@Article{Salama2010,
journal="Archives of Medical Science",
issn="1734-1922",
volume="6",
number="3",
year="2010",
title="Clinical research  The effects of L-thyroxin replacement therapy on bone minerals and body composition in hypothyroid children",
abstract=" Introduction:  Prolonged treatment with levothyroxine 4 (L-T4) is a well known risk factor for osteoporosis. Patients on L-T4 replacement occasionally have a subnormal TSH, which carries a risk of development of bone loss. Thyroid hormones directly affect bone cells, stimulating osteoclastic and osteoblastic activity with a predominance of bone resorption and decrease of bone mineral density (BMD).    Material and methods:  The study included 35 hypothyroid patients with mean age 11.57 \&#177;5.06, while 26 age- and sex-matched children served as controls. Dual energy X-ray absorptiometry (DXA) was done to detect the bone mineral density (BMD), bone mineral content (BMC) and Z score in lumbar and femur neck regions. Body composition was also studied by DXA. Calcium, phosphorus, osteocalcin as a bone formation marker, osteoprotegerin as an indicator of osteoclast activity and urinary deoxypyridinoline as a bone collagen breakdown marker were assessed.   Results:  No significant differences were detected in lumbar Z score (\&#8211;0.12 \&#177;0.66) and femur Z score (\&#8211;0.17 \&#177;0.58) compared to controls (\&#8211;0.33 \&#177;0.74 and \&#8211;0.21 \&#177;0.53 respectively). Bone mineral density and BMC were not significantly different from controls. No significant difference was detected between cases and controls in body composition. A positive correlation was detected between BMD and age (r = 0.857, p < 0.01), and with the period of treatment (r = 0.766, p < 0.01). A positive correlation was found between BMD and total body fat (r = 0.693, p < 0.01), and with abdominal fat (r = 0.667, p < 0.01).    Conclusions:  Levothyroxine 4 treatment in hypothyroid children does not alter bone metabolism and body composition",
author="Salama, Hassan M.
and El-Dayem, Soha A.
and Yousef, Hala
and Fawzy, Ashraf
and Abou-Ismail, Laila
and El-lebedy, Dalia",
pages="407--413",
doi="10.5114/aoms.2010.14264",
url="http://dx.doi.org/10.5114/aoms.2010.14264"
}