The Study
Effects of Suppressive Doses of Levothyroxine Treatment on Sex-Hormone-Binding Globulin and Bone Metabolism
This study looked at whether a thyroid medicine changes certain body chemicals in women, and found a small difference in one chemical in younger women. But it didn't randomly assign who got the medicine, so we can't say the medicine caused the change — it might just be something else about those women.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
This study looked at women taking high doses of thyroid medicine for years to see if it affected their bones or liver.
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 534 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Higher bone turnover in premenopausal women may mean faster bone remodeling, but it doesn't mean bones are weaker — especially since estrogen seems to protect postmenopausal women.
- 2In premenopausal women, a bone marker (osteocalcin) was much higher (9.6 vs 6.7 ng/mL).
- 3In postmenopausal women on estrogen, bone markers and density stayed the same.
- 4Liver marker (SHBG) didn't change in any group.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Thyroid
Year
1995
Authors
P. Lecomte, N. Lécureuil, C. Osorio-Salazar, M. Lécureuil, Chantal Valat
Related Content
Claims (4)
Hyperthyroidism leads to faster breakdown and rebuilding of bone, which causes higher levels of alkaline phosphatase in the blood.
Premenopausal women taking high-dose levothyroxine for 3 to 5 years for thyroid conditions have higher levels of osteocalcin in their blood than similar women not on this therapy, indicating increased bone turnover.
Taking levothyroxine at doses of 150–184 mcg per day for 3 to 5 years does not change sex-hormone-binding globulin levels in women, regardless of whether they are premenopausal or postmenopausal.
In postmenopausal women taking estrogen therapy, long-term high-dose levothyroxine does not change bone density or osteocalcin levels compared to similar women not taking levothyroxine.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.