Change of Bone Mineral Density and Biochemical Markers of Bone Turnover in Patients on Suppressive Levothyroxine Therapy for Differentiated Thyroid Carcinoma

Abstract

Untreated hyperthyroidism and high-dose thyroid hormone are associated with osteoporosis, and increased bone mineral density (BMD) has been demonstrated in postmenopausal females with hypoparathyroidism. Studies on the effect of suppressive levothyroxine (LT4) therapy on BMD and bone metabolism after total thyroidectomy in patients with differentiated thyroid carcinoma have presented conflicting results, and few studies in relation to the status of hypoparathyroidism have been studied. One hundred postmenopausal women and 24 premenopausal women on LT4 suppression therapy were included in this study. BMD of lumbar spine and femur and bone turnover markers were measured at the baseline and during the follow-up period up to 18 months using dual energy X-ray absorptiometry. Biochemical marker of bone resorption was measured by urine deoxypyridinoline and bone formation by serum osteocalcin. The age ranged from 36 to 64 years old. Thyroid stimulating hormone (TSH) was suppressed during the study. The results showed that BMD of femur and lumbar spine were not significantly changed in both pre- and postmenopausal women except femur neck in postmenopausal women without hypoparathyroidism. Patients with hypoparathyroidism had higher BMD gain than those without hypoparathyroidism in total hip (1.25 vs. -1.18%, P=0.015). Biochemical markers of bone turnover, serum osteocalcin, and urine deoxypyridinoline did not show significant change. In conclusion, patients with well differentiated thyroid carcinoma are not at a great risk of bone loss after LT4 suppressive therapy. The state of hypoparathyroidism is associated with increased BMD, particularly in postmenopausal women.

Bone Mineral Density in Thyroid Cancer Patients: Data from the Korea National Health and Nutrition Examination Survey

“…In the subgroup analysis, there was also no difference in BMD in women and post-menopausal women. These results were consistent with several previous Korean studies (4,5).…”

“…Hypoparathyroidism is a well-known post-operative complication of thyroid surgery. Post-operative hypoparathyroidism has a protective effect in BMD, as compared to normal parathyroid function (5,8). Therefore, the decreased PTH level observed in the present study can be related to the lack of differences in BMD.…”

“…However, 2 case-control studies in Korean women showed that the TSH suppression did not decrease BMD (4,5).…”

Association between Hemoglobin Level and Bone Mineral Density in Korean Adults

“…Of these subjects, 1,620 patients who were currently taking osteoporosis drugs or female hormones were excluded. In addition, 1,899 patients with chronic renal failure, liver cirrhosis, diabetes mellitus, thyroid disease,[ 19 ] rheumatoid arthritis, and all types of cancer, which are known to affect bone metabolism, were excluded. Therefore, 13,127 subjects (6,412 men and 6,715 women) were finally selected.…”

Effects of levothyroxine therapy on bone mineral density and bone turnover markers in premenopausal women with thyroid cancer after thyroidectomy

“…The American Thyroid Association (ATA) recommend treating patients with levels of TSH less than 0.1 mIU/L if they are older than 65 years or suffer from cardiovascular diseases or osteoporosis [19]. However, the effect of long-term TSH suppressive therapy on BMD and BTMs in patients with DTC after thyroidectomy is still unclear [20][21][22], and most of these studies involved postmenopausal women, who have a higher risk of osteoporosis. In this study, we try to investigate the impact of long-term LT4 treatment on Du Fu-Man, Department of Endocrinology, Heilongjiang Provincial Hospital, Harbin, 150036, Heilongjiang Province, China; e-mail: physiciandu@outlook.com…”