Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020438 (hypercalciuria)
 2,502 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Urinary acidification, bone metabolism and urinary excretion of calcium and citrate were evaluated in 10 recurrent stone formers with incomplete renal tubular acidosis (iRTA), 10 recurrent stone formers with normal urinary acidification (NUA) and 10 normal controls (NC). Patients with iRTA had lower plasma standard bicarbonate after fasting (P < 0.01) and lower urinary excretion of titratable acid (P < 0.05) and citrate (P < 0.01) compared with NUA patients and NC, and higher urinary excretion of ammonia (P < 0.05) compared with NC (P < 0.05). Hypercalciuria was found in 6 of 10 patients with iRTA compared with 3 of 10 with NUA, and 0 of 10 NC. The citrate/calcium ratio in urine was significantly reduced in iRTA compared with the value in NUA (P < 0.01), and in NUA compared with NC (P < 0.05). Biochemical markers of bone formation (serum osteocalcin) and bone resorption (urinary hydroxyproline) were significantly increased in iRTA compared with NUA and NC (P < 0.01), indicating increased bone turnover in stone formers with iRTA. Stone formers with iRTA thus presented with disturbed calcium, bone and citrate metabolism--the same metabolic abnormalities which characterize classic type 1 RTA. Mild non-carbonic acidosis during fasting may be a pathophysilogical factor of both nephrolithiasis and disturbed bone metabolism in stone formers with iRTA.
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PMID:Pathophysiology of incomplete renal tubular acidosis in recurrent renal stone formers: evidence of disturbed calcium, bone and citrate metabolism. 834 50

Renal stones containing calcium can occur in patients with type 1 glycogen storage disease. We studied 11 patients with glycogen storage disease. Five patients had renal calculi, nephrocalcinosis, or both, and five had hypercalciuria. Serum levels of calcium, phosphorus, parathyroid hormone, and urate were normal. Serum levels of 1,25-dihydroxyvitamin D were elevated in each patient. None of the patients had a metabolic acidosis, but all nine who were tested had evidence of impaired acid excretion. In response to an acid load, eight of the nine patients had subnormal titratable acid excretion, and nine had subnormal ammonia excretion; six of nine patients were unable to secrete hydrogen ions in response to bicarbonate administration. These data indicate that patients with type 1 glycogen storage disease have an incomplete form of distal renal tubular acidosis. This may be the cause of hypercalciuria and nephrocalcinosis in these patients.
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PMID:Nephrolithiasis, hypocitraturia, and a distal renal tubular acidification defect in type 1 glycogen storage disease. 844 Oct 93

To elucidate the frequency and clinical picture of renal tubular acidosis-1 (RTA-1) in nephrolithiasis, the acid-loading test was performed in 474 patients with calcium-containing stones. RTA-1 was detected in a total of 11 patients (6 men and 5 women, 2.3%). The incidence of RTA-1 in female patients tended to be higher than in male patients (3.2 vs. 1.9%). One male patient had the complete form, the others had incomplete form. There was a tendency that RTA-1 patients were younger than non-RTA-1 patients in men, and the former were older than the latter in women. The percentages of positive family history and positive past history were 27 and 45%, respectively. Stones were single in 7 cases and multiple in 4 cases. They were unilateral in 10 cases, and bilateral in 1 case. Hypercalciuria was detected in 2 of the 11 cases, hyperuricosuria was present in none of the 11 cases, and hyperoxaluria in 2 of 8 cases examined. Stones were composed of calcium oxalate in 2 cases, calcium phosphate in 2, and calcium oxalate mixed with calcium phosphate in 3.
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PMID:Incidence and clinical features of renal tubular acidosis-1 in urolithiasis. 846 Apr 53

Eight patients (6 women and 2 men) with osteoporosis caused or aggravated by renal acidification defects are presented. Three of the female patients were premenopausal; the others were 9, 20 and 22 years postmenopausal, and two of them were on hormonal replacement therapy. Two patients had nephrolithiasis: one male with recurrent calcium phosphate stones and a left sided staghorn calculus, and one female with nephrocalcinosis due to medullary sponge kidney and hypercalciuria (patients No. 1 and 2, respectively, Table 1). In the remaining subjects, clinical suspicion was based on: a) Hip fracture in a 44-yr-old premenopausal female without any risk factor (No. 3, Table 2). b) Several vertebral compression fractures in a 45-yr-old male without hypogonadism or other predisposing factors (No. 7, Table 2). c) Lack of response to antiosteoporotic therapy in 3 women (patients No. 4, 6 and 8, Table 2). Serum bicarbonate levels and urine acidification capacity were studied in all patients. Three had low serum bicarbonate (two of whom showed high fractional excretion of bicarbonate), four had a distal defect, and one had a mixed form. Serum creatinine and potassium, and venous blood pH were normal in all cases, suggesting incomplete renal tubular acidosis. Bone mineral density in Z-score (means +/- s.e.m.) was - 1.75 +/- 0.08 in the lumbar spine (n = 8), and - 1.57 +/- 0.09 in the femoral neck (n = 4) [Tables 1 and 2; Figs 1 and 2]. Following one year treatment with oral sodium bicarbonate and potassium citrate, total skeletal calcium increased by 3-10% in five of the patients. Whereas the high prevalence of renal acidification defects among renal stone formers with or without hypercalciuria is well acknowledged, renal tubular acidosis is not included in the list of entities causing secondary osteoporosis. As shown in 6 patients of this series, incomplete RTA should be considered as another disease capable of causing osteoporosis or worsening involutional bone loss.
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PMID:[Renal acidification mechanism disorders in patients with osteoporosis]. 854 15

About 80% of all renal stones contain calcium oxalate and/or calcium phosphate as their main crystalline components. The most important risk factors for increases in calcium oxalate crystallization are low urine volume, hyperoxaluria and hypocitraturia. Hypercalciuria, however, is of secondary importance as a cause of increased crystallization: whereas calcium and oxalate crystallize in a 1:1 ratio, the molar concentration ratio in urine amounts to about 10:1 in favor of calcium. Therefore, increases in urinary calcium will not be followed by a rise in crystallization as long as oxalate remains constant, whereas even the slightest increases in urinary oxalate immediately cause more crystals to precipitate. Thus, low calcium diet is not only unnecessary but is contraindicated since it may cause secondary hyperoxaluria (increased intestinal oxalate absorption) and osteopenia (negative calcium balance). On the other hand, overconsumption of animal protein (meat, poultry, fish) induces more pronounced hyperoxaluria and hypocitraturia and contributes to an overall negative calcium balance. It is, however, only by the interplay of "bad" dietary habits with underlying abnormalities such as up-regulation of calcitriol production, incomplete renal tubular acidosis or defective macromolecular crystallization inhibitors, that people become recurrent calcium renal stone formers.
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PMID:[Diagnostic markers in calcium nephrolithiasis--current and traditional ideas with a new look]. 857 Oct 96

We reevaluated the medical records of 112 children with urolithiasis. The prevalence of this condition was 1/4.500 children admitted to our hospital. The mean age was 8.2 years and 54.4% of the afflicted patients were males. Fifty percent of the patients studied had a family history of urolithiasis. The two most frequent etiologies were urinary tract infections and metabolic disorders (hypercalciuria states, distal renal tubular acidosis and cystinuria). The etiology of the urolithiasis was unknown in 15% of our patients. The levels of magnesium and citrate, inhibitors of crystallization, were moderately low in some of the cases in which it was determined. Fifty percent of the children with urolithiasis showed urinary or renal complications. The extracorporeal lithotripsy was an effective treatment of urolithiasis in the patients in which it was performed. The recurrence rate was 8%. In one third of the urolithiasis associated with urinary infections and/or urinary tract malformations we found chronic pyelonephritis.
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PMID:[Nephrolithiasis in children]. 883 May 95

Growth retardation is a cardinal feature of children with renal tubular acidosis. This is reversible by correcting the non-uremic acidosis with alkali therapy. Sodium bicarbonate solutions or citrate solutions have been used for this purpose. However, the odious taste of these medications almost invariably causes medical noncompliance. The persistent and often profound metabolic acidosis from medical noncompliance, precipitates hypercalciuria and hypocitraturia, and increases the risk of nephrocalcinosis. The mechanism of the growth retardation in renal tubular acidosis is thought to be related to a blunting of anterior pituitary growth hormone secretion. In experimental metabolic acidosis, the growth hormone secretory pulse areas are reduced. Just as importantly, hepatic growth hormone receptor expression and IGF-I mRNA were blunted in metabolic acidosis. In uremia, growth retardation is secondary to a host of factors including metabolic acidosis, renal osteodystrophy, and the side effects of treatment such as corticosteroids, which compound the growth retardation. Growth hormone secretion by individual pituitary cells was stimulated by corticosteroids but, paradoxically, the total number of somatotropes was suppressed. In uremia, the secretion of growth hormone was not different from controls at any level of growth-hormone-releasing hormone challenges. Hepatic IGF-I mRNA was markedly reduced in uremic rats. Growth hormone receptor expression was significantly reduced in uremic acidotic rats. The growth hormone and IGF-I expression on the growth plate of the long bone of uremic rats was reduced. IGF-I immunoreactivity was present in both the hypertrophic and proliferative zones. The lack of growth of the proliferative zones suggested growth hormone and IGF-I resistance in uremic chondrocytes.
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PMID:Growth hormone and insulin-like growth factor in non-uremic acidosis and uremic acidosis. 906 56

Increased renal medullary echogenicity by renal ultrasound associated with hypercalciuria and nephrocalcinosis is often present in childhood. 17 children, 9 boys and 8 girls, aged from 8 months to 10 years were classified into three groups based on ultrasound findings according to Patriquin and Robitaille: type A faint hyperechogenic rim around the sides and tip of the medullary pyramid; type B more intense echogenic rim of the pyramids; type C intense echoes throughout the pyramid. Clinic-echographic correlations showed a pattern C in 4 children with distal renal tubular acidosis and in an infant treated with furosemide; pattern B in 3 patients having different types of tubulopathy associated with hypercalciuria; pattern A in 6 children with congenital tubulopathy and in 3 children treated with vitamin D. Abdominal X-rays detected medullary calcinosis in 2 (11.7%) of total 17 patients. Ultrasonography appears to be an important tool in early diagnosis of renal medullary nephrocalcinosis.
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PMID:[Hyperechogenicity of the renal medulla in children: clinico-echographic correlations]. 916 41

The routine use of ultrasonography has resulted in an explosion in the number of conditions reported to be associated with nephrocalcinosis. It has also been increasingly recognized that urolithiasis and nephrocalcinosis can coexist in the same patient. The two conditions most commonly associated with nephrocalcinosis in childhood are the use of furosemide in infancy and the treatment of patients with hypophosphatemic rickets with phosphate and vitamin D preparations. Although originally thought to be related to hypercalciuria, more recent studies in humans and research animals indicate a multifactorial etiology for furosemide-related nephrocalcinosis. In patients with hypophosphatemic rickets, it seems that the dose of phosphate and in particular the development of secondary hyperparathyroidism play a central role in the development of nephrocalcinosis. Among the entities recently reported to be associated with nephrocalcinosis are some that characteristically include Fanconi's syndrome. These findings dispute the previous teaching of lack of renal calcifications in this syndrome, which involves proximal renal tubular acidosis. The diagnosis of nephrocalcinosis requires a metabolic work-up to identify the offending factor. When identified, appropriate intervention should be instituted.
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PMID:Nephrocalcinosis. 920 44

This study demonstrates that a missense mutation in the voltage gated chloride channel, CLCN5, can cause X-linked renal failure without X-linked recessive hypophosphatemic rickets. A large kindred (Family A), initially evaluated in 1974 with an inherited syndrome characterized by hypercalciuria, nephrocalcinosis, low molecular weight proteinuria, renal tubular acidosis, and renal failure, was clinically re-evaluated and genetically characterized. Medical histories, physical examinations, blood chemistries, and 24-hour urine collections were obtained from 48 family members. Both female and male family members exhibited hypercalciuria, nephrolithiasis, and low molecular weight proteinuria. However, only men developed renal insufficiency, consistent with an X-linked recessive gene defect. Genetic linkage located the disease locus on the proximal short arm of the X chromosome (Xp11) where a voltage gated chloride channel gene, CLCN5, had previously been mapped. DNA sequence of the CLCN5 gene demonstrated a missense mutation (Ser244Leu) in affected family members. The same missense mutation has previously been shown to cause X-linked recessive hypophosphatemic rickets. No affected member of Family A had evidence of chronic hypophosphatemia, clinically significant rickets, or osteomalacia. We hypothesize that genetic background, environment, diet, or an unidentified modifying gene may account for the differing phenotypes resulting from this shared gene defect.
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PMID:CLCN5 mutation Ser244Leu is associated with X-linked renal failure without X-linked recessive hypophosphatemic rickets. 945 24


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