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Gary C. Curhan - One of the best experts on this subject based on the ideXlab platform.
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Frequency of Rare Allelic Variation in Candidate Genes among Individuals with Low and High Urinary Calcium Excretion
2016Co-Authors: Hakan R Toka, Giulio Genovese, David B Mount, Martin R Pollak, Gary C. CurhanAbstract:Our study investigated the association of rare allelic variants with extremes of 24-hour Urinary Calcium excretion because higher Urinary Calcium excretion is a dominant risk factor for Calcium-based kidney stone formation. We resequenced 40 candidate genes potentially related to Urinary Calcium excretion in individuals from the Nurses ’ Health Studies I & II and the Health Professionals Follow-up Study. A total of 960 participants were selected based on availability of 24-hour urine collection data and level of Urinary Calcium excretion (low vs. high). We utilized DNA sample pooling, droplet-based target gene enrichment, multiplexing, and high-throughput sequencing. Approximately 64 % of samples (n = 615) showed both successful target enrichment and sequencing data with.20-fold deep coverage. A total of 259 novel allelic variants were identified. None of the rare gene variants (allele frequencies,2%) were found with increased frequency in the low vs. high Urinary Calcium groups; most of these variants were only observed in single individuals. Unadjusted analysis of variants with allele frequencies$2 % suggested an association of the Claudin14 SNP rs113831133 with lower Urinary Calcium excretion (6/ 520 versus 29/710 haplotypes, P value = 0.003). Our data, together with previous human and animal studies, suggest a possible role for Claudin14 in Urinary Calcium excretion. Genetic validation studies in larger sample sets will be necessary to confirm our findings for rs113831133. In the tested set of candidate genes, rare allelic variants do not appear to contribut
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frequency of rare allelic variation in candidate genes among individuals with low and high Urinary Calcium excretion
PLOS ONE, 2013Co-Authors: Giulio Genovese, Hakan R Toka, David B Mount, Martin R Pollak, Gary C. CurhanAbstract:Our study investigated the association of rare allelic variants with extremes of 24-hour Urinary Calcium excretion because higher Urinary Calcium excretion is a dominant risk factor for Calcium-based kidney stone formation. We resequenced 40 candidate genes potentially related to Urinary Calcium excretion in individuals from the Nurses’ Health Studies I & II and the Health Professionals Follow-up Study. A total of 960 participants were selected based on availability of 24-hour urine collection data and level of Urinary Calcium excretion (low vs. high). We utilized DNA sample pooling, droplet-based target gene enrichment, multiplexing, and high-throughput sequencing. Approximately 64% of samples (n=615) showed both successful target enrichment and sequencing data with .20-fold deep coverage. A total of 259 novel allelic variants were identified. None of the rare gene variants (allele frequencies ,2%) were found with increased frequency in the low vs. high Urinary Calcium groups; most of these variants were only observed in single individuals. Unadjusted analysis of variants with allele frequencies $2% suggested an association of the Claudin14 SNP rs113831133 with lower Urinary Calcium excretion (6/ 520 versus 29/710 haplotypes, P value=0.003). Our data, together with previous human and animal studies, suggest a possible role for Claudin14 in Urinary Calcium excretion. Genetic validation studies in larger sample sets will be necessary to confirm our findings for rs113831133. In the tested set of candidate genes, rare allelic variants do not appear to contribute significantly to differences in Urinary Calcium excretion between individuals.
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effect of vitamin d repletion on Urinary Calcium excretion among kidney stone formers
Clinical Journal of The American Society of Nephrology, 2012Co-Authors: David E Leaf, Eric N. Taylor, Ruslan Korets, Jie Tang, John R Asplin, David S Goldfarb, Mantu Gupta, Gary C. CurhanAbstract:Summary Background and objectives Despite the important role of vitamin D in maintaining bone health, many clinicians are reluctant to treat vitamin D deficiency in kidney stone formers because of the theoretical risk of increasing Urinary Calcium excretion. This study examined the effect of vitamin D repletion on Urinary Calcium excretion among stone formers. Design, setting, participants, & measurements Participants ( n =29) were recruited from urology clinics affiliated with New York Presbyterian Hospital. Enrollment criteria included a history of nephrolithiasis, Urinary Calcium excretion between 150 and 400 mg/d, and a serum 25-hydroxyvitamin D level Results Levels of 25-hydroxyvitamin D increased significantly after vitamin D repletion (17±6 and 35±10 ng/ml, P P =0.91). However, 11 participants had an increase in Urinary Calcium excretion ≥20 mg/d; these participants also had an increase in urine sodium excretion, likely reflecting dietary variability. No participant experienced adverse effects from vitamin D, including hypercalcemia. Conclusions Among stone formers with vitamin D deficiency, a limited course of vitamin D repletion does not seem to increase mean Urinary Calcium excretion, although a subset of individuals may have an increase. These data suggest that vitamin D therapy, if indicated, should not be withheld solely on the basis of stone disease, but 24-hour Urinary Calcium excretion should be monitored after repletion.
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effect of vitamin d repletion on Urinary Calcium excretion among kidney stone formers
Clinical Journal of The American Society of Nephrology, 2012Co-Authors: David E Leaf, Eric N. Taylor, Ruslan Korets, Jie Tang, John R Asplin, David S Goldfarb, Mantu Gupta, Gary C. CurhanAbstract:Summary Background and objectives Despite the important role of vitamin D in maintaining bone health, many clinicians are reluctant to treat vitamin D deficiency in kidney stone formers because of the theoretical risk of increasing Urinary Calcium excretion. This study examined the effect of vitamin D repletion on Urinary Calcium excretion among stone formers. Design, setting, participants, & measurements Participants (n=29) were recruited from urology clinics affiliated with New York Presbyterian Hospital. Enrollment criteria included a history of nephrolithiasis, Urinary Calcium excretion between 150 and 400 mg/d, and a serum 25-hydroxyvitamin D level Results Levels of 25-hydroxyvitamin D increased significantly after vitamin D repletion (17±6 and 35±10 ng/ml, P Conclusions Among stone formers with vitamin D deficiency, a limited course of vitamin D repletion does not seem to increase mean Urinary Calcium excretion, although a subset of individuals may have an increase. These data suggest that vitamin D therapy, if indicated, should not be withheld solely on the basis of stone disease, but 24-hour Urinary Calcium excretion should be monitored after repletion.
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Demographic, dietary, and Urinary factors and 24-h Urinary Calcium excretion.
Clinical journal of the American Society of Nephrology : CJASN, 2009Co-Authors: Eric N. Taylor, Gary C. CurhanAbstract:Background and objectives: Higher Urinary Calcium is a risk factor for nephrolithiasis. This study delineated associations between demographic, dietary, and Urinary factors and 24-h Urinary Calcium. Design, setting, participants, & measurements: Cross-sectional studies were conducted of 2201 stone formers (SF) and 1167 nonstone formers (NSF) in the Health Professionals Follow-up Study (men) and Nurses' Health Studies I and II (older and younger women). Results: Median Urinary Calcium was 182 mg/d in men, 182 mg/d in older women, and 192 mg/d in younger women. Compared with NSF, Urinary Calcium as a fraction of Calcium intake was 33 to 38% higher in SF (P values ≤0.01). In regression analyses, participants were combined because associations with Urinary Calcium were similar in each cohort and in SF and NSF. After multivariate adjustment, participants in the highest quartile of Calcium intake excreted 18 mg/d more Urinary Calcium than those in the lowest (P trend =0.01). Caffeine and family history of nephrolithiasis were positively associated, whereas Urinary potassium, thiazides, gout, and age were inversely associated, with Urinary Calcium. After multivariate adjustment, participants in the highest quartiles of Urinary magnesium, sodium, sulfate, citrate, phosphorus, and volume excreted 71 mg/d, 37 mg/d, 44 mg/d, 61 mg/d, 37 mg/d, and 24 mg/d more Urinary Calcium, respectively, than participants in the lowest (P values trend ≤0.01). Conclusions: Intestinal Calcium absorption and/or negative Calcium balance is greater in SF than NSF. Higher Calcium intakes at levels typically observed in free-living individuals are associated with only small increases in Urinary Calcium.
Fernando Larrea - One of the best experts on this subject based on the ideXlab platform.
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decreased fractional Urinary Calcium excretion and serum 1 25 dihydroxyvitamin d and igf i levels in preeclampsia
The Journal of Steroid Biochemistry and Molecular Biology, 2007Co-Authors: Ali Halhali, Lorenza Díaz, Euclides Avila, Ana Carolina Ariza, Michèle Garabédian, Fernando LarreaAbstract:During preeclampsia several alterations of Calcium metabolism have been described, the most common of them is hypocalciuria, which pathophysiology is still unclear. In order to assess the contribution of calciotropic hormones to Urinary Calcium excretion, a cross-sectional study was done including 26 preeclamptic Mexican women (PE group) and 26 normotensive control pregnant women (NT group). Total and fractional Urinary Calcium excretion were significantly lower (P<0.0001) in the PE group than in the NT group (82+/-7 versus 171+/-7 mg/24h and 0.62+/-0.38 versus 1.38+/-0.71%, respectively), without significant differences in creatinine clearance, Urinary sodium excretion and phosphate tubular reabsorption. In addition, serum 1,25-(OH)(2)D and IGF-I levels were significantly (P<0.05) lower in the PE than in NT group (43+/-9 versus 50+/-9 pg/mL and 195+/-67 versus 293+/-105 ng/mL, respectively), without significant differences in serum PTH levels. In the NT group, association analysis showed that total and fractional Urinary Calcium excretions positively correlated with serum levels of 1,25-(OH)(2)D (P<0.01) and IGF-I (P<0.001). In the PE group, total Urinary Calcium excretion positively correlated only with serum 1,25-(OH)(2)D (P<0.05). In conclusion, the results obtained in this study confirm that PE is associated with hypocalciuria and suggest that 1,25-(OH)(2)D and/or IGF-I may be involved in the regulation of Urinary Calcium excretion.
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Decreased fractional Urinary Calcium excretion and serum 1,25-dihydroxyvitamin D and IGF-I levels in preeclampsia.
The Journal of Steroid Biochemistry and Molecular Biology, 2007Co-Authors: Ali Halhali, Lorenza Díaz, Euclides Avila, Ana Carolina Ariza, Michèle Garabédian, Fernando LarreaAbstract:During preeclampsia several alterations of Calcium metabolism have been described, the most common of them is hypocalciuria, which pathophysiology is still unclear. In order to assess the contribution of calciotropic hormones to Urinary Calcium excretion, a cross-sectional study was done including 26 preeclamptic Mexican women (PE group) and 26 normotensive control pregnant women (NT group). Total and fractional Urinary Calcium excretion were significantly lower (P
Albrecht Hesse - One of the best experts on this subject based on the ideXlab platform.
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Urinary Calcium Oxalate Saturation in Healthy Infants and Children
The Journal of urology, 1997Co-Authors: Bernd Hoppe, Andrea Jahnen, Dietmar Bach, Albrecht HesseAbstract:AbstractPurpose: A number of factors influence the development of renal calculi, the most essential of which is the supersaturation of urine with lithogenic substances. Calcium oxalate stones occur most frequently in adult and pediatric patients with urolithiasis. Therefore, we established normal age and sex related data for Urinary Calcium oxalate saturation in infancy and childhood to allow a more specific prediction of the risk of (recurrent) stone disease.Materials and Methods: We collected 24-hour urine samples from 473 healthy infants and children without a history of renal stones. Urinary lithogenic and stone inhibitory substances were measured, and the Urinary Calcium oxalate saturation was calculated using a computer program.Results: Mean Urinary Calcium oxalate saturation was always higher in boys than in girls, which was significant in infancy (5.22 versus 2.03, p
O Trocki - One of the best experts on this subject based on the ideXlab platform.
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a longitudinal study of Urinary Calcium magnesium and zinc excretion in lactating and nonlactating postpartum women
The American Journal of Clinical Nutrition, 1995Co-Authors: C J Klein, Phylis B Moserveillon, L W Douglass, K A Ruben, O TrockiAbstract:Postpartum lactating (n=12) and nonlactating (n=11) women and never pregnant women (n=14) collected urine samples and diet records 2 d each month for 6 mo to determine whether postpartum women conserved Urinary Calcium, magnesium, or zinc. Mean daily excretions were analyzed by repeated-measures analysis of variance and covariance to assess group and time effects. Lactating women excreted less Urinary Calcium (1-6 mo) than never pregnant (n=8) and nonlactating (n=4) women who did not use oral contraceptives (P<0.01); however, excretion rose (P<0.05) by 3 mo postpartum. In the nonlactating and never pregnant groups, women using oral contraceptives excreted less Urinary Calcium than the other women (P<0.01), Lactating women excreted less Urinary zinc (1-6 mo) than did control and nonlactating women (P<0.01). Mechanisms may possibly be operating during lactation that depress Urinary Calcium for ≥2 mo and Urinary zinc ≤6 mo postpartum
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A longitudinal study of Urinary Calcium, magnesium, and zinc excretion in lactating and nonlactating postpartum women.
The American journal of clinical nutrition, 1995Co-Authors: C J Klein, L W Douglass, K A Ruben, Phylis B. Moser-veillon, O TrockiAbstract:Postpartum lactating (n=12) and nonlactating (n=11) women and never pregnant women (n=14) collected urine samples and diet records 2 d each month for 6 mo to determine whether postpartum women conserved Urinary Calcium, magnesium, or zinc. Mean daily excretions were analyzed by repeated-measures analysis of variance and covariance to assess group and time effects. Lactating women excreted less Urinary Calcium (1-6 mo) than never pregnant (n=8) and nonlactating (n=4) women who did not use oral contraceptives (P
Ali Halhali - One of the best experts on this subject based on the ideXlab platform.
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decreased fractional Urinary Calcium excretion and serum 1 25 dihydroxyvitamin d and igf i levels in preeclampsia
The Journal of Steroid Biochemistry and Molecular Biology, 2007Co-Authors: Ali Halhali, Lorenza Díaz, Euclides Avila, Ana Carolina Ariza, Michèle Garabédian, Fernando LarreaAbstract:During preeclampsia several alterations of Calcium metabolism have been described, the most common of them is hypocalciuria, which pathophysiology is still unclear. In order to assess the contribution of calciotropic hormones to Urinary Calcium excretion, a cross-sectional study was done including 26 preeclamptic Mexican women (PE group) and 26 normotensive control pregnant women (NT group). Total and fractional Urinary Calcium excretion were significantly lower (P<0.0001) in the PE group than in the NT group (82+/-7 versus 171+/-7 mg/24h and 0.62+/-0.38 versus 1.38+/-0.71%, respectively), without significant differences in creatinine clearance, Urinary sodium excretion and phosphate tubular reabsorption. In addition, serum 1,25-(OH)(2)D and IGF-I levels were significantly (P<0.05) lower in the PE than in NT group (43+/-9 versus 50+/-9 pg/mL and 195+/-67 versus 293+/-105 ng/mL, respectively), without significant differences in serum PTH levels. In the NT group, association analysis showed that total and fractional Urinary Calcium excretions positively correlated with serum levels of 1,25-(OH)(2)D (P<0.01) and IGF-I (P<0.001). In the PE group, total Urinary Calcium excretion positively correlated only with serum 1,25-(OH)(2)D (P<0.05). In conclusion, the results obtained in this study confirm that PE is associated with hypocalciuria and suggest that 1,25-(OH)(2)D and/or IGF-I may be involved in the regulation of Urinary Calcium excretion.
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Decreased fractional Urinary Calcium excretion and serum 1,25-dihydroxyvitamin D and IGF-I levels in preeclampsia.
The Journal of Steroid Biochemistry and Molecular Biology, 2007Co-Authors: Ali Halhali, Lorenza Díaz, Euclides Avila, Ana Carolina Ariza, Michèle Garabédian, Fernando LarreaAbstract:During preeclampsia several alterations of Calcium metabolism have been described, the most common of them is hypocalciuria, which pathophysiology is still unclear. In order to assess the contribution of calciotropic hormones to Urinary Calcium excretion, a cross-sectional study was done including 26 preeclamptic Mexican women (PE group) and 26 normotensive control pregnant women (NT group). Total and fractional Urinary Calcium excretion were significantly lower (P
