Obesity Paradox in Ischemic Stroke: Clinical and Molecular Insights

Association between BMI-based metabolic phenotypes and prevalence of intracranial atherosclerotic stenosis: a cross-sectional study

BACKGROUND

Obesity and metabolic syndrome (MetS) have been acknowledged to commonly co-exist and lead to increased risks of stroke, whereas the association between various BMI-based metabolic phenotypes and development of intracranial atherosclerotic stenosis (ICAS) remained controversial.

METHODS

A total of 5355 participants were included from the Asymptomatic Polyvascular Abnormalities Community (APAC) study. Participants were categorized into six groups according to their body mass index (BMI) and MetS status. ICAS was assessed using transcranial Doppler (TCD) Ultrasonography. Logistic regression was employed to evaluate the association between BMI-based metabolic phenotypes and ICAS.

RESULTS

704 participants were diagnosed with ICAS. Compared to the metabolic healthy normal weight (MH-NW) group, the metabolic unhealthy normal weight (MUH-NW) group demonstrated a higher risk of ICAS (full-adjusted odds ratio [OR], 1.91; 95% confidence interval [CI], 1.42-2.57), while no significant association was observed in the metabolic unhealthy obesity (MUO) group (full-adjusted OR, 1.07; 95% CI, 0.70-1.65) and other metabolic healthy groups regardless of BMI. The results were consistent across gender, age, smoking, alcohol intake, and physical activity subgroups.

CONCLUSION

The present study suggested that MUH-NW individuals had a significant association with increased risk of ICAS compared with MH-NW individuals.

Adaptive Metabolic Responses Facilitate Blood-Brain Barrier Repair in Ischemic Stroke via BHB-Mediated Epigenetic Modification of ZO-1 Expression

Adaptive metabolic responses and innate metabolites hold promising therapeutic potential for stroke, while targeted interventions require a thorough understanding of underlying mechanisms. Adiposity is a noted modifiable metabolic risk factor for stroke, and recent research suggests that it benefits neurological rehabilitation. During the early phase of experimental stroke, the lipidomic results showed that fat depots underwent pronounced lipolysis and released fatty acids (FAs) that feed into consequent hepatic FA oxidation and ketogenesis. Systemic supplementation with the predominant ketone beta-hydroxybutyrate (BHB) is found to exert discernible effects on preserving blood-brain barrier (BBB) integrity and facilitating neuroinflammation resolution. Meanwhile, blocking FAO-ketogenesis processes by administration of CPT1α antagonist or shRNA targeting HMGCS2 exacerbated endothelial damage and aggravated stroke severity, whereas BHB supplementation blunted these injuries. Mechanistically, it is unveiled that BHB infusion is taken up by monocarboxylic acid transporter 1 (MCT1) specifically expressed in cerebral endothelium and upregulated the expression of tight junction protein ZO-1 by enhancing local β-hydroxybutyrylation of H3K9 at the promoter of TJP1 gene. Conclusively, an adaptive metabolic mechanism is elucidated by which acute lipolysis stimulates FAO-ketogenesis processes to restore BBB integrity after stroke. Ketogenesis functions as an early metabolic responder to restrain stroke progression, providing novel prospectives for clinical translation.

Prognosis of patients with coexisting obesity and malnutrition after ischemic stroke: A cohort study

BACKGROUND

The double burden of malnutrition, defined as the coexistence of obesity and malnutrition, is an increasing global health concern and is unclear in patients after ischemic stroke. The current study explored the combined impacts of obesity and malnutrition on patients with ischemic stroke.

METHODS

We conducted a single-center prospective cohort study with patients with ischemic stroke enrolled in Minhang Hospital in China between January 2018 and December 2022. Patients were stratified into four categories based on their obesity (defined by body mass index) and nutritional status (classified according to the Controlling Nutritional Status score): (1) nourished nonobese, (2) malnourished nonobese, (3) nourished obese, and (4) malnourished obese. The primary end points were poor outcomes and all-cause mortality at 3 months.

RESULTS

A total of 3160 participants with ischemic stroke were included in our study, of which 64.7% were male and the mean age was 69 years. Over 50% of patients were malnourished. At 3-month follow-up, the malnourished nonobese had the worst outcomes (34.4%), followed by the malnourished obese (33.2%), nourished nonobese (25.1%), and nourished obese (21.8%; P < 0.001). In multivariable analyses, with nourished nonobese group as the reference, the malnourished nonobese group displayed poorer outcomes (odds ratio [OR], 1.395 [95% CI, 1.169-1.664], P < 0.001) and higher all-cause mortality (OR, 1.541 [95% CI, 1.054-2.253], P = 0.026), but only a nonsignificant increase in poor prognosis rate (33.2% vs. 25.1%, P = 0.102) and mortality (4.2% vs. 3.6%, P = 0.902) were observed in the malnourished obese group.

CONCLUSION

A high prevalence of malnutrition is observed in the large population suffering from ischemic attack, even in the obese. Malnourished patients have the worst prognosis particularly in those with severe nutritional status regardless of obesity, while the best functional outcomes and the lowest mortality are demonstrated in nourished obese participants.

The Influence of Body Mass Index on Outcomes in Patients Undergoing Mechanical Thrombectomy for Anterior Circulation Large Vessel Occlusion: Institutional Experience and Meta-analysis

BACKGROUND

An obesity paradox, whereby patients with higher body mass index (BMI) experience improved outcomes, has been described for ischemic stroke. It is unclear whether this applies to patients undergoing mechanical thrombectomy (MT) for large vessel occlusion (LVO).

METHODS

Mechanical thrombectomies for anterior circulation LVO between 2015 and 2021 at a single institution were reviewed. Multivariable logistic regressions were used to determine the association between BMI and favorable functional outcome (90-day modified Rankin Scale 0-2), intracranial hemorrhage, and malignant middle cerebral infarction. A systematic review was performed to identify studies reporting the effect of BMI on outcomes among patients receiving MT for LVO. The data from the systematic review were combined with the institutional data by using a random effects model.

RESULTS

The institutional cohort comprised 390 patients with a median BMI of 27 kg/m2. Most patients were obese [36.7% (BMI ≥ 30 kg/m2)], followed by overweight [30.5% (BMI ≥ 25 and < 30 kg/m2)], normal [27.9% (BMI ≥ 18.5 and < 25 kg/m2)], and underweight [4.9% (BMI < 18.5 kg/m2)]. As a continuous variable, BMI was not associated with any of the outcomes. When analyzing BMI ordinally, obesity was associated with lower odds of favorable 90-day modified Rankin Scale (odds ratio 0.42, 95% confidence interval 0.20-0.86). The systematic review identified three eligible studies comprising 1,348 patients for a total of 1,738 patients. In the random effects model, there was no association between obesity and favorable outcome (odds ratio 0.89, 95% confidence interval 0.63-1.24).

CONCLUSIONS

Obesity is not associated with favorable outcomes in patients undergoing MT for LVO.

N6-methyladenosine modification in ischemic stroke: Functions, regulation, and therapeutic potential

N6-methyladenosine (m6A) modification is the most frequently occurring internal modification in eukaryotic RNAs. By modulating various aspects of the RNA life cycle, it has been implicated in a wide range of pathological and physiological processes associated with human diseases. Ischemic stroke is a major cause of death and disability worldwide with few treatment options and a narrow therapeutic window, and accumulating evidence has indicated the involvement of m6A modifications in the development and progression of this type of stroke. In this review, which provides insights for the prevention and clinical treatment of stroke, we present an overview of the roles played by m6A modification in ischemic stroke from three main perspectives: (1) the association of m6A modification with established risk factors for stroke, including hypertension, diabetes mellitus, hyperlipidemia, obesity, and heart disease; (2) the roles of m6A modification regulators and their functional regulation in the pathophysiological injury mechanisms of stroke, namely oxidative stress, mitochondrial dysfunction, endothelial dysfunction, neuroinflammation, and cell death processes; and (3) the diagnostic and therapeutic potential of m6A regulators in the treatment of stroke.

Effects of body mass index on the immune response within the first days after major stroke in humans

INTRODUCTION

Immunological alterations associated with increased susceptibility to infection are an essential aspect of stroke pathophysiology. Several immunological functions of adipose tissue are altered by obesity and are accompanied by chronic immune activation. The purpose of this study was to examine immune function (monocytes, granulocytes, cytokines) as a function of body mass index (BMI: 1st group: 25; 2nd group: 25 BMI 30; 3rd group: 30) and changes in body weight post stroke.

METHOD

Fat status was assessed using standardized weight measurements on days 1, 2, 3, 4, 5, and 7 after ischemic stroke in a cohort of 40 stroke patients and 16 control patients. Liver fat and visceral fat were assessed by MRI on day 1 or 2 [I] and on day 5 or 7 [II]. Leukocyte subpopulations in peripheral blood, cytokines, chemokines, and adipokine concentrations in sera were quantified. In a second cohort (stroke and control group, n = 17), multiple regression analysis was used to identify correlations between BMI and monocyte and granulocyte subpopulations.

RESULTS

Weight and fat loss occurred from the day of admission to day 1 after stroke without further reduction in the postischemic course. No significant changes in liver or visceral fat were observed between MRI I and MRI II. BMI was inversely associated with IL-6 levels, while proinflammatory cytokines such as eotaxin, IFN-β, IFN -γ and TNF-α were upregulated when BMI increased. The numbers of anti-inflammatory CD14+CD16+ monocytes and CD16+CD62L- granulocytes were reduced in patients with higher BMI values, while that of proinflammatory CD16dimCD62L+ granulocytes was increased.

CONCLUSION

A small weight loss in stroke patients was detectable. The data demonstrate a positive correlation between BMI and a proinflammatory poststroke immune response. This provides a potential link to how obesity may affect the clinical outcome of stroke patients.

The nonalcoholic fatty liver risk in prediction of unfavorable outcome after stroke: A nationwide registry analysis

Few researches have looked at the relationship between nonalcoholic fatty liver disease (NAFLD) at the time of admission and the long-term outcomes of patients suffering from acute ischemic stroke (AIS). We aimed to probe the relationship between NAFLD risk evaluated by NAFLD indices and long-term endpoints, along with the prognostic value of merging NAFLD indices with established risk markers for the prognosis of AIS patients. The fatty liver index (FLI) and the Hepatic steatosis index (HSI) were used to evaluate NAFLD risk in the Third China National Stroke Registry (CNSR-III), a large, prospective, national, multicenter cohort registry study. NAFLD was defined as FLI ≥35 for males and FLI ≥ 20 for females, as well as HSI>36. Death or major disability (modified Rankin Scale score ≥3) were the primary outcomes following the beginning of a stroke. On patient outcomes, the prognostic performance of two objective NAFLD parameters was evaluated. NAFLD was detected in 32.10-51.90% of AIS patients. After 1-year, 14.5% of the participants had died or suffered a severe outcome. After controlling for known risk factors, NAFLD was associated with a modest probability of adverse outcome (odds ratio,0.72[95% CI, 0.61-0.86] for FLI; odds ratio,0.68[95% CI, 0.55-0.85] for HSI). The inclusion of the two NAFLD indicators in the conventional prediction model was justified by the integrated discrimination index, continuing to increase the model's overall predictive value for long-term adverse outcomes. NAFLD risk was linked to a lower risk of long-term death or major disability in people with AIS. The predictive value of objective NAFLD after AIS was demonstrated in our study.

Risk factors for stroke among anthropometric indices and lipid profiles in the Korean population: a large-scale cross-sectional study

Stroke is strongly associated with death and disability. However, the associations between stroke and lipid profiles such as total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), and red blood cells (RBCs) and anthropometric indices such as waist circumference and waist-to-height ratio (WHtR) remain unclear. The objective of this study was to investigate these relationships in a Korean population. This large-scale cross-sectional study included data from 38,190 subjects collected from 2010 to 2018 by the Korea National Health and Nutrition Examination Survey (KNHANES). Simple logistic regression models and multiple logistic regression models were used to evaluate the association of stroke with lipid profiles and anthropometric indices in the crude model, adjusted Model 1, and fully adjusted Model 2. In men, stroke was negatively associated with height, weight, and hematocrit level. Total cholesterol and triglycerides were strongly negatively associated with stroke in Model 2. Creatinine level and stroke were weakly associated. Additionally, height, weight, total cholesterol, triglycerides, and hematocrit and creatinine levels were associated with stroke both before and after adjustment. In women, in Model 2, stroke was positively associated with height, weight, and creatinine level. A strong negative association was found between total cholesterol and stroke. Stroke was negatively associated with hemoglobin level, hematocrit level, and RBCs. Additionally, total cholesterol, hemoglobin level, hematocrit level, creatinine level, and RBCs were associated with stroke both before and after adjustment. Weight and height were more closely associated with stroke than waist circumference and WHtR in Korean men. Our results suggested that the association of stroke with triglycerides, height, and weight differed according to sex and that HDL-C was not associated with stroke in people of either sex.

Cholestyramine resin administration alleviated cerebral ischemic injury in obese mice by improving gut dysbiosis and modulating the bile acid profile

Obesity is a risk factor for cerebrovascular diseases. Accumulating evidence has revealed that gut dysbiosis plays an important role in the pathophysiology of cerebrovascular diseases. However, little is known about the role of gut dysbiosis in stroke in obesity. In this study, we established a rodent middle cerebral artery occlusion (MCAO) model to investigate whether obesity-induced gut dysbiosis exacerbates cerebral ischemic injury and the role of the bile salt sequestrant cholestyramine resin (CR) in gut microbiota and stroke outcome in obese mice. Long-term 45% high-fat diet (HFD) diet (8 weeks) induced an obesity phenotype and caused gut dysbiosis, resulting in a larger infarct volume and higher serum levels of inflammatory cytokines after stroke, compared to those in the lean counterparts. LC-MS/MS and GC analysis revealed that obese mice with stroke developed an obviously perturbed bile acid (BA) profile characterized by higher levels of deoxycholic acid and its conjugated forms, and lower levels of butyrate in the cecal content. CR administration improved the obesity-induced dysbiotic microbiome, attenuated ischemic brain injury and modulated the stroke-perturbed BA profile. Furthermore, fecal microbiota transplantation (FMT) experiments revealed that the impact of obesity on stroke and the neuroprotective effects of CR were mediated by gut microbiota. In conclusion, Obesity induces gut dysbiosis, worsens stroke outcomes, and perturbs the BA profile. The dysbiotic microbiome is an important linkage between obesity and stroke. CR confers metabolic benefits and neuroprotective effects in obesity, perhaps by modulating gut microbial composition and BA metabolism.

Impact of Obesity on Early In-Hospital Outcomes after Coronary Artery Bypass Grafting Surgery in Acute Coronary Syndrome: A Propensity Score Matching Analysis

Recent advances in perioperative care have considerably improved outcomes after coronary artery bypass graft (CABG) surgery. However, obesity can increase postoperative complication rates and can lead to increased morbidity and mortality. Between June 2011 and October 2019, a total of 1375 patients with acute coronary syndrome (ACS) underwent cardiac surgery and were retrospectively analyzed. Patients were divided into 2 groups: non-obese (body mass index (BMI) < 30 kg/m2, n = 967) and obese (BMI ≥ 30 kg/m2, n = 379). Underweight patients (n = 29) were excluded from the analysis. To compare the unequal patient groups, a propensity score-based matching (PSM) was applied (non-obese group (n = 372) vs. obese group (n = 372)). The mean age of the mentioned groups was 67 ± 10 (non-obese group) vs. 66 ± 10 (obese group) years, p = 0.724. All-cause in-hospital mortality did not significantly differ between the groups before PSM (p = 0.566) and after PSM (p = 0.780). The median length of ICU (p = 0.306 before PSM and p = 0.538 after PSM) and hospital stay (p = 0.795 before PSM and p = 0.131 after PSM) was not significantly higher in the obese group compared with the non-obese group. No significant differences regarding further postoperative parameters were observed between the unadjusted and the adjusted group. Obesity does not predict increased all-cause in-hospital mortality in patients undergoing CABG procedure. Therefore, CABG is a safe procedure for overweight patients.

Malnutrition Defined by Geriatric Nutritional Risk Index Predicts Outcomes in Severe Stroke Patients: A Propensity Score-Matched Analysis

Background: Malnutrition’s prognostic impact in patients with severe stroke requiring ICU admission is not well known. This study aimed to assess the nutritional status of severe stroke patients using the geriatric nutritional risk index (GNRI) and examine the association of GNRI with mortality in that population. Methods: We identified 1145 severe stroke patients requiring ICU admission from the Medical Information Mart for Intensive Care (MIMIC-III) database and divided them into low GNRI (≤98) or high GNRI (>98) groups. We used a propensity score matching (PSM) method to reduce confounding. Cox proportional hazards regression and restricted cubic splines were used to elucidate the association between GNRI and mortality. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated. Results: A total of 397 (35%) patients were in the low GNRI group (at risk of malnutrition). After PSM, patients in the low GNRI group still suffered higher mortality compared with the high GNRI group at 28 days (27.9 vs. 20.8%), 90 days (35.5 vs. 25.7%), and 1 year (43.4 vs. 30.9%) (p < 0.05). A low GNRI was significantly associated with an increased mortality (HR: 1.38, 95% CI 1.03−1.86 in 28 days; HR: 1.45, 95% CI 1.11−1.89 in 90 days; HR: 1.51, 95% CI 1.19−1.92 in 1 year). Sensitivity analyses yielded consistent results. Restricted cubic splines showed a progressively decreasing risk of mortality with increasing GNRI scores up to 110, approximately. Conclusion: Severe stroke patients with malnutrition experienced an increased risk of death compared to those without malnutrition. GNRI, as a simple and practical nutritional screening tool, can be used as a routine approach to the nutritional status of stroke patients.

The Smoking Paradox in Stroke Patients Under Reperfusion Treatment Is Associated With Endothelial Dysfunction

Objective

This study aimed to explore the association between smoking habit and the serum levels of soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK), in relation with the functional outcome of patients with acute ischemic stroke undergoing reperfusion treatment.

Methods

Observational and retrospective study of a series of patients with acute ischemic stroke subjected to reperfusion treatments. Clinical, analytical, and neuroimaging parameters were analyzed. The main endpoint was the functional outcome at 3 months, measured by the modified Ranking Scale (mRS). Logistic regression models were used to analyze the association between smoking and sTWEAK levels with functional outcome and leukoaraiosis.

Results

The results showed that smoking habit was associated with a good functional outcome at 3 months in patients with stroke (OR: 3.52; 95% CI: 1.03–11.9; p = 0.044). However, this independent association was lost after adjusting by sTWEAK levels (OR 1.73; 95% CI: 0.86–13.28; p = 0.116). sTWEAK levels were significantly lower in smoker patients [4015.5 (973.66–7921.83) pg/ml vs. 5,628 (2,848–10,202) pg/ml, p < 0.0001], while sTWEAK levels were significantly higher in patients with poor functional outcomes at 3 months [10,284 (7,388–13.247) pg/ml vs. 3,405 (2,329–6,629) pg/ml, p < 0.0001].

Conclusion

The decrease in sTWEAK levels was associated with a good functional outcome in smoker patients with stroke undergoing reperfusion therapy.

Associations between RNA-Binding Motif Protein 3, Fibroblast Growth Factor 21, and Clinical Outcome in Patients with Stroke

Background: RNA-binding motif protein 3 (RBM3) is a cold-induced marker of good functional outcome of ischemic stroke that is promising as a protective target. Fibroblast growth factor 21 (FGF21) is an obesity- and temperature-related hormone that upregulates the expression of RBM3, which is beneficial as a recombinant treatment and has been tested under different experimental pathological conditions, including stroke. However, the interaction between RBM3 and FGF21 has not yet been tested for clinical stroke conditions. Methods: In a sample of 66 stroke patients, we analyzed the associations between the FGF21 and RBM3 serum concentrations on admission and at 72 h, body weight, maximum temperature during the first 24 h, and the outcome of patients at 3 months. We also analyzed their association with biomarkers of obesity (adiponectin and leptin) and inflammation (interleukin-6 (IL-6) and interleukin (IL-10)). Results: Higher concentrations of FGF21 on admission and RBM3 at 72 h were associated with good outcomes. Serum FGF21 and RBM3 were directly related to body mass index and inversely related to the maximum temperature during the first 24 h. We found a positive association between the FGF21 concentrations in obese patients with leptin and a negative correlation with adiponectin in non-obese participants. Conclusions: This clinical study demonstrates the association between RBM3 and FGF21 levels and the outcome of stroke patients. Although further investigations are required, these data support the pharmacological induction of RBM3 as a promising protective therapy.

Body mass index, blood glucose, and mortality in patients with ischemic stroke in the intensive care unit: A retrospective cohort study

BACKGROUND

Excessive BMI was associated with lower mortality after stroke. However, some believed that excessive BMI can lead to a poor prognosis because of some physiological mechanism, such as glucose metabolism disorder. Therefore, this study aims to discuss the association between mortality, BMI, and blood glucose.

MATERIALS AND METHODS

This was a retrospective observational study and all data were extracted from the Medical Information Mart for Intensive Care III database. The exposure was BMI classified into the normal weight group and the excessive weight group. The outcome concluded 30-day, 90-day, and 1-year mortality. The association between two groups and mortality was elucidated by Cox regression models, propensity score matching (PSM) and inverse probability of treatment weighting (IPTW). The underlying effect of blood glucose on the "obesity paradox" was analyzed by causal mediation analysis.

RESULTS

According to Cox regression models, a significant beneficial effect of excessive BMI in terms of mortality was observed: 30-day mortality (HR 0.57, 95% CI 0.35-0.90, P = 0.017), 90-day mortality (HR 0.53, 95% CI 0.36-0.78, P = 0.001), and 1-year mortality (HR 0.65, 95% CI 0.46-0.91, P = 0.013). After PSM and IPTW, we got a similar conclusion. The causal mediation analysis showed that the protective effect of excessive BMI on 30-day mortality reduced with the increase of blood glucose.

CONCLUSION

For ischemic stroke patients in the Intensive Care Unit, those with excessive BMI are associated with both lower short-term mortality and lower long-term mortality, while the protective effect on 30-day mortality weakened accompanied by the increase of blood glucose.

Association Between Body Mass Index and Intracranial Aneurysm Rupture: A Multicenter Retrospective Study

Background and Aims: It has recently emerged the concept of “obesity paradox,” a term used to describe an inverse association between obesity and clinical outcomes in cardiovascular diseases and stroke. The purpose of this study was to investigate the association between body mass index (BMI) and the risk of intracranial aneurysm rupture.

Methods: In this study, we conducted a retrospective analysis of a prospectively maintained database of patients with intracranial aneurysms from 21 medical centers in China. A total of 3,965 patients with 4,632 saccular intracranial aneurysms were enrolled. Patients were separated into unruptured (n = 1,977) and ruptured groups (n = 1,988). Univariable and multivariable logistic regression analyses were performed to determine the association between BMI and intracranial aneurysm rupture.

Results: Compared to the patients with normal BMI (18.5 to < 24.0 kg/m²), the odds of intracranial aneurysm rupture were significantly lower in patients with BMI 24.0 to < 28.0 kg/m² (OR = 0.745, 95% CI = 0.638–0.868, P = 0.000) and patients with BMI ≥ 28.0 kg/m² (OR = 0.628, 95% CI = 0.443–0.890, P = 0.009). Low BMI (<18.0 kg/m²) was not associated with intracranial aneurysm rupture (OR = 0.894, 95% CI = 0.483–1.657, P = 0.505). For males, both the BMI 24.0 to < 28.0 kg/m² (OR = 0.606, 95% CI = 0.469–0.784, P = 0.000) and the BMI ≥ 28.0 kg/m² (OR = 0.384, 95% CI = 0.224–0.658, P = 0.001) were associated with a lower rupture risk, whereas the inverse association was not observed in females. Both the BMI 24.0 to < 28.0 kg/m² (OR = 0.722 for aged 50–60y, 95% CI = 0.554–0.938, P = 0.015; OR = 0.737 for aged >60y, 95% CI = 0.586–0.928, P = 0.009) and the BMI ≥ 28.0 kg/m² (OR = 0.517 for aged 50–60y, 95% CI = 0.281–0.950, P = 0.0034; OR = 0.535 for aged >60y, 95% CI = 0.318–0.899, P = 0.0018) was associated with a lower rupture risk in patients aged ≥50 years, whereas the association was not significant in patients aged <50 years.

Conclusions: Increased BMI is significantly and inversely associated with saccular intracranial aneurysm rupture in males and patients aged ≥50 years.

Association Between Weight Loss and Activities of Daily Living in Obese and Overweight Patients after Stroke: A Cross-Sectional Study

OBJECTIVE

Whether weight loss during hospitalization is associated with improvement in activities of daily living (ADL) in overweight and obese stroke patients remains unclear. This study investigated the association between decreases in body mass index (BMI), fat-free mass (FFM), and fat mass (FM) and ADL improvement.

MATERIALS AND METHODS

In this cross-sectional study, we analyzed data of patients admitted to acute care hospitals with stroke. Patients were classified into two groups based on their change in BMI during their hospital stay (i.e. decreased or nondecreased group). To control and adjust for patient characteristics and confounders, we created an inverse probability-weighted (IPW) model using propensity scoring, which was used to compare the Functional Independence Measure Motor (FIM-M) efficacy between the two groups. We also compared FFM and FM between admission and discharge in each group.

RESULTS

A total of 556 patients were analyzed, among whom 391 (70.3%) had a decrease in BMI and 165 (29.7%) had a nondecrease. After IPW adjustment, efficiency of FIM-M was significantly higher in the nondecreased group as compared to that in the decreased group (median: 0.44 vs. 0.29, P < 0.001). FFM and FM were significantly decreased from admission to discharge in the decreased group, but there was no significanct difference observed in the nondecreased group. Preserving BMI during hospitalization was associated with a positive improvement in ADL in overweight and obese stroke patients undergoing rehabilitation.

CONCLUSIONS

Risks and benefits of weight loss should be balanced in nutritional care and rehabilitation for overweight and obese stroke patients.

Association of BMI, comorbidities and all-cause mortality by using a baseline mortality risk model

Objective

The association of body mass index (BMI) and all-cause mortality is controversial, frequently referred to as a paradox. Whether the cause is metabolic factors or statistical biases is still controversial. We assessed the association of BMI and all-cause mortality considering a wide range of comorbidities and baseline mortality risk.

Methods

Retrospective cohort study of Olmsted County residents with at least one BMI measurement between 2000–2005, clinical data in the electronic health record and minimum 8 year follow-up or death within this time. The cohort was categorized based on baseline mortality risk: Low, Medium, Medium-high, High and Very-high. All-cause mortality was assessed for BMI intervals of 5 and 0.5 Kg/m².

Results

Of 39,739 subjects (average age 52.6, range 18–89; 38.1% male) 11.86% died during 8-year follow-up. The 8-year all-cause mortality risk had a “U” shape with a flat nadir in all the risk groups. Extreme BMI showed higher risk (BMI <15 = 36.4%, 15 to <20 = 15.4% and ≥45 = 13.7%), while intermediate BMI categories showed a plateau between 10.6 and 12.5%. The increased risk attributed to baseline risk and comorbidities was more obvious than the risk based on BMI increase within the same risk groups.

Conclusions

There is a complex association between BMI and all-cause mortality when evaluated including comorbidities and baseline mortality risk. In general, comorbidities are better predictors of mortality risk except at extreme BMIs. In patients with no or few comorbidities, BMI seems to better define mortality risk. Aggressive management of comorbidities may provide better survival outcome for patients with body mass between normal and moderate obesity.

Impact of Obesity-Induced Inflammation on Cardiovascular Diseases (CVD)

Overweight and obesity are key risk factors of cardiovascular disease (CVD). Obesity is currently presented as a pro-inflammatory state with an expansion in the outflow of inflammatory cytokines, such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), alongside the expanded emission of leptin. The present review aimed to evaluate the relationship between obesity and inflammation and their impacts on the development of cardiovascular disease. A literature search was conducted by employing three academic databases, namely PubMed (Medline), Scopus (EMBASE), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL). The search presented 786 items, and by inclusion and exclusion filterers, 59 works were considered for final review. The Newcastle–Ottawa Scale (NOS) method was adopted to conduct quality assessment; 19 papers were further selected based on the quality score. Obesity-related inflammation leads to a low-grade inflammatory state in organisms by upregulating pro-inflammatory markers and downregulating anti-inflammatory cytokines, thereby contributing to cardiovascular disease pathogenesis. Because of inflammatory and infectious symptoms, adipocytes appear to instigate articulation and discharge a few intense stage reactants and carriers of inflammation. Obesity and inflammatory markers are strongly associated, and are important factors in the development of CVD. Hence, weight management can help prevent cardiovascular risks and poor outcomes by inhibiting inflammatory mechanisms.

Obesity and Stroke: Does the Paradox Apply for Stroke?

Historically, obesity has been identified as one of the most important risk factors for developing cardiovascular diseases including stroke; however, a theory called "The Obesity Paradox" has been recently considered. The paradoxical theory is that obese or overweight patients (according to body mass index score) can have better outcomes compared to leaner or malnourished patients. The paradox was initially discovered in patients with heart failure. The purpose of this manuscript was to investigate whether this paradox also applies to stroke patients, according to information available in the current literature.

Obesity paradox and stroke: a narrative review

BACKGROUND

Despite obesity is an established risk factor for stroke, several studies reported a better outcome after stroke in obese and overweight patients. This counterintuitive finding, which was described in the whole spectrum of cardiovascular diseases, is known as obesity paradox.

OBJECTIVE

This is a narrative overview on the obesity paradox and stroke.

METHODS

We used as sources MEDLINE/PubMed, CINAHL, EMBASE, and Cochrane Library from inception to 2019, and selected papers that discussed the association of obesity with outcome and mortality after stroke.

RESULTS

The majority of studies reported lower mortality rates and better functional outcome after stroke in obese and overweight patients compared with normal weight and underweight patients, suggesting the existence of an obesity paradox in stroke. However, available studies are limited by several major methodological concerns including absence of randomized trials, retrospective nature of most studies, assessment of obesity with body mass index (BMI), non-linear relationship between BMI and outcome, short follow-up period, and differences in co-morbid conditions and stroke characteristics.

CONCLUSIONS

The existence of an obesity paradox in stroke is still controversial and further higher quality evidence is needed to clarify the relationship between obesity and stroke outcome.

LEVEL OF EVIDENCE

Level V, narrative review.

Metabolically healthy obesity and risk of stroke: a meta-analysis of prospective cohort studies

Background

Metabolic healthy obesity (MHO) is a unique subgroup of overweight and obese individuals with normal metabolic characteristics. Its association with the risk of stroke remains unclear. We aimed to examine the risk of stroke in MHO individuals and the further associations between stroke and metabolic abnormalities under different bodyweight conditions.

Methods

We systematically searched PubMed, Embase and Cochrane Library from December 1946 to January 2019, and only included prospective cohort studies. Random effects models were used to evaluate the pooled risk ratios (RR) and 95% confidence intervals (95% CI) of incident stroke.

Results

A total of eight studies comprising 4,256,888 participants were included in the meta-analysis. MHO individuals had an increased risk of stroke compared with metabolically healthy normal weight (MH-NW) individuals (RR =1.17, 95% CI: 1.11–1.23). However, the stroke risk of metabolically healthy overweight individuals was the same (RR =1.02, 95% CI: 0.84–1.23). All groups with unhealthy metabolism had a similarly elevated risk: normal weight (RR =1.83, 95% CI: 1.57–2.14), overweight (RR =1.93, 95% CI: 1.44–2.58), and obesity (RR =2.00, 95% CI: 1.40–2.87).

Conclusions

The meta-analysis confirms a positive association between MHO phenotype and the risk of stroke. Individuals with metabolic abnormalities under different bodyweight conditions are at elevated risk.

Western Diet: Implications for Brain Function and Behavior

The Western diet (WD) pattern characterized by high daily intake of saturated fats and refined carbohydrates often leads to obesity and overweight, and it has been linked to cognitive impairment and emotional disorders in both animal models and humans. This dietary pattern alters the composition of gut microbiota, influencing brain function by different mechanisms involving the gut-brain axis. In addition, long-term exposure to highly palatable foods typical of WD could induce addictive-like eating behaviors and hypothalamic-pituitary-adrenal (HPA) axis dysregulation associated with chronic stress, anxiety, and depression. In turn, chronic stress modulates eating behavior, and it could have detrimental effects on different brain regions such as the hippocampus, hypothalamus, amygdala, and several cortical regions. Moreover, obesity and overweight induce neuroinflammation, causing neuronal dysfunction. In this review, we summarize the current scientific evidence about the mechanisms and factors relating WD consumption with altered brain function and behavior. Possible therapeutic interventions and limitations are also discussed, aiming to tackle and prevent this current pandemic.

Reprint of: Recent Updates on Obesity Treatments: Available Drugs and Future Directions

In the last thirty years, obesity has reached epidemic proportions and is now regarded as a major health issue in contemporary society trending to serious economic and social burdens. The latest projections of the World Health Organization are alarming. By 2030, nearly 60% of the worldwide population could be either obese or overweight, highlighting the needs to find innovative treatments. Currently, bariatric surgery is the most effective way to efficiently lower body mass. Although great improvements in terms of recovery and patient care were made in these surgical procedures, bariatric surgery remains an option for extreme forms of obesity and seems unable to tackle obesity pandemic expansion. Throughout the last century, numerous pharmacological strategies targeting either peripheral or central components of the energy balance regulatory system were designed to reduce body mass, some of them reaching sufficient levels of efficiency and safety. Nevertheless, obesity drug therapy remains quite limited on its effectiveness to actually overcome the obesogenic environment. Thus, innovative unimolecular polypharmacology strategies, able to simultaneously target multiple actors involved in the obesity initiation and expansion, were developed during the last ten years opening a new promising avenue in the pharmacological management of obesity. In this review, we first describe the clinical features of obesity-associated conditions and then focus on the outcomes of currently approved drug therapies for obesity as well as new ones expecting to reach the clinic in the near future.

Regulation of Glycemia in the Recovery Phase After Stroke Counteracts the Detrimental Effect of Obesity-Induced Type 2 Diabetes on Neurological Recovery

The interplay between obesity and type 2 diabetes (T2D) in poststroke recovery is unclear. Moreover, the impact of glucose control during the chronic phase after stroke is undetermined. We investigated whether obesity-induced T2D impairs neurological recovery after stroke by using a clinically relevant experimental design. We also investigated the potential efficacy of two clinically used T2D drugs: the dipeptidyl peptidase 4 inhibitor linagliptin and the sulfonylurea glimepiride. We induced transient middle cerebral artery occlusion (tMCAO) in T2D/obese mice (after 7 months of high-fat diet [HFD]) and age-matched controls. After stroke, we replaced HFD with standard diet for 8 weeks to mimic the poststroke clinical situation. Linagliptin or glimepiride were administered daily from 3 days after tMCAO for 8 weeks. We assessed neurological recovery weekly by upper-limb grip strength. Brain damage, neuroinflammation, stroke-induced neurogenesis, and atrophy of parvalbumin-positive (PV⁺) interneurons were quantified by immunohistochemistry. T2D/obesity impaired poststroke neurological recovery in association with hyperglycemia, neuroinflammation, and atrophy of PV⁺ interneurons. Both drugs counteracted these effects. In nondiabetic mice, only linagliptin accelerated recovery. These findings shed light on the interplay between obesity and T2D in stroke recovery. Moreover, they promote the use of rehabilitative strategies that are based on efficacious glycemia regulation, even if initiated days after stroke.

Recent Updates on Obesity Treatments: Available Drugs and Future Directions

In the last thirty years, obesity has reached epidemic proportions and is now regarded as a major health issue in contemporary society trending to serious economic and social burdens. The latest projections of the World Health Organization are alarming. By 2030, nearly 60% of the worldwide population could be either obese or overweight, highlighting the needs to find innovative treatments. Currently, bariatric surgery is the most effective way to efficiently lower body mass. Although great improvements in terms of recovery and patient care were made in these surgical procedures, bariatric surgery remains an option for extreme forms of obesity and seems unable to tackle obesity pandemic expansion. Throughout the last century, numerous pharmacological strategies targeting either peripheral or central components of the energy balance regulatory system were designed to reduce body mass, some of them reaching sufficient levels of efficiency and safety. Nevertheless, obesity drug therapy remains quite limited on its effectiveness to actually overcome the obesogenic environment. Thus, innovative unimolecular polypharmacology strategies, able to simultaneously target multiple actors involved in the obesity initiation and expansion, were developed during the last ten years opening a new promising avenue in the pharmacological management of obesity. In this review, we first describe the clinical features of obesity-associated conditions and then focus on the outcomes of currently approved drug therapies for obesity as well as new ones expecting to reach the clinic in the near future.