Original Article: Clinical Investigation
Recurrent stone-forming patients have high visceral fat ratio based
on computed tomography images compared to ﬁrst-time
Shimpei Yamashita, Takashi Iguchi, Satoshi Nishizawa, Akinori Iba, Yasuo Kohjimoto and Isao Hara
Department of Urology, Wakayama Medical University, Wakayama, Japan
Abbreviations & Acronyms
AUC = area under the curve
BMI = body mass index
CT = computed tomography
MetS = metabolic syndrome
ROC = receiver operating
SFA = subcutaneous fat area
SFV = subcutaneous fat
VFA = visceral fat area
VFAR = visceral fat area
VFV = visceral fat volume
VFVR = visceral fat volume
Yamashita M.D., Department of
Urology, Wakayama Medical
University, 811-1 Kimiidera,
Wakayama 641-0012, Japan.
Received 18 September 2017;
accepted 14 February 2018.
Online publication 12 April
Objectives: To compare various fat parameters based on computed tomography
images between recurrent stone-forming patients and patients forming stones for the
Methods: Included in the present study were 300 patients with upper urinary tract
calculi who had undergone active stone removal in our hospital. Using pretreatment
computed tomography images, we measured visceral fat area and volume, subcutaneous
fat area and volume, visceral fat area ratio and visceral fat volume ratio. We compared
patient backgrounds and these fat parameters between those who recurrently formed
stones and those who formed stones for the ﬁrst time. We also performed logistic
regression analysis to identify factors that contribute to severe stones.
Results: A total of 148 (49.3%) patients were recurrent stone-forming patients.
Recurrent stone-forming patients were statistically signiﬁcantly younger (P < 0.01) and
there were more male patients (P < 0.01). In addition, visceral fat area ratio and visceral
fat volume ratio in recurrent stone-forming patients were signiﬁcantly higher than those
in ﬁrst-time stone-forming patients (P = 0.03 and P = 0.01, respectively). On the other
hand, there was no signiﬁcant difference in visceral fat area (P = 0.32), subcutaneous fat
area (P = 0.36), visceral fat volume (P = 0.38) or subcutaneous fat volume (P = 0.23).
Receiver operating characteristics analysis showed that area under the curve of visceral
fat volume ratio (0.583) for recurrent stones was larger than that of visceral fat area
ratio (0.571). In multivariate analysis, increasing visceral fat volume ratio was an
independent signiﬁcant predictor of recurrent stones (P = 0.04).
Conclusions: Recurrent stone-forming patients have high visceral fat ratios compared
to ﬁrst-time stone-forming patients, shown here for the ﬁrst time.
metabolic syndrome, urolithiasis, visceral fat ratio.
MetS is characterized by obesity, hypertension, diabetes mellitus, dyslipidemia and an overall
proinﬂammatory state. Accumulation of visceral fat is known as a major cause of various fea-
tures of MetS.
Although waist circumference is a simple indicator of the amount of visceral
fat and the criteria for MetS includes waist circumference as an obligatory feature of this syn-
waist circumference reﬂects not only the amount of visceral fat, but also that of sub-
CT images are more useful than simple waist-measurement indicators of
visceral obesity and various associated MetS-related disorders, according to recently reported
visceral fat parameters in several studies.
Such CT images include VFA at the umbilical
level, VFAR and VFV.
Several large-scale cross-sectional studies have shown that MetS is associated with urinary
Moreover, MetS trait clustering has been recently reported to be associated
with severity of kidney stone disease.
However, to our knowledge, previous studies do not
evaluate the association between the visceral fat parameters mentioned above and urinary
The present study compares various fat parameters based on CT images between recur-
rent stone-forming patients and ﬁrst-time stone-forming patients in a urinary stone forming
© 2018 The Japanese Urological Association
International Journal of Urology (2018) 25, 569--573 doi: 10.1111/iju.13564