Intervention and Prevention
Obesity (2008) 16 7, 1579–1584. doi:10.1038/oby.2008.244
Evaluation of Urinary Oxalate Levels in Patients Receiving Gastrointestinal Lipase Inhibitor
Kemal Sarica1, Ersin Akarsu2,3, Sakip Erturhan2,3, Faruk Yagci2,3, Sebnem Aktaran2,3 and Bulent Altay1
- 1Department of Urology, Memorial Hospital, Istanbul, Turkey
- 2Department of Urology, Sahinbey Medical Center, University of Gaziantep, Medical School, Gaziantep, Turkey
- 3Department of Endocrinology, Sahinbey Medical Center, University of Gaziantep, Medical School, Gaziantep, Turkey
Correspondence: Kemal Sarica (kemalsarica@superonline.com)
Received 29 December 2006; Accepted 22 October 2007; Published online 24 April 2008.
Abstract
Objective:
The purpose of this study was to examine the possible effects of a gastrointestinal lipase inhibitor "Orlistat (Xenical)" on the intestinal absorption of oxalate and thereby on the urinary levels of oxalate excretion in overweight patients.
Methods and Procedures:
Long-term follow-up data of 95 cases (57 men, 38 women; M/W= 1.5) were documented. Patients were randomly assigned into two groups. While the patients in group I (n = 55) were treated with orlistat (Xenical) for 6 months, patients in group II (n = 40) received no specific medication. Calcium, oxalate, and citrate levels were determined in a 24-h urine collection from each patient. To evaluate the significance in the groups as well as the differences between the two groups, ANOVA test was performed and the results were given as mean 
s.d.
Results:
Comparative evaluation of urinary oxalate levels during 3-month follow-up clearly showed that urinary oxalate excretion significantly increased in 34/55 patients (61.8%) in the first group (P < 0.05). Of these 34 patients, 30 (88.2%) continued to have increased urinary oxalate excretion during 6-month follow-up (P = 0.001). However, our data did not show any significant effect of this medication on urinary citrate and calcium levels during 3- and 6-month follow-up evaluation (P = 0.05).
Discussion:
Our results suggest that increased intestinal absorption of dietary oxalate due to this type of medication in obese patients could make a substantial contribution to urinary oxalate excretion and may increase the risk of stone formation.
