Hip bone mineral density, bone turnover and risk of fracture in patients on long-term suppressive L-thyroxine therapy for differentiated thyroid carcinoma

Abstract

Objective: Untreated hyperthyroidism and treatment with high doses of thyroid hormone are associated with osteoporosis. However, their effect on bone turnover, their contribution to bone mineral density (BMD) in the context of other clinical risk factors for osteoporosis and the prevalence of vertebral fractures is not well documented. Design: Cross-sectional study. Methods: We studied 59 patients receiving L-thyroxine suppressive therapy for differentiated thyroid carcinoma (DTC). BMD of the hip was measured by dual X-ray absorptiometry (DXA) and lateral DXA pictures of the lumbar and thoracic vertebrae were performed. Bone resorption was measured by C-telopeptides of type I collagen (ICTP) and bone formation by procollagen type I N-propeptide (PINP). Clinical risk factors for osteoporosis were evaluated using a questionnaire. Results: Z-scores of BMD were similar as the NHANES (National Health and Nutrition Examination Survey) III reference group in women and men, also after long-term (.10 years) suppression therapy. Patients in the lowest and highest quartile of BMD showed significant differences in the presence of clinical risk factors. ICTP levels were significantly higher than in age-matched controls, PINP levels were not different. We found four patients with a prevalent vertebral fracture. Conclusions: We conclude that patients with well-differentiated thyroid carcinoma are not at increased risk of developing low bone mass nor have a higher prevalence of vertebral fracture at least when treated with relatively low doses of L-thyroxine.

Prevalence of silent vertebral fractures detected by vertebral fracture assessment in young Portuguese men with hyperthyroidism

“…Several studies carried out in patients with iatrogenic hyperthyroidism showed that the risk for fracture was higher in older men and mainly in women with a very low TSH level (30,31,32). However, it is not totally clear that iatrogenic hyperthyroidism does affect bone in a totally similar way as hyperthyroidism due to toxic goiter or autoimmune diseases.…”

L-thyroxine-treated patients with nodular goiter have lower serum TSH and lower frequency of papillary thyroid cancer: results of a cross-sectional study on 27 914 patients

“…First, it is possible that a large part of the cancers we have detected would not have had deleterious effects if not removed by surgery, as longitudinal studies on this matter are missing. Secondly, and more importantly, L-T 4 treatment is not without risk, with the negative effects of TSH-suppressive treatment with L-T 4 on cardiovascular system in aged subjects (Biondi et al 2002, Fazio et al 2004) and development of osteoporosis in post-menopausal women (Williams 1997, Heijckmann et al 2005) being well documented. Longitudinal case-control studies and careful evaluation of the cost-effectiveness of L-T 4 treatment are required to address this question.…”

Studies of Osteoporosis in Cancer Patients in Slovakia – Experience from Single Institute

“…Similar results were published also in the past (Shomon, 1995). Some on the other hand has confirmed that long term suppressive therapy affects bone turnover and bone mineral density in pre and postmenopausal women with TC (Heijekmann et al, 2005). Decrese in BMD as a result of suppressive therapy in TC was confirmed but this effect was ameliorated by preventive substitution of calcium and calcitonin (Mikosch et al, 2006).…”