Clinical Characteristics and Outcomes of Acute Ischemic Stroke in Patients with Type 2 Diabetes: A Single-Center, Retrospective Study in Southern China

Hyperglycemia exacerbates cerebral ischemia/reperfusion injury by up-regulating autophagy through p53-Sesn2-AMPK pathway

Hyperglycemia exacerbates ischemic brain injury by up-regulating autophagy. However, the underlying mechanisms are unknown. This study aims to determine whether hyperglycemia activates autophagy through the p53-Sesn2-AMPK signaling pathway. Rats were subjected to 30-min middle cerebral artery occlusion (MCAO) with reperfusion for 1- and 3-day under normo- and hyperglycemic conditions; and HT22 cells were exposed to oxygen deprivation (OG) or oxygen-glucose deprivation and re-oxygenation (OGD/R) with high glucose. Autophagy inhibitors, 3-MA and ARI, were used both in vivo and in vitro. The results showed that, compared with the normoglycemia group (NG), hyperglycemia (HG) increased infarct volume and apoptosis in penumbra area, worsened neurological deficit, and augmented autophagy. after MCAO followed by 1-day reperfusion. Further, HG promoted the conversion of LC-3I to LC-3II, decreased p62, increased protein levels of aldose reductase, p53, P-p53ser15, Sesn2, AMPK and numbers of autophagosomes and autolysosomes, detected by transmission electron microscopy and mRFP-GFP-LC3 molecular probe, in the cerebral cortex after ischemia and reperfusion injury in animals or in cultured HT22 cells exposed to hypoxia with high glucose content. Finally, experiments with autophagy inhibitors 3-MA and aldose reductase inhibitor (ARI) revealed that while both inhibitors reduced the number of TUNEL positive neurons and reversed the effects of hyperglycemic ischemia on LC3 and p62, only ARI decreased the levels of p53, P-p53ser15. These results suggested that hyperglycemia might induce excessive autophagy to aggravate the brain injury resulted from I/R and that hyperglycemia might activate the p53-Sesn2-AMPK signaling pathway, in addition to the classical PI3K/AKT/mTOR autophagy pathway.

Impact of Diabetes on Platelet Function in Acute Ischemic Stroke Patients Taking Dual Antiplatelet Therapy

Objectives: Diabetes mellitus (DM) is a significant risk factor for ischemic stroke and associated with platelet reactivity. We aim to evaluate the effect of DM on platelet function in acute ischemic stroke patients taking dual antiplatelet therapy (DAPT).

Methods: We consecutively included patients with acute ischemic stroke taking DAPT. Platelet function was assessed by thromboelastography and the arachidonic acid (AA) or adenosine diphosphate (ADP) induced platelet inhibition rate were used to confirmed the high-residual on-treatment platelet reactivity (HRPR) to aspirin or clopidogrel. We classified patients into DM and non-DM groups. The association between DM and platelet function was assessed and the confounding factors were adjusted by propensity score matching (PSM) analysis. The independent risk factors of HRPR were determined by multivariate logistic regression analysis.

Results: A total of 1,071 acute ischemic stroke patients, 712 in the non-DM group and 359 in the DM group, were included. Patients with DM had a significantly higher maximum amplitude (63.0 vs. 62.0 mm, P < 0.01), ADP-induced clot strength (34.6 vs. 30.3 mm, P < 0.01) and clopidogrel HRPR rate (22.6% vs. 17.3%, P = 0.038) than those without DM. Among 662 patients after PSM, the maximum amplitude (63.1 vs. 62.5 mm, P = 0.032), ADP-induced clot strength (34.6 vs. 29.3 mm, P < 0.01) and clopidogrel HRPR rate (23.0% vs. 15.7%, P = 0.018) is still higher in the DM group. DM was an independent factor of clopidogrel HRPR (OR = 1.48, 95% CI: 1.03–2.07, P < 0.05).

Conclusions: In acute ischemic stroke patients taking DAPT, DM is associated with increased platelet reactivity and higher prevalence of clopidogrel HRPR.