title: Comparison of renal function and metabolic abnormalities of cystine stone patients and calcium oxalate stone patients in China.
abstract: OBJECTIVE
  To compare renal function and metabolic abnormalities of cystine stone patients and calcium oxalate stone patients in China.
  
  
  METHODS
  Between 2008 and 2011, thirty cystine stone patients were involved in our study, and an equal number of age- and gender pair-matched patients with calcium oxalate stones. Non-stone forming individuals were elected as controls. The evaluation included blood chemistry studies and 24-h urine collection in both groups of patients.
  
  
  RESULTS
  The cystine stone patients had higher mean values of serum blood urea nitrogen, urate and creatinine levels than patients in other two groups. With respect to urine risk factors, cystine stone patients had higher urinary citrate and lower urinary oxalate and creatinine than calcium oxalate stone patients. When compared to non-stone forming individuals, cystine stone patients had higher urinary urate excretion and lower urinary creatinine excretion. Metabolic abnormalities could be demonstrated in 80 % of the cystine stone patients and in 100 % of the calcium oxalate stone patients. We also compared urine risk factors among cystine stone patients with different urine cystine excretion (<1 mmol/24 h, 1-2 mmol/24 h and >2 mmol/24 h). No significant difference was found in urine risk factors among three groups.
  
  
  CONCLUSIONS
  This study suggested that cystine stone patients were at greater risk for the loss of renal function than calcium oxalate stone patients, but the risk of the formation of calcium oxalate stones was lower. Our results also indicated that urinary cystine had little or no impact on the excretion of urine chemistries in cystine stone patients.
authors.affiliation: Department of Urology, The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School, Zhongshan Road 321, Nanjing, 210008, Jiangsu, China, shenluming2008@163.com.
authors.forename: Luming
authors.initials: L
authors.lastname: Shen
authors.forename: Xizhao
authors.initials: X
authors.lastname: Sun
authors.forename: Huaijun
authors.initials: H
authors.lastname: Zhu
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Cong
authors.forename: Benxiang
authors.initials: B
authors.lastname: Ning
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People; D001806:Blood Urea Nitrogen; D002129:Calcium Oxalate / Q000032:analysis*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003404:Creatinine / Q000097:blood; D003553:Cystine / Q000032:analysis*; D005260:Female; D006801:Humans; D053565:Hypercalciuria / Q000453:epidemiology / Q000378:metabolism; D006959:Hyperoxaluria / Q000453:epidemiology / Q000378:metabolism; D015994:Incidence; D007223:Infant; D007668:Kidney / Q000378:metabolism* / Q000503:physiopathology*; D007669:Kidney Calculi / Q000737:chemistry* / Q000150:complications* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
chemical_list: D002129:Calcium Oxalate; D003553:Cystine; D003404:Creatinine