Journal article
Oxalate absorption and endogenous oxalate synthesis from ascorbate in calcium oxalate stone formers and non-stone formers
American journal of kidney diseases, Vol.44(6), pp.1060-1069
2004
Handle:
https://hdl.handle.net/2376/108197
PMID: 15558527
Abstract
Background:
Increased rates of either oxalate absorption or endogenous oxalate synthesis can contribute to hyperoxaluria, a primary risk factor for the formation of calcium oxalate-containing kidney stones. This study involves a comparative assessment of oxalate absorption and endogenous oxalate synthesis in subpopulations of stone formers (SFs) and non-stone formers (NSFs) and an assessment of the effect of ascorbate supplementation on oxalate absorption and endogenous oxalate synthesis.
Methods:
Twenty-nine individuals with a history of calcium oxalate kidney stones (19 men, 10 women) and 19 age-matched NSFs (8 men, 11 women) participated in two 6-day controlled feeding experimental periods: ascorbate-supplement (2 g/d) and no-supplement treatments. An oxalate load consisting of 118 mg of unlabeled oxalate and 18 mg of
13C
2-oxalic acid was administered the morning of day 6 of each experimental period.
Results:
Mean
13C
2-oxalic acid absorption averaged across the ascorbate and no-supplement treatments was significantly greater in SFs (9.9%) than NSFs (8.0%). SFs also had significantly greater 24-hour post-oxalate load urinary total oxalate and endogenous oxalate levels with both treatments. Twenty-four-hour urinary total oxalate level correlated strongly with both
13C
2-oxalic acid absorption (SFs,
r = 0.76;
P < 0.01; NSFs,
r = 0.62;
P < 0.01) and endogenous oxalate synthesis (SFs,
r = 0.95;
P < 0.01; NSFs,
r = 0.92;
P < 0.01).
Conclusion:
SFs are characterized by greater rates of both oxalate absorption and endogenous oxalate synthesis, and both these factors contribute to the hyperoxaluric state. The finding that ascorbate supplementation increased urinary total and endogenous oxalate levels suggested that this practice is a risk factor for individuals predisposed to kidney stones.
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Details
- Title
- Oxalate absorption and endogenous oxalate synthesis from ascorbate in calcium oxalate stone formers and non-stone formers
- Creators
- Weiwen Chai - Department of Family and Consumer Sciences (Nutrition), University of Wyoming, Laramie, WYMichael Liebman - Department of Family and Consumer Sciences (Nutrition), University of Wyoming, Laramie, WYSusan Kynast-Gales - Department of Food Science and Human Nutrition, Washington State University, Spokane, WALinda Massey - Department of Food Science and Human Nutrition, Washington State University, Spokane, WA
- Publication Details
- American journal of kidney diseases, Vol.44(6), pp.1060-1069
- Academic Unit
- Nutrition and Exercise Physiology, Department of
- Publisher
- Elsevier Inc
- Identifiers
- 99900547488201842
- Language
- English
- Resource Type
- Journal article