AUA 2017: Stone Disease: Epidemiology & Evaluation I

Boston, MA (UroToday.com) Obesity is a common problem in United States and worldwide. It has been shown that the body mass index (BMI) is suboptimal measurement of body fat. Unlike BMI, visceral fat has been shown to be an accurate surrogate for percent of body fat. Studies have shown that visceral fat is metabolically active and an increased amount of visceral fat if related to variety of malignancies such as colon cancer and kidney cancer. Additionally, prior studies have shown positive correlations between uric acid stone formation and low urine pH, visceral fat area (VFA) and the ratio of visceral to subcutaneous adipose tissue (VFA%). Authors in this study assessed the association of CT-based visceral obesity with 24-hour urine metabolic risk factors stone composition in kidney stone formers (KSF).

In order to assess this hypothesis, authors performed a retrospective analysis of 99 kidney stone formers who had abdominal computer tomography (CT) imaging and 24-hour urine studies at a single institution. For each patient, a single axial area measurement was obtained at L3-4 in females and L2-3 in males for visceral fat area (VFA) and subcutaneous fat area (SFA). Patient demographics, serum chemistry, 24-hour urine parameters and stone composition were collected for each patient.

Authors reported that KSF warrant screening to visceral obesity and VFA can be assessed efficiently on non-contrast CT imaging already obtained for the diagnosis of nephrolithiasis. High urinary sodium and low protein were associated with uric acid stone formation. CT based diagnosis of visceral obesity can direct which patients may benefit from alkali therapy to treat calculi with dissolution or decrease in size.

Authors: Nishant D Patel MD*, Ryan Ward MD, Juan Calle MD, Erick Remer MD, Manoj Monga MD

Affiliation: Cleveland Clinic, Cleveland, OH

Written By: Zhamshid Okhunov, MD, Department of Urology, University of California, Irvine

at the 2017 AUA Annual Meeting - May 12 - 16, 2017 – Boston, Massachusetts, USA