The visceral fat compartment is independently associated with changes in urine constituent excretion in a stone forming population

Abstract

The objective of this study was to identify the independent effect of visceral fat on urine constituent excretion in a stone forming population. Using a database of 382 kidney stone patients with available visceral fat quantification, we created multiple linear regression models predicting changes in urinary solutes based on visceral fat area and body mass-index, divided by gender. Chi-square tests were used to compare stone composition by body mass-index and visceral fat area. Visceral fat predicts increases in urinary creatinine, sodium, and volume in men, but only urinary phosphate in women. In women, total body mass-index does not appear to modify this effect, but in men it is more pronounced in overweight patients for creatinine and volume only. Elevated visceral fat is associated with increased probability of uric acid stone composition. Different fat compartments likely effect urine composition in different ways. This effect appears to be different in men and women. Understanding and quantifying the effects of different fat compartments is probably important to understanding the metabolism of urolithiasis.

The Relationship Between Nephrolithiasis Risk with Body Fat Measured by Body Composition Analyzer in Obese Peopale

“…Low urinary pH abnormally is the major determinant in the increasing idiopathic uric acid stones ( 20 ). Elevated visceral fat is associated with increased probability of uric acid stone composition ( 6 , 25 ) and has better predictive value than BMI or urinary pH to classify the types of stone ( 6 ). There is also an evidence to suggest that higher adiposity, especially subcutaneous (non-visceral) fat, may also be associated with better outcomes in the end-stage renal disease patients ( 26 ).…”

Editorial Comment to Recurrent stone‐forming patients have high visceral fat ratio based on computed tomography images compared to first‐time stone‐forming patients

“…In addition to the present study, other earlier studies showed that visceral fat is associated with uric acid stones and predicts increases in urinary parameters, such as sodium and phosphate . As the present study did not include subanalysis for the stone component, type and data of urinary parameters, validation from those aspects might be more useful to better understand their result as to why a high visceral fat volume ratio results in stone recurrence.…”

“…In addition to the present study, other earlier studies showed that visceral fat is associated with uric acid stones and predicts increases in urinary parameters, such as sodium and phosphate. 4,5 As the present study did not include subanalysis for the stone component, type and data of urinary parameters, validation from those aspects might be more useful to better understand their result as to why a high visceral fat volume ratio results in stone recurrence. Furthermore, the number of participants in these previous studies was similar to that in the present study (between 262 and 382); therefore, a much larger cohort study will be required to determine a feasible use of visceral fat calculation over our practice.…”

Subcutaneous Adipose Tissue Accumulation Is an Independent Risk Factor of Urinary Stone in Young People

“…Many studies have shown the association between urolithiasis and MetS or its components (3)(4)(5). VAT seems to have a closer relationship with urinary stone than SAT does among people of all ages (17)(18)(19). SAT is insulin-sensitive and is considered an "energy sink" to store excess energy physiologically, the visceral fat begins to increase when the subcutaneous adipose tissue is unable to handle the calorie surplus due to excess energy accumulation (6).Thus, the accumulation of SAT should happen earlier than the increase in VAT and MetS.…”

“…Fram et al. suggested that VFA was significantly associated with an increased excretion of urine sodium in male patients with either normal or increased BMI ( 19 ). However, our study showed no significant association between the VFA and the occurrence of stone episodes.…”