TY - JOUR
T1 - Racial differences in risk factors for kidney stone formation
AU - Zisman, Anna L.
AU - Coe, Fredric L.
AU - Cohen, Andrew J.
AU - Riedinger, Christopher B.
AU - Worcester, Elaine M.
N1 - Funding Information:
F. Coe, E. Worcester, and A. Zisman are supported by National Institute of Diabetes and Digestive and Kidney Diseases grant P01 DK056788.
Publisher Copyright:
© 2020 by the American Society of Nephrology.
PY - 2020/8/7
Y1 - 2020/8/7
N2 - Background andobjectives Incidence of kidney stone disease is rising. It isnot knownwhether mechanisms of stone formation differ across racial groups. Our objective was to identify differing lithogenic risk factors across racial groups in idiopathic nephrolithiasis. Design, setting, participants, & measurements We conducted a retrospective cohort study evaluating metabolic risk factors in black and age-matched white idiopathic stone formers at our tertiary referral center. We compared serum and urine metabolic risk factors pre-and post-treatment across racial groups using analysis of covariance. Generalized linear modeling was used to build regression models for risk of stone formation in both groups. Results Among 117 black and 172 white stone formers, urine volume was lower in black stone formers (1.4±0.8 versus 2.0±0.8 L/d, P<0.001). Urine calcium was lower in black stone formers (116±70 versus 217±115 mg/d, P<0.001). Supersaturations for calcium oxalate were similar among the groups, whereas calcium phosphate supersaturation was higher in white stone formers, and uric acid supersaturation was higher in black stone formers. Electrolyte free water clearance was significantly lower in black stone formers (207±780 versus 435±759 ml/d, P=0.02). In the subgroup of 77 black patients and 107 white patients with post-treatment evaluations, urine volume rose significantly and similarly in both groups. Urine sodium was unchanged in whites but increased in blacks by 40 mmol/d (95% confidence interval, 32 to 48 mmol/d). Electrolyte free water clearance remained lower in black stone formers (385±891 versus 706±893 ml/d, P=0.02). Post-treatment supersaturations were similar across the groups except for calcium phosphate, which improved with treatment in whites. Conclusions Black stone formers have lower 24-hour urine calcium excretion and urine volume. Increases in urine volume with treatment were associated with increased solute, but not free water, excretion in black stone formers.
AB - Background andobjectives Incidence of kidney stone disease is rising. It isnot knownwhether mechanisms of stone formation differ across racial groups. Our objective was to identify differing lithogenic risk factors across racial groups in idiopathic nephrolithiasis. Design, setting, participants, & measurements We conducted a retrospective cohort study evaluating metabolic risk factors in black and age-matched white idiopathic stone formers at our tertiary referral center. We compared serum and urine metabolic risk factors pre-and post-treatment across racial groups using analysis of covariance. Generalized linear modeling was used to build regression models for risk of stone formation in both groups. Results Among 117 black and 172 white stone formers, urine volume was lower in black stone formers (1.4±0.8 versus 2.0±0.8 L/d, P<0.001). Urine calcium was lower in black stone formers (116±70 versus 217±115 mg/d, P<0.001). Supersaturations for calcium oxalate were similar among the groups, whereas calcium phosphate supersaturation was higher in white stone formers, and uric acid supersaturation was higher in black stone formers. Electrolyte free water clearance was significantly lower in black stone formers (207±780 versus 435±759 ml/d, P=0.02). In the subgroup of 77 black patients and 107 white patients with post-treatment evaluations, urine volume rose significantly and similarly in both groups. Urine sodium was unchanged in whites but increased in blacks by 40 mmol/d (95% confidence interval, 32 to 48 mmol/d). Electrolyte free water clearance remained lower in black stone formers (385±891 versus 706±893 ml/d, P=0.02). Post-treatment supersaturations were similar across the groups except for calcium phosphate, which improved with treatment in whites. Conclusions Black stone formers have lower 24-hour urine calcium excretion and urine volume. Increases in urine volume with treatment were associated with increased solute, but not free water, excretion in black stone formers.
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U2 - 10.2215/CJN.12671019
DO - 10.2215/CJN.12671019
M3 - Article
C2 - 32561654
AN - SCOPUS:85089301600
SN - 1555-9041
VL - 15
SP - 1166
EP - 1173
JO - Clinical Journal of the American Society of Nephrology
JF - Clinical Journal of the American Society of Nephrology
IS - 8
ER -