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 cm2. 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.