Hyperlipidemia in Stroke Pathobiology and Therapy: Insights and Perspectives

Novel insight into the role of A-kinase anchoring proteins (AKAPs) in ischemic stroke and therapeutic potentials

Ischemic stroke, a devastating disease associated with high mortality and disability worldwide, has emerged as an urgent public health issue. A-kinase anchoring proteins (AKAPs) are a group of signal-organizing molecules that compartmentalize and anchor a wide range of receptors and effector proteins and have a major role in stabilizing mitochondrial function and promoting neurodevelopmental development in the central nervous system (CNS). Growing evidence suggests that dysregulation of AKAPs expression and activity is closely associated with oxidative stress, ion disorder, mitochondrial dysfunction, and blood-brain barrier (BBB) impairment in ischemic stroke. However, the underlying mechanisms remain inadequately understood. This review provides a comprehensive overview of the composition and structure of A-kinase anchoring protein (AKAP) family members, emphasizing their physiological functions in the CNS. We explored in depth the molecular and cellular mechanisms of AKAP complexes in the pathological progression and risk factors of ischemic stroke, including hypertension, hyperglycemia, lipid metabolism disorders, and atrial fibrillation. Herein, we highlight the potential of AKAP complexes as a pharmacological target against ischemic stroke in the hope of inspiring translational research and innovative clinical approaches.

Statin treatment in stroke patient with low-density lipoprotein cholesterol levels below 70 mg/dL

BACKGROUND AND PURPOSE

The effectiveness of hyperlipidemia treatment in strokes secondary prevention has been established. However, whether pretreatment with statins could confer protective effects when a patient's baseline low-density lipoprotein cholesterol (LDL-C) level is <70 mg/dL remains uncertain. Additionally, the ability of statin treatment to reduce poststroke complications, mortality, and recurrence in this patient group is unclear.

METHODS AND RESULTS

In this retrospective observational study, we enrolled patients who had experienced an ischemic stroke with LDL-C levels <70 mg/dL. We analyzed the association of statin use with baseline characteristics, stroke severity, in-hospital complications, mortality rates, stroke recurrence rate, and mortality rate. Patients who used and patients who did not use statins were similar in terms of age and sex. Patients using statins had higher rates of diabetes mellitus, hypertension, prior stroke, and coronary artery disease but a lower incidence of atrial fibrillation. Stroke severity was less pronounced in those using statins. We also evaluated the relationship between in-hospital statin use and complications. We noted that in-hospital statin use was associated with lower rates of infection, hemorrhagic transformation, gastrointestinal hemorrhage, and mortality, as well as higher rates of positive functional outcomes. The 1-year recurrence rate was similar in both groups.

CONCLUSIONS

Statin use is associated with milder strokes and improved poststroke outcomes, even in patients with well-controlled LDL levels. Neurologists may consider prescribing statins for patients with ischemic stroke who do not overt hyperlipidemia. Further research into potential underlying mechanisms is warranted.

Nutritional roles and therapeutic potentials of dietary sphingomyelin in brain diseases

Sphingolipids have recently gained interest as potential players in variety of diseases due to their import roles in human body particularly, the brain. As sphingomyelin is the most common type of sphingolipids, deficits in its distribution to brain cells may contribute to neurological anomalies. However, data is limited regarding the impact of different levels of dietary sphingomyelin intake on neural function especially if this approach can boost cognition and prevent neurological disorders. This review evaluates the effect of dietary sphingomyelin and its metabolites (ceramide and sphingosine-1-phosphate) in animal models and in humans, with a primary focus on its impact on brain health. Additionally, it proposes multiple neuroenhancing effects of sphingomyelin-rich diet. This presents an opportunity to stimulate further research that aims to determine the therapeutic value of dietary sphingomyelin in preventing, improving or slowing the progression of central nervous system disorders.

Dyslipidemia versus obesity as predictors of ischemic stroke prognosis: a multi-center study in China

BACKGROUND

This multicenter observational study aimed to determine whether dyslipidemia or obesity contributes more significantly to unfavorable clinical outcomes in patients experiencing a first-ever ischemic stroke (IS).

METHODS

The study employed a machine learning predictive model to investigate associations among body mass index (BMI), body fat percentage (BFP), high-density lipoprotein (HDL), triglycerides (TG), and total cholesterol (TC) with adverse outcomes in IS patients. Extensive real-world clinical data was utilized, and risk factors significantly linked to adverse outcomes were identified through multivariate analysis, propensity score matching (PSM), and regression discontinuity design (RDD) techniques. Furthermore, these findings were validated via a nationwide multicenter prospective cohort study.

RESULTS

In the derived cohort, a total of 45,162 patients diagnosed with IS were assessed, with 522 experiencing adverse outcomes. A multifactorial analysis incorporating PSM and RDD methods identified TG (adjusted odds ratio (OR) = 1.110; 95% confidence interval (CI): 1.041-1.183; P <  0.01) and TC (adjusted OR = 1.139; 95%CI: 1.039-1.248; P <  0.01) as risk factors. However, BMI, BFP, and HDL showed no significant effect. In the validation cohort, 1410 controls and 941 patients were enrolled, confirming that lipid levels are more strongly correlated with the prognosis of IS patients compared to obesity (TC, OR = 1.369; 95%CI: 1.069-1.754; P <  0.05; TG, OR = 1.332; 95%CI: 1.097-1.618; P <  0.01).

CONCLUSION

This study suggests that dyslipidemia has a more substantial impact on the prognosis of IS patients compared to obesity. This highlights the importance of prioritizing dyslipidemia management in the treatment and prevention of adverse outcomes in IS patients.

A Parametric Time-to-Event Modelling of Recurrent Ischemic Stroke After Index Stroke Among Patients With and Without Diabetes Mellitus: Implementation of Temporal Validation of the Model

Objectives Compared with the first stroke, neurological impairment caused by stroke recurrence is more serious, more difficult to treat, and has a higher mortality rate, especially among ischemic stroke (IS) patients with diabetes mellitus (DM). Although there are established correlations between factors and IS recurrence, there were some issues regarding the naive hazard of IS recurrence with no risk factor influence, and how does the baseline hazard differ among patients with DM and non-DM? To answer all these questions, two time-to-event (TTE) models of recurrent IS after the index IS were developed among IS patients with DM and non-DM. Method A total of 7697 patients with an index IS attack were extracted from the Malaysian Registry of Neurology and stratified according to DM status. Several parametric survival models were evaluated using nonlinear mixed-effect modeling software (NONMEM 7.5). The final model was determined according to the lowest objective function value, graphical evaluation, numerical diagnostics, and clinical plausibility. Additionally, the final model was validated internally and temporally using Kaplan-Meier visual predictive checks (KM-VPCs). Results One hundred ninety-five (5.82%) of 3493 DM patients and 138 (3.28%) of 4204 non-DM patients developed a recurrent IS with a maximum follow-up of 7.37 years. Gompertz's model best fitted the data. With no influence on risk factors, the index IS attack was predicted to contribute to the hazard of recurrent IS by 0.356 and 0.253 within the first six months after the index IS among patients with and without DM, respectively. Even after six months of index IS, the recurrent IS baseline hazard was not equal to zero among both groups (0.0023, 0.0018). Moreover, after incorporating the time and risk factors, the recurrent hazards increased exponentially during the first three years after the index IS followed by an exponential reduction afterward. The recurrent IS predictors among DM patients were ischemic heart disease (IHD) and hyperlipidemia (HPLD). IHD and HPLD increased the hazard of recurrent IS by 2.40 and 1.88 times, respectively, compared to those without IHD and HPLD before index IS (HR, 2.40 (1.79-3.20)), and (HR, 1.88 (1.44-2.45)) respectively. Conclusion The baseline hazard was the highest during the first six months after the index IS. Moreover, receiving medications for secondary prevention failed to demonstrate a significant association with reducing IS recurrence among IS patients with DM, suggesting a need for more intensive patient screening and new strategies for secondary prevention among IS patients with DM.

Capsaicin, The Vanilloid Receptor TRPV1 Agonist in Neuroprotection: Mechanisms Involved and Significance

Hot peppers, also called chilli, chilli pepper, or paprika of the plant genus Capsicum (family Solanaceae), are one of the most used vegetables and spices worldwide. Capsaicin (8-methyl N-vanillyl-6-noneamide) is the main pungent principle of hot green and red peppers. By acting on the capsaicin receptor or transient receptor potential cation channel vanilloid subfamily member 1 (TRPV1), capsaicin selectively stimulates and in high doses defunctionalizes capsaicin-sensitive chemonociceptors with C and Aδ afferent fibers. This channel, which is involved in a wide range of neuronal processes, is expressed in peripheral and central branches of capsaicin-sensitive nociceptive neurons, sensory ganglia, the spinal cord, and different brain regions in neuronal cell bodies, dendrites, astrocytes, and pericytes. Several experimental and clinical studies provided evidence that capsaicin protected against ischaemic or excitotoxic cerebral neuronal injury and may lower the risk of cerebral stroke. By preventing neuronal death, memory impairment and inhibiting the amyloidogenic process, capsaicin may also be beneficial in neurodegenerative disorders such as Parkinson's or Alzheimer's diseases. Capsaicin given in systemic inflammation/sepsis exerted beneficial antioxidant and anti-inflammatory effects while defunctionalization of capsaicin-sensitive vagal afferents has been demonstrated to increase brain oxidative stress. Capsaicin may act in the periphery via the vagal sensory fibers expressing TRPV1 receptors to reduce immune oxidative and inflammatory signalling to the brain. Capsaicin given in small doses has also been reported to inhibit the experimentally-induced epileptic seizures. The aim of this review is to provide a concise account on the most recent findings related to this topic. We attempted to delineate such mechanisms by which capsaicin exerts its neuronal protective effects. We also aimed to provide the reader with the current knowledge on the mechanism of action of capsaicin on sensory receptors.

Effects of Serum Cholesterol on Severity of Stroke and Dosage of Statins on Functional Outcome in Acute Ischemic Stroke

Background

A high dose of statin is used to obtain an intensive lipid-lowering in stroke patients, even in patients with normal lipid levels. There are limited data on effect of dosage of statins and functional outcome in stroke patients.

Objectives

To compare serum cholesterol levels with severity of stroke measured by infarct volume. To compare functional outcome measured by mRS at day 90 with the dose of statin.

Materials and Methods

This retrospective observational study was conducted in KMC Hospital Manipal, India between 2016 and 2018.

Result

A total of 100 consecutive patients were included in the study, out of which 60 (60.0%) were males. Hyperlipidemia was present in 65 (65.0%) patients. On comparing the serum cholesterol levels with infarct volume using MRI, patients with low volume of ≤70 ml had higher mean serum total cholesterol concentration (223.83 mg/dl), whereas patients with high volume of >70 ml had low mean cholesterol level (218.70 mg/dl). The patients were divided into those who received low dose (≤20 mg) versus high dose (≥40 mg equivalent) of Atorvastatin. On comparing the mRS values at baseline and on day 90 with the dose of statins, patients who received a higher dosage had a statistically significant fall in mRS (p-0.045) at day 90.

Conclusion

It was found that serum cholesterol levels were inversely related to the stroke severity. However, a higher the dose of statins resulted in better functional outcome and survival in post-stroke patients, possibly due to its neuroprotective effect.

Elevated ApoB/ApoA-Ι ratio is associated with poor outcome in acute ischemic stroke

BACKGROUND

Apolipoproteins are known atherogenic factors that play important roles in many mechanisms related to acute ischemic stroke (AIS). However, it is unclear whether the ApoB/ApoA-Ι ratio is related to the prognosis of patients with AIS.

METHODS

We conducted a prospective cohort study in the Department of Neurology, Yangpu Hospital, School of Medicine, Tongji University and investigated the association between ApoB/ApoA-Ι ratio and poor outcomes at 3 months of AIS.

RESULTS

1,247 patients that met the eligibility criteria were enrolled in our study. We found that ApoA-Ι (Adjusted odds ratios (adjOR) 0.529, 95 %CI 0.327-0.855), ApoB (adjOR 3.015, 95 %CI 1.746-5.207), and ApoB/ApoA-Ι ratio (adjOR 3.986, 95 %CI 2.220-7.155) were independently associated with poor outcomes in acute ischemic stroke. During subgroup analysis, the ApoB/ApoA-Ι ratio was more likely associated with poor AIS outcomes in males and patients younger than 80 with SAO(Small Artery Occlusion) and no history of diabetes or statin use. Restricted cubic spline analyses explored the correlation between poor outcomes and ApoB/ApoA-Ι ratio.

CONCLUSIONS

Higher ApoB, lower ApoA-Ι, and higher ApoB/ApoA-Ι ratios were independently associated with poor outcomes in AIS. However, ApoB and ApoA-Ι were not related to hemorrhagic transformation in AIS.

Association of cholesterol levels with hemorrhagic transformation and cerebral edema after reperfusion therapies

Background:

The association between cholesterol levels and cerebral edema (CED) or hemorrhagic transformation (HT) as an expressions of blood-brain barrier (BBB) dysfunction after ischemic stroke is not well established. The aim of this study is to determine the association of total cholesterol (TC) levels with the incidence of HT and CED after reperfusion therapies.

Methods:

We analyzed SITS Thrombolysis and Thrombectomy Registry data from January 2011 to December 2017. We identified patients with data on TC levels at baseline. TC values were categorized in three groups (reference group ⩾200 mg/dl). The two primary outcomes were any parenchymal hemorrhage (PH) and moderate to severe CED on follow up imaging. Secondary outcomes included death and functional independence (mRS 0–2) at 3 months. Multivariable logistic regression analysis adjusted for baseline factors including statin pretreatment was used to assess the association between TC levels and outcomes.

Results:

Of 35,314 patients with available information on TC levels at baseline, 3372 (9.5%) presented with TC levels ⩽130 mg/dl, 8203 (23.2%) with TC 130–200 mg/dl and 23,739 (67.3%) with TC ⩾ 200 mg/dl. In the adjusted analyses, TC level as continuous variable was inversely associated with moderate to severe CED (OR 0.99, 95% CI 0.99–1.00, p = 0.025) and as categorical variable lower TC levels were associated with a higher risk of moderate to severe CED (aOR 1.24, 95% CI 1.10–1.40, p = 0.003). TC levels were not associated with any PH, functional independence, and mortality at 3 months.

Conclusions:

Our findings indicate an independent association between low levels of TC and higher odds of moderate/severe CED. Further studies are needed to confirm these findings.

Comparing the Relationships of Genetically Proxied PCSK9 Inhibition With Mood Disorders, Cognition, and Dementia Between Men and Women: A Drug‐Target Mendelian Randomization Study

Background

PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitors are important therapeutic options for reducing cardiovascular disease risk; however, questions remain regarding potential differences in the neuropsychiatric impact of long‐term PCSK9 inhibition between men and women.

Methods and Results

Using PCSK9 gene single‐nucleotide polymorphisms from European ancestry–based genome‐wide association studies of low‐density lipoprotein cholesterol (N=1 320 016), circulating PCSK9 protein levels (N=10 186), tissue‐specific PCSK9 gene expression, sex‐specific genome‐wide association studies of anxiety, depression, cognition, insomnia, and dementia (ranging from 54 321 to 194 174), we used drug‐target inverse variance–weighted Mendelian randomization (MR) and complementary MR methods (MR Egger, weighted median, and weighted mode) to investigate potential neuropsychiatric consequences of genetically proxied PCSK9 inhibition in men and women. We failed to find evidence surpassing correction for multiple comparisons of relationships between genetically proxied PCSK9 inhibition and the risk for the 12 neuropsychiatric end points in either men or women. Drug‐target analyses were generally well‐powered to detect effect estimates at several hypothesized thresholds for both combined‐sex and sex‐specific end points, especially analyses using PCSK9 instruments derived from protein and expression quantitative trait loci. Further, MR estimates across complementary MR methods and additional models using genetic instruments derived from circulating PCSK9 protein levels and tissue‐specific PCSK9 expression were in alignment, strengthening causal inference.

Conclusions

Genetically proxied PCSK9 inhibition showed a neutral neuropsychiatric side effect profile with no major sex‐specific differences. Given statistical power considerations, replication with larger samples, as well as data from other ancestral populations, are necessary. These findings may have important clinical implications for lipid‐lowering drug‐prescribing practices and side effect monitoring of approved and future PCSK9 therapies.

Data-driven identification of heart failure disease states and progression pathways using electronic health records

Heart failure (HF) is a leading cause of morbidity, healthcare costs, and mortality. Guideline based segmentation of HF into distinct subtypes is coarse and unlikely to reflect the heterogeneity of etiologies and disease trajectories of patients. While analyses of electronic health records show promise in expanding our understanding of complex syndromes like HF in an evidence-driven way, limitations in data quality have presented challenges for large-scale EHR-based insight generation and decision-making. We present a hypothesis-free approach to generating real-world characteristics and progression patterns of HF. Patient disease state snapshots are extracted from the complaints mentioned in unstructured clinical notes. Typical disease states are generated by clustering and characterized in terms of their distinguishing features, temporal relationships, and risk of important clinical events. Our analysis generates a comprehensive "disease phenome" of real-world patients computed from large, noisy, secondary-use EHR datasets created in a routine clinical setting.

Molecular mechanisms underlying some major common risk factors of stroke

Ischemic and hemorrhagic strokes are the most common known cerebrovascular disease which can be induced by modifiable and non-modifiable risk factors. Age and race are the most common non-modifiable risk factors of stroke. However, hypertension, diabetes, obesity, dyslipidemia, physical inactivity, and cardiovascular disorders are major modifiable risk factors. Understanding the molecular mechanism mediating each of these risk factors is expected to contribute significantly to reducing the risk of stroke, preventing neural damage, enhancing rehabilitation, and designing suitable treatments. Abnormalities in the structure of the blood-brain barrier and blood vessels, thrombosis, vasoconstriction, atherosclerosis, reduced cerebral blood flow, neural oxidative stress, inflammation, and apoptosis, impaired synaptic transmission, excitotoxicity, altered expression/activities of many channels and signaling proteins are the most knows mechanisms responsible for stroke induction. However, the molecular role of risk factors in each of these mechanisms is not well understood and requires a lot of search and reading. This review was designed to provide the reader with a single source of information that discusses the current update of the prevalence, pathophysiology, and all possible molecular mechanisms underlying some major risk factors of stroke namely, hypertension, diabetes mellitus, dyslipidemia, and lipid fraction, and physical inactivity. This provides a full resource for understanding the molecular effect of each of these risk factors in stroke.

Association of intermittent versus continuous hemodialysis modalities with mortality in the setting of acute stroke among patients with end-stage renal disease

Patients with end-stage renal disease (ESRD) are 8-10 times more likely to suffer from a stroke compared with the general public. Despite this risk, there are minimal data elucidating which hemodialysis modality is best for patients with ESRD following a stroke, and guidelines for their management are lacking. We retrospectively queried the US Renal Data System administrative database for all-cause mortality in ESRD stroke patients who received either intermittent hemodialysis (IHD) or continuous renal replacement therapy (CRRT). Acute ischemic stroke and hemorrhagic stroke were identified using the International Classification of Diseases 9th Revision (ICD-9)/ICD-10 codes, and hemodialysis modality was determined using Healthcare Common Procedure Coding System (HCPCS) codes. Time to death from the first stroke diagnosis was the outcome of interest. Cox proportional hazards modeling was used, and associations were expressed as adjusted HRs. From the inclusion cohort of 87,910 patients, 92.9% of patients received IHD while 7.1% of patients received CRRT. After controlling for age, race, sex, ethnicity, and common stroke risk factors such as hypertension, diabetes, tobacco use, atrial fibrillation, and hyperlipidemia, those who were placed on CRRT within 7 days of a stroke had an increased risk of death compared with those placed on IHD (HR=1.28, 95% CI 1.25 to 1.32). It is possible that ESRD stroke patients who received CRRT are more critically ill. However, even when the cohort was limited to only those patients in the intensive care unit and additional risk factors for mortality were controlled for, CRRT was still associated with an increased risk of death (HR=1.32, 95% CI 1.27 to 1.37). Therefore, further prospective clinical trials are warranted to address these findings.

Diagnosis and Management of Stroke in Adults with Primary Brain Tumor

Purpose of Review

This article reviews the risk factors, clinical presentations, differential diagnosis, and the types of strokes frequently seen in patients with primary brain neoplasms. This includes a discussion of approaches with a review of the available literature and provides recommendations for primary and secondary prevention specific to this patient population.

Recent Findings

Strokes in patients with brain tumors are often multifactorial. However, tailored approaches to stroke care are necessary to achieve optimal patient outcomes, AHA/ASA stroke guidelines provide little information on the management of stroke in cancer patients. A comprehensive algorithm for diagnosis for stroke in primary CNS tumor patients is proposed.

Summary

Understanding the potential complex etiology of stroke in patients with brain tumors is essential to provide appropriate treatment and initiate optimal prevention measures early in the cancer treatment program. Optimal care therefore requires a comprehensive approach including a variety of specialists and healthcare providers.

Correlation between HbA1C and Infarct Volume in Acute Ischemic Stroke

BACKGROUND: Stroke is second leading cause of death worldwide. Chronic hyperglycemia can promote neuronal toxicity. The previous study shows that acute hyperglycemia is correlated with infarct volume of ischemic stroke. AIM: This study aims to investigate the correlation between hemoglobin A1C (HbA1C) and infarct volume on acute ischemic stroke. METHODS: This is a cross-sectional study in acute ischemic stroke patient in Dr. Moewardi General Hospital, Surakarta, Indonesia. Data of infarct volume were collected from head computed tomography (CT)-scan and calculated with A × B × C/2 formula. We also collected lipid and patients’ glycemic profile from patients’ blood laboratory result. Head CT-scan and laboratory data of participants analyzed with Pearson and Spearman’s rho test for parametric and non-parametric data, respectively. We also performed multivariate analysis to evaluate confounding covariates. p < 0.05 was considered as statistically significant. RESULTS: A total of 38 participants were included in this study, with mean infarct volume was 0.46 ± 0.64cc and mean HbA1C was 6.96 ± 2.69%. Bivariate analysis shows strong positive correlation between infarct volume and HbA1C with r = 0.898 (p < 0.001). Other variable that showed a significant correlation with infarct volume were diabetes mellitus history (r = 0.671; p < 0.001), random blood su gar (r = 0.466; p = 0.003), fasting blood sugar (r = 0.636; p < 0.001), 2-h postprandial glucose level (r = 0.646; p ≤ 0.001), high density lipoprotein (r = −0.354; p = 0.029), and triglyceride (r = 0.429; p = 0.007). Based on multivariate analysis, HbA1C regression coefficient on infarct volume was B = 0.222 (p < 0.001), indicating that HbA1C as one of the variables contributing to volume of infarct. CONCLUSIONS: There is a strong positive correlation between infarct volume and HbA1C, and HbA1C is variable contribute to the volume of infarct.

Antioxidant Polyphenols of Antirhea borbonica Medicinal Plant and Caffeic Acid Reduce Cerebrovascular, Inflammatory and Metabolic Disorders Aggravated by High-Fat Diet-Induced Obesity in a Mouse Model of Stroke

Metabolic disorders related to obesity and type 2 diabetes are associated with aggravated cerebrovascular damages during stroke. In particular, hyperglycemia alters redox and inflammatory status, leading to cerebral endothelial cell dysfunction, blood–brain barrier (BBB) disruption and brain homeostasis loss. Polyphenols constitute the most abundant dietary antioxidants and exert anti-inflammatory effects that may improve cerebrovascular complications in stroke. This study evaluated the effects of the characterized polyphenol-rich extract of Antirhea borbonica medicinal plant and its major constituent caffeic acid on a high-fat diet (HFD)-induced obesity mouse model during ischemic stroke, and murine bEnd3 cerebral endothelial cells in high glucose condition. In vivo, polyphenols administered by oral gavage for 12 weeks attenuated insulin resistance, hyperglycemia, hyperinsulinemia and dyslipidemia caused by HFD-induced obesity. Polyphenols limited brain infarct, hemorrhagic transformation and BBB disruption aggravated by obesity during stroke. Polyphenols exhibited anti-inflammatory and antioxidant properties by reducing IL-1β, IL-6, MCP-1, TNF-α and Nrf2 overproduction as well as total SOD activity elevation at the cerebral or peripheral levels in obese mice. In vitro, polyphenols decreased MMP-2 activity that correlated with MCP-1 secretion and ROS intracellular levels in hyperglycemic condition. Protective effects of polyphenols were linked to their bioavailability with evidence for circulating metabolites including caffeic acid, quercetin and hippuric acid. Altogether, these findings show that antioxidant polyphenols reduced cerebrovascular, inflammatory and metabolic disorders aggravated by obesity in a mouse model of stroke. It will be relevant to assess polyphenol-based strategies to improve the clinical consequences of stroke in the context of obesity and diabetes.

State of Knowledge on Molecular Adaptations to Exercise in Humans: Historical Perspectives and Future Directions

For centuries, regular exercise has been acknowledged as a potent stimulus to promote, maintain, and restore healthy functioning of nearly every physiological system of the human body. With advancing understanding of the complexity of human physiology, continually evolving methodological possibilities, and an increasingly dire public health situation, the study of exercise as a preventative or therapeutic treatment has never been more interdisciplinary, or more impactful. During the early stages of the NIH Common Fund Molecular Transducers of Physical Activity Consortium (MoTrPAC) Initiative, the field is well-positioned to build substantially upon the existing understanding of the mechanisms underlying benefits associated with exercise. Thus, we present a comprehensive body of the knowledge detailing the current literature basis surrounding the molecular adaptations to exercise in humans to provide a view of the state of the field at this critical juncture, as well as a resource for scientists bringing external expertise to the field of exercise physiology. In reviewing current literature related to molecular and cellular processes underlying exercise-induced benefits and adaptations, we also draw attention to existing knowledge gaps warranting continued research effort. © 2021 American Physiological Society. Compr Physiol 12:3193-3279, 2022.

Prevalence and predictors of stroke among individuals with prediabetes and diabetes in Florida

Background

The prevalence of both prediabetes and diabetes have been increasing in Florida. These increasing trends will likely result in increases of stroke burden since both conditions are major risk factors of stroke. However, not much is known about the prevalence and predictors of stroke among adults with prediabetes and diabetes and yet this information is critical for guiding health programs aimed at reducing stroke burden. Therefore, the objectives of this study were to estimate the prevalence and identify predictors of stroke among persons with either prediabetes or diabetes in Florida.

Methods

The 2019 Behavioral Risk Factor Surveillance System (BRFSS) survey data were obtained from the Florida Department of Health and used for the study. Weighted prevalence estimates of stroke and potential predictor variables as well as their 95% confidence intervals were computed for adults with prediabetes and diabetes. A conceptual model of predictors of stroke among adults with prediabetes and diabetes was constructed to guide statistical model building. Two multivariable logistic models were built to investigate predictors of stroke among adults with prediabetes and diabetes.

Results

The prevalence of stroke among respondents with prediabetes and diabetes were 7.8% and 11.2%, respectively. The odds of stroke were significantly (p ≤ 0.05) higher among respondents with prediabetes that were ≥ 45 years old (Odds ratio [OR] = 2.82; 95% Confidence Interval [CI] = 0.74, 10.69), had hypertension (OR = 5.86; CI = 2.90, 11.84) and hypercholesterolemia (OR = 3.93; CI = 1.84, 8.40). On the other hand, the odds of stroke among respondents with diabetes were significantly (p ≤ 0.05) higher if respondents were non-Hispanic Black (OR = 1.79; CI = 1.01, 3.19), hypertensive (OR = 3.56; CI = 1.87, 6.78) and had depression (OR = 2.02; CI = 1.14, 3.59).

Conclusions

Stroke prevalence in Florida is higher among adults with prediabetes and diabetes than the general population of the state. There is evidence of differences in the importance of predictors of stroke among populations with prediabetes and those with diabetes. These findings are useful for guiding health programs geared towards reducing stroke burden among populations with prediabetes and diabetes.

Association Cystatin C and Risk of Stroke in Elderly Patients With Obstructive Sleep Apnea: A Prospective Cohort Study

Background: Few prospective cohort studies have assessed the relationship between Cystatin C (Cys-C) and risk of stroke in elderly patients with obstructive sleep apnea (OSA). The study sought to examine the association between baseline serum Cys-C and long-term risk of stroke among elderly OSA patients.

Methods: A total of 932 patients with OSA, no history of stroke, ≥60 years of age, and complete serum Cys-C records were included in this study. All patients had completed polysomnography (PSG). OSA was defined as an apnea-hypopnea index (AHI) of ≥5 events per hour. Participants were categorized into four groups according to baseline serum Cys-C concentration, split into quartiles. Multivariate Cox regression were used to evaluate the association between Cys-C and the incidence of new-onset stroke.

Results: Stroke occurred in 61 patients during the median 42-month follow-up period. The cumulative incidence rate of stroke was 6.5%, which included 54 patients with ischemic stroke and 7 patients with hemorrhagic stroke. The cumulative incidence of stroke was higher among patients with baseline serum Cys-C concentration of ≥1.15 mg/L when compared with other groups (P_Log–rank < 0.001). After adjusting for potential confounding factors in the Cox regression model, patients with a serum Cys-C concentration of ≥1.15 mg/L had a 2.16-fold higher risk of developing stroke compared with patients with serum Cys-C ≤ 0.81 mg/L (HR, 2.16, 95%CI, 1.09–6.60; P = 0.017). Additionally, there was a higher risk in those of age ≥70 years (HR, 3.23, 95%CI, 1.05–9.24; P = 0.010). The receiver-operating characteristic curves showed that the capability of Cys-C to identify elderly patients with OSA who had a long-time risk of stroke was moderate (AUC = 0.731, 95% CI: 0.683–0.779, P = 0.001).

Conclusion: Increased Cys-C concentration was identified as a risk factor in the incidence of stroke in elderly patients with OSA, independent of gender, BMI, hypertension and other risk factors. Additionally, it conferred a higher risk in patients of age ≥70 years.

Ginsenoside-Mc1 reduces cerebral ischemia-reperfusion injury in hyperlipidemia through mitochondrial improvement and attenuation of oxidative/endoplasmic reticulum stress

The neuroprotective effect of ginsenoside-Mc1 (GMc1) in hyperlipidemic rats in the setting of cerebral ischemiareperfusion injury (I/RI), as well as the role of mitochondrial ATP-sensitive potassium (mitoKATP) channels and oxidative/ endoplasmic reticulum (ER) stress, was investigated. Hyperlipidemia (8 weeks) was induced by a high-fat diet in Sprague Dawley rats. GMc1 (10 mg/kg, i.p.) was given to hyperlipidemic rats daily for one month before I/RI. Rat brains were subjected to 2 h of local ischemia followed by 24 h reperfusion. The cerebral infarcted injury was measured by triphenyltetrazolium chloride staining and the levels of oxidative stress indicators were detected by ELISA and spectrophotometry. A fluorometric technique was employed to evaluate mitochondrial function. Western blotting was used to detect changes in the expression of ER stress proteins. GMc1 reduced cerebral infarct volume in hyperlipidemic rats in comparison to untreated ones (P<0.01). GMc1 reduced cerebral infarct volume in hyperlipidemic rats as compared to untreated rats (P<0.01). GMc1 significantly decreased mitochondrial membrane depolarization, mitochondrial reactive oxygen species (mitoROS) and malondialdehyde levels (P<0.01), while increasing the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione-peroxidase (GPx) (P<0.001). GMc1 administration reduced the expression of ER stress markers, including phosphorylated (p)-endoplasmic reticulum kinase (PERK), p-eukaryotic translation initiation factor 2 subunit 1 (elF2?), and C/EBP homologous protein (CHOP). Inhibition of mitoKATP channels with hydroxydecanoate significantly eliminated the protective impacts of GMc1 in hyperlipidemic rats subjected to cerebral I/RI. The neuroprotective effect of GMc1 preconditioning was remarkably improved by increasing mitoKATP channel activity and decreasing oxidative and ER stress levels in hyperlipidemic rats, implying that this compound could be an appropriate candidate for reducing cerebral I/RI in comorbidities.

A Contemporary Review of Epidemiology, Risk Factors, Etiology, and Outcomes of Premature Stroke

PURPOSE OF REVIEW

Recent data identifies increases in young ischemic and hemorrhagic strokes. We provide a contemporary overview of current literature on stroke among young patients or premature stroke along with directions for future investigation.

RECENT FINDINGS

Strokes in the young are highly heterogenous and often cryptogenic. Sex distribution and risk factors shift from women among the youngest age groups (< 35) to men over the age of 45, with a coinciding rise in traditional vascular risk factors. Incidence is higher in minority and socioeconomically disadvantaged populations, and the impact of stroke among these communities may be exaggerated by disparities in symptom recognition and access to care. Special diagnostic work-up may be needed, and a lower threshold for diagnosis is warranted as potential misdiagnosis is a concern and may preclude necessary triage and management. Although "premature strokes" form a relatively small proportion of total incidence, they vary greatly across subgroups and present an outsized impact on quality of life and productivity.

The prognostic significance of the lipid profile after an ischemic stroke

BACKGROUND

The role that cholesterol levels play in stroke is still uncertain, especially in secondary prevention. The aim was to determine how a comprehensive analysis of the lipid profile can be associated with post-stroke outcomes.

Consecutive patients diagnosed with ischemic stroke were included in our cohort and followed up for 24months. Baseline clinical and demographic data were collected as well as a complete lipid profile 6-months after the index stroke. Lipid variables were analyzed quantitatively and qualitatively. Clinical outcomes included stroke recurrence, major cardiovascular events, and functional performance (assessed with the modified Rankin scale).

RESULTS

The study included 588 patients with an average age of 58.3 years. There were 148 (25.2%) patients with high total cholesterol, 260 (44.2%) with low HDL, 180 (30.6%) with high LDL, and 204 (34.7%) with high triglycerides. There were 164 (27.9%) patients with no abnormalities in the lipid profile. After the follow-up, 108 (18.3%) had another stroke, 32 (5.4%) had major cardiovascular events, and 360 (61.2%) presented good functional outcomes. A higher LDL-C/HDL-C ratio and a low HDL-C level were significantly associated with worse cardiovascular outcomes. The detection of LDL-C > 70 mg/dL was an independent predictor of a higher risk of stroke recurrence and worse functional performance. The greater the number of altered lipid variables, the greater the chance of developing an unfavorable composite outcome and presenting cardiovascular events after the stroke.

CONCLUSIONS

The complete analysis of the lipid panel allows the determination of the prognosis of patients who suffered a stroke.

Moyamoya Disease and Syndrome: A National Inpatient Study of Ischemic Stroke Predictors

OBJECTIVES

Ischemic stroke and hemorrhagic stroke are the most common sequelae of the Moyamoya variants [Moyamoya disease (MMD) and syndrome (MMS)]. We sought to determine the rates of stroke subtypes and the predictive factors of arterial ischemic stroke (AIS) utilizing a large data sample of MMD and MMS patients in the US.

MATERIALS AND METHODS

We queried the 2016 and 2017 National Inpatient Sample database for Moyamoya diagnosis plus any of the following associated conditions; sickle cell disease, neurofibromatosis type 1, cranial radiation therapy or Down Syndrome. Multivariate regression determined the risk factors for AIS onset in MMD and MMS.

RESULTS

2323 patients with a diagnosis of Moyamoya were included; 668 (28.8%) patients were classified as MMS and 1655 (71.2%) as MMD. AIS was the most common presentation in both cohorts; however, MMD patients had higher rates of AIS (20.4 vs 6%, p < 0.001), hemorrhagic stroke (7.4vs 2.5%, p < 0.001), and TIA (3.3vs 0.9%, p = 0.001) compared to MMS patients. Multivariate analysis showed that increasing age [OR = 1.017 95%CI: 1.008-1.03, p < 0.001], lipidemia [OR = 1.32 95%CI: 1.02-1.74, p = 0.049], and current smoking status [OR = 1.43 95%CI: 1.04-1.97, p = 0.026] were independent risk factors for AIS in MMD patients, whereas hypertension [OR = 2.61 95%CI: 1.29-5.25, p = 0.007] and African-American race [OR = 0.274, 95%CI: .117-.64, p = 0.003] were independent predictors in the MMS cohort.

CONCLUSION

AIS is the most common presentation in both, MMD and MMS. However, MMD patients had higher rates of stroke events compared to MMS. Risk factors for AIS in MMD included increasing age, lipidemia and smoking status, whereas in MMS hypertension was the only independent risk factor.

Preclinical Stroke Research and Translational Failure: A Bird's Eye View on Preventable Variables

Despite achieving remarkable success in understanding the cellular, molecular and pathophysiological aspects of stroke, translation from preclinical research has always remained an area of debate. Although thousands of experimental compounds have been reported to be neuro-protective, their failures in clinical setting have left the researchers and stakeholders in doldrums. Though the failures described have been excruciating, they also give us a chance to refocus on the shortcomings. For better translational value, evidences from preclinical studies should be robust and reliable. Preclinical study design has a plethora of variables affecting the study outcome. Hence, this review focusses on the factors to be considered for a well-planned preclinical study while adhering to guidelines with emphasis on the study design, commonly used animal models, their limitations with special attention on various preventable attritions including comorbidities, aged animals, time of dosing, outcome measures and physiological variables along with the concept of multicentric preclinical randomized controlled trials. Here, we provide an overview of a panorama of practical aspects, which could be implemented, so that a well-defined preclinical study would result in a neuro-protectant with better translational value.

The Effects of Local Food-Based Enteral Nutrition to Improve Nutritional Status of Post-Stroke Patients

Objective  We used local-based enteral formula for post-stroke patients to see its effects on the nutritional status.

Materials and Methods  This is an experimental research with a pre- and post-test study design in post-stroke patients. Participants underwent clinical and laboratory examinations to assess their nutritional status before and after the enteral nutrition supplementation. The enteral formula preparation, containing arrowroot powder, cork fish, tempeh (fermented soybeans), nondairy creamer, and pumpkin, was performed in a nationally standardized Food Processing Technology Laboratory in Yogyakarta, Indonesia. The enteral formula was given twice a day for 3 consecutive weeks in addition to the patients’ daily meal.

Statistical Analysis  Nutritional indices before and after enteral nutrition supplementation were analyzed using t-test . All statistical analyses were at 5% significance level.

Results  Of the 22 post-stroke patients, we used the cutoff point of National Institutes of Health Stroke Scale ≥3 and Barthel Index <90 to represent dependency. Our findings showed significantly reduced mid-upper arm circumference and increased body mass index in independent post-stroke patients after the enteral nutrition supplementation. The tendency of increasing total cholesterol level should be carefully watched in dependent post-stroke patients.

Conclusion  Local food-based enteral nutrition supplementation for 3 consecutive weeks in post-stroke patients may improve their nutritional status.

Promoting Successful Cognitive Aging: A Ten-Year Update

A decade has passed since we published a comprehensive review in this journal addressing the topic of promoting successful cognitive aging, making this a good time to take stock of the field. Because there have been limited large-scale, randomized controlled trials, especially following individuals from middle age to late life, some experts have questioned whether recommendations can be legitimately offered about reducing the risk of cognitive decline and dementia. Despite uncertainties, clinicians often need to at least make provisional recommendations to patients based on the highest quality data available. Converging lines of evidence from epidemiological/cohort studies, animal/basic science studies, human proof-of-concept studies, and human intervention studies can provide guidance, highlighting strategies for enhancing cognitive reserve and preventing loss of cognitive capacity. Many of the suggestions made in 2010 have been supported by additional research. Importantly, there is a growing consensus among major health organizations about recommendations to mitigate cognitive decline and promote healthy cognitive aging. Regular physical activity and treatment of cardiovascular risk factors have been supported by all of these organizations. Most organizations have also embraced cognitively stimulating activities, a heart-healthy diet, smoking cessation, and countering metabolic syndrome. Other behaviors like regular social engagement, limiting alcohol use, stress management, getting adequate sleep, avoiding anticholinergic medications, addressing sensory deficits, and protecting the brain against physical and toxic damage also have been endorsed, although less consistently. In this update, we review the evidence for each of these recommendations and offer practical advice about behavior-change techniques to help patients adopt brain-healthy behaviors.

Can miRNAs Be Considered as Diagnostic and Therapeutic Molecules in Ischemic Stroke Pathogenesis?-Current Status

Ischemic stroke is one of the leading causes of death worldwide. Clinical manifestations of stroke are long-lasting and causing economic burden on the patients and society. Current therapeutic modalities to treat ischemic stroke (IS) are unsatisfactory due to the intricate pathophysiology and poor functional recovery of brain cellular compartment. MicroRNAs (miRNA) are endogenously expressed small non-coding RNA molecules, which can act as translation inhibitors and play a pivotal role in the pathophysiology associated with IS. Moreover, miRNAs may be used as potential diagnostic and therapeutic tools in clinical practice; yet, the complete role of miRNAs is enigmatic during IS. In this review, we explored the role of miRNAs in the regulation of stroke risk factors viz., arterial hypertension, metabolic disorders, and atherosclerosis. Furthermore, the role of miRNAs were reviewed during IS pathogenesis accompanied by excitotoxicity, oxidative stress, inflammation, apoptosis, angiogenesis, neurogenesis, and Alzheimer's disease. The functional role of miRNAs is a double-edged sword effect in cerebral ischemia as they could modulate pathological mechanisms associated with risk factors of IS. miRNAs pertaining to IS pathogenesis could be potential biomarkers for stroke; they could help researchers to identify a particular stroke type and enable medical professionals to evaluate the severity of brain injury. Thus, ascertaining the role of miRNAs may be useful in deciphering their diagnostic role consequently it is plausible to envisage a suitable therapeutic modality against IS.

Effects of Lipids and Lipoproteins on Mesenchymal Stem Cells Used in Cardiac Tissue Regeneration

Mesenchymal stem cells (MSCs) have two characteristics of interest for this paper: the ability to self-renew, and the potential for multiple-lineage differentiation into various cells. MSCs have been used in cardiac tissue regeneration for over a decade. Adult cardiac tissue regeneration ability is quite low; it cannot repair itself after injury, as the heart cells are replaced by fibroblasts and lose function. It is therefore important to search for a feasible way to repair and restore heart function through stem cell therapy. Stem cells can differentiate and provide a source of progenitor cells for cardiomyocytes, endothelial cells, and supporting cells. Studies have shown that the concentrations of blood lipids and lipoproteins affect cardiovascular diseases, such as atherosclerosis, hypertension, and obesity. Furthermore, the MSC lipid profiles, such as the triglyceride and cholesterol content, have been revealed by lipidomics, as well as their correlation with MSC differentiation. Abnormal blood lipids can cause serious damage to internal organs, especially heart tissue. In the past decade, the accumulated literature has indicated that lipids/lipoproteins affect stem cell behavior and biological functions, including their multiple lineage capability, and in turn affect the outcome of regenerative medicine. This review will focus on the effect of lipids/lipoproteins on MSC cardiac regenerative medicine, as well as the effect of lipid-lowering drugs in promoting cardiomyogenesis-associated MSC differentiation.

Adjunctive Chinese Herbal Products Therapy Reduces the Risk of Ischemic Stroke Among Patients With Rheumatoid Arthritis

We performed a retrospective cohort study to investigate the association between the risk of ischemic stroke (IS) and the use of Chinese herbal products (CHP) in combination with western medicine (WM) among patients with rheumatoid arthritis (RA). The data were sourced from the registry for beneficiaries, inpatient and ambulatory care claims, and Registry for Catastrophic Illness from the National Health Insurance Research Database (NHIRD) in Taiwan between 1997 and 2011. Patients, who were newly diagnosed with RA between 1997 and 2010, were classified as the CHP group or non-CHP group depending on the presence of absence the adjunctive use of CHP following a diagnosis of RA. A total of 4,148 RA patients were in both the CHP and non-CHP groups after 1:1 matching. Patients in the CHP group had a significantly lower risk of IS compared to patients in the non-CHP group (adjusted hazard ratio [aHR], 0.67; 95% confidence interval [CI], 0.52-0.86). In the CHP group, patients who used CHP for more than 30 days had a lower risk of IS than their counterparts (aHR: 0.61, 95% CI: 0.40-0.91). Gui-Zhi-Shao-Yao-Zhi-Mu-Tang, Shu-Jin-Huo-Xie-Tang, and Du-Huo-Ji-Sheng-Tang might be associated with a lower risk of IS. Finally, the use of CHP in combination with WM was associated with a decreased risk of IS in patients with RA, especially among those who had used CHP for more than 30 days. A further randomized control trial is required to clarify the casual relationship between these results.

The Association Between an Antecedent of Transient Ischemic Attack Prior to Onset of Stroke and Functional Ambulatory Outcome

BACKGROUND

Specific clinical risk factors linked to transient ischemic attack (TIA) could affect functional ambulatory outcome following thrombolytic therapy in patients having ischemic stroke with a prior TIA (TIA-ischemic stroke). This issue was investigated in this study.

METHODS

We retrospectively analyzed data from 6379 ischemic stroke patients of which 1387 presented with an antecedent TIA prior to onset of stroke. We used logistic regression model to identify demographic and clinical risk factors that are associated with functional ambulatory outcome in patients with TIA-ischemic stroke treated with thrombolytic therapy.

RESULTS

In a population of TIA-ischemic stroke who received recombinant tissue plasminogen activator, patients with a history of stroke (odds ratio [OR] = 3.229, 95% confidence interval [CI] = 1.494-6.98, P = .003) were associated with increasing odds of improvement in functional ambulation, while the female gender (OR = 0.462, 95% CI = 0.223-0.956, P = .037) was associated with reducing odds of improvement. In the non-TIA group, dyslipidemia (OR = 1.351, 95% CI = 1.026-1.781, P = .032) and blood glucose (OR = 1.003, 95% CI = 1.0-1.005, P = .041) were associated with the increasing odds of improvement while older patients (OR = 0.989, 95% CI = 0.98-0.999, P = .029) with heart failure (OR = 0.513, 95% CI = 0.326-0.808, P = .004) and higher lipid level (OR = 0.834, 95% CI = 0.728-0.955, P = .009) were associated with reducing odds of improvement in ambulation.

CONCLUSION

In a population of TIA-ischemic stroke with thrombolytic therapy and a clearly defined TIA without focal ischemic injury, regardless of associated clinical risk factors, a TIA prior to a stroke is not associated with reducing odds of improved ambulatory outcome, except in female patients with TIA-ischemic stroke.

Reflection on the development of the nurse consultant role

The role of nurse consultant was introduced in the late 1990s to strengthen leadership in nursing, improve patient outcomes and enhance the quality of healthcare services. Nurse consultants have a wide-ranging remit that includes expert practice, professional leadership and consultancy, education, and service development. In this article, the author reflects on her experience of being one of the first nurse consultants, which included setting up nurse-led clinics, maintaining professional relationships with medical colleagues and assuming increasing responsibility for services. The article also examines the changes that the nurse consultant role has undergone since its inception in the 1990s.