Calcium-phosphorus metabolism and bone metabolism in patients with diffuse toxic goiter

Abstract

Three groups of premenopausal women with diffuse toxic goiter (DTG) of different duration and different activity of thyrotoxicosis were examined for assessing calcium-phosphorus metabolism, osseous metabolism, and mineral compactness of bone tissue by ultrasonic (US) densitometry and bienergetic x-ray absorptiometry. Manifest hypercalciuria and hyperphosphaturia with normal levels of Ca2+ and inorganic phosphorus in the blood were revealed in patients with newly detected and recurrent DTG. In patients with hyperthyrosis the blood alkaline phosphatase activity and hydroxyproline excretion with the urine on an empty stomach were increased, these changes being most of all expressed in the group with newly detected thyrotoxicosis; however, these shifts were liable to normalize when stable drug-induced euthyrosis was attained. A reliable correlation between free T4 in the blood serum and osseous metabolism was revealed, which may indicate a direct effect of TH excess on bone tissue metabolism. The osteopenic syndrome was detected primarily in the proximal portions of the femoral bone, the severity of osteopenia reliably correlating with the disease duration. The authors come to a conclusion about the informative value of US densitometry and bienergy x-ray absorptiometry for the diagnosis of early stages of the osteopenic syndrome in DTG.