Endocrine Abstracts

Objectives: The objective was to evaluate effects of hyperthyroidism and hypothyroidism on bone metabolism in premenopausal women with special emphasis to osteoprotegerin (OPG) and vitamin D₃ (vD).

Materials and methods: A total of 119 women aged 18–52 years were studied (38 with recently diagnosed hyperthyroidism; 40 with newly diagnosed hypothyroidism; 41 healthy women as controls). Patients were followed up for a period of 1 year. BMD, bone turnover markers and hormonal analyses with regard to seasonal changes in 25(OH)D₃ were carried out at 0, 6 and 12 months.

Results: On the initial evaluation lower femoral neck BMD was found in patients with hyperthyroidism compared to hypothyroidism. Higher bone markers, osteocalcin (OC) and collagen type one crosslinked C-telopeptides (CTX) were noted in hyperthyroidism than in controls and hypothyroidism. A difference was not found in OPG nor vD among the studied groups. After 6-month in patients treated due to hyperthyroidism, higher OC was demonstrated (vs hypothyroidism and controls) and CTX (vs controls). In this group a decrease in CTX was also demonstrated. No difference was shown in OPG among the studied groups. However, a statistically significant lower vitamin D₃ was demonstrated in he treated group with hypothyroidism and the control group. In the group with hyperthyroidism decrease of OC and CTX were observed. After 1 year increase in OPG was seen in the group treated due to hyperthyroidism and hypothyroidism.

Conclusions: A negative effect on bone metabolism is observed only in the group of female patients with hyperthyroidism. Osteoprotegerin seems not to be a useful marker of bone metabolism in thyroid dysfunction. Vitamin D₃ was significantly decreased, independent of the season, in all groups studied.