title: Can obese stone formers follow dietary recommendations?
abstract: BACKGROUND
  Obese patients have an increased risk of kidney stones, and several studies have identified specific urinary derangements on 24-hour collections. The objective of this study was to assess obese and super-obese stone formers, and their compliance with dietary modifications over time, based on 24-hour urine outcomes.
  
  
  METHODS
  A retrospective review was performed searching for all stone formers who completed a 24-hour urine collection before and after dietary counseling for stone prevention. Patients were excluded if placed on medical therapy in addition to dietary therapy. Patients were divided in three main groups according to their body mass index (BMI): 30, 30-40, and >40 kg/m(2). Demographic data and 24-hour urine stone risk parameters (volume, sodium, uric acid, citrate, and oxalate) were assessed. Initial 24-hour urine results were compared to follow-up results after dietary counseling. Then, the outcomes from each group were compared to each other.
  
  
  RESULTS
  Two hundred and fourteen stone formers (67% male) were identified with a mean age of 49.5±15.0 years. One hundred twenty-eight (59.8%) patients had BMI <30 kg/m(2), 61 (28.5%) between 30-40 kg/m(2), and 25 (11.7%) >40 kg/m(2). Among patients with BMI <30 kg/m(2), there were significant improvements in all urinary parameters (p<0.001) as well as in the group with BMI between 30 to 40 kg/m(2) (p=0.02 for oxalate, p<0.001 for other parameters). Among super-obese patients, there were significant improvements in the urinary volume (p=0.03), sodium (p<0.001), uric acid (p=0.001), and oxalate (p<0.001). There were no significant differences in the improvements observed in the urinary volume (p=0.69), sodium (p=0.08), uric acid (p=0.17), and citrate levels (p=0.97) between the groups.
  
  
  CONCLUSIONS
  Dietary recommendations can be an equally effective strategy in decreasing the risk or stone recurrence in obese and super-obese kidney stone formers as it is in those who are not obese.
authors.affiliation: Stevan B. Streem Center for Endourology & Stone Disease, Glickman Urological & Kidney Institute , The Cleveland Clinic, Cleveland, Ohio.
authors.forename: Fabio Cesar Miranda
authors.initials: FC
authors.lastname: Torricelli
authors.forename: Shubha
authors.initials: S
authors.lastname: De
authors.forename: Ina
authors.initials: I
authors.lastname: Li
authors.forename: Carl
authors.initials: C
authors.lastname: Sarkissian
authors.forename: Manoj
authors.initials: M
authors.lastname: Monga
mesh_terms: D000328:Adult; D015992:Body Mass Index; D019343:Citric Acid / Q000652:urine; D019587:Dietary Supplements; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007669:Kidney Calculi / Q000178:diet therapy* / Q000209:etiology / Q000652:urine; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000652:urine; D010070:Oxalates / Q000652:urine; D012189:Retrospective Studies; D012964:Sodium / Q000652:urine; D014527:Uric Acid / Q000652:urine
chemical_list: D010070:Oxalates; D014527:Uric Acid; D019343:Citric Acid; D012964:Sodium