Context:Serum thyroid hormone levels differ between children and adults, but have not been studied longitudinally through childhood.Objective:To assess changes in thyroid-stimulating hormone (TSH) and thyroid hormone levels over childhood and their interrelationships.Design:Cohort study.Setting:The Avon Longitudinal Study of Parents and Children, a population-based birth cohort.Participants:A total of 4442 children who had thyroid function measured at age 7, and 1263 children who had thyroid function measured at age 15. Eight hundred eighty-four children had measurements at both ages.Main Outcome Measures:Reference ranges for TSH, free tri-iodothyronine (FT3), free thyroxine (FT4), their longitudinal stability, and interrelationships.Results:Children at age 7 years had a higher FT3 [6.17 pmol/L, standard deviation (SD) 0.62] than children at age 15 (5.83 pmol/L, SD 0.74); P < 0.0001 with 23.2% of children at age 7 having FT3 above the adult reference range. Higher FT3 levels at age 7 in boys (P = 0.0001) and girls (P = 0.04) were associated with attainment of a more advanced pubertal stage at age 13. TSH was positively associated with FT3 at age 7 and age 15 even after adjusting for confounders. In contrast, TSH was negatively associated with FT4.Conclusions:There are substantial changes in TSH and thyroid hormone levels over childhood, in particular for FT3, which appear to relate to pubertal readiness. Our data provide increased insight into the evolution of the pituitary–thyroid axis over childhood and may have implications for determining optimal ranges for thyroid hormone replacement in children.

Thyrotrophin predicts overt hyperthyroidism in asymptomatic individuals with subclinical hyperthyroidism. Patients with TSH < 0·10 mU/l have a higher risk of progressing to hyperthyroidism than those with TSH 0·10-0·39 mU/l.

BackgroundAlthough the majority of thyroid nodules are benign the process of excluding malignancy is challenging and sometimes involves unnecessary surgical procedures. We explored the development of a predictive model for malignancy in thyroid nodules by integrating a combination of simple demographic, biochemical, and ultrasound characteristics.MethodsRetrospective case-record review.We reviewed records of patients with thyroid nodules referred to our institution from 2004 to 2011 (n = 536; female 84 %, mean age 51 years). All malignancy was proven histologically while benign disease was either confirmed histologically, or on cytology with minimum 36-month observation period. We focused on the following predictors: age, sex, smoking status, thyroid hormones (FT4 and TSH) and nodule characteristics on ultrasound. Variables were included in a multivariate logistic regression and bootstrap analyses were used to confirm results.ResultsIndependent predictors of malignancy in the fully adjusted model were TSH (OR 1.53, 95 % CI 1.10, 2.12, p = 0.01), male gender (OR 3.45, 95 % CI 1.33, 8.92, p = 0.01), microcalcifications (OR 6.32, 95 % CI 2.82, 14.1, p < 0.001), and irregular nodule margins (OR 5.45, 95 % CI 1.61, 18.6, p = 0.006) Bootstrap analyses strengthened these associations and a parsimonious analysis consisting of these variables and age-group demonstrated an area under the curve of 0.77. A predictive score was sensitive (86.9 %) at low scores and highly specific (94.87 %) at higher scores for distinguishing benign from malignant disease.ConclusionsA predictive model for malignancy using a combination of clinical, biochemical, and radiological characteristics may support clinicians in reducing unnecessary invasive procedures in patients with thyroid nodules.Electronic supplementary materialThe online version of this article (doi:10.1186/s13044-016-0033-y) contains supplementary material, which is available to authorized users.