The relationship between renal volume and renal function in autosomal dominant polycystic kidney disease

Background In patients with autosomal dominant polycystic kidney disease (ADPKD), renal cysts grow exponentially. Since remaining renal parenchyma has a capacity to compensate for the loss of glomerular filtration, the glomerular filtration rate (GFR) may be sustained until the disease progresses. The purpose of this study was to determine if renal volumetric indices and clinical parameters are associated with renal function in Japanese patients with ADPKD. Methods In 73 ADPKD patients (28 men, 45 women), the associations of mean systolic blood pressure, mean diastolic blood pressure, estimated GFR (eGFR), the amount of proteinuria and albuminuria, body mass index (BMI), brachial-ankle pulse wave velocity (baPWV), ankle-brachial index, and total kidney volume (TKV) were retrospectively analyzed. Results Multivariate linear regression analysis showed that eGFR was significantly and independently inversely correlated with patients' age and BMI. The median change in eGFR per year (Delta eGFR/y) was -2.8 ml/min/1.73 m(2)/year. Multiple linear regression analysis showed that Delta eGFR/y was significantly and independently inversely correlated with the change in TKV per year (Delta TKV/y). Multiple linear regression analysis showed that Delta TKV/y was significantly related to initial TKV and the change in albuminuria per year. Conclusions This study demonstrated a significant relationship between the change in renal function and the change in renal volume in Japanese ADPKD patients without renal insufficiency. It is possible that the volume measurements can be used as useful markers for disease progression in Japanese ADPKD patients.