Plasma levels of osteocalcin and retinol binding protein-4 in patients with medullary thyroid carcinoma

Thyroid carcinoma is the most frequent malignant tumor of the endocrine system in human body and accounts for nearly 1% of all cancers. Medullary thyroid carcinoma is the third frequent of thyroid cancer and accounts about 5-8% of thyroid cancer. Osteocalcin, known as a Bone Gamma-carboxyglutamic Acid-containing Protein (BGLAP), is the most non collagenous protein. Retinol binding proteins are the family of proteins that have diverse actions but mainly transport retinol in human body. In this study to evaluate effect of existence medullary thyroid carcinoma on metabolism of bone and adipose tissue, plasma level of two mentioned proteins had analyzed. Population in this study consists of 46 individuals with medullary thyroid carcinoma and 44 healthy subjects referred individuals to Research Institute for Endo-crine Sciences, Shahid Beheshti University of Medical Sciences. People with the disease after diagnosis of medullary thyroid carcinoma and pathologically confirmed by biopsy in the initial stages of the study were called. After informed consent, 10 ml of blood from the antecubital vein of left hand in sitting position obtained and after cen-trifugation, plasma was isolated from all samples until analyzed kept in the freezer. Plasma levels of hormones were measured by sandwich type ELISA method. Obtained results were analyzed by SPSS version 16 with independent t-test method. Mean plasma level of osteocalcin in patients was 33.1±3.5 and in healthy sub-jects was 12.5±1.2 ng/ml (Mean±SD) and Odds Ratio (OR) value was 1.04. In patients, mean plasma level of retinol binding protein was 82.5±2.7 and in healthy subjects was 22.8±1.6 μg/ml and OR value was 2.1. The confidence level considered at 95%. These differences of plasma levels were statistically significant (P= 0.001). According to difference between plasma levels of osteocalcin and retinol binding protein-4 in patients suffered of medullary thyroid carcinoma comparison with normal subjects, it can be said that, probably medullary thyroid carcinoma has effect on bone and adipose tissue metabolism, so osteocalcin and retinol binding protein-4 hormones have potential to be used for confirmation of diagnosis or following treatment of medullary thyroid carcinoma.