Influence of Age, Sex, and Season upon Radioiodine Uptake by the Human Thyroid.

Abstract

The percentage of a tracer dose of radioactive iodine deposited in the thyroid gland at the end of 24 hrs. was detd. by measurement of radioactivity directly over the gland in 1050 tests in 1952 apparently euthyroid individuals. Within the New York area, there is statistically no effect of season on the average uptake of radioiodine by euthyroid individuals. The 24-hr. uptake of radioiodine decreases progressively with age, though slightly with each decade. The extent of fall is statistically, but not clinically significant. Women in all age groups show a slightly higher uptake than men. The difference is not clinically significant.