Bone metabolism during anti-thyroid drug treatment of endogenous subclinical hyperthyroidism.
OBJECTIVE
There is recent evidence that both exogenous and endogenous subclinical thyrotoxicoses are associated with decreased bone mineral density. Scanty information is available on bone metabolism in these conditions when euthyroidism is restored. We evaluated the effect of anti-thyroid drug treatment on bone metabolism in endogenous subclinical hyperthyroidism.


METHODS
Prospective follow-up study over 2 years during treatment with methimazole, with an untreated control group.


METHODS
Sixteen post-menopausal women with endogenous subclinical hyperthyroidism associated with multinodular goitre, eight of whom were treated with methimazole.


METHODS
Serum concentrations of free T4, total T3, TSH, osteocalcin, urinary excretion of hydroxyproline and forearm bone mineral density were measured at regular intervals.


RESULTS
Significant changes in serum osteocalcin concentration or urinary hydroxyproline excretion were not observed in either group. Distal, but not proximal, forearm bone mineral density, expressed as a percentage of the base-line value, was significantly (P < 0.05) higher in the treated than in the untreated subjects in the second year of treatment.


CONCLUSIONS
Treatment with methimazole in post-menopausal women with endogenous subclinical hyperthyroidism associated with multinodular goitre can prevent excessive loss of bone, at least in the distal forearm.
Department of Internal Medicine, Slingeland Ziekenhuis, Doetinchem, The Netherlands.
A H
AH
Mudde
A J
AJ
Houben
A C
AC
Nieuwenhuijzen Kruseman
D015519:Bone Density / Q000187:drug effects; D001842:Bone and Bones / Q000378:metabolism*; D005260:Female; D005542:Forearm; D006042:Goiter / Q000097:blood / Q000652:urine; D006801:Humans; D006909:Hydroxyproline / Q000652:urine; D006980:Hyperthyroidism / Q000188:drug therapy* / Q000378:metabolism; D008713:Methimazole / Q000627:therapeutic use*; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood; D017698:Postmenopause / Q000097:blood / Q000652:urine; D011446:Prospective Studies; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D014284:Triiodothyronine; D015675:Osteocalcin; D008713:Methimazole; D013972:Thyrotropin; D013974:Thyroxine; D006909:Hydroxyproline