The highly unusual action of autoantibodies that stimulate TSH receptor is unique to the development of hyperthyroidism in Grave's disease. Assay of these antibodies has been used as a prognostic tool in monitoring response to antithyroid treatment, disease remission and relapse. The objective of this study was to evaluate the clinical value of TRab titre in terms of predicting responsiveness to antithyroid treatment by achieving a biochemical euthyroid status with minimum maintenance doses of antithyroid drugs. We followed up 28 patients (25 females, 3 males), 20 to 63 years old, who were newly diagnosed with Grave's disease. TSH receptor antibody (TRab) was measured prior to initiation of antithyroid medication. Based on TRab titres, patients were grouped into A (1.5-4.9 U/L), B(5-15 U/L) and C (>15 U/L). Our results showed that patients with lower levels of TRab (<5 U/L) before antithyroid drug therapy have statistically greater chance of achieving euthyroid status (33% in 6 months and 83.3% in 12 months) than those with higher TRab concentrations (combined B and C, 0% in 6 months and 18.8% in 12 months). This study suggests that TRab titre, detected by radioreceptor assay, is useful for predicting the outcome of antithyroid drug therapy in our patients with untreated Grave's hyperthyroidism.
Human ; Male ; Female ; Middle Aged ; Adult ; Young Adult ; RECEPTORS, THYROTROPIN ; GRAVES DISEASE ; ANTITHYROID AGENTS ; HORMONES, HORMONE SUBSTITUTES, AND HORMONE ANTAGONISTS ; HORMONE ANTAGONISTS

We performed this research to determine the prevalence of low bone mineral density in patients given levothyroxine and to investigate the effects of replacement and suppressive doses of levothyroxine, age, body mass index, and TSH level on bone mineral density. One hundred and ten Asian women taking levothyroxine for at least six months were grouped into levothyroxine replacement group (levothyroxine dose that will maintain TSH level of 0.5-5.0 ulU / mL) and TSH-suppressive group (dose that will maintain TSH level of less than 0.5 uIU/mL). Bone mineral density (BMD) was measured by dual-energy x-ray absorptiometry at the lumbar spine, femoral neck and total hip. The prevalence of low bone mineral density on levothyroxine replacement and TSH-suppressive groups were 58 % and 45.8%, respectively. In the levothyroxine replacement group significant associations between levothyroxine dose, as well as body mass index, and low BMD in both spine and femoral neck were detected. An inverse relationship between duration of therapy and low bone density was also observed. Even normal TSH level in this group correlated with low bone mass in the total hip. Age and menopausal status were also significantly associated with low bone density. In the group of patients taking TSH-suppressive doses of levothyroxine, only age showed an inverse correlation with BMD. This may be secondary to the small population size generated for this group.

Human ; Female ; Middle Aged ; Adult ; Young Adult ; Adolescent ; Child ; Hormones ; Hormones, Hormone Substitutes, And Hormone Antagonists ; Thyroxine ; Absorptiometry, Photon ; Body Mass Index ; Bone Density ; Femur Neck ; Lumbar Vertebrae ; Population Density ; Prevalence ; Thyroid Hormones