The Role of Vitamin D, Platelet-Derived Growth Factor and Insulin-Like Growth Factor 1 in the Progression of Thyroid Diseases

BACKGROUND: Thyroid cancer (TC) is a common malignant tumor, however the role of total vitamin D: 25(OH)D, Platelet Derived Growth Factor (PDGF) and Insulin Like Growth Factor 1 (IGF-1) in the development of TC is still unclear. AIM: To assess the roles of 25(OH)D, PDGF and IGF-1 in the progression of thyroid diseases. METHODS: The serum levels of 25(OH)D, PDGF and IGF-1 were assessed in 70 patients with papillary thyroid cancer (PTC), 60 patients with benign thyroid nodules (BN) compared to 60 normal controls (NC) using ELISA technique. RESULTS: There was a significant decrease in the serum level of 25(OH)D in TC patients compared to NC (P<0.001) and BN patients (P=0.006). There was a significant increase in the serum levels of PDGF and IGF-1 in TC patients (P<0.001), and BN patients (P<0.001) compared to NC, while there were no significant differences between TC and BN (P=0.087, and 0.258; respectively). PDGF correlated significantly with IGF-1 (r=0.412, P<0.001), TSH (r=0.146, P=0.045), and inversely correlated with 25(OH)D (r= -0.156, P=0.013) and FT4 (r=-0.178, P=0.014). There was a significant inverse correlation between the serum levels of IGF-1 and FT4 (r=-0.172, P=0.017). Sensitivity and specificity for assessment of TC patients were (65.7% and 58.3%, P= 0.001) for 25(OH)D, (65.7% and 58.3%, P=0.021) for IGF-1, and (68.6% and 61.7%, P=0.006) for PDGF. Multivariate analysis demonstrated that serum 25(OH)D (OR=0.578, 95%CI= 0.426-0.783), IGF-1 (OR=1.019, 95%CI= 1.010-1.029) and PDGF (OR=1.007, 95%CI= 1.004-1.009) were considered independent risk factors for thyroid cancer (P<0.001, for all). CONCLUSION: 25(OH) D, IGF-1 and PDGF are significantly different in TC and BN cases compared to control. They have an important role in the progression of TC. However, these data should be validated on a larger sample size.