Endocrine Abstracts

Introduction: Antithyroid drugs (ATD) remain the first-line therapy in patients with Graves’ disease (GD), despite high relapse rate. The purpose of the present study was to identify predictors of long term remission of GD in patients who received ATD as primary treatment.

Description of methods/design: We restrospectively identified patients with Graves’ disease initially treated with ATD between 1984 and 2011 and extracted relevant data from the electronic records database. Patients with follow-up data of >6 months after ATD discontinuation were included.

Results: Two-hundred and eleven patients (mean age 47.2±13.8 years, 44 males) were studied. One-hundred and thirty-five (64%) were treated with ATD only, 82 of which (61%) maintained remission during a follow-up of 56.6±57.5 months. Mean duration of first ATD therapy was 38.6±26.3 months.

Females (P=0.049), non-smokers (P=0.017), patients without orbitopathy (P=0.033) and those who developed hypothyroidism during therapy (P=0.018) experienced longer remission.

Duration of remission was positively associated with ATD therapy duration (rs=0.151, P=0.03), maximum TSH levels during ATD therapy (rs=0.241, P=0.001), TSH levels at the end of treatment (rs=0.280, P<0.0001) and at 3 months after ATD discontinuation (rs=0.341, P=0.003). There was a negative association with FT4 (rs=−0.426, P<0.0001) and FT3 levels at 6 months after ATD discontinuation (rs=−0.467, P=0.038). Age, block-and-replace therapy, type or dose of ATD were not associated with longer remission.

Conclusions: Female gender, non-smoking status, absence of orbitopathy and occurence of hypothyroidism during therapy were favorable predictors of remission in patients with GD treated with ATD. Longer duration of therapy, higher TSH levels during, at the end and at 3 months after ATD discontinuation, lower FT4 and FT3 levels at 6 months after ATD discontinuation were associated with longer remission.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector