Homeostasis model assessment of insulin resistance and outcome of ischemic stroke in non-diabetic patients - a prospective observational study

A Nonlinear Relation between Body Mass Index and Long-Term Poststroke Functional Outcome-The Importance of Insulin Resistance, Inflammation, and Insulin-like Growth Factor-Binding Protein-1

Both high serum insulin-like growth factor-binding protein-1 (s-IGFBP-1) and insulin resistance (IR) are associated with poor functional outcome poststroke, whereas overweight body mass index (BMI; 25-30) is related to fewer deaths and favorable functional outcome in a phenomenon labeled "the obesity paradox". Furthermore, IGFBP-1 is inversely related to BMI, in contrast to the linear relation between IR and BMI. Here, we investigated s-IGFBP-1 and IR concerning BMI and 7-year poststroke functional outcome. We included 451 stroke patients from the Sahlgrenska Study on Ischemic Stroke (SAHLSIS) with baseline measurements of s-IGFBP1, homeostasis model assessment of IR (HOMA-IR), BMI (categories: normal-weight (8.5-25), overweight (25-30), and obesity (>30)), and high-sensitivity C-reactive protein (hs-CRP) as a measure of general inflammation. Associations with poor functional outcome (modified Rankin scale [mRS] score: 3-6) after 7 years were evaluated using multivariable binary logistic regression, with overweight as reference due to the nonlinear relationship. Both normal-weight (odds-ratio [OR] 2.32, 95% confidence interval [CI] 1.30-4.14) and obese (OR 2.25, 95% CI 1.08-4.71) patients had an increased risk of poor functional outcome, driven by deaths only in the normal-weight. In normal-weight, s-IGFBP-1 modestly attenuated (8.3%) this association. In the obese, the association was instead attenuated by HOMA-IR (22.4%) and hs-CRP (10.4%). Thus, a nonlinear relation between BMI and poor 7-year functional outcome was differently attenuated in the normal-weight and the obese.

Association between the triglyceride-glucose index and stroke in middle-aged and older non-diabetic population: A prospective cohort study

BACKGROUND AND AIMS

Data regarding the association between insulin resistance (IR) and stroke among the non-diabetic population is still limited and inconsistent. This study aimed to investigate the association between IR measured by the triglyceride-glucose (TyG) index and the risk of stroke among the middle-aged and elderly Chinese without diabetes.

METHODS AND RESULTS

A total of 17,708 middle-aged and elderly (main respondents≥45 years) individuals without diabetes were enrolled from the China Health and Retirement Longitudinal Study. Participants were divided into 4 categories according to quartiles of the TyG index. During a median follow-up of 7.00 years, a total of 305 (3.93%) incident strokes occurred. With the increase in the TyG index quartiles, stroke incidence increased substantially, compared with the Q1 group, the fully adjusted hazard ratios (HRs) were 1.64 (95% confidence interval [CI], 1.13-2.38), 1.65 (95% CI, 1.10-2.46), and 1.76 (95% CI, 1.21-2.57) for Q2, Q3, and Q4 groups, respectively. The cutoff value we determined for the TyG index was 8.28. Furthermore, the addition of the TyG index to a conventional risk model had an incremental effect on the predictive value for stroke (integrated discrimination improvement 0.17%, P = 0.0025; category-free net reclassification improvement 17.91%, P = 0.0025).

CONCLUSION

TyG index was significantly associated with a higher risk of stroke among the middle-aged and elderly non-diabetic population. Our findings indicated that the TyG index may be a good tool in the prediction of stroke risk for clinical and public health fields.

Serum IGFBP-1 Concentration as a Predictor of Outcome after Ischemic Stroke-A Prospective Observational Study

Insulin-like growth factor-binding protein-1 (IGFBP-1) regulates insulin-like growth factor-I (IGF-I) bioactivity, and is a central player in normal growth, metabolism, and stroke recovery. However, the role of serum IGFBP-1 (s-IGFBP-1) after ischemic stroke is unclear. We determined whether s-IGFBP-1 is predictive of poststroke outcome. The study population comprised patients (n = 470) and controls (n = 471) from the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS). Functional outcome was evaluated after 3 months, 2, and 7 years using the modified Rankin Scale (mRS). Survival was followed for a minimum of 7 years or until death. S-IGFBP-1 was increased after 3 months (p < 0.01), but not in the acute phase after stroke, compared with the controls. Higher acute s-IGFBP-1 was associated with poor functional outcome (mRS score > 2) after 7 years [fully adjusted odds ratio (OR) per log increase 2.9, 95% confidence interval (CI): 1.4-5.9]. Moreover, higher s-IGFBP-1 after 3 months was associated with a risk of poor functional outcome after 2 and 7 years (fully adjusted: OR 3.4, 95% CI: 1.4-8.5 and OR 5.7, 95% CI: 2.5-12.8, respectively) and with increased mortality risk (fully adjusted: HR 2.0, 95% CI: 1.1-3.7). Thus, high acute s-IGFBP-1 was only associated with poor functional outcome after 7 years, whereas s-IGFBP-1 after 3 months was an independent predictor of poor long-term functional outcome and poststroke mortality.

Triglyceride-glucose index, symptomatic intracranial artery stenosis and recurrence risk in minor stroke patients with hypertension

BACKGROUND

The triglyceride-glucose (TyG) index, a simple measure of insulin resistance, is associated with intracranial atherosclerosis (ICAS) and stroke. In hypertensive populations, this association may be pronounced. The aim was to investigate the relationship between TyG and symptomatic intracranial atherosclerosis (sICAS) and recurrence risk in ischemic stroke patients with hypertension.

METHODS

This prospective, multicenter cohort study included patients with acute minor ischemic stroke with a preadmission diagnosis of hypertension from September 2019 to November 2021 with a 3-month follow-up. The presence of sICAS was determined by a combination of clinical manifestations, the location of the infarction, and the corresponding artery with moderate-to-severe stenosis. ICAS burden was determined by the degree and number of ICAS occurrences. Fasting blood glucose (FBG) and triglyceride (TG) were measured to calculate TyG. The main outcome was ischemic stroke recurrence during the 90-day follow-up. Multivariate regression models were used to explore the association of TyG, sICAS, and ICAS burden with stroke recurrence.

RESULTS

There were 1281 patients with a mean age of 61.6 ± 11.6 years; 70.1% were male, and 26.4% were diagnosed with sICAS. There were 117 patients who experienced stroke recurrence during follow-up. Patients were categorized according to quartiles of TyG. After adjusting for confounders, the risk of sICAS was greater (OR 1.59, 95% CI 1.04-2.43, p = 0.033) and the risk of stroke recurrence was significantly higher (HR 2.02, 95% CI 1.07-3.84, p = 0.025) in the fourth TyG quartile than in the first quartile. The restricted cubic spline (RCS) plot revealed a linear relationship between TyG and sICAS, and the threshold value for TyG was 8.4. Patients were then dichotomized into low and high TyG groups by the threshold. Patients with high TyG combined with sICAS had a higher risk of recurrence (HR 2.54, 95% CI 1.39-4.65) than patients with low TyG without sICAS. An interaction effect on stroke recurrence between TyG and sICAS was found (p = 0.043).

CONCLUSION

TyG is a significant risk factor for sICAS in hypertensive patients, and there is a synergistic effect of sICAS and higher TyG on ischemic stroke recurrence.

TRIAL REGISTRATION NUMBER

The study was registered on 16 August 2019 at https://www.chictr.org.cn/showprojen.aspx?proj=41160 (No. ChiCTR1900025214).

The pivotal role of JAK/STAT and IRS/PI3K signaling pathways in neurodegenerative diseases: Mechanistic approaches to polyphenols and alkaloids

BACKGROUND

Neurodegenerative diseases (NDDs) are characterized by progressive neuronal dysfunctionality which results in disability and human life-threatening events. In recent decades, NDDs are on the rise. Besides, conventional drugs have not shown potential effectiveness to attenuate the complications of NDDs. So, exploring novel therapeutic agents is an urgent need to combat such disorders. Accordingly, growing evidence indicates that polyphenols and alkaloids are promising natural candidates, possessing several beneficial pharmacological effects against diseases. Considering the complex pathophysiological mechanisms behind NDDs, Janus kinase (JAK), insulin receptor substrate (IRS), phosphoinositide 3-kinase (PI3K), and signal transducer and activator of transcription (STAT) seem to play critical roles during neurodegeneration/neuroregeneration. In this line, modulation of the JAK/STAT and IRS/PI3K signaling pathways and their interconnected mediators by polyphenols/alkaloids could play pivotal roles in combating NDDs, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), stroke, aging, multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), depression and other neurological disorders.

PURPOSE

Thus, the present study aimed to investigate the neuroprotective roles of polyphenols/alkaloids as multi-target natural products against NDDs which are critically passing through the modulation of the JAK/STAT and IRS/PI3K signaling pathways.

STUDY DESIGN AND METHODS

A systematic and comprehensive review was performed to highlight the modulatory roles of polyphenols and alkaloids on the JAK/STAT and IRS/PI3K signaling pathways in NDDs, according to the PRISMA guideline, using scholarly electronic databases, including Scopus, PubMed, ScienceDirect, and associated reference lists.

RESULTS

In the present study 141 articles were included from a total of 1267 results. The results showed that phenolic compounds such as curcumin, epigallocatechin-3-gallate, and quercetin, and alkaloids such as berberine could be introduced as new strategies in combating NDDs through JAK/STAT and IRS/PI3K signaling pathways. This is the first systematic review that reveals the correlation between the JAK/STAT and IRS/PI3K axis which is targeted by phytochemicals in NDDs. Hence, this review highlighted promising insights into the neuroprotective potential of polyphenols and alkaloids through the JAK/STAT and IRS/PI3K signaling pathway and interconnected mediators toward neuroprotection.

CONCLUSION

Amongst natural products, phenolic compounds and alkaloids are multi-targeting agents with the most antioxidants and anti-inflammatory effects possessing the potential of combating NDDs with high efficacy and lower toxicity. However, additional reports are needed to prove the efficacy and possible side effects of natural products.

The Pre-Stroke Induction and Normalization of Insulin Resistance Respectively Worsens and Improves Functional Recovery

Type 2 diabetes (T2D) impairs post-stroke recovery, and the underlying mechanisms are unknown. Insulin resistance (IR), a T2D hallmark that is also closely linked to aging, has been associated with impaired post-stroke recovery. However, whether IR worsens stroke recovery is unknown. We addressed this question in mouse models where early IR, with or without hyperglycemia, was induced by chronic high-fat diet feeding or sucrose supplementation in the drinking water, respectively. Furthermore, we used 10-month-old mice, spontaneously developing IR but not hyperglycemia, where IR was normalized pharmacologically pre-stroke with Rosiglitazone. Stroke was induced by transient middle cerebral artery occlusion and recovery was assessed by sensorimotor tests. Neuronal survival, neuroinflammation and the density of striatal cholinergic interneurons were also assessed by immunohistochemistry/quantitative microscopy. Pre-stroke induction and normalization of IR, respectively, worsened and improved post-stroke neurological recovery. Moreover, our data indicate a potential association of this impaired recovery with exacerbated neuroinflammation and a decreased density of striatal cholinergic interneurons. The global diabetes epidemic and population aging are dramatically increasing the percentage of people in need of post-stroke treatment/care. Our results suggest that future clinical studies should target pre-stroke IR to reduce stroke sequelae in both diabetics and elderly people with prediabetes.

HOMA estimated insulin resistance as a marker for angiographic severity of coronary artery disease in non-diabetic and non-obese patients

Background

Insulin resistance (IR) examined by homeostasis model assessment of insulin resistance (HOMA-IR) measures increased carotid atherosclerosis risks in non-diabetic and non-obese persons. The information about the relationship between IR and coronary atherosclerosis severity among non-diabetic and non- obese population showed conflicting results. The goal of the current study was to assess the relationship that links IR and coronary artery disease (CAD) among non-diabetic and non-obese Egyptian populations.

Methods

112 non-diabetic and non-obese patients were included in this study. These patients underwent coronary angiogram (CA) either due to acute coronary syndrome (ACS) or chronic stable angina with positive exercise tests.

Results

Our study found a strong association between HOMA-IR and Gensini score (r = 0.831, with p<0.001) in general population. The HOMA-IR was the most influential independent predictor for the presence of extensive coronary atherosclerosis. Non-diabetic and non-obese people carrying the risk of developing the three-vessel disease (3VD) may be identified with a HOMA-IR score of over 5.9 according to the ROC curve analysis with a sensitivity of 67.7%.

Conclusion

IR that developes in non-diabetic non-obese individuals coincides with more severe and more outspread CAD. In non-diabetic non-obese populations who need a CA, a single HOMA-IR value is higher than 5.9 may imply an elevated risk for clinically significant CAD. As insulin resistance is a reversible process, risk stratifications of CAD in non-diabetic non-obese populations could include HOMA-IR as one of its parameters.

L-carnitine supplementation ameliorates insulin resistance in critically ill acute stroke patients: a randomized, double-blinded, placebo-controlled clinical trial

Background and purpose

Insulin resistance (IR) can negatively affect clinical outcomes in acute ischemic stroke (IS) patients. Safe and cost-saving interventions are still needed to improve glycemic indices in this population. The primary objective was to evaluate L-carnitine (LC) effects in acute IS patients' homeostatic model assessment of IR (HOMA-IR).

Experimental approach

In this randomized, double-blind placebo-controlled clinical trial, critically ill IS patients were allocated to receive daily oral L-carnitine (1.5 g) or a placebo for six days. Fasting serum levels of glucose, insulin, C-reactive protein, LC, and HOMA-IR were measured on days 1 and 7. Mechanical ventilation duration, ICU/hospital duration, illness severity score, sepsis, and death events were assessed.

Findings/Results

Forty-eight patients were allocated to the research groups, 24 patients in each group, and all were included in the final analysis. LC administration showed a decrease in mean difference of HOMA-IR and insulin levels at day 7 compared to placebo, -0.94 ± 1.92 vs 0.87 ± 2.24 (P = 0.01) and -2.26 ± 6.81 vs 0.88 ± 4.95 (P = 0.03), respectively. However, LC administration did not result in significant improvement in clinical outcomes compared to placebo. The short duration of intervention and low sample size limited our results.

Conclusion and implication

Supplementation of L-carnitine improved HOMA-IR index in acute IS patients admitted to the critical care unit. Supplementation of LC would be a potential option to help to control IR in critically ill acute IS patients.

Predictive Value of Insulin Resistance as Determined by Homeostasis Model Assessment in Acute Ischemic Stroke Patients: A Systematic Review and Meta-Analysis

Studies on association between homeostasis model assessment of insulin resistance (HOMA-IR) and adverse outcomes have yielded conflicting results in patients with acute ischemic stroke (AIS). This meta-analysis aimed to assess the predictive value of HOMA-IR in AIS patients. Two authors comprehensively searched PubMed and Embase databases until February 28, 2021. All observational studies investigating the association between HOMA-IR and adverse outcomes in AIS patients were included. Outcome measures were poor functional outcome (Modified Rankin Scale≥3), all-cause mortality, stroke recurrence, and neurologic worsening. Seven studies (eight articles) involving 8330 AIS patients were identified. For the highest versus lowest HOMA-IR, the pooled risk ratio (RR) of poor functional outcome was 2.55 (95% CI 1.76-3.70) after adjustment of conventional confounding factors. In addition, elevated HOMA-IR was associated with higher risk of neurologic worsening (RR 1.93; 95% CI 1.15-3.26). However, there were conflicting findings on the association of HOMA-IR with stroke recurrence and all-cause mortality. This meta-analysis confirms that HOMA-IR is significantly associated with an increased risk of poor functional outcome in patients with AIS. However, interpretation of the results of mortality, stroke recurrence, and neurologic worsening should be done with caution due to small number of studies available.

Insulin-Like Growth Factor-II and Ischemic Stroke-A Prospective Observational Study

Insulin-like growth factor-II (IGF-II) regulates prenatal brain development, but the role in adult brain function and injury is unclear. Here, we determined whether serum levels of IGF-II (s-IGF-II) are associated with mortality and functional outcome after ischemic stroke (IS). The study population comprised ischemic stroke cases (n = 492) and controls (n = 514) from the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS). Functional outcome was evaluated after 3 months and 2 years using the modified Rankin Scale (mRS), and additionally, survival was followed at a minimum of 7 years or until death. S-IGF-II levels were higher in IS cases both in the acute phase and at 3-month follow-up compared to controls (p < 0.05 and p < 0.01, respectively). The lowest quintile of acute s-IGF-II was, compared to the four higher quintiles, associated with an increased risk of post-stroke mortality (median follow-up 10.6 years, crude hazard ratio (HR) 2.34, 95% confidence interval (CI) 1.56–3.49, and fully adjusted HR 1.64, 95% CI 1.02–2.61). In contrast, crude associations with poor functional outcome (mRS 3–6) lost significance after full adjustment for covariates. In conclusion, s-IGF-II was higher in IS cases than in controls, and low acute s-IGF-II was an independent risk marker of increased mortality.

Association between insulin resistance and post-ischaemic stroke outcome in patients without diabetes: protocol for a systematic review and meta-analysis

INTRODUCTION

Insulin resistance is an independent risk factor for atherosclerosis, coronary artery disease and ischaemic stroke. Currently, insulin resistance is not usually included in post-stroke risk stratification. This systematic review and meta-analysis intends to determine if available scientific knowledge supports an association between insulin resistance and post-stroke outcomes in patients without diabetes.

METHODS AND ANALYSIS

The authors will conduct a literature search in Medline, Embase, Web of Science and Cochrane Central. The review will include studies that assess the association between elevated insulin homeostasis model of insulin resistance (HOMA-IR) and post-stroke outcome (functional outcome and recurrent stroke). The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines will be used. The primary outcome will be post-stroke functional outcome (Modified Rankin Scale), and the secondary outcome will be recurrent ischaemic stroke. Comparison of outcome will be made between highest and lowest HOMA-IR range (as defined in each article included in this systematic review). Risk of bias will be assessed qualitatively. Meta-analysis will be performed if sufficient homogeneity exists between studies. Heterogeneity of outcomes will be assessed by I².

ETHICS AND DISSEMINATION

No human or animal subjects or samples were/will be used. The results will be published in a peer-reviewed journal, and will be disseminated at local and international neurology conferences.

PROSPERO REGISTRATION NUMBER

CRD42020173608.

The Combination of Insulin Resistance and Serum Interleukin-1β Correlates with Post-Stroke Depression in Patients with Acute Ischemic Stroke

PURPOSE

Previous studies have shown that insulin resistance and inflammation may be associated with the pathophysiological mechanisms of mood disorders. Here, we investigated whether homeostatic model assessment of insulin resistance (HOMA-IR) and serum interleukin-1β (IL-1β) in acute ischemic stroke patients might be associated with post-stroke depression (PSD).

MATERIALS AND METHODS

The prospective study was conducted in China from February 2019 to September 2020. HOMA-IR and clinical data were collected at the time of admission. Serum levels of IL-1β were determined with enzyme-linked immunosorbent assays. Symptoms of depression and anxiety were screened by using the Hamilton Depression and Anxiety Scale at 6 months after stroke, and PSD was diagnosed on the basis of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) criteria. The association of potential risk factors with PSD was analyzed with multivariate logistic regression analysis. Finally, the ability of HOMA-IR and IL-1β to predict PSD was assessed with receiver operating characteristic curve.

RESULTS

A total of 305 people was included in the study; 65% were male, and the median age was 69.5±11.8 years. At the 6-month follow-up, 113 patients (37.5%) showed depressive symptoms. In multivariate logistic regression analysis, HOMA-IR and IL-1β as graded variables were associated with an increased risk of PSD (P < 0.05). Receiver operating characteristic curve analysis indicated the highest sensitivity and specificity when the HOMA-IR and IL-1β were 1.96 and 38.71 pg/mL, respectively (P < 0.001). IL-1β improved the ability of HOMA-IR to diagnose PSD combined model area under the curve (AUC): 0.78; 95% CI: 0.72-0.83; P < 0.001).

CONCLUSION

This study suggests that HOMA-IR and IL-1β are strongly associated with PSD at 6 months after stroke in patients with acute ischemic stroke. These two factors together improve the ability for early PSD assessment.

Insulin Resistance Predicts Severity of Coronary Atherosclerotic Disease in Non-Diabetic Patients

Background: Insulin resistance (IR) in patients with type 2 diabetes mellitus (T2DM) represents a predictor of coronary artery disease (CAD). However, how IR is able to impact the severity of coronary atherosclerosis in non-diabetic patients is unknown. Objectives. We investigated the relation between the IR and the extent and severity of coronary atherosclerosis in non-diabetic patients referred to coronary angiography (CA) Methods: Consecutive patients undergoing to CA for acute coronary syndromes or stable angina were analyzed. The IR was assessed by mean of the homeostasis model assessment of insulin resistance (HOMA-IR) whereas the SYNTAX score (SS) was used as index of the severity of coronary atherosclerosis Results: Overall, 126 patients were included, with a median SS of 12 (IQR 5.25–20.5). Patients were divided in four groups according to the distribution in quartiles of SS (SS1-2-3-4). A significant correlation between HOMA-IR and SS was observed, especially in women. A progressive increase of HOMA-IR was observed in parallel with the increasing severity (from SS1 to SS4) and extension (1-2-3-vessel disease) of coronary atherosclerosis. Multivariable analysis showed that the HOMA-IR was the strongest independent predictor of severe (SS4) and extensive (three-vessel disease) coronary atherosclerosis. Conclusion: Insulin resistance goes hand in hand with the extension and severity of coronary atherosclerosis in non-diabetic patients. The HOMA index is an independent predictor of three-vessel disease at CA. The HOMA index could be useful for risk stratification of CAD even in absence of T2DM.

Triglyceride Glucose Index and Prognosis of Patients With Ischemic Stroke

Background: The triglyceride glucose index (TyG index) has been proposed as a simple and credible surrogate marker of insulin resistance. However, it is unclear whether TyG index correlates with adverse clinical outcomes in patients with ischemic stroke. Accordingly, this study aimed to explore the relationship between baseline TyG index and clinical outcomes of ischemic stroke individuals. Methods: We included eligible subjects with ischemic stroke from the China National Stroke Registry II for the current analysis. TyG index was calculated and divided into quartiles to explore the relationship with the outcomes of ischemic stroke. Outcomes included stroke recurrence, all-cause mortality, poor functional outcome at 12 months, and neurologic worsening at discharge. Multivariable Cox regression and logistic regression models were performed to explore the correlation of baseline TyG index with the outcomes. Results: Among the 16,310 patients enrolled in the study, the average age was 64.83 ± 11.9 years, and 63.48% were men. The median TyG index was 8.73 (interquartile range, 8.33-9.21). After adjustment for multiple potential covariates, the fourth quartile of TyG index was associated with an increased risk of stroke recurrence (adjusted HR, 1.32; 95% CI, 1.11-1.57; P = 0.002), all-cause mortality (adjusted HR, 1.25; 95%CI, 1.06-1.47; P = 0.01) at 12-month follow-up, and neurological worsening (adjusted OR, 1.26; 95% CI, 1.02-1.55; P = 0.03) at discharge, but not poor functional outcome compared with the first quartile. Conclusion: TyG index representing insulin resistance was associated with an increased risk of stroke recurrence, all-cause mortality, and neurologic worsening in patients with ischemic stroke.