**3.1 Physiological pathways linking diabetes and cognition**

The link between diabetes and cognitive impairment was first reported in 1922 [58]. The exact physiologic pathways linking the two conditions remain unclear. The hypothetical mechanisms include which is related to cerebrovascular complications, neuronal glucose processing and frequent episodes of hypoglycaemia [3, 59, 60]. The diabetic patients are more prone to develop comorbid cardiovascular disease, which is itself predictive of cognitive decline through cerebrovascular events and other pathways [61].
