Interestingly, visfatin was also associated to several OA and OP shared metabolic alterations, namely cardiovascular hypertension and obesity [9,12,13,14,15,73,74], insulin resistance [75,76], and type 1 (T1DM) [16] and 2 diabetes mellitus (T2DM) [17,18,77] (Figure 2). This evidence concerns the gene NAMPT and obesity due to melanocortin 4 receptor deficiency.