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Restricted intraindividual urinary iodine concentration variability in nonfasting subjects
B Busnardo1, D Nacamulli, L Zambonin
1Endocrinology Unit, Department of Medical and Surgical Sciences, University of Padua, Padua, Italy. benedetto.busnardo@unipd.it
European Journal of Clinical Nutrition
|January 5, 2006
Summary
Urinary iodine concentration (UIC) varies widely between individuals but is more stable within a single person over time. A single urine sample can provide a rough estimate of an individual's iodine status.
Area of Science:
- Biochemistry
- Nutritional Science
- Clinical Chemistry
Background:
- Urinary iodine concentration (UIC) is a biomarker for recent iodine intake.
- Individual eating habits are generally consistent, suggesting stable UIC within a person.
Purpose of the Study:
- To investigate the stability of urinary iodine concentration (UIC) within individuals over time.
- To determine if a single urine sample can reliably reflect an individual's iodine status.
Main Methods:
- Prospective study involving 131 healthy volunteers.
- Collected single urine samples between 0900-1100 hours in a nonfasting state.
- A subset of 11 subjects provided multiple repeated urine samples (mean 14 each) for intraindividual analysis.
Main Results:
- Wide interindividual variation in UIC was observed (range 21-382 microg/l, CV 62%).
- Repeated sampling in a subset of subjects revealed considerable differences in average UIC levels between individuals.
- Intraindividual UIC variation was significantly lower (CV 36%) compared to interindividual variation.
Conclusions:
- Urinary iodine concentration (UIC) is more stable from day to day within a single individual than across different individuals.
- Mid-morning, nonfasting UIC measurements reflect individual eating habits and iodine status.
- A single urine sample, even when not fasting, can offer a general indication of an individual's iodine status.
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