MMP9 and metabolic syndrome: On reviewing the results of correlation to identify factors most strongly correlated with MMP9 expression, beside the significant correlations previously illustrated between MMP-9 gene expression and bone turnover markers and mediators (tissue protein expression of RANKL, OPG, serum ALP, OC and pyridinoline), the present study revealed also a significant correlation between MMP-9 gene expression and dyslipidemia and inflammation markers (serum levels of TC, TGs, HDL, serum TNF-α, IL6, CRP, nitric oxide, gene expression of NF-KB), which represent major risk factors for CVD.