Peer-reviewed veterinary case report
IGF-1 hormone levels change after radioactive iodine treatment
By Shin, Dongheon et al.·Published in Journal of feline medicine and surgery·2025·College of Veterinary Medicine, South Korea·View original on PubMed →
PetCaseFinder translated the abstract of this peer-reviewed paper into plain English so pet owners can read it. We do not publish original research — every detail traces back to the citation above. How we work →
Original publication title: Change in insulin-like growth factor type 1 concentration after radioactive iodine treatment in cats with hyperthyroidism.
- Species:
- cat
Plain-English summary
A group of 13 cats with hyperthyroidism underwent radioactive iodine treatment to help manage their condition. Before treatment, their thyroid hormone levels were high, but after treatment, these levels dropped significantly, while insulin-like growth factor 1 (IGF-1) levels increased, indicating improved health. The cats also showed a rise in kidney function markers, but overall, the treatment appeared to restore a healthier balance in their bodies. Most importantly, the cats seemed to benefit from the treatment, suggesting it can be effective for managing hyperthyroidism.
People also search for: cat hyperthyroidism treatment · radioactive iodine for cats · cat kidney function after treatment
Abstract
ObjectivesThis study aimed to evaluate changes in serum insulin-like growth factor type 1 (IGF-1) concentrations in cats with hyperthyroidism before and after radioactive iodine (RAI) treatment, as well as investigate the correlation between thyroid volume and serum IGF-1 concentrations.MethodsA total of 13 cats with hyperthyroidism and 14 healthy controls were included. Serum total thyroxine (TT4)/thyroid-stimulating hormone (TSH) and IGF-1/insulin-like growth factor binding protein-3 (IGFBP-3) concentrations were measured using chemiluminescence immunoassay and ELISA, respectively, at presentation and 6 months after RAI treatment. The results were compared with thyroid volume measured using scintigraphy. Data are presented as median (interquartile range [IQR]) and analysed using non-parametric tests.ResultsSerum TT4 concentrations significantly decreased from 9.30 µg/dl (IQR 6.49-12.7) to 2.23 µg/dl (IQR 1.34-2.94) after RAI treatment (<0.001), while TSH levels increased from 0.021 ng/ml (IQR 0.021-0.021) to 0.125 ng/ml (IQR 0.050-0.257) ( = 0.002). IGF-1 levels significantly increased from 329 ng/ml (IQR 240-479) to 572 ng/ml (IQR 402-1038) after RAI treatment ( = 0.011), while IGFBP-3 levels did not differ. Serum creatinine concentrations significantly increased from 1.3 mg/dl (IQR 1.2-1.6) to 2.0 mg/dl (IQR 1.7-2.3) after RAI treatment ( = 0.006). No correlation was observed between IGF-1 and any variable, except IGFBP-3 ( = 0.587; = 0.039) in the pretreatment group. IGF-1 and body weight were significantly positively correlated after RAI treatment ( = 0.696; = 0.011) but not before. In healthy cats, IGF-1 was negatively correlated with serum TT4 ( = -0.627; = 0.019).Conclusions and relevanceThe increased serum IGF-1 concentrations after RAI treatment may reflect the restoration of anabolic status in cats with hyperthyroidism. In this study population, no correlation was found between thyroid volume and serum IGF-1 concentrations.
Find similar cases for your pet
PetCaseFinder finds other peer-reviewed reports of pets with the same symptoms, plus a plain-English summary of what was tried across them.
Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/41170923/