Thyroid hormone treatment aiming at reduced, but not suppressed, serum thyroid-stimulating hormone levels in nontoxic goitre: effects on bone metabolism amongst premenopausal women.
OBJECTIVE
To study the effects of six months' treatment with either T4 or T3, aiming at reduced but not totally suppressed serum TSH levels, as measured by a third generation TSH assay, on biochemical bone turnover parameters as well as bone mass in patients with nontoxic goitre.


METHODS
Prospective randomized study with a matched control group, not blinded.


METHODS
Two University Hospital Clinics in Copenhagen.


METHODS
Twenty-four consecutive premenopausal women with moderate sized nontoxic goitre. Fourteen patients randomized to T4 or T3 treatment for six months with monthly titration of the dose, aiming at TSH values between 0.005 and 0.2 mUL(-1). Ten controls.


METHODS
Serum parathyroid hormone (PTH), serum procollagen I C-terminal propeptide (PICP), serum alkaline phosphatase, serum osteocalcin, u-pyridinoline, u-deoxypyridinoline, u-hydroxyproline. Bone mass (BMD) at the lumbar spine and at both femoral necks.


RESULTS
Serum TSH was generally kept within the desired interval. There was no difference in any marker of bone metabolism between the effects of T4 and T3. Consequently, these groups were combined in order to evaluate the effect of thyroid hormones on the bone and mineral metabolism. Thyroid hormone treatment resulted in increased levels of serum ionized calcium (Ca) (P=0.02), serum alkaline phosphatase (P=0.007), serum-PICP (P=0.003), serum osteocalcin (P=0.02) and urinary excretion of deoxypridinoline (P=0.03) compared to untreated controls. Bone mass did not change.


CONCLUSIONS
Six months treatment with either T4 or T3 of premenopausal women with nontoxic goitre, aiming at reduced but not totally suppressed TSH values, resulted in biochemical signs of increased bone turnover, whereas bone mass remained unaltered. No differences were found between the effects of T4 or T3 treatment.
Knudsen
N
N
Department of Endocrinology E, Frederiksberg Hospital, Denmark.
Faber
J
J
Sierbaek-Nielsen
A
A
Vadstrup
S
S
Sørensen
H A
HA
Hegedüs
L
L
D000328:Adult; D001842:Bone and Bones / Q000378:metabolism*; D005260:Female; D006042:Goiter / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism*; D006801:Humans; D016555:Matched-Pair Analysis; D008875:Middle Aged; D017697:Premenopause / Q000378:metabolism*; D011446:Prospective Studies; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000627:therapeutic use*; D016896:Treatment Outcome; D014284:Triiodothyronine / Q000627:therapeutic use*
D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine