Hypothyroidism among patients with glioblastoma multiforme.

Background: Patients with glioblastoma multiforme (GBM) are prone to various metabolic changes such as hypothyroidism. The present study was planned to assess the frequency of hypothyroidism in these patients. Methods: Fifty-two patients with GBM were included. All of them had been treated by tumor resection followed by cranial irradiation. Thyroid function was assessed by measurement of serum thyroid stimulating hormone (TSH), free thyroxin (FT4), and free triiodothyronine (FT3). Results: There were 33 men and 19 women. The average age was 52.4 ± 12.8 years. Among these, 32 (61%) had normal thyroid function test, whereas 4 (8%) had subclinical hypothyroidism, 5 (10%) had overt primary hypothyroidism, and 11 (21%) had secondary hypothyroidism. Sixteen patients (31%) needed thyroid hormone replacement therapy. Conclusion: Hypothyroidism is relatively prevalent in patients with treated GBM. Regular thyroid function test is advised to aid the introduction of appropriate hormone replacement therapy.