INS and diabetes mellitus: Early literature showed increased urinary and serum levels of 2HB in patients with various clinical disorders combined with ketoacidosis and lactic acidosis (Landaas and Pettersen 1975), but more recent studies suggest that serum 2HB is a significant biomarker associated with insulin sensitivity, diabetes mellitus and cardiovascular diseases (Syed Ikmal et al. 2013; Gall et al. 2010).