Design, patients, and measurements. In a prospective group of 24 fasting female patients with Graves’ disease (mean age (CI 95 % ): 40 years (33–47)), we measured serum thyroxine, triiodothyronine, thyrotropine (TSH), TSH receptor antibodies, anti-thyroid peroxidase, leptin, body composition, body mass index (BMI) and IGF-related peptides at diagnosis and after 12 months of treatment with thiamazol (ATD).
Results. In thyrotoxic patients IGF-I plus IGF-II correlated positively with IGFBP-3 at baseline (r=0.90, p<0.1×10−16) and after 12 months follow-up (r=0.87, p<0.1×10−16). In the thyrotoxic state total IGF-I, IGF-II, IGF binding protein 3 (IGFBP-3) and acid-labile subunit (ALS) but not free IGF-I decreased significantly from 223 μg/L (189–260) (mean (CI 95 % ), 877 μg/L (801–953), 4165 μg/L (3772–4577) and 22 mg/L (18–26)) to 198 μg/L (172–226), 788 μg/L (711–865), 3431 μg/L (3135–3741) and 19 mg/L (16–26) (p<0.006), respectively, after 12 months of ATD despite an increase in BMI from 22 (21–23) to 23 kg/m2 (22–25) (p<0.0004) but no significant changes in leptin.
Conclusions. The complex IGF systems seemed intact in thyrotoxic patients but change in body composition and the regulation of leptin and insulin secretion during treatment of autoimmune thyroid disease influence IGF-related peptides leaving the patient in a state somewhat similar to partial GHD, but the mechanism behind these alterations remains unclear.