INS and tuberculosis: A metabolomics study done by Du Preez and Loots (2013), showed a 10 fold increase in the concentrations of the norepinephrine derivative; normetanephrine, in TB-positive patients, explaining the associated glucose intolerance (additionally contributing to the increased D-gluconic acid d-lactone detected in their study), since elevated levels of normetanephrine are also associated with insulin resistance and impaired insulin secretion (Murabayashi et al., 2018).