A prospective evaluation of obesometric parameters associated with renal stone recurrence.

INTRODUCTION

Our aim was to evaluate whether obesometric serum hormones and body fat distribution are associated with renal stone recurrence.

METHODS

We conducted a prospective cohort study of participants undergoing renal stone (RS) intervention at a single institution from November 2009-June 2010 and followed them for a median 62 months. Obesometric parameters were measured at baseline, including body mass index (BMI), fasting serum leptin and adiponectin, and proportion of visceral adipose tissue (%VAT) averaged from three fixed axial computed tomography (CT) slices. The primary study outcome was stone recurrence.

RESULTS

A total of 110 participants were enrolled. Elevated %VAT was associated RS recurrence; participants with %VAT in the highest quartile had a five-year stone-free rate of 47.1% compared to 72.2% among other participants (p=0.004). Adjusting for gender, elevated %VAT was independently predictive of renal stone recurrence among initial stone formers (n=74; hazard ratio [HR] 4.53, 95% confidence interval [CI] 1.08-19.02), but not among recurrent stone formers (n=19; HR 0.51, 95% CI 0.054-4.72). Other obesometric factors, including leptin, adiponectin, and BMI, were not significantly predictive of recurrence.

CONCLUSIONS

We report a novel association between an elevated %VAT and stone recurrence. These findings may inform patient counselling and followup regimens. The metabolic basis for these findings requires further investigation.