title: Effects of visceral fat area and other metabolic parameters on stone composition in patients undergoing percutaneous nephrolithotomy.
abstract: OBJECTIVE
  Obesity is a risk factor for metabolic syndrome and urolithiasis, particularly uric acid stones. As estimated by visceral fat area, visceral obesity is a more specific measure of the risk of metabolic syndrome than body mass index. We investigated the effects of visceral fat area and other metabolic factors on uric acid stone formation in patients treated with percutaneous nephrolithotomy.
  
  
  METHODS
  We retrospectively reviewed the records of 269 patients who underwent percutaneous nephrolithotomy. Visceral fat area was measured in each patient on a CT axial slice at the umbilical level using the Aquarius iNtuition fat analysis tool. Analysis was performed to determine the effect of visceral fat area and other comorbidities on uric acid stone formation.
  
  
  RESULTS
  Of the 269 patients analyzed there was no difference in baseline comorbidities between uric acid and nonuric acid stone formers. Patients with uric acid stones had a significantly higher mean visceral fat area (209.3 vs 161.9 cm², p = 0.001), and rates of hypertension (67.4% vs 47.3%) and coronary artery disease (14.3% vs 4.6%, each p = 0.011). On logistic regression analysis hypertension (OR 2.16, 95% CI 1.05-4.45, p = 0.04) and a high visceral fat area (OR 3.64, 95% CI 1.22-10.85, p = 0.02) were independent risk factors for uric acid stones.
  
  
  CONCLUSIONS
  As a marker of visceral obesity, visceral fat area contributes to the risk of metabolic syndrome and urolithiasis. Uric acid stone formers showed a significantly higher hypertension rate and mean visceral fat area, which were independent risk factors for uric acid urolithiasis. Evaluating these characteristics in stone formers may facilitate a tailored metabolic assessment and treatment plan.
authors.affiliation: Montefiore Medical Center, Bronx, New York.
authors.forename: Tian
authors.initials: T
authors.lastname: Zhou
authors.forename: Kara
authors.initials: K
authors.lastname: Watts
authors.forename: Ilir
authors.initials: I
authors.lastname: Agalliu
authors.forename: Joseph
authors.initials: J
authors.lastname: DiVito
authors.forename: David M
authors.initials: DM
authors.lastname: Hoenig
mesh_terms: D005260:Female; D006801:Humans; D050152:Intra-Abdominal Fat / Q000473:pathology*; D007669:Kidney Calculi / Q000737:chemistry* / Q000150:complications / Q000378:metabolism / Q000628:therapy*; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications / Q000378:metabolism; D008875:Middle Aged; D009403:Nephrostomy, Percutaneous; D012189:Retrospective Studies; D018570:Risk Assessment; D014527:Uric Acid / Q000032:analysis*
chemical_list: D014527:Uric Acid
keywords: BMI; CAD; CT; HTN; PCNL; UA; VFA; body mass index; computerized tomography; coronary artery disease; hypertension; intra-abdominal fat; kidney; nephrolithiasis; obesity; percutaneous nephrolithotomy; uric acid; visceral fat area