Thyroid screening in HIV-infected patients with antiretroviral therapy

Abstract

Background: The literature reports an increased incidence of thyroid disorders in human immunodeficiency virus (HIV)-positive persons. We therefore retrospectively analyzed the strategy of collecting thyroid parameters on a routine basis.

Methods: Overall 410 patients (147 women, 263 men; age, 10-74 years; median age, 45 years) were included. For screening purposes, three parameters were determined; basal thyroid-stimulating hormone (TSH), free thyroxine (fT4), and free triiodothyronine (fT3). Descriptive and statistical analyses were performed in the patient groups with increased bTSH (> 4.0 µU/ml) and with decreased fT4 (< 8.9 pg/ml) to evaluate possible correlation with age, gender, duration of antiretroviral therapy (ART), substance classes of ART (nucleosidal reverse transcriptase inhibitors (NRTIs), nonnucleosidal reverse transcriptase inhibitors, and protease inhibitors (PIs)), Centers for Disease Control and Prevention (CDC) disease stage, lowest number of CD4 cells during course of disease, and coexistent hepatitis C.

Results: Elevated bTSH was found in 27 patients (median, 5.26 µU/ml), who also showed a correlation with ART duration and NRTI use. Decreased fT4 was seen in 53 persons, and a correlation with PI intake was observed. Of these patients, 31 exhibited normalization in follow-up. Decreased fT3 was observed in eight cases related to nonthyroid illness, and fT3 was elevated in ten patients. No overt hyperthyroidism was noticed; three cases of subclinical hyperthyroidism were transient.

Conclusions: In the examined group of patients, the prevalence of abnormal thyroidal parameters was 23 %. Decreased fT4, which does not require therapy, was observed most frequently (12 %) and correlated with PI use. On the other hand, elevated bTSH (6 %) correlated with ART duration and NRTI use. In mild subclinical hypothyroidism as observed in this patient population, thyroxine medication is not indicated in principle. Annual TSH screening is probably sufficient in HIV-infected patients with no clinical symptoms suggestive for thyroid disease.