Elevation in serum thyroglobulin during prolonged Antarctic residence: effect of thyroxine supplement in the polar 3,5,3'-triiodothyronine syndrome.

What Was Tested

This randomized controlled trial looks at Thyroxine.

It is not clear whether these adaptations reflect changes in clearance alone or whether intrinsic thyroidal synthetic activity also changes.

Thyroglobulin (Tg) secretion is an independent marker of intrinsic thyroid activity whose kinetics are independent of those of T(3) and T(4).

Who Took Part

The abstract describes 12 subjects taking part.

PubMed indexes the participants as adults, both men and women.

How the Study Was Run

The researchers set it up as a randomized and placebo-controlled study.

The subjects were allocated by chance, so the Thyroxine group and the comparison group should start out alike.

A placebo (an inactive look-alike) gave the Thyroxine group a baseline to be compared against.

What Was Measured

In this study the researchers examined changes in Tg levels in healthy subjects before and during AR and their responses to thyroid supplementation to help determine whether alterations in thyroid activity, and not just kinetics of clearance, underlie the changes seen with the polar T(3) syndrome.

The subject headings attached to it are Antarctic Regions, Biomarkers, Climate, Cohort Studies, Syndrome, Thyroglobulin and Thyroid Gland.

What This Means in Plain Language

The paper is a randomized and placebo-controlled study of Thyroxine in 12 subjects.

With fewer than 40 people, it is a small study, so it is better read as an early signal for further research than as a settled answer.

The publication is from 2004 (The Journal of clinical endocrinology and metabolism), a journal based in United States.

More context: all human trials.