The Study
Effects of metabolic and organ function factors on the efficacy of radioactive iodine therapy for hyperthyroidism
This study looked at a group of people who got radioactive iodine treatment and noticed that older people and those with higher creatinine levels tended to have different thyroid test results afterward. But it didn’t change anything on purpose — it just watched what happened, so we can’t say those things caused the changes.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
This study looked at how body factors like age and kidney function affect how well radioactive iodine works to treat an overactive thyroid.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 556 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — older patients may need closer monitoring, and kidney function might help predict how well the treatment lowers thyroid hormones.
- 2For every year older a patient is, they're 4.3% less likely to improve.
- 3Higher kidney health markers (creatinine) linked to bigger drops in thyroid hormones and higher TSH.
- 4Blood iodine levels predicted hormone changes better than urine iodine.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Frontiers in Endocrinology
Year
2025
Authors
Yue Hu, Shan Liu, Xiaoliang Xiong, Lixing Wang, Yinlong Zhao
Related Content
Claims (6)
Radioactive iodine therapy and surgical removal of the thyroid permanently decrease thyroid function in people with Graves' disease.
Among adults treated with radioactive iodine for an overactive thyroid, older patients are less likely to show clinical improvement than younger patients, with each year of age reducing the chance of improvement by about 4.3%.
In patients treated with radioactive iodine for hyperthyroidism, those with higher normal levels of serum creatinine experience larger decreases in free triiodothyronine and free thyroxine and higher levels of thyroid-stimulating hormone.
In people with overactive thyroid treated with radioactive iodine, changes in kidney function markers (creatinine) are more closely linked to thyroid hormone changes than changes in liver function markers.
After radioactive iodine therapy, higher levels of iodine in the blood are linked to higher thyroid-stimulating hormone levels in the early period and lower levels at six months, while iodine levels in urine show no consistent link to these hormone changes.
In patients receiving radioactive iodine treatment for an overactive thyroid, the amount of iodine in the blood correlates more closely with changes in thyroid hormone regulation markers than the amount of iodine in the urine.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.