Effects of thyroxine therapy on bone metabolism in postmenopausal women with hypothyroidism.
OBJECTIVE
To evaluate whether thyroid stimulating hormone-suppressive thyroxine replacement therapy increases bone loss in postmenopausal women.


METHODS
The study had a cross-sectional design. Fifty-four postmenopausal women on long-term treatment with thyroxine for primary hypothyroidism, who showed suppressed thyroid stimulating hormone levels were enrolled in our study. In these patients and in a control group of 54 healthy postmenopausal women we evaluated bone mineral density at distal radius and the main biochemical parameters of bone turnover. Student's t test, Wilcoxon signed rank-test, Chi-square test and the univariate linear regression in the statistical analysis of the data were employed.


RESULTS
Bone mineral density values, expressed as z-scores, in the treated group were significantly decreased in comparison with the control group (p < 0.01). We did not detect a significant relationship between different L-thyroxine doses administered and bone mineral density z-scores. On the contrary, an inverse correlation was detected between length of treatment and bone mineral density z-scores. Treated patients showed a significantly higher concentration of serum alkaline phosphatase, osteocalcin, urinary calcium/creatinine and hydroxyproline/creatinine in comparison with the controls.


CONCLUSIONS
Our study suggests that thyroxine replacement therapy in patients with suppressed thyroid stimulating hormone levels increases postmenopausal bone loss.
Affinito
P
P
Department of Obstetrics & Gynecology, School of Medicine, University Federico 2nd of Naples, Italy.
Sorrentino
C
C
Farace
M J
MJ
di Carlo
C
C
Moccia
G
G
Canciello
P
P
Palomba
S
S
Nappi
C
C
D015519:Bone Density / Q000187:drug effects*; D016723:Bone Remodeling / Q000187:drug effects*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000150:complications / Q000188:drug therapy*; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000139:chemically induced* / Q000453:epidemiology; D017698:Postmenopause; D012307:Risk Factors; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000009:adverse effects* / Q000627:therapeutic use; D013997:Time Factors
D013972:Thyrotropin; D013974:Thyroxine