Evidence for disordered acid-base handling in calcium stone-forming patients.
Am J Physiol Renal Physiol
; 318(2): F363-F374, 2020 02 01.
Article
em En
| MEDLINE
| ID: mdl-31790303
ABSTRACT
In stone formers (SFs) with idiopathic hypercalciuria, urine pH governs the mineral phase of stones. Calcium phosphate (CaP) SFs have higher urine pH than calcium oxalate (CaOx) SFs. Normal women have higher urine pH than men on fixed diets, accompanied by greater absorption of food alkali. Female CaP and male CaOx SFs have similar urine pH as same sex normal individuals, but male CaP and female CaOx SFs may have abnormal acid-base handling. We studied 25 normal individuals (13 men and 12 women), 17 CaOx SFs (11 men and 6 women), and 15 CaP SFs (8 men and 7 women) on fixed diets. Urine and blood samples were collected under fasting and fed conditions. Female CaOx SFs had lower urine pH and lower alkali absorption, fed, compared with normal women; their urine NH4 was higher and urine citrate excretion lower than in normal women, consistent with their higher net acid excretion. Male CaOx SFs had higher urine citrate excretion and higher serum ultrafilterable citrate levels than normal men. Both male and female CaP SFs had higher urine pH fasting than same sex normal individuals, but only men were higher in the fed period, and there were no differences from normal in gut alkali absorption. CaP SFs of both sexes had higher urine NH4 and lower urine citrate than same sex normal individuals. The lower urine pH of female CaOx SFs seems related to decreased gut alkali absorption, while the higher pH of CaP SFs, accompanied by higher urine NH4 and lower urine citrate, suggests a proximal tubule disorder.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Equilíbrio Ácido-Base
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Desequilíbrio Ácido-Base
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Oxalato de Cálcio
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Fosfatos de Cálcio
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Cálculos Renais
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Hipercalciúria
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Túbulos Renais Proximais
Tipo de estudo:
Diagnostic_studies
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Etiology_studies
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Observational_studies
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Risk_factors_studies
Limite:
Adult
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Am J Physiol Renal Physiol
Assunto da revista:
FISIOLOGIA
/
NEFROLOGIA
Ano de publicação:
2020
Tipo de documento:
Article