The urinary excretion of calcium and inorganic phosphate in 344 patients with calcium stone of renal origin

Hodgkinson, A.; Pyrah, L. N.

doi:10.1002/bjs.18004619504

Cited by 312 publications

(112 citation statements)

References 33 publications

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“…mg/day in men [1], or 4 mg/kg body weight in either sex [2;3]; these excretions are higher than those in 80% of normal individuals in our experience.…”

mentioning

confidence: 78%

New Insights Into the Pathogenesis of Idiopathic Hypercalciuria

Worcester

Coe

2008

Seminars in Nephrology

146

125

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Idiopathic hypercalciuria (IH) is the commonest metabolic abnormality in patients with calcium kidney stones. It is characterized by normocalcemia, absence of diseases that cause increased urine calcium, and calcium excretion that is above 250 mg/day in women and 300 mg/day in men. Subjects with IH have a generalized increase in calcium turnover, which includes increased gut calcium absorption, decreased renal calcium reabsorption, and a tendency to lose calcium from bone. Despite the increase in intestinal calcium absorption, negative calcium balance is commonly seen in balance studies, especially on a low calcium diet. The mediator of decreased renal calcium reabsorption is not clear; it is not associated with either an increase in filtered load of calcium or altered PTH levels. There is an increased incidence of hypercalciuria in first-degree relatives of those with IH, but IH appears to be a complex polygenic trait with a large contribution from diet to expression of increased calcium excretion. Increased tissue vitamin D response may be responsible for the manifestations of IH in at least some patients. Definition of HypercalciuriaCalcium, the most abundant cation in human beings, is an important participant in many physiologic processes, including hormonal secretion, cardiac contraction, blood clotting, and neurotransmission. In addition, growth and repair of our skeleton demands an adequate supply of calcium, and careful maintenance of extracellular calcium concentrations. For this reason, prevailing levels of intracellular and extracellular calcium are tightly regulated, by a complex system of control mechanisms. These mechanisms control calcium absorption by gut and renal tubular epithelia, as well as fluxes of calcium on and off bone, during varying dietary calcium intakes. In healthy, non-pregnant adults, whose skeleton is no longer growing, net intestinal calcium absorption is matched by renal excretion, and provides sufficient calcium for skeletal maintenance; however, under pathologic conditions, some urine calcium may derive from bone loss.Abnormalities of calcium homeostasis could result in a number of undesired consequences, including abnormally high or low serum calcium levels, or inadequate maintenance of bone mineral. Hypercalciuria might be defined as any level of urine calcium that exceeds net intestinal absorption, leading to net loss of calcium. However, in practice net intestinal absorption is seldom measured, and under the assumption that urine calcium is primarily derived from intestinal absorption, the working definition of hypercalciuria is urine calcium excretion that exceeds that found in the majority of healthy adults eating their usual diets. In practice, this is usually defined as a daily calcium excretion over 250 mg/day in women or 300Mailing address: Elaine Worcester, M.D., Nephrology Section, Suite 511 / MC 5100, University of Chicago, 5841 S. Maryland Avenue, Chicago, Illinois 60637, Phone: 773-702-7459, Fax: 773-702-5818. Publisher's Disclaimer: This is a PDF file ...

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“…mg/day in men [1], or 4 mg/kg body weight in either sex [2;3]; these excretions are higher than those in 80% of normal individuals in our experience.…”

mentioning

confidence: 78%

New Insights Into the Pathogenesis of Idiopathic Hypercalciuria

Worcester

Coe

2008

Seminars in Nephrology

146

125

View full text Add to dashboard Cite

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“…Hypercalciuria was defined as urinary calcium >250 mg/24 h for females, >300 mg/24 h for males and/or ≥4 mg kg -1 24 h -1 for either sex (18).…”

Section: Urinary Calciummentioning

confidence: 99%

Response to an oral calcium load in nephrolithiasis patients with fluctuating parathyroid hormone and ionized calcium levels

Gomes

Lage

Lazaretti-Castro

et al. 2004

Braz J Med Biol Res

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The response to an oral calcium load test was assessed in 17 hypercalciuric nephrolithiasis patients who presented elevated parathyroid hormone (PTH) irrespective of the ionized calcium (sCa 2+ ) levels. Blood samples were collected at baseline (0 min) and at 60 and 180 min after 1 g calcium load for serum PTH, total calcium, sCa 2+ , and 1.25(OH) 2 D 3 determinations. According to the sCa 2+ level at baseline, patients were classified as normocalcemic (N = 9) or hypercalcemic (N = 8). Six healthy subjects were also evaluated as controls. Bone mineral density was reduced in 14/17 patients. In the normocalcemic group, mean PTH levels at 0, 60 and 180 min (95 ± 76, 56 ± 40, 57 ± 45 pg/ml, respectively) did not differ from the hypercalcemic group (130 ± 75, 68 ± 35, 80 ± 33 pg/ml) but were significantly higher compared to healthy subjects despite a similar elevation in sCa 2+ after 60 and 180 min vs baseline in all 3 groups. Mean total calcium and 1.25(OH) 2 D 3 were similar in the 3 groups. Additionally, we observed that 5 of 9 normocalcemic patients presented a significantly higher concentration-time curve for serum PTH (AUC 0',60',180' ) than the other 4 patients and the healthy subjects, suggesting a primary parathyroid dysfunction. These data suggest that the individual response to an oral calcium load test may be a valuable dynamic tool to disclose a subtle primary hyperparathyroidism in patients with high PTH and fluctuating sCa 2+ levels, avoiding repeated measurements of both parameters.

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“…Forty percent of patients recur within 5 years, and 75% recur within 20 years (2,5). Approximately 90% of individuals with recurrent urolithiasis have a demonstrable metabolic abnormality, with hypercalciuria accounting for 40%-60% of identifiable abnormalities (6,7).…”

Section: Introductionmentioning

confidence: 99%

Risk of Fracture in Urolithiasis

Denburg

Leonard

Haynes

et al. 2014

Clinical Journal of the American Society of Nephrology

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Background and objectives Studies have shown decreased bone mineral density in individuals with urolithiasis, but their burden of fracture remains unclear. This study sought to determine whether urolithiasis is associated with increased fracture risk across the lifespan and to delineate sex effects.Design, setting, participants, & measurements A population-based retrospective cohort study using The Health Improvement Network was performed. The median calendar year for the start of the observation period was 2004 (1994-2012). This study identified 51,785 participants with $1 of 87 diagnostic codes for urolithiasis and 517,267 randomly selected age-, sex-, and practice-matched participants. Cox regression was used to estimate the hazard ratio (HR) for first fracture. Fractures identified using diagnostic codes were classified by anatomic site.Results Median age was 53 years, and 67% of participants were men, confirming their greater urolithiasis burden. Median time from urolithiasis diagnosis to fracture was 10 years. The HR for fracture associated with urolithiasis differed by sex and age (P for interactions, P#0.003). In men, the adjusted HR was greatest in adolescence (1.55; 95% confidence interval [95% CI], 1.07 to 2.25) with an overall HR of 1.10 (95% CI, 1.05 to 1.16). Urolithiasis was associated with higher fracture risk in women aged 30-79 years (HR, 1.17-1.52), and was highest in women aged 30-39 years (HR, 1.52; 95% CI, 1.23 to 1.87). Peak background fracture rates were highest in boys aged 10-19 years and in women aged 70-79 years. The incidence per 10,000 person-years in participants with versus without urolithiasis was 392 versus 258 in male participants aged 10-19 years, and 263 versus 218 in women aged 70-79 years. Distribution of fracture site within sex did not differ between participants with versus without urolithiasis.Conclusions Urolithiasis was associated with higher incident fracture risk. The significantly higher risk at times of peak background fracture incidence in adolescent boys and elderly women has profound public health implications.

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The urinary excretion of calcium and inorganic phosphate in 344 patients with calcium stone of renal origin

Cited by 312 publications

References 33 publications

New Insights Into the Pathogenesis of Idiopathic Hypercalciuria

New Insights Into the Pathogenesis of Idiopathic Hypercalciuria

Response to an oral calcium load in nephrolithiasis patients with fluctuating parathyroid hormone and ionized calcium levels

Risk of Fracture in Urolithiasis

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