Bone mineral density and metabolism in levothyroxine-treated adolescent girls with euthyroid diffuse goiter.
Bone and mineral metabolism is influenced by thyroid hormones, and levothyroxine (LT(4)) therapy may be associated with reduced bone mass in postmenopausal women. The aim of the study was to assess the influence of one year of LT(4) treatment in a group of 21 adolescent girls with euthyroid diffuse goiter. Lumbar (L(2)-L(4)) and total body bone mineral density (TOBMD) (Lunar - DXA), serum PTH, osteocalcin, bone alkaline phosphate, vitamin D(3), calcium, and phosphorus levels and urinary excretion of Ca, P, and hydroxyproline were measured before and after one year of combined LT(4) and iodine treatment. Patients were matched for age, sex, BMI, and maturation status, with controls treated with iodine only. Markers of bone turnover changed in a similar manner in both groups. There was no significant difference in TOBMD value after one year of therapy between LT(4) treated group and controls. Densitometric lumbar spine parameters increased significantly after 12 months in both groups, with no significant differences between them. It can be concluded that one year of LT(4) treatment of adolescent girls with euthyroid diffuse goiter does not have a negative impact on their bone remodelling and metabolism. (Pol J Endocrinol 2010; 61 (1): 14-19).