Vitamin D and diabetic peripheral neuropathy: A multi-centre nerve conduction study among Chinese patients with type 2 diabetes.

AIMS: Increasing numbers of reports link vitamin D deficiency to diabetic peripheral neuropathy (DPN), yet evidence regarding neurological deficits and electromyogram is scarce. The present multi-centre study sought to investigate these associations based on objective quantifications. MATERIALS AND METHODS: Information on DPN-related symptoms, signs, all diabetic microvascular complications, and nerve conduction abilities (quantified by nerve conduction amplitude and velocity, F-wave minimum latency (FML) of peripheral nerves) were collected from a derivation cohort of 1192 patients with type 2 diabetes (T2D). Correlation, regression analysis, and restricted cubic splines (RCS) were used to explore linear and non-linear relationships between vitamin D and DPN, which were validated in an external cohort of 223 patients. RESULTS: Patients with DPN showed lower levels of vitamin D than those without DPN; patients with vitamin D deficiency (<30 nmol/L) tended to suffer more DPN-related neurological deficits (paraesthesia, prickling, abnormal temperature, ankle hyporeflexia, and distal pall hypoesthesia correlating with MNSI-exam score (Y = -0.005306X + 2.105, P = 0.048). Worse nerve conduction abilities (decreased motor nerve amplitude, sensory nerve amplitude, motor nerve velocity, and increased FML) were also observed in these patients. Vitamin D had a significant threshold association with DPN (adjusted OR = 4.136, P = 0.003; RCS P for non-linearity = 0.003) and correlates with other microvascular complications (diabetic retinopathy and diabetic nephropathy). CONCLUSIONS: Vitamin D is associated with the conduction ability of peripheral nerves and may have a nerve- and threshold-selective relationship with the prevalence and severity of DPN among patients with T2D.

Neuron-specific enolase in hypertension patients with acute ischemic stroke and its value forecasting long-term functional outcomes.

BACKGROUND: Neuron Specific Enolase (NSE), a neuro-biochemical protein marker, may correlate with the prognosis of stroke patients. Moreover, hypertension is the most common comorbidities in patients with acute ischemic stroke (AIS), and the relationship between NSE levels and long-term functional outcomes in such an increasingly large population is unclear. The aim of the study was to investigate the relationships mentioned above and optimize the prediction models. METHODS: From 2018 to 2020, 1086 admissions for AIS were grouped as hypertension and non-hypertension, while hypertension group was randomly divided into development and validation cohorts for internal validation. The severity of the stroke was staged by National Institutes of Health Stroke Scale (NIHSS) score. Stroke prognosis after 1 year of follow up was documented by modified Rankin Scale (mRS) score. RESULTS: Analysis revealed the following findings:(i) Serum NSE levels increased greatly in hypertension subjects with poor functional outcomes(p = 0.046). However, there was no association in non-hypertension individuals(p = 0.386). (ii) In addition to the conventional factors (age and NIHSS score), NSE (OR:1.241, 95% CI: 1.025-1.502) and prothrombin time were significantly related to the incidence of unfavorable outcomes. (iii)Based on the above four indicators, a novel nomogram was established to predict the prognosis of stoke in hypertension patients with the c-index values of 0.8851. CONCLUSIONS: Overall, high baseline NSE is associated with poor 1-year AIS outcomes in hypertension patients, suggesting NSE may be a potential prognostic and therapeutic target for stroke in hypertension patients.

The protective effect of astaxanthin on learning and memory deficits and oxidative stress in a mouse model of repeated cerebral ischemia/reperfusion.

Oxidative stress has been implicated in the pathogenesis of neurodegenerative disorders, such as vascular cognitive impairment (VCI). The present study was performed to investigate the potential neuroprotective effect of the antioxidant astaxanthin (ATX) in a mouse model of VCI. VCI was induced in male ICR mice by repeated occlusion of the bilateral common carotid artery, leading to repeated cerebral ischemia/reperfusion (IR) injury. After surgery, the mice received ATX or an equal volume of vehicle by daily intragastric administration for 28days. The results showed that ATX treatment ameliorated learning and memory deficits after repeated cerebral IR. ATX administration rescued the number of surviving pyramidal neurons in the CA1 and CA3 regions. The concentration of malondialdehyde was decreased, and the levels of reduced glutathione and superoxide dismutase in the hippocampus were increased. Electron microphotography revealed that damage to the ultrastructure of neurons was also reduced by ATX administration. In addition, the expression levels of Cytochrome C (Cyt C), cleaved Caspase-3 and Bax were lower and the expression of Bcl-2 was higher compared to control IR mice. Our findings demonstrate that ATX is able to suppresse learning and memory impairment caused by repeated cerebral IR and that this effect is associated with attenuation of oxidative stress.

Salidroside protects against kainic acid-induced status epilepticus via suppressing oxidative stress.

There are numerous mechanisms by which the brain generates seizures. It is well known that oxidative stress plays a pivotal role in status epilepticus (SE). Salidroside (SDS) extracted from Rhodiola rosea L. shows multiple bioactive properties, such as neuroprotection and antioxidant activity in vitro and in vivo. This study explored the role of SDS in kainic acid (KA)-induced SE and investigated the underlying mechanism. Latency to SE increased in the SDS-pretreated mice compared to the KA group, while the percentage of incidence of SE was significantly reduced. These results suggested that pretreatment with SDS not only delayed SE, but it also decreased the incidence of SE induced by KA. KA increased MDA level and reduced the production of SOD and GSH at multiple timepoints after KA administration. SDS inhibited the change of MDA, SOD and GSH induced by KA prior to SE onset, indicating that SDS protects against KA-induced SE via suppressing oxidative stress. Based on these results, we investigated the possible molecular mechanism of SDS. Pretreatment with SDS reversed the KA-induced decrease in AMP-activated protein kinase (AMPK); increased the sirtuin 1 (SIRT1) deacetylase activity in KA-treated mice, which had no demonstrable effect on SIRT1 mRNA and protein; and suppressed the KA-induced increase in Ace-FoxO1. These results showed that AMPK/SIRT1/FoxO1 signaling is possibly the molecular mechanism of neuroprotection by SDS.