Serum TSH level stability after 5 years in euthyroid adults at low risk for thyroid dysfunction

Abstract

Objective: To evaluate changes in thyroid function after 5 years, the interval proposed for new assessment, in initially euthyroid adults. Subjects and methods: Initially, 1,426 apparently healthy adults considered low risk for thyroid dysfunction, were evaluated by measurement of TSH. After 5 years, 1,215 (85.2%) subjects were reevaluated. Results: After 5 years, four subjects were receiving levothyroxine (L-T4) replacement therapy and 25 others had TSH > 4 mIU/L, only two of them with TSH > 10 mIU/L. All of these subjects had TSH > 3 mIU/L in the initial evaluation. During reassessment, none of the subjects had been or was treated for hyperthyroidism and 22 had TSH < 0.4 mIU/L (none of them < 0.1 mIU/L). Nineteen of these subjects had TSH ≤ 0.6 mIU/L in the initial evaluation. Among the 1,098 subjects with TSH between 0.6 and 3 mIU/L in the initial evaluation, reassessment showed that none of the subjects was using L-T4; only three had TSH > 4 mIU/L (none of them > 10 mIU/L); none had been or was treated for hyperthyroidism, and only three had TSH < 0.4 mIU/L (none of them < 0.1 mIU/L). These results did not differ between men and women or between subjects ≤ 60 and > 60 years. Conclusion: Repeat TSH measurement within an interval of only 5 years would not be cost-effective in adults without known thyroid disease or risk factors for dysfunction who exhibit TSH between 0.6 and 3 mIU/L. Arch Endocrinol Metab. 2018;62(3):362-5

Relationship of gender and age on thyroid hormone parameters in a large Chinese population

“…(34) recommended that individuals with TSH levels above the upper limit of normal should be reassessed every 6-12 months to exclude transient TSH level increase. Individuals with heritable longevity and exceptional longevity have been shown to have higher serum TSH (34)(35)(36). Thus, we may speculate that higher serum TSH is beneficial for older adults.…”

Diffusely Increased 18F-FDG Uptake in the Thyroid Gland and Risk of Thyroid Dysfunction: A Cohort Study

“…Fourth, the association of uptake intensity, or SUV as a continuous variable, with risk of thyroid dysfunction was not assessed. Lastly, while the longitudinal study design is one of the main strengths of our study, the duration of follow-up (median, 2.5 years) was relatively short compared to other longitudinal studies on progression of thyroid diseases [28,29]. An extended follow-up is needed for a better understanding of the prognosis.…”