Association between abnormal body weight and stroke outcome: A meta-analysis and systematic review

Correlation of TyG-BMI and TyG-WC with severity and short-term outcome in new-onset acute ischemic stroke

Objectives

To research the connection between the indexes of the indexes of triglyceride-glucose (TyG) combined with obesity indices and the initial neurological severity and short-term outcome of new-onset acute ischemic stroke.

Methods

Data of patients with acute ischemic stroke admitted to the Stroke Ward of the Affiliated Hospital of Beihua University from November 2021 to October 2023, were collected. The two indexes were calculated by combining TyG and obesity indices: TyG-body mass index (TyG-BMI) and TyG-waist circumference (TyG-WC). The National Institute of Health Stroke Scale (NIHSS) was used to assess and group patients with neurological deficits within 24 hours of admission: mild stroke (NIHSS ≤5) and moderate-severe stroke (NIHSS >5). Short-term prognosis was evaluated using the modified Rankin Scale (mRS) at discharge or 14 days after onset of the disease and grouped: good outcome (mRS ≤2) and poor outcome (mRS >2). According to the quartiles of TyG-BMI and TyG-WC, the patients were placed into four groups: Q1, Q2, Q3 and Q4. Multi-factor logistic regression analysis was utilized to evaluate the correlation of TyG-BMI and TyG-WC with the severity and short-term outcome.

Results

The study included 456 patients. After adjusting for multiple variables, the results showed that compared with the quartile 1, patients in quartile 4 of TyG-BMI had a reduced risk of moderate-severe stroke [Q4: OR: 0.407, 95%CI (0.185-0.894), P = 0.025]; Patients in quartiles 2, 3 and 4 of TyG-BMI had sequentially lower risk of short-term adverse outcomes [Q2: OR: 0.394, 95%CI (0.215-0.722), P = 0.003; Q3: OR: 0.324, 95%CI (0.163-0.642), P = 0.001; Q4: OR: 0.158, 95%CI (0.027-0.349), P <0.001]; Patients in quartiles 3 and 4 of TyG-WC had sequentially lower risk of moderate-severe stroke [Q3: OR: 0.355, 95%CI (0.173-0.728), P = 0.005; Q4: OR: 0.140, 95%CI (0.056-0.351), P <0.001]; Patients in quartiles 3 and 4 of TyG-WC had sequentially lower risk of short-term adverse outcomes [Q3: OR: 0.350, 95%CI (0.175-0.700), P = 0.003; Q4: OR: 0.178, 95%CI (0.071-0.451), P <0.001].

Conclusions

TyG-WC and TyG-BMI were correlated with the severity and short-term outcome of new-onset acute ischemic stroke. As TyG-WC and TyG-BMI increased, stroke severity decreased and short-term outcome was better.

Clinical impact of body mass index on outcomes of ischemic and hemorrhagic strokes

BACKGROUND AND AIM

To investigate the prognostic implication of body mass index (BMI) on clinical outcomes after acute ischemic and hemorrhagic stroke.

METHODS

The subjects of the study included adult patients with available baseline body weight and height data who had suffered an acute stroke and were registered in the Japan Stroke Data Bank-a hospital-based, multicenter stroke registration database-between January 2006 and December 2020. The outcome measures included unfavorable outcomes defined as a modified Rankin Scale (mRS) score of 5-6 and favorable outcomes (mRS 0-2) at discharge, and in-hospital mortality. Mixed effects logistic regression analysis was conducted to determine the relationship between BMI categories (underweight, normal weight, overweight, class I obesity, class II obesity; <18.5, 18.5-23.0, 23.0-25.0, 25-30, ⩾30 kg/m2) and the outcomes, after adjustment for covariates.

RESULTS

A total of 56,230 patients were assigned to one of the following groups: ischemic stroke (IS, n = 43,668), intracerebral hemorrhage (ICH, n = 9741), and subarachnoid hemorrhage (SAH, n = 2821). In the IS group, being underweight was associated with an increased likelihood of unfavorable outcomes (odds ratio, 1.47 (95% confidence interval (CI):1.31-1.65)) and in-hospital mortality (1.55 (1.31-1.83)) compared to outcomes in those with normal weight. Being overweight was associated with an increased likelihood of favorable outcomes (1.09 (1.01-1.18)). Similar associations were observed between underweight and these outcomes in specific IS subtypes (cardioembolic stroke, large artery stroke, and small-vessel occlusion). Patients with a BMI ⩾30.0 kg/m2 was associated with an increased likelihood of unfavorable outcomes (1.44 (1.01-2.17)) and in-hospital mortality (2.42 (1.26-4.65)) in large artery stroke. In patients with ICH, but not those with SAH, being underweight was associated with an increased likelihood of unfavorable outcomes (1.41 (1.01-1.99)).

CONCLUSIONS

BMI substantially impacts functional outcomes following IS and ICH. Lower BMI consistently affected post-stroke disability and mortality, while higher BMI values similarly affected these outcomes after large artery stroke.

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.

Effect of abnormal body weight on mortality and functional recovery in adults after stroke: An umbrella review

BACKGROUND

Several published systematic reviews have drawn conflicting conclusions on the effect of abnormal body weight (i.e. being underweight, overweight or obese) on outcomes following stroke. The 'obesity paradox' seen in several diseases (wherein obesity, often associated with mortality and morbidity, appears to be protective and improve outcomes) may be evident after stroke, but inconsistent results of existing reviews, and the issue of being underweight, are worth investigating further.

AIMS

To better understand the impact of body weight on prognosis after stroke, we aimed to answer the following research question: What is the effect of abnormal body weight (underweight, overweight, or obesity) on mortality and functional recovery in adults after stroke?

SUMMARY OF REVIEW

We conducted an umbrella review to synthesize existing evidence on the effects of abnormal body weight on stroke outcomes. We searched Cumulated Index to Nursing and Allied Health Literature (CINAHL) Complete, COCHRANE Database of Systematic Reviews, PubMed, Medline, PEDro, and EMBASE Classic + EMBASE, from inception until 28 February 2023. Seven systematic reviews (1,136,929 participants) from 184 primary studies (counting duplicates) were included. While the risk of mortality increases with being underweight (body mass index (BMI) < 18.5 kg/m2), excess body weight (being overweight (BMI = 25-29.9 kg/m2) or obese (BMI > 30 kg/m2)) is associated with reduced mortality. The impact of abnormal body weight on functional recovery is less clear; data from studies of being underweight are associated with poor functional outcomes while those from studies of excess body weight are inconclusive.

CONCLUSION

Abnormal body weight effects post-stroke outcomes and should be considered in clinical decision-making, prognostic research, and clinical trials of rehabilitation interventions. The "obesity paradox" is evident after stroke, and excess body weight is associated with reduced mortality compared to normal body weight. It is recommended that body weight is routinely recorded for stroke patients, and further research, including well-designed cohort studies with reliable weight data, is needed to further investigate the impact of body weight and distribution on post-stroke outcomes.

Mfat-1 ameliorates cachexia after hypoxic-ischemic brain damage in mice by protecting the hypothalamus-pituitary-adrenal axis

AIMS

Cachexia, a metabolic syndrome, affects 21 % of patients suffering from ischemic encephalopathy. However, the specific mechanism and prevention measures are still unclear. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) have been proven to reduce inflammatory cytokine levels during ischemic events, but whether they have a protective effect against cachexia after hypoxic-ischemic brain damage (HIBD) remains unclear.

MAIN METHODS

C57BL/6J wild-type and mfat-1 transgenic male mice were treated with and without HIBD. One day after HIBD, the epididymal white fat, gastrocnemius muscle and hypothalamus were weighed and analyzed the phenotypic changes. RNA sequencing was applied to gastrocnemius muscle to identify differential genes and pathways in HIBD groups. The effect of HPA axis on cachexia post-HIBD was examined via adrenalectomy, dexamethasone (0.1 mg/kg), and corticosterone injection (100 mg/kg).

KEY FINDINGS

The results showed that the incidence of cachexia in mfat-1 mice, which produce high proportion of n-3 PUFAs, was significantly lower than that in wild-type mice post-HIBD. Cachexia-related factors, such as inflammation, muscle atrophy and lipid metabolism were significantly improved in mfat-1 HIBD. RNA sequencing revealed that catabolic and proteasome pathways were significantly downregulated. In hypothalamus, inflammatory cytokines, lipid peroxidation levels were reduced. Corticosterone, glucocorticoid receptor, and dexamethasone suppression test all showed that mfat-1 improved the dysfunction of the HPA axis post-HIBD. The present study elucidated for the first time that mfat-1 reduced HIBD-induced hyperactivation of the HPA axis in mice by reducing inflammation and oxidative stress and contributed to the reduction of metabolic imbalance in peripheral tissues.

SIGNIFICANCE

Our study provides mechanistic information for the development of intervention strategies to prevent cachexia.

Low body mass index patients have worse outcomes after mechanical thrombectomy

BACKGROUND

There is evidence that frailty is an independent predictor of worse outcomes after stroke. Similarly, although obesity is associated with a higher risk for stroke, there are multiple reports describing improved mortality and functional outcomes in higher body mass index (BMI) patients in a phenomenon known as the obesity paradox. We investigated the effect of low BMI on outcomes after mechanical thrombectomy (MT).

METHODS

We conducted a retrospective analysis of 231 stroke patients who underwent MT at an academic medical center between 2020-2022. The patients' BMI data were collected from admission records and coded based on the Centers for Disease Control and Prevention (CDC) obesity guidelines. Recursive partitioning analysis (RPA) in R software was employed to automatically detect a BMI threshold associated with a significant survival benefit. Frailty was quantified using the Modified Frailty Index 5 and 11.

RESULTS

In our dataset, by CDC classification, 2.6% of patients were underweight, 27.3% were normal BMI, 30.7% were overweight, 19.9% were class I obese, 9.5% were class II obese, and 10% were class III obese. There were no significant differences between these groups. RPA identified a clinically significant BMI threshold of 23.62 kg/m2. Independent of frailty, patients with a BMI ≤23.62 kg/m2 had significantly worse overall survival (P<0.001) and 90-day modified Rankin Scale (P=0.027) than patients above the threshold.

CONCLUSIONS

Underweight patients had worse survival and functional outcomes after MT. Further research should focus on the pathophysiology underlying poor prognosis in underweight MT patients, and whether optimizing nutritional status confers any neuroprotective benefit.

Non-linear dose-response relationship between body mass index and stroke risk in middle-aged and elderly Chinese men: a nationwide Longitudinal Cohort Study from CHARLS

Objective

Body mass index (BMI) and stroke risk have been linked, but these findings are still debated. This study investigated the relationship between BMI and stroke risk in a middle-aged and elderly Chinese population.

Methods

This study used four waves of CHARLS data (2011, 2013, 2015, and 2018), including 12,161 participants. The CHARLS sample was obtained by multi-stage probability sampling and all participants were assessed by one-to-one interviews using a standardized questionnaire. We used a Cox proportional-hazards regression model to examine the relationship between BMI and stroke risk. We used Cox proportional hazards regression with cubic spline functions and smooth curve fitting to identify the non-linear relationship between them. A series of sensitivity analyses were also conducted.

Results

The multivariate Cox proportional hazards regression model identified a positive association between BMI and stroke risk (HR=1.025, 95% CI: 1.010-1.040). We also found a non-linear relationship between BMI and stroke incidence, with an inflection point at 26.63 kg/m2 for BMI. Each 1 kg/m2 increase in BMI to the left of the inflection point was related to a 4.4% increase in stroke risk (HR=1.044, 95% CI: 1.019-1.069). We stratified individuals by gender to further investigate their association and found a particular non-linear relationship and saturation effect between BMI and stroke risk in men, with the inflection point at 25.94 kg/m2. Each 1 kg/m2 increase in BMI to the left of the inflection point was related to a 7.6% increase in stroke risk (HR=1.076, 95% CI 1.034-1.119). The association was linear in women, with each 1 kg/m2 increase in BMI associated with a 2.1% increase in stroke risk (HR=1.021, 95% CI 1.002, 1.040).

Conclusion

In men, there was a specific non-linear association and saturation effect of BMI with stroke (inflection point of 25.94 kg/m2), while in women, there was none. When males had a BMI below 25.94 kg/m2, the risk of stroke was significantly and positively associated with BMI. By controlling BMI below 25.94 kg/m2 in men, a further decrease in BMI may promote a significant reduction in stroke risk.

Non-linear association between body weight and functional outcome after acute ischemic stroke

This study aimed to determine whether body weight is associated with functional outcome after acute ischemic stroke. We measured the body mass index (BMI) and assessed clinical outcomes in patients with acute ischemic stroke. The BMI was categorized into underweight (< 18.5 kg/m²), normal weight (18.5-22.9 kg/m²), overweight (23.0-24.9 kg/m²), and obesity (≥ 25.0 kg/m²). The association between BMI and a poor functional outcome (modified Rankin Scale [mRS] score: 3-6) was evaluated. We included 11,749 patients with acute ischemic stroke (70.3 ± 12.2 years, 36.1% women). The risk of a 3-month poor functional outcome was higher for underweight, lower for overweight, and did not change for obesity in reference to a normal weight even after adjusting for covariates by logistic regression analysis. Restricted cubic splines and SHapley Additive exPlanation values in eXtreme Gradient Boosting model also showed non-linear relationships. Associations between BMI and a poor functional outcome were maintained even after excluding death (mRS score: 3-5) or including mild disability (mRS score: 2-6) as the outcome. The associations were strong in older patients, non-diabetic patients, and patients with mild stroke. Body weight has a non-linear relationship with the risk of a poor functional outcome after acute ischemic stroke.

Geriatric Nutritional Risk Index and the Prognosis of Patients with Stroke: A Meta-Analysis

Malnutrition evidenced by low geriatric nutritional risk index (GNRI) has been suggested as a potential predictor of poor prognosis of patients with various clinical conditions. We performed a meta-analysis to systematically assess the association between GNRI and the prognosis of patients after stroke. Cohort studies were identified by search of PubMed, Embase, Cochrane's Library and Web of Science databases from inception to March 25, 2022, according to the aim of the meta-analysis. A random-effect model incorporating the potential between-study heterogeneity was used to pool the results. Eight cohort studies with 13573 patients with stroke contributed to the meta-analysis. Pooled results showed that malnutrition as evidenced by low GNRI was independently associated with a higher risk of poor functional outcome [risk ratio (RR): 1.54, 95% confidence interval (CI): 1.19 to 1.98, p<0.001; I2=69%] and an increased incidence of all-cause mortality (RR: 1.82, 95% CI: 1.35 to 2.47, p<0.001; I2=74%). Sensitivity analyses showed consistent results in patients with ischemic stroke, and in prospective cohort studies. Subgroup analyses showed that the associations were not significant for patients with GNRI-defined mild malnutrition (p=0.18 and 0.20 for functional and mortality outcomes, respectively), but significant for patients with moderate-severe malnutrition (both p<0.001). Difference in follow-up durations did not significantly affect the associations (p for subgroup difference=0.75 and 0.70, respectively). In conclusion, a low GNRI is associated with poor functional and survival outcomes in patients after stroke.

The relationship between body mass index and stroke: a systemic review and meta-analysis

BACKGROUND

Stroke is an acute cerebrovascular event closely related to brain tissue damage, and is one of the major causes of death and disability in worldwide. Various studies have reported the effects of body mass index (BMI) on the risk of stroke, but the results remain varied and these results have not been synthesized. Therefore, a meta-analysis was performed to evaluate the relationship between BMI and the risk of stroke.

OBJECTIVES

This systematic review was conducted to explore the relationship between BMI and the risk of stroke.

METHODS

PubMed, EMBASE, Web of Science and Cochrane Library, China Knowledge Resource Integrated Database (CNKI), WanFang Database, Chinese Biomedical Database (CBM), and CQVIP were comprehensively searched for studies exploring the relationship between BMI and stroke from inception to December 1, 2021.

RESULTS

This review included 24 studies involving 5,798,826 subjects. The results of meta-analysis showed that the pooled RR of stroke risk was 0.93 (95% confidence interval [CI] 0.82-1.06, I² = 88.8%, P = 0.29) for the underweight group. Higher BMI (overweight or obese group) was associated with an increased overall risk of stroke, with pooled RR values of 1.25 (95% CI 1.16-1.34, I² = 84.8%, P = 0.00) and 1.47 (95% CI: 1.02-2.11, I² = 99.4%, P = 0.04).

CONCLUSION

The risk of stroke was positively correlated with BMI, and the association was stronger in male and ischemic stroke. Lowering BMI can be used as a way to prevent stroke, and for people who are overweight or obese, lowering body weight can reduce the risk of stroke.

Hypertriglyceridemic waist phenotype: Association with initial neurological severity and etiologic subtypes in patients with acute ischemic stroke

OBJECTIVE

To explore the relationship of hypertriglyceridemic waist phenotype (HTWP) with initial neurological severity and etiologic subtypes in patients with acute ischemic stroke.

METHODS

The data for this study were collected from hospitalized patients within 72 h of acute ischemic stroke onset at the Department of Neurology of the Affiliated Hospital of Beihua University from 1 July 2020 to 30 June 2022. The initial neurological severity was assessed by the National Institute of Health Stroke Scale (NIHSS) on the day of admission: NIHSS <6 was defined as mild stroke, and NIHSS ≥6 as moderate to severe stroke. HTWP was defined by fasting serum triglycerides ≥1.7 mmol/L and waist circumference ≥90 cm in men and ≥80 cm in women. Differentiation of etiologic subtypes was based on the method reported in the Trial of Org 10 172 in Acute Stroke Treatment. Multivariate logistic regression analysis was used to analyze the association of HTWP with initial neurological severity and etiologic subtypes.

RESULTS

The study included 431 patients. Compared with the normal waist-normal blood triglyceride group, patients with HTWP had reduced risks of moderate to severe stroke [odds ratio (OR): 0.384, 95% confidence interval (CI): 0.170-0.869; P = 0.022]. In addition, the risk of small-artery occlusion stroke was 2.318 times higher in the HTWP group than in the normal triglyceride-normal waist (NWNT) group (OR: 2.318, 95% CI: 1.244-4.319; P = 0.008).

CONCLUSION

Initial neurological severity was less severe in patients with HTWP, and HTWP was associated with an increased risk of small-artery occlusion stroke.