COL1A1 and hyperinsulinism: Downregulation of MMP9 (FCNG, 0.1+ins = 0.63, p = 0.003; FCNG, 1.0+ins = 0.54, p = 0.002) and COL1A1 levels (FCNG, 0.1+ins = 0.80; FCNG, 1.0+ins = 0.52, p = 0.021, p = 0.054 vs FCNG, 0.1+ins and p = 0.057 vs FCNG, 1.0) was reduced at the low metformin concentration under the influence of hyperinsulinemia, but was further increased when 1.0 mmol/L metformin was combined with insulin.