Lack of deleterious effect on bone mineral density of long-term thyroxine suppressive therapy for differentiated thyroid carcinoma

Abstract

The effect of subclinical hyperthyroidism on bone mineral density is controversial and could be significant in patients with differentiated thyroid carcinoma who receive suppressive doses of levothyroxine (LT4). To ascertain whether prolonged treatment with LT4 to suppress thyrotropin had a deleterious effect on bone mineral density and/or calcium metabolism in patients thyroidectomized for differentiated thyroid cancer we have performed a cross-sectional study in a group of 88 women (meantSD age: 51t12 years) treated with LT4 after near-total thyroidectomy and in a control group of 88 healthy women (51t11 years) matched for body mass index and menopausal status. We determined calcium metabolism parameters, bone turnover marker N-telopeptide and bone mass density by dual-energy X-ray absorptiometry. No differences were found between patients and controls in calcium metabolism parameters or N-telopeptide except for PTH, which was significantly increased in controls. No differences were found between groups in bone mineral density in femoral neck (0.971t0.148 gr/cm 2 vs 0.956t0.130 gr/cm 2 in patients and controls respectively, P = 0.5). In lumbar spine, bone mineral density values were lower in controls than in patients (1.058t0.329 gr/cm 2 vs 1.155t0.224 gr/cm 2 respectively, P<0.05). When premenopausal (n = 44) and postmenopausal (n = 44) patients were compared with their respective controls, bone mineral density was similar both in femoral neck and lumbar spine. The proportion of women with normal bone mass density, osteopenia and osteoporosis in patient and control groups was similar in pre-and postmenopausal women. In conclusion, long-term suppressive LT4 treatment does not appear to affect skeletal integrity in women with differentiated thyroid carcinoma.

Thyroid hormone independent associations between serum TSH levels and indicators of bone turnover in cured patients with differentiated thyroid carcinoma.

“…In our study, which involved a different patient group in many respects, we did not find a relationship between serum levels of FT 4 , TSH, and BMD, which may well be due to the fact that serum thyroid hormone and TSH levels have changed after the thyroidectomy. Indeed, despite the low serum TSH levels in most patients, overall BMD was within the normal age-corrected range, which is in line with a recent report in DTC patients (35).…”

Bone mineral density in treated at a young age for differentiated thyroid cancer after Chernobyl female patients on TSH-suppressive therapy receiving or not Calcium-D3 supplementation

“…A modest inverse relationship has been found between lumbar spine and whole body BMD and LDL-cholesterol levels in post-menopausal women, and between BMD and LDL levels in pre-menopausal women [30]. This is consistent with another investigation, which reported an inverse correlation between serum cholesterol level and spine BMD parameters in 340 post-menopausal Danish women suppressive therapy on BMD, which is consistent with the results of a previous study that did not show an adverse effect of such therapy on bone integrity in women with DTC regardless of their estrogen status [38]. A systematic review of 21 studies of the effect of L-T4 therapy on BMD found that post-menopausal women with subclinical hyperthyroidism are at higher risk for developing osteoporosis, while men and premenopausal women are not [10].…”

Bone mineral density and bone microarchitecture after long-term suppressive levothyroxine treatment of differentiated thyroid carcinoma in young adult patients

“…Previous studies in patients with well-differentiated thyroid cancer receiving suppressive LT 4 therapy have shown conflicting results: no decrease in BMD at any age [5,6], bone loss only in postmenopausal women [17], or deleterious effects in both premenopausa and postmenopausal patients [18,19]. Systematic reviews of BMD in these patients have reported diverse conclusions [3,4].…”

“…TSH-suppressive therapy has not been associated with decreased BMD in premenopausal women and men as evaluated by dual-energy X-ray absorptiometry (DXA) [3][4][5][6]. A study with young patients also did not suggest a detrimental effect of LT 4 on the attainment of peak bone mass [7].…”