Hypertension and Renal Function in Autosomal Dominant Polycystic Kidney Disease according to Renal Structural Indices

Lee, Kyu Beck; Kim, Hyang; Lee, Youngrae

Abstract

Autosomal dominant polycystic kidney disease (ADPKD) is a common hereditary disorder, and its major morbidities are hypertension and renal failure. It is a characteristic feature of ADPKD that renal cysts increase in size and number with age continuously. Hypertension and renal failure in ADPKD result from compression of residual normal renal parenchyma by expanding cysts, since renal tissue is trapped within the poorly distensible renal capsule. Renal structural deformities in ADPKD occur prior to hypertension and renal failure. The present study was undertaken to explore the potential role of renal cyst enlargement in initiating hypertension and renal failure in ADPKD. We therefore measured renal structural indices by computed tomography(CT) to examine the relation between clinical progression and renal structural deformities. Sixty-seven adult subjects(45+/-12 years, male-female ratio 42 : 25) with ADPKD were studied at our PKD clinic from 1997 to 2000, and a complete abdominal CT was performed on all subjects. One radiologist measured the renal structural indices which were renal length, volume, RSI(anatomical renal severity index) and maximal cyst size. The renal structural indices were significantly greater in hypertensive group compared to the normotensive group (hypertensive 833+/-585 vs. normotensive 360+/-154mL/1.73m2, p<0.01). The renal structural indices were significantly greater in renal failure group compared to the normal renal function group(renal failure 1,171+/-700 vs. normal 499+/-335mL/1.73m2, p<0.01). The renal function in ADPKD correlated with the renal structural indices. We concluded that the clinical progression in ADPKD correlates with the renal structural indices well. These structural indices provide considerable information about the progression of ADPKD.