Objective To explore the value of serum insulin-like growth factor-1 (IGF-1) levels in diagnosis and treatment of primary hyperthyroidism.

Methods 150 patients with primary hyperthyroidism (hyperthyroidism group) and 85 patients with hypothyroidism (hypothyroidism group) were selected as study subjects. During the same period, 60 healthy individuals were selected as control group. The levels of serum IGF-1, thyroid peroxidase antibody (TPOAb), thyroid stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), triiodothyronine (T3) and total thyroxine (T4) were measured in the three groups. The serum visfatin levels in the three groups were detected using an enzyme-linked immunosorbent assay. Multifactor Logistic regression analysis was used to screen for risk factors of primary hyperthyroidism.

Results The levels of IGF-1, FT3, FT4, T3 and T4 in the hyperthyroidism group were significantly higher than those in the hypothyroidism and control groups, while TSH levels were significantly lower (P < 0.05). TPOAb and visfatin levels in the hyperthyroidism group were significantly higher than those in the control group, but significantly lower than those in the hypothyroidism group (P < 0.05). The serum IGF-1 levels in patients with primary hyperthyroidism before and after 3 months of treatment were (60.11±7.23) and (30.23± 3.22) μg/L, respectively, showing a statistically significant difference (t=8.436, P < 0.001). Serum FT3, FT4, T3, T4, TPOAb, IGF-1 and visfatin levels increased and serum TSH levels decreased as risk factors for primary hyperthyroidism (P < 0.05).

Conclusion The level of serum IGF-1 is closely related to thyroid function and may serve as an important reference indicator for the diagnosis and monitoring of the efficacy of primary hyperthyroidism treatment.