Renal vascular changes in renal disease independent of hypertension.

Abstract

Cardiovascular disease is common in patients with renal disease, but little is known about the effect of renal disease and loss of renal function on vascular morphology. Intima proliferation of small renal arteries, which correlates with atherosclerosis in the aorta, is sometimes present in renal disease and has been shown to increase with age and hypertension. We studied the effect of chronic renal disease and renal function, independent of hypertension, on intima proliferation. We retrospectively selected renal biopsies of subjects in whom a glomerular filtration rate (GFR) measurement with [(125)I] iothalamate had been performed. To separate the effects of renal disease and renal function, we selected biopsies from (A) normotensive controls undergoing nephrectomy because of renal carcinomas; (B) normotensive patients with renal disease and GFR > 90 ml/min; (C) normotensive patients with GFR 30-90 ml/min, and (D) hypertensive patients with a GFR < 90 ml/min. The area of the arteriolar lumen, intima, and media were measured. No significant changes from control subjects were observed in group B. Intima proliferation was observed when renal function declined (intima/total vessel surface ratio was 0.262 +/- 0.071 in group C, 0.192 +/- 0.032 in group A, and 0.205 +/- 0.035 in group B, P < 0.05). The intima proliferation was aggravated in patients with renal insufficiency and hypertension (0.333 +/- 0.121, P < 0.05). Media surface area was not different between groups. Renal disease with preserved GFR does not cause significant intima proliferation of small renal arteries. Loss of renal function is accompanied by intima proliferation, even in the absence of systemic hypertension.