Endocrine Abstracts

Introduction: The aim of the study was to assess the function and immunogenicity of thyroid gland of patients undergoing chronic treatment with the opiate agonist Methadone.

Material and methods: Cross-sectional, observational study included patients from 18 to 40 years of age undergoing chronic treatment with Methadone for at least 6 months. A total of 176 participants took part in the study. 140 patients were from five clinical programs in Bulgaria and 36 clinically healthy people from the same age and without a history of thyroid disorder were selected as a control group. Patients’ group was subdivided into different groups by dose of methadone, time of exposition and duration of heroin abuse before starting the methadone treatment by using the 25, 50, and 75 percentile of each value. We investigated thyroid function by measuring levels of fT₃, fT₄ and TSH in the serum of our participants. Also immunogenicity of thyroid gland was investigated by assessing levels of anti-Tpo-antibody and anti-Tg- antibody.

Results: Mean daily dose of Methadone was 98.9/±41/mg. Mean duration of treatment was 33.91/±24.57/months and the mean duration of heroin abuse prior starting the treatment with Methadone was 6.61/±4/years. The patients’ and the control group were identical by the factors sex, age and BMI. We found statistically significant higher levels of free T₄ in the patients’ group. Also statistically significant differences were found in some of the groups compared with controls when analyzing factors duration of treatment with Methadone, daily dose and duration of heroin abuse. There were no statistically significant differences regarding levels of free T₃ and TSH. We did not found differences in immunogenicity between the groups.

Conclusions: Chronic Methadone treatment is associated with isolated higher levels of fT₄ without changing levels of TSH, fT₃ or immunogenicity of thyroid gland.