Unpuzzling the Comorbid Type 2 Diabetes and Hypertension-Related Cognitive Dysfunction and Stroke

Abstract

Type 2 diabetes (T2D) is a highly disabling, major socioeconomic burden, whose long-term complications (particularly those affecting the central nervous system (CNS), as Alzheimer disease (AD)) can be further exacerbated by the frequent development of comorbid hypertension. Although the precise mechanisms involved herein remain elusive, it is conceivable that chronic T2D-related brain insulin resistance (IRES) and hyperglycemia may crosstalk with an overactivated brain renin-angiotensin-II-aldosterone system (RAAS) further potentiating the hypertension-related injury and culminating in cognitive dysfunction and AD. Indeed, several studies showed the contribution of abnormal RAAS activation upon hypertension per se to the pathophysiology of CNS disorders, such as stroke and AD. However, most of this available knowledge relies on the indirect effects of pharmacological inhibition of RAAS by drugs belonging either to the angiotensin II receptor blockers (ARBs) or angiotensin-converting enzyme (ACE) inhibitors (ACEi) groups. For instance, antihypertensive drugs have also shown anti-neuroinflammatory properties, widely known to play a pivotal role in brain and cognitive dysfunction.