We adjusted for Ln-HD duration, mean blood pressure, pH, serum albumin, and presence of DM, which were independently and significantly associated with cerebral rSO2 in the multivariable linear regression analysis, and the cerebral rSO2 and Hb levels demonstrated a linear relationship (p for linearity = 0.79, Fig 3). This evidence concerns the gene GSTM1 and diabetes mellitus.