized beta coefficient -0.40; p<0.001), smoking habit (-0.34; p= 0.00 4), and scrum LDI-cholesterol (-0.24; p<0.035). Conclusions: The renal hemodynamic profile in atherosclerotic patients migh t constitute functional evidence of the silent phase of ischemic renal dise ase. The findings suggest that renal function should be carefully assessed in patients with extrarenal atherosclerosis, particularly in those with cla ssic cardiovascular risk factors.