Biochemical profile of stone-forming patients with diabetes mellitus.
OBJECTIVE
To test the hypothesis that stone-forming patients with type II diabetes (DM-II) have a high prevalence of uric acid (UA) stones and present with some of the biochemical features of gouty diathesis (GD).


METHODS
The demographic and initial biochemical data from 59 stone-forming patients with DM-II (serum glucose greater than 126 mg/dL, no insulin therapy, older than 35 years of age) from Dallas, Texas and Durham, North Carolina were retrieved and compared with data from 58 patients with GD and 116 with hyperuricosuric calcium oxalate urolithiasis (HUCU) without DM.


RESULTS
UA stones were detected in 33.9% of patients with DM-II compared with 6.2% of stone-forming patients without DM (P <0.001). Despite similar ingestion of alkali, the urinary pH in patients with DM-II and UA stones (n = 20) was low (pH = 5.5), as it is in patients with GD, and was significantly lower than in patients with HUCU. The urinary pH in patients with DM-II and calcium stones (n = 39) was intermediate between that in those with DM-II and UA stones and those with HUCU. However, both DM groups had fractional excretion of urate that was not depressed, as it is in those with GD, and was comparable to the value obtained in those with HUCU. The urinary content of undissociated UA was significantly higher, and the saturation of calcium phosphate (brushite) and sodium urate was significantly lower in those with DM-II and UA stones than in those with HUCU.


CONCLUSIONS
Stone-forming patients with DM-II have a high prevalence of UA stones. Diabetic patients with UA stones share a key feature of those with GD, namely the passage of unusually acid urine, but not the low fractional excretion of urate.
Pak
Charles Y C
CY
Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas 75390-8885, USA.
Sakhaee
Khashayar
K
Moe
Orson
O
Preminger
Glenn M
GM
Poindexter
John R
JR
Peterson
Roy D
RD
Pietrow
Paul
P
Ekeruo
Wesley
W
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D002129:Calcium Oxalate / Q000652:urine; D015897:Comorbidity; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000378:metabolism* / Q000652:urine; D004198:Disease Susceptibility; D005260:Female; D006073:Gout / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D014527:Uric Acid / Q000652:urine; D014545:Urinary Calculi / Q000453:epidemiology / Q000378:metabolism* / Q000652:urine; D014556:Urine / Q000737:chemistry
D001786:Blood Glucose; D002129:Calcium Oxalate; D014527:Uric Acid