The Impact of Visceral Fat Accumulation on 24-h Urine Chemistries and Stone-Recurrence in Patients With Urolithiasis.

Objectives: Visceral fat accumulation is significantly associated with urinary stone disease. Meanwhile, abnormalities in urine composition that may cause stone formation can be identified by 24-h urine chemistries. We investigate the effect of visceral fat area (VFA) on 24-h urine chemistries and stone recurrence.

Methods: We retrospectively reviewed the records of consecutive patients with upper urinary stones that underwent 24-h urine chemistries at our hospital. We analyzed two cohorts according to exclusion criteria: Cohort 1 included 194 patients and Cohort 2 included 164 patients after exclusion of 30 patients with short follow-up. Body composition parameters, including VFA, were automatically measured from noncontrast-computed tomography. In Cohort 1, we performed logistic regression analyses to identify predictors associated with the past stone history and compared 24-h urine chemistries parameters according to VFA. In Cohort 2, the log-rank test was performed to examine factors associated with stone recurrence.

Results: In Cohort 1, 67% of the patients had a past stone history. Larger VFA and higher VFAR were significant independent factors associated with past stone history (p = 0.04 and 0.03). Additionally, urine volume (p = 0.01) and urinary excretion of creatinine, uric acid, sodium, phosphate (all p < 0.01), and oxalate (p = 0.03) were significantly higher in the patients with VFA ≥ 100 cm. In Cohort 2, 48% had stone recurrence, and the median follow-up period from 24-h urine chemistries was 42 months (r = 28-80 months). Only VFA was significantly associated with stone recurrence (p = 0.03).

Conclusions: Larger VFA resulted in abnormal urine chemistries that promote urinary stone formation, leading to the increased risk of stone recurrence.