This increased peripheral chemosensitivity observed both in prediabetes and type 2 diabetes was shown to be associated with increased CB weight, with an increase in the percentage of CB chemoreceptor cells and CB tyrosine hydroxylase activity as well as with augmented CB release of catecholamines and CSN activity in metabolic disease animals [13,18,19,22] and with an increase in CB size of approximately 25% in type 2 diabetes patients [23]. This evidence concerns the gene TH and type 2 diabetes mellitus.