Thyroid hormones profile in students of Makerere College of Health

Abstract

Serum concentrations of thyroxine (T4), triiodothyronine (T3) and Thyroid Stimulating Hormone (TSH) are used to assess thyroid function. It is recommended that each laboratory or hospital should establish its own reference values of T4, T3 and TSH for their clients because these hormones vary with ethnicity, geographical and climatic conditions of a population. There is no documented study which has been done to determine the Thyroid hormones profile in Ugandan general population. This study is one of the first attempts to determine Thyroid hormones profile in healthy Ugandans. The main objective of this study was to determine the thyroid hormones profile of students of the Makerere College of Health Sciences in Kampala, Uganda. A cross sectional descriptive study was done involving 72 students, with the mean age of 24.17 ± 4.48 years. Subjects who volunteered to participate in the study were interviewed; their height and body weight measured, 5ml of blood withdrawn, and sera harvested. FT4 and T3 Radioimmuno Assay (RIA) were done and TSH was assayed using Immunoradiometric Assay (IRMA) technique. The mean serum concentration of FT4 was 17.016 + 3.847 ρmol/L. For T3, mean serum concentration was 1.43 + 0.825 nmol/L, and mean serum TSH level was 2.412 +2.284 μIU/ml. Variations of serum concentrations of FT4, T3 and TSH with sex, age, or region of origin were not statistically significant. Serum concentration of TSH increased with increased body mass index (BMI). It was 2.073 ± 1.907 μIU/ml for subjects with BMI of ≤ 24.9 Kg/m2, 3.588 ± 1.495 μIU/ml for subjects with BMI of 25 - 29.9 kg/m2 and 4.450 ± 0.593 μIU/ml for subjects with BMI ≥30kg/m2(P=0.009). However, BMI had no effect on serum concentrations of FT4 and T3. Serum concentrations of T4, T3 and TSH obtained from this study all differ with the values which are currently used as reference ranges in the country. We recommend a similar study involving a population representative of Ugandans to be conducted so as to establish normal reference values of T4, T3 and TSH for Ugandans. We also recommend BMI of patients to be taken into consideration during interpretation of serum TSH concentrations results.