Increase of urinary 5-hydroxyindoleacetic acid excretion but not serum chromogranin A following over-the-counter 5-hydroxytryptophan intake.
Can J Gastroenterol
; 22(1): 49-53, 2008 Jan.
Article
em En
| MEDLINE
| ID: mdl-18209781
ABSTRACT
BACKGROUND:
5-hydroxyindoleacetic acid (5-HIAA) excretion is commonly measured for biochemical detection of carcinoid tumours. A 77-year-old woman was referred for elevated 24 h urine 5-HIAA excretion (510 micromol/day; normal is less than 45 micromol/day) and serum chromogranin A (CgA) (72.1 U/L; normal is less than 18 U/L), both subsequently normalized after discontinuation of 5-hydroxytryptophan (5-HTP). 5-HTP, a precursor of serotonin, is not commonly listed as a substance that increases 5-HIAA levels in urine. The effect of 5-HTP on CgA has not been previously described.OBJECTIVES:
To determine whether, and to what extent, oral 5-HTP increases urine 5-HIAA excretion and serum CgA levels in healthy volunteers. PATIENTS ANDMETHODS:
A randomized, prospective, double-blind, placebo-controlled crossover study, with a four-day washout period, was performed in a general community setting. Eight healthy subjects aged 22 to 58 years were recruited by advertising. Bedtime ingestion of 5-HTP 100 mg/day was compared with placebo ingestion for 10 days. Twenty-four hour urine excretion of 5-HIAA and serum CgA were the main outcome measures.RESULTS:
Median (range) urinary 5-HIAA excretion was 204 micromol/day (22 micromol/day to 459 micromol/day) during 5-HTP intake, compared with 18 micromol/day (12 micromol/day to 36 micromol/day) during placebo intake (P=0.017). 5-HTP did not affect clinical symptoms or serum CgA levels.CONCLUSIONS:
Oral 5-HTP increases urinary 5-HIAA excretion with considerable interindividual variation. In a small number of subjects, oral 5-HTP did not affect serum CgA levels. Therefore, increased 5-HIAA levels with normal CgA levels may suggest 5-HTP ingestion. The use of over-the-counter 5-HTP should be excluded as the cause of increased urinary 5-HIAA levels before initiating diagnostic tests to search for a carcinoid tumour. 5-HTP should be added to popular references as a substance that may cause increased 5-HIAA excretion.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Biomarcadores
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5-Hidroxitriptofano
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Cromogranina A
/
Ácido Hidroxi-Indolacético
Tipo de estudo:
Clinical_trials
/
Diagnostic_studies
/
Observational_studies
Limite:
Adult
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Female
/
Humans
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Male
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Middle aged
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article