SFRP1 and osteoporosis: Patients in the group with advanced osteoporosis (Group 4) demonstrated a correlation on the borderline of statistical significance between: the number of spine fractures and DKK1 gene expression (R=0.572 p = 0.107) and the total number of all fractures and the expression level of SFRP1 (R=−0.641, p = 0.063) and the number of forearm fractures and WNT1 expression (R=0.639, p = 0.064).